Our objective was to determine the emergence and evolution of DRAM during LLV in HIV-1-infected patients while receiving antiretroviral therapy (ART).Drug-resistance mutations (DRAM) are frequently selected in patients with virological failure defined as viral load (pVL) above 500 copies/ml (c/mL), but few resistance data are available at low-level viremia (LLV). Retrospective analysis of patients presenting a LLV episode defined as pVL between 40 and 500 c/mL on at least 3 occasions during a 6-month period or longer while on the same ART. Resistance genotypic testing was performed at the onset and at the end of LLV period. Emerging DRAM was defined during LLV if never detected on baseline genotype or before.48 patients including 4 naive and 44 pretreated (median 9 years) presented a LLV episode with a median duration of 11 months. Current ART included 2NRTI (94%), ritonavir-boosted PI (94%), NNRTI (23%), and/or raltegravir (19%). Median pVL during LLV was 134 c/mL. Successful resistance testing at both onset and end of the LLV episode were obtained for 37 patients (77%), among who 11 (30%) acquired at least 1 DRAM during the LLV period: for NRTI in 6, for NNRTI in 1, for PI in 4, and for raltegravir in 2. During the LLV period, number of drugs with genotypic resistance increased from a median of 4.5 to 6 drugs. Duration and pVL level of LLV episode, duration of previous ART, current and nadir CD4 count, number of baseline DRAM and GSS were not identified as predictive factors of resistance acquisition during LLV, probably due to limited number of patients.Persistent LLV episodes below 500 c/ml while receiving ART is associated with emerging DRAM for all drug classes and a decreasing in further therapeutic options, suggesting to earlier consider resistance monitoring and ART optimization in this setting. HIV drug resistance is related to the selection of viral variants harbouring drug resistance associated mutations (DRAM) in the target genes of antiretroviral drugs, promoted by ongoing viral replication in patients receiving antiretroviral therapy (ART).Cross-sectional studies showed that DRAMs occurred in 88% of HIV-infected patients on ART when virological failure (VF), defined as a plasma viral load (pVL) above 1000 copies/mL (c/mL) blip. Episodes of LLV are reported associated with higher immune activation In recent years, the improvement of assays to quantify pVL led to progressively decrease the threshold of VF. In French recommendations, VF was defined as two consecutive plasma HIV-1 RNA quantifications above 1000 copies/ml in 2004 Although accumulation of DRAM is well known for pVL above 400 c/mL, the diagnosis and the management of emerging drug resistance during LLV remain a clinical challenge since standard genotypic tests fail to amplify HIV-1 RNA below 500 c/mL in 45% To longitudinally detect the development of DRAM during LLV, we retrospectively analyzed HIV-1-infected patients followed in two French hospital clinical cohorts. We aim to describe the clinical and virological characteristics of those patients experiencing LLV, and to analyze the dynamics of emergence of genotypic drug-resistance in this setting.This study was a non-interventional study with no addition to usual procedures. Biological material and clinical data were obtained only for standard viral diagnostic following physicians' prescriptions . Data analyses were carried out using an anonymized database. The protocol was approved by the local ethical research committee , which confirmed exemption from patient informed consent, according to the French Public Health Law CSP Art. L 1121-1.1.Subjects were retrospectively identified from a routine virological monitoring database from two French Infectious Diseases clinics. LLV cases were defined as subjects who experienced pVL between 50 and 500 c/mL on at least 3 occasions during a 6-month period or longer while on the same ART regimen. During the LLV period, no more than 3 pVL below 50 c/mL were allowed.The onset of LLV period was different according to the pVL at the beginning of the current treatment. In naïve patients and in patients failing previous treatment, the onset of LLV period was defined as the first date of pVL between 50–500 c/mL during the follow-up after having received at least 6 months of the same ART regimen. In patients virologically suppressed, the onset of LLV period was defined as the date of the first pVL between 50–500 c/mL. The LLV period ended at the last low-level viral load measurement between 50–500 c/mL and before VF (defined as a confirmed pVL above 500 c/mL or a single pVL above 1000 c/mL), or before ART modification decided by the physician.To analyze the emergence of DRAM, resistance genotyping tests (RGT) were performed from several plasma time-points of the LLV period. The first RGT (G1) was performed at the beginning of the ART regimen under which LLV was detected, or at the onset of the LLV period. A second RGT (G2) was performed at the end of the LLV period or if the PCR amplification failed, from prior available samples with detectable viremia during the LLV period.pol gene containing protease, reverse transcriptase (RT) and integrase  genes were amplified by RT-PCR followed by nested PCR (www.hivfrenchresistance.org).RNA was extracted from 1 to 1.5 ml of frozen plasma using the QIAamp viral RNA minikit  after a 2 hours-ultracentrifugation at 28 000XG at 4°C to pellet virus particles. Regions of the Population sequencing was performed on purified amplicons  with the Taq Dye Deoxy Terminator cycle sequencing kits  and resolved on an ABI 3730 automated DNA sequencer. Sequences were processed using SmartGene® HIV-1 Sequence Analysis and Database Module  and aligned to the HIV-1 subtype B reference strain HXB2 (GenBank accession no. K03455).www.iasusa.org) and drug susceptibility was assessed using the 2009 ANRS HIV-1 drug-resistance algorithm v18 (www.hivfrenchresistance.org). Genotypic susceptibility score (GSS) to the current regimen was calculated as the sum of active ( = 1), partially active ( = 0.5) and inactive ( = 0) drugs. Mixtures of a mutated and wild-type HXB2 strain were counted as mutations. Mutations present at G1 were assumed to be still present at G2 as it has been shown that once a mutation has been accumulated, it persists in minority viruses even if it is not detected by population sequencing Drug-resistance mutations were identified according to the 2009 International AIDS Society (IAS)-USA list  for continuous variables and percent for categorical variables. A logistic regression model was used to investigate whether the following variables were associated with an increase risk of the emergence of a new DRAM: ART type, treatment duration, nadir and current CD4 cell count baseline pVL, number of DRAM at G1, GSS, duration of LLV period, level of pVL during LLV and number of LLV episodes above 50 c/mL.We included in the study 48 HIV-1-infected patients with an identified episode of LLV . PatientThe median of pVL and CD4 cell count at the initiation of the current ART were 3.7  log10 c/mL and 255 (98 to 430) cells/mL, respectively. Current ART included at least 2 NRTI in 45 patients (94%): lamivudine (3TC) or emtricitabine (FTC) in 43 patients (90%), tenofovir (TDF) in 27 patients (56%) and abacavir (ABC) in 13 patients (27%). Forty five patients (94%) received ritonavir boosted-PI (PI/r): lopinavir (LPV) in 13 patients (29%) and darunavir (DRV) in 15 patients (33%). Eleven (23%) and 9 (19%) patients received NNRTI and raltegravir (RAL) based-regimen, respectively.The median duration of the LLV period was 11 (9 to 16) months. During the LLV period, the median higher pVL was 222 (150 to 341) c/mL and the median of the average pVL was 134 (104 to 194) c/mL. The median number of pVL measurements above 50 c/mL was 4 (3 to 6). A single pVL above 500 c/mL was observed in 4 (8%) patients. The median CD4 cells count at entry in the LLV period was 371 [238 to 548] and the end of the LLV period the median was 415 [243 to 576].For the 48 patients, we generated a total of 96 RT and PR sequences from the samples corresponding to G1 and G2, including 72 plasmas with low-level of replication (median 133 c/mL) for which the rate of successful amplification was 71% (51/72). For the 9 patients receiving a RAL-containing regimen, we successfully amplified the integrase gene in 9 from the 13 (75%) plasmas analyzed (median 213 c/mL). Overall, successful resistance genotypic tests for both G1 and G2 were obtained in 37 patients among 48 (77%) : three wThe median (IQR) numbers of DRAM in G1 for each antiretroviral drug class were 3 (0 to 5) for NRTI, 1 (0 to 2) for NNRTI, 1 (0 to 4) for PI (major mutations) . The mosAccording to the 2009 ANRS HIV-1 drug-resistance algorithm v18, DRAM present in G1 or in previous RGT conferred resistance to a median (IQR) of 4.5 (1–11.9) antiretroviral drugs: 1 (0–4.4) for NRTI, 0 (0–2) for NNRTI and 1.75 (0.5–6) for PI . The medOverall, 11 patients among 37, (30%), all pretreated, acquired at least one new DRAM  over the study period . New resDuring the LLV period, the median number of drugs with genotypic resistance increased from 4.5 at G1 to 6 (1.1–11.9) at G2 . The senWe investigated if some virological or therapeutic factors were predictive to the emergence of new DRAM during LLV. Among ART type, treatment duration, nadir and current CD4 cell count, baseline pVL, number of DRAM at G1, GSS, duration of LLV period, level of pVL during LLV and number of LLV episodes above 50 c/mL, no factors was significantly associated with the emergence of new DRAM (data not shown).We retrospectively analyzed 48 patients from two hospital cohorts presenting LLV episodes defined by at least three pVL between 50 and 500 c/mL after 6 months of ART regardless of treatment lines and regimen. All these patients were followed in “real-life” conditions and were heterogeneous for ART history, for prior treatment failure and for presence of drug-resistant viruses. When comparing RGT before and at end of the LLV period, we found that new DRAM occurred in 30% of evaluable cases during LLV and according to the regimen, new mutations conferring resistance to NRTI, NNRTI, PI and raltegravir were observed in 14%, 12.5%, 12.5% and 29% of patients, respectively.Detection, but not selection, of DRAM for pVL below 500 c/mL under ART, is frequent in transversal cohorts Ritonavir boosted PI-based regimen are at lower risk of selection of DRAM both in the RT and in the protease genes Emerging resistance to low-genetic barrier drug was detected in three patients for 3TC/FTC (9%) and in one for EFV (12.5%). Selection of DRAM during LLV was previously reported in 67% of naïve and pretreated patients receiving 3TC and EFV based-regimen In addition, new raltegravir-associated DRAM were detected in 2 of the 7 (29%) patients who were receiving raltegravir. Selection of DRAM in the integrase gene was previously reported in 8% of 39 highly-pretreated patients receiving a raltegravir and boosted-PI containing regimen, who experienced at least one episode of detectable viremia below 500 c/mL Finally, higher level of pVL and non-Hispanic black ethnicity were previously associated with the risk of emerging resistance in patients receiving an initial ART and presenting LLV In conclusion, our study lead in standard clinical practice, confirms that new DRAM during LLV can emerge, regardless of the ARV antiretroviral target genes, and can remarkably reduce the current therapeutic options for further regimen. Both French and American 2010 antiretroviral guidelines recommend a rapid therapeutic intervention when VF if pVL is over 200 c/mL


While the introduction of combination highly active antiretroviral therapy (HAART) regimens represents an important advance in the management of human immunodeficiency virus (HIV)-infected patients, tolerability can be an issue and the use of several different agents may produce problems. The switch of combination HAART to ritonavir-boosted protease inhibitor (PI) monotherapy may offer the opportunity to maintain antiviral efficacy while reducing treatment complexity and the risks of toxicity. Current European AIDS Clinical Society (EACS) guidelines recognise ritonavir-boosted PI monotherapy with twice-daily lopinavir/ritonavir or once-daily darunavir/ritonavir as a possible option in patients who have intolerance to nucleoside reverse transcriptase inhibitors, or for treatment simplification. Clinical trials data for PI boosted monotherapy are encouraging, showing substantial efficacy in the majority of patients; however, further data are required before this approach can be recommended as a routine treatment. Available data indicate that the most suitable candidates for the use of boosted PI monotherapy are long-term virologically suppressed patients who have demonstrated good adherence to antiretroviral therapy, who do not have chronic hepatitis B, have no history of treatment failure on PIs and are able to tolerate low-dose ritonavir. While the introduction of highly active antiretroviral therapy (HAART), typically involving three drugs in combination, has been an important advance in the treatment of people infected with human immunodeficiency type-1 virus (HIV-1), many patients do not remain on their original treatment regimen one year after starting HAART  or reactive (in response to poor tolerability or other issues). For example, in pregnant women the regimen may be switched to avoid risk of teratogenicity and to optimise pharmacokinetics, while in other patients regimens may be switched to improve adherence or convenience, to preserve future treatment options, to avoid drug interactions or to reduce costs. Maintenance of virological control is paramount when switching therapies, and treatment switches in virologically suppressed patients was considered by the panel members to be one of the most common therapeutic interventions in HIV therapy in late 2011.While intermittent therapy, sequential or prolonged treatment interruptions are no longer recommended as switch strategies by HIV treatment guidelines, there reThe current European AIDS Clinical Society (EACS) guidelines for the management of HIV-infected patients list three principal indications for the use of switch strategies in virologically suppressed patients :•switch for toxicity – including documented toxicity, the management of potential drug interactions, side effects, and planned pregnancy•switch for the prevention of long-term toxicity – including pre-emptive switching; ageing and/or co-morbidity with a possible negative impact of drug(s) in the current regimen (e.g. on cardiovascular risk and metabolic parameters)•switch for simplification – including the wish to simplify the regimen or because the treatment regimen is no longer recommended.The EACS 2011 guidelines state that PI/r monotherapy with lopinavir twice daily or darunavir once daily might represent an option in those patients intolerant to NRTIs, or for treatment simplification in > 90% of examined patients), or with proven short-term (3–6 months) efficacy with respect to cognitive function or CSF viral load decay when evaluated as single agents or in controlled studies in peer reviewed papers. According to this definition, agents with demonstrated clear CSF penetration are the NRTIs zidovudine and abacavir, the NNRTIs efavirenz and nevirapine, the boosted PIs darunavir/r, lopinavir/r and indinavir/r, and the entry inhibitor maraviroc, while agents with ‘proven efficacy’ are the NRTIs zidovudine, stavudine and abacavir, and the boosted PI lopinavir/r in mono- or triple therapy in suppressed HIV-1-infected patients). The PIVOT trial planned to include 560 patients in the UK and be of 5 years’ duration. Patients with a plasma viral load < 50 HIV-1 RNA copies/mL at screening (and for at least 24 weeks prior to screening) and a CD4 cell count > 100 cells/mmThe phase IIIb PROTEA study is investigating the efficacy and tolerability of darunavir/r monotherapy versus darunavir/r-containing triple therapy in approximately 260 virologically suppressed (for at least 48 weeks) HIV-1-infected patients. The primary objective is to demonstrate the non-inferior efficacy of darunavir/r monotherapy  versus triple therapy containing darunavir/r. This study will also assess changes in neurocognitive function over 48 and 96 weeks of treatment and whether there is any correlation between plasma and CSF viral load and neurocognitive function. In addition, PROTEA will study the evolution of the viral genotype and determine whether there is any loss of treatment options at weeks 48 and 96, as defined by the emergence of phenotypic drug resistance.The switch from triple-drug combination therapy to boosted PI monotherapy appears to be a promising strategy to maintain antiviral efficacy. Available data from PI/r monotherapy trials are encouraging, showing slightly lower efficacy than triple therapy regimens. However, further data – particularly with regard to the long-term efficacy and tolerability of treatment – are required before this approach can be recommended as a routine treatment option. In this regard, further studies are ongoing, which will further elucidate the long-term utility of boosted PI monotherapy. In the meantime, the available data indicate that the most suitable candidates for the use of boosted PI monotherapy are long-term virologically suppressed patients who have demonstrated good adherence to ART, have no history of PI failure, do not have chronic hepatitis B, do not have HIV-associated neurocognitive disorders and who are able to tolerate low dose ritonavir.ART: antiretroviral therapy; BMD: bone mineral density; CNS: central nervous system; CPE: CNS penetration effectiveness rank; CSF: cerebrospinal fluid; DHHS: Department of Health and Human Services; EACS: European AIDS Clinical Society; EC: effective concentration; HAART: highly active ART; HIV: human immunodeficiency virus; IAS-USA: International AIDS Society-USA; IC: inhibitory concentration; ITT: intent-to-treat; NNRTI: non-nucleoside reverse transcriptase inhibitor; NRTI: nucleoside reverse transcriptase inhibitor; PI: protease inhibitor; TLOVR: time to loss of virological response; VF: virological failure.Professor JR Arribas has received advisory fees, speaker fees and grant support from the following sources: Abbott, Bristol-Myers Squibb, Gilead, Janssen, MSD, Tibotec and ViiV Healthcare. Dr M Doroana has received speaker fees from different sources: Gilead, Roche, Janssen and Abbott. Dr D Turner has received honoraria from the following sources: Abbott, Biotis, GlaxoSmithKline, Janssen, MSD, Neopharm, Roche and Schering-Plough. Professor L Vandekerckhove has received advisory fees, speaker fees and grant support from the following sources: Gilead, Janssen, MSD, Bristol-Myers Squibb, Pfizer and ViiV Healthcare. Professor A Streinu Cercel has relationships with all major pharmaceutical companies but without any specific arrangements.All authors substantially contributed to development of all drafts of the manuscript and have read and approved the final draft. The corresponding author had full access to the source literature and takes full responsibility for the content of the paper and for the decision to submit.Panel members: Professor José Arribas (Spain); Professor Giovanni Di Perri ; Professor Pierre-Marie Girard (France); Dr Alan Winston (UK); Professor Hans-Jürgen Stellbrink (Germany); Professor Adrian Streinu-Cercel (Romania); Professor Linos Vandekerckhove (Belgium); Professor Adriano Lazzarin ; Dr Dan Turner (Israel); Dra Manuela Doroana ; Dr Esteban Martinez (Spain); Dr Markus Bickel (Germany); Dr Panagiotis Kollaras (Greece); Dr George Panos (Greece); Dr Giovanni Guaraldi ; Professor Sorin Rugina (Romania); Professor Carmen Dorobat (Romania); Dr Dan Duiculescu (Romania).


The nucleoside(tide) reverse transcriptase inhibitors (NRTIs) have traditionally been an important ‘back-bone’ of an antiretroviral therapy (ART) regimen. However all agents have been associated with both short- and long-term toxicity. There have also been concerns regarding the efficacy and safety of a treatment sequencing strategy in which those with past exposure and/or resistance to one or more NRTIs are re-exposed to ‘recycled’ NRTIs in subsequent ART regimens. Newer, potent and possible safer, agents from various ART classes continue to become available. There has therefore been growing interest in evaluating NRTI-sparing regimens. In this review, we examined studies of NRTI-sparing regimens in adult HIV-positive patients with varying degrees of ART experience. We found that in treatment experienced patients currently on a failing regimen with detectable viral load, there now exists a robust evidence for the use of NRTI-sparing regimens including raltegravir with a boosted-protease inhibitor with or without a third agent. In those on a virologically suppressive regimen switching to a NRTI-sparing regimen or in those ART-naïve patients initiating an NRTI-sparing regimen, evidence is sparse and largely comes from small exploratory trials or observational studies. Overall, these studies suggest that caution needs to be exercised in carefully selecting the right candidate and agents, especially in the context of a dual-therapy regimen, to minimise the risks of virological failure. There is residual toxicity conferred by the ritonavir boost in protease-inhibitor containing NRTI-sparing regimens. Fully-powered studies are needed to explore the place of N (t)RTI-sparing regimens in the sequencing of ART. Additionally research is required to explore how to minimise the adverse effects associated with ritonavir-based pharmacoenhancement. The nucleoside(tide) reverse transcriptase inhibitor (NRTI) class has formed the ‘back-bone’ of antiretroviral therapy (ART) regimens since the early ART era. All major treatment guidelines currently recommend the selection of 2 NRTIs and a third agent from a separate class in the initial management of ART naïve HIV-positive patients; some guidelines suggest recycling NRTI agents as far as possible in ART-experienced HIV-positive patients experiencing virological failure -4. HowevThe main purpose of this review is to explore the current state of our knowledge on the efficacy and safety of NRTI class-sparing antiretroviral regimens used in the management of adult HIV-positive patients. The review is restricted to studies conducted on adult HIV-1 mono-infected individuals published in the English language. The review has a greater focus on studies published since 2006 (so as to ensure relevance to contemporary practice). We included clinical trials as well as non-randomised small clinical studies, both published and unpublished (conference presentations).The thymidine analogue NRTIs, such as zidovudine and in particular stavudine d4T) have been associated with serious mitochondrial toxicity which has been linked to lipoatrophy. In addition, zidovudine has been associated with anaemia and didanosine with peripheral neuropathy. As a consequence these agents are no longer recommended as preferred components of therapy; in the case of stavudine it has been recommended that it’s use be phased out, even in low- and middle-income countries . HoweverT have beOne of the main concerns prompting studies on NRTI-sparing regimens in failing patients has been that of possible reduced potency of NRTI agents due to current or archived nucleoside mutations such as thymidine analogue associated mutations (TAMs). As a result, if NRTIs are being recycled in such patients, they could potentially be exposed to a regimen with <2 or 3 fully-active agents. This is especially of concern in resource limited settings where NRTIs are recommended for recycling following treatment failure identified through immunological or virological failure. This surrogate means of identifying virological failure is associated with substantial degrees of resistance which may significantly compromise the action of recycled NRTIs in future ART regimens . MoreoveSeveral newer agents from various classes with a good safety profile to date continue to become available. These include new integrase inhibitors, newer non-nucleoside reverse transcriptase inhibotors , the CCR5 attachment inhibitor maraviroc and the PIs lopinavir, darunavir and atazanavir. It is therefore possible to construct regimens containing 2-3 fully-active agents which are NRTI-sparing.We next discuss NRTI-sparing regimens that have been evaluated in each of the three main types of patient populations: treatment-experienced failing patients where most of the evidence is concentrated; virologically suppressed patients; and ART-naïve patients.Recent large clinical trials have evaluated NRTI-sparing regimens in treatment experienced patients experiencing virological failure (key studies summarised in Table The SECOND-LINE study (n=541)  evaluate3 and viral load <10,000 or >10,000 copies/mL with no PI mutations), as well as virological outcome . The investigators also found no difference in grade 3/4 events at 96-weeks follow-up. Of note, the monotherapy arm was found to be virologically inferior to the control and LPV/r plus raltegravir arms.The EARNEST study  was simiThe OPTIONS study  was condA few smaller observational studies confirm these findings in routine clinic settings Table . In one Collectively, these studies confirm that in virologically failing patients, the strategy of selecting 2 or 3 fully-active pharmacologically compatible agents is a feasible strategy. Of note, all of these studies have included a boosted-PI, and because of their high genetic barrier to resistance, the data should not be extrapolated to other 2-class regimens. Also, recycled NRTI agents seem to retain efficacy (i.e. non-inferior to the comparator arms), which is reassuring in settings where newer agents are not yet widely available.Switching to a NRTI-sparing regimen in a virologically suppressed patient needs consideration of several factors. These include the treatment history, archived mutations, duration of viral suppression, expected level of adherence, the choice of agents as well as the patient motivation to switch from a stable regimen. Large, well powered trials in such patients are few and difficult to recruit, although several smaller studies have identified promising regimens. Key studies on this patient population are summarised in Table In the ACTG 5116 trial , virologIn a more recent small exploratory study , viroloSince most studies on NRTI-sparing regimens have included a boosted-PI regimen, residual toxicity concerns with ritonavir as the booster  have been seen as a relative disadvantage. With several new agents now available, it is now possible to conceive regimens which exclude not only NRTIs but also ritonavir, as well as first-generation NNRTIs such as efavirenz  or nevirapine. This strategy is especially attractive in virologically suppressed patients with minimal treatment experience, where good adherence can be presumed and the possible adverse impact of high viral load on regimen efficacy is less of a concern.3 log copies/mL were first treated with tenofovir/emtricitabine, raltegravir and maraviroc for six months after which those with plasma viral load <50 copies/mL at 24 weeks were continued on a two-drug combination of raltegravir and maraviroc for a further 24 weeks. All patients retained viral load <50 copies/mL on dual therapy. However, in another similar study (RocNRaL) on more treatment experienced patients, this dual regimen demonstrated lower efficacy [In one recent cohort study on treatment experienced, virologically suppressed patients switching to dual therapy of etravirine with raltegravir, 91% maintained virological suppression at 48 weeks . In anotefficacy . CollectGiven the high genetic barrier of boosted PIs, several large studies have evaluated this simplification strategy. Boosted-PI monotherapy trials have been extensively reviewed previously ,38 and aLarge, fully powered trials evaluating NRTI sparing regimens in ART naïve patients are few and most smaller studies have suggested that care must be exercised in selecting both suitable agents and candidates for such regimens. Key studies are summarised in Table The ACTG 5142 trial randomised ART-naïve patients to standard ART arms with LPV/r or efavirenz, both given with investigator selected 2NRTIs and a NRTI-sparing arm of LPV/r and efavirenz . Though More recent pilot studies have explored a dual therapy regimen of raltegravir with a boosted-PI. These studies suggest that a high baseline plasma viral load could adversely impact the success of the regimen in such patients. In a single arm study of 112 patients receiving raltegravir and DRV/r, virological failure (>50 copies/mL) was 26% at 48 weeks . Most  vs. LPV/r+2 NRTIs, the dual therapy arm demonstrated non-inferior efficacy of >85% at 48 weeks regardless of baseline viral load, with fewer toxicity-related discontinuations . This stNRTI-sparing regimens appear to be promising and if established, will be an important step towards optimising ART to maximise patient safety. However, there are a few important points to consider. First, trials evaluating such regimens will need to show a clear benefit in terms of long-term safety so as to convince clinicians to move away from much more familiar NRTI-based regimens. Promising regimens such as the use of a boosted-PI with raltegravir have shown a higher risk of dyslipidemia in some studies likely attributable to ritonavir and possibly the absence of tenofovir. Future studies considering regimens without NRTIs, ritonavir and efavirenz (due to neuro-psychaitric adverse events) will be important in identifying safer, better tolerated ART regimens. A recent study by our group suggested that most HIV-positive patients will have such regimen options available to them regardless of their treatment experience .In addition, most clinical trials follow participants up for 48 to 96 weeks, which, along with their enrolment number, is not of sufficient duration to demonstrate differences in hard clinical endpoints such as renal failure or fractures. Cohort studies will be instrumental in this regard. Also, most of the studies are small and unpublished. Better quality evidence is therefore clearly needed in this area.Second, many of the studies on NRTI-sparing two drug regimens suggest that in selected patients , the risk of virological failure and selection of resistance mutations to the non-PI component are a risk. This suggests that such regimens, especially ones without a boosted-PI support, should ideally be first evaluated in virologically suppressed patients.nd dose of raltegravir in DRV/r + raltegravir regimen). However, both etravirine and maraviroc have pharmacokinetic and clinical data supporting once-daily dosing [Finally, many NRTI-sparing regimens are may require twice daily dosing frequency and ≥1-2 pills/day. This may impact the adherence (example selective lower adherence to the 2y dosing ,54, and In conclusion, there has now accumulated a sizeable evidence base that supports the use of NRTI-sparing regimens of 2–3 fully-active agents for HIV-positive patients currently on a failing ART regimen. For virologically suppressed patients, an NRTI-sparing regimen may be an option is some patients although further, more definitive studies are needed. Finally, the evidence is sparse for such regimens in the ART naïve patient population and more research is required to generate robust evidence. Future studies such as A4001095 and NEAT protocol 001/ ANRS 143 will be instrumental in informing the evidence base for such regimens.ACA has received Gilead Australia Fellowship for the year 2013. MB has received research grant support and honoraria for serving on advisory boards and educational presentations from AbbVie, Boehringer Ingelheim, Bristol Myers Squibb, Gilead Sciences, Janssen Pharmaceuticals, and Merck.MAB conceived the idea. ACA and MAB both performed the literature search and planned the structure of the review. ACA conducted the review and wrote the first draft and subsequent changes to the manuscript. MAB provided key input to the contents and provided overall supervision of the project. All authors read and approved the final manuscript.


Lipoatrophy and/or central fat gain are observed frequently in patients on antiretroviral therapy (ART). Both are assumed to be antiretroviral adverse drug reactions.We conducted a systematic review to determine whether fat loss or gain was more common in HIV-infected patients on ART than in uninfected controls; was associated with specific antiretrovirals; and would reverse after switching antiretrovirals.Twenty-seven studies met our inclusion criteria. One cohort study reported more lipoatrophy, less subcutaneous fat gain, but no difference in central fat gain in HIV-infected patients on ART than in controls. Randomised controlled trials (RCTs) showed more limb fat loss (or less fat gain) with the following regimens: stavudine (versus other nucleoside reverse transcriptase inhibitors (NRTIs)); efavirenz (versus protease inhibitors (PIs)); and NRTI-containing (versus NRTI-sparing). RCTs showed increased subcutaneous fat after switching to NRTI-sparing regimens or from stavudine/zidovudine to abacavir/tenofovir. There were no significant between-group differences in trunk and/or visceral fat gain in RCTs of various regimens, but results from efavirenz versus PI regimens were inconsistent. There was no significant between-group differences in central fat gain in RCTs switched to NRTI-sparing regimens, or from PI-containing regimens.There is clear evidence of a causal relationship between NRTIs  and lipoatrophy, with concomitant PIs possibly having an ameliorating effect or efavirenz causing additive toxicity. By contrast, central fat gain appears to be a consequence of treating HIV infection, because it is not different from controls, is not linked to any antiretroviral class, and doesn't improve on switching. Fat redistribution, also called lipodystrophy, is frequently observed in patients on long term antiretroviral therapy (ART) Lipoatrophy has been associated with exposure to thymidine analogue nucleoside reverse transcriptase inhibitors (NRTIs) If fat loss and fat gain were adverse antiretroviral drug reactions they would occur more commonly in HIV-infected patients on ART than in HIV-uninfected controls. Second, fat loss and/or fat gain would be associated with specific antiretroviral drugs or drug classes. Third, fat loss and/or fat gain would reverse after switching the identified antiretroviral drugs. We conducted a systematic review to test those three assumptions.To answer the question ‘Does fat loss and/or fat gain occur more commonly in patients on ART than in HIV-uninfected controls?’ we included prospective cohort studies comparing HIV-infected patients with ART exposure to population controls either known or presumed to be HIV-uninfected. To answer the questions ‘Is fat loss and/or fat gain associated with specific antiretroviral drugs?’ we included randomised controlled trials comparing antiretroviral regimens. To answer the question ‘Is fat loss and/or fat gain reversed after switching antiretroviral drugs?’ we included studies where participants with virologic suppression were randomised to continue their current ART regimen or switch to an alternative regimen.We included both ART-naïve and ART-experienced HIV-infected patients who were at least 12 years old. For the cohort studies we included control participants who were presumed to be HIV-uninfected. We excluded studies with fewer than 20 participants in any arm.We included studies that used any antiretroviral regimens, given for at least 24 weeks, with the exception of those containing hydroxyurea.We included studies with at least one objective measure of fat distribution done at baseline, and repeated at least once, at a minimum of 24 weeks after baseline. Objective methods of measuring fat distribution included: dual-energy x-ray absorptiometry (DEXA), computerized tomography (CT), or magnetic resonance imaging (MRI). We included measures done both as primary or secondary outcomes, and in the whole study population, or within a sub-study. Specific outcomes included:To assess fat loss:Change from baseline in limb fatChange from baseline in subcutaneous adipose tissue (SAT)Proportion with ≥20% loss in limb fatProportion with ≥20% loss in SATTo assess fat gain:Change from baseline in trunk fatChange from baseline in visceral adipose tissue (VAT)Proportion with ≥20% gain in trunk fatProportion with ≥20% gain in VAT.We searched two electronic journal databases, PubMed and EMBASE, for articles published between 1 January 1990 and 7 July 2011. We hand-searched electronic databases for the Conferences on Retroviruses and Opportunistic Infections and the International AIDS Society conferences, from 2001. There was no language restriction, provided that an English translation of the abstract was available. The PubMed search strategy terms were as follows:HIV Infections[MeSH] OR HIV[MeSH] OR hiv[tw] OR hiv-1*[tw] OR hiv-2*[tw] OR hiv1[tw] OR hiv2[tw] OR hiv infect*[tw] OR human immunodeficiency virus[tw] OR human immunedeficiency virus[tw] OR human immuno-deficiency virus[tw] OR human immune-deficiency virus[tw] OR ((human immun*) AND (deficiency virus[tw])) OR acquired immunodeficiency syndrome[tw] OR acquired immunedeficiency syndrome[tw] OR acquired immuno-deficiency syndrome[tw] OR acquired immune-deficiency syndrome[tw] OR ((acquired immun*) AND (deficiency syndrome[tw])) OR “sexually transmitted diseases, viral”[MH:noexp]ANDSearch Antiretroviral Therapy, Highly Active[MeSH] OR Anti-Retroviral Agents[MeSH] OR Antiviral Agents[MeSH:NoExp] OR ((anti) AND (hiv[tw])) OR antiretroviral*[tw] OR ((anti) AND ) OR HAART[tw] OR ((anti) AND (acquired immunodeficiency[tw])) OR ((anti) AND (acquired immunedeficiency[tw])) OR ((anti) AND (acquired immuno-deficiency[tw])) OR ((anti) AND (acquired immune-deficiency[tw])) OR ((anti) AND (acquired immun*) AND (deficiency[tw]))ORSearch zalcitabine OR zidovudine OR lamivudine OR stavudine OR didanosine OR tenofovir OR abacavir OR emtricitabine OR nevirapine OR efavirenz OR delavirdine OR etravirine OR rilpivirine OR amprenavir OR atazanavir OR tipranavir OR indinavir OR saquinavir OR lopinavir OR fosamprenavir OR ritonavir OR darunavir OR nelfinavir OR enfurvirtide OR maraviroc OR raltegravirANDSearch Lipodystrophy[mh] OR lipodystrophy[tiab] OR lypodystrophy[tiab] OR lipodystrophies[tiab] OR lipohypertrophy[tiab] OR lipoatrophy[tiab] OR body fat distribution[mh] OR fat[tiab] OR fats[tiab] OR abdominal fat[mh] OR adipose tissue[mh] OR adipose [tiab] OR adiposity[tiab] OR temporal wasting[tiab] OR buffalo hump[tiab].Two authors (RdW and KC) independently reviewed all study abstracts identified by the search strategy, using a specially designed eligibility form. We obtained the full articles, conference abstracts or conference posters for all studies that met the inclusion criteria. An independent translator reviewed articles that were published in languages other than English. We resolved disagreements as to study eligibility through consensus and discussion with the third author (GM) if necessary. One author (RdW) extracted data using a data extraction form; another author (KC) checked the extracted data. Two authors (RdW and KC) assessed the risk of bias of all included studies We identified a total of 27 studies for inclusion in the review: one cohort study comparing HIV-infected patients with controls Fat distribution measures were done in all participants for 15 studies: one cohort study Twelve randomised controlled trials enrolled antiretroviral-naïve participants All included studies involved a comparison of different antiretroviral regimens, with the exception of the cohort study that compared HIV-infected people with people who were known or presumed to be HIV-uninfected An objective measure of fat distribution was the primary study endpoint in 15 studies The FRAM2 study compared fat distribution in HIV-infected patients with healthy controls, using MRI at two time-points separated by about five years th percentile of controls) after five years of observation. Longer duration of stavudine use was associated with less leg SAT. After five years there was significantly less SAT at all sites in HIV-infected men, but only in the limbs in HIV-infected women. Multivariable analysis showed that increase in SAT over five years was less in HIV-infected people at all sites except the lower trunk.There was clear evidence of fat loss in HIV-infected people, 53% of whom had lipoatrophy  SAT or limb fat over time than those on NRTI-containing regimens. However one study that compared an abacavir-containing regimen with an NRTI-sparing regimen found no significant between-arm differences in change in subcutaneous thigh fat or SAT There were no significant differences in average gains in SAT or limb fat over time in the four studies that compared abacavir- with tenofovir-based regimens Unboosted atazanavir was associated with significant reduction in limb fat at 96 weeks, while there was no significant change in limb fat in the ritonavir-boosted atazanavir arm (both arms were on stavudine and lamivudine) In the one study that compared raltegravir with efavirenz, average gains in limb fat over time and the incidence of lipoatrophy were similar in both groups In general, participants randomised to different ART regimens gained similar amounts of trunk fat or VAT over time. The changes from baseline in trunk fat and VAT are summarised in There were no significant between-group differences in changes from baseline in trunk fat or VAT in the six studies that compared NRTI-sparing and NRTI-containing regimens 2 versus 14.1 cm2 respectively, 95% confidence interval for the difference: −10.4 to 12.6 cm2) The results of studies that compared PIs and NNRTIs were not consistent. One study found that participants who received ritonavir-boosted atazanavir had significantly greater increases in trunk fat at week 96 than those who received efavirenz  There were no significant between-group changes from baseline in trunk fat or VAT in those who received ritonavir-boosted atazanavir compared with unboosted atazanavir in one study In the one study that compared raltegravir with efavirenz, gains in trunk fat over time were similar in both groups In general, participants who were switched away from NRTI-containing, or more specifically thymidine analogue-containing, regimens gained limb fat over time, when compared with participants who continued NRTI- or thymidine analogue-containing regimens, who generally lost limb fat There were no significant between-group differences in changes from baseline in limb fat or SAT in studies that switched to NNRTI- from PI-containing regimens Changes from baseline in limb fat, subcutaneous thigh fat and SAT are summarized in In general, participants who were switched away from NRTI-containing regimens, or from thymidine analogue-containing regimens, had similar increases in trunk fat over time to those who continued NRTI- or thymidine analogue-containing regimens There were no significant between-group differences in changes from baseline in trunk fat or VAT in studies that switched to NNRTI- from PI-containing regimens Changes from baseline in trunk fat and VAT are summarised in We found overwhelming evidence that lipoatrophy is an antiretroviral adverse drug reaction. Subcutaneous fat volumes are considerably lower in patients on ART than in controls, subcutaneous fat loss progresses on ART, is associated with stavudine and zidovudine use, and partially reverses after switching to abacavir, tenofovir or an NRTI-sparing regimen. By contrast, central fat gain does not appear to be an antiretroviral adverse drug reaction. Visceral and trunk fat volume is no different in women on ART compared with control women, and is less in men on ART than in control men. Visceral fat accumulates at the same rate in patients on ART and controls. Finally, central fat gain generally occurs at similar rates in HIV-infected patients randomised to different ART regimens, is not associated with any specific antiretroviral drug or drug class, and does not reverse on switching antiretrovirals. We believe that this evidence indicates that central fat gain is a consequence of treating HIV infection, which normalizes the concentrations of inflammatory markers such as TNF-α  that are known to cause wasting Efavirenz is associated with a higher risk of limb fat loss than PIs when combined with NRTIs that cause fat loss. A possible explanation for this observation is that the anti-apoptotic properties of PIs partially ameliorate the loss of adipocytes by increased apoptosis that is induced by NRTIs Our study has several limitations. First, many of the studies that reported objective measures of fat redistribution by ART regimen were convenience sub-studies of randomised controlled trials, therefore patients undergoing DEXA and/or CT scans were not randomised. However, fat distribution sub-studies generally reported that the characteristics of the patients undergoing imaging of fat tissue were not different from the parent trial population. Many RCTs were powered according to efficacy end-points, and not for objective measures of fat distribution. Second, many studies reported only summary statistics and different outcome measures were reported, which prevented us from pooling data from different studies. Third, some studies did not report statistical analyses of changes in body fat distribution by study arm. Fourth, we were unable to assess the role of older protease inhibitors (other than nelfinavir) or nevirapine in fat redistribution as no studies with those antiretrovirals fulfilled our inclusion criteria. Fifth, we found only one study that compared fat changes over time in patients on ART and HIV-infected controls that was conducted in the United States. This limits our ability to generalise findings to other populations. Finally, we cannot exclude the causative role of specific antiretrovirals in focal forms of fat gain, such as buffalo humps, as the included studies reported trunk or visceral fat changes only.In conclusion, our systematic review supports the hypothesis that peripheral lipoatrophy, but not central fat gain, is an antiretroviral adverse drug reaction. Lipoatrophy can be avoided and at least partially reversed by avoiding thymidine analogue nucleoside reverse transcriptase inhibitors. Central fat gain appears to be a consequence of treating HIV-infection, and reflects patterns of fat gain seen in the HIV-uninfected population.Table S1Excluded studies.(DOCX)Click here for additional data file.Table S2Risk of bias.(DOCX)Click here for additional data file.


There has been major improvement in the survival of HIV-1 infected individuals since the South African Government introduced highly active anti-retroviral therapy (HAART) in the public sector in 2004. This has brought new challenges which include the effects of stavudine-related toxicities.Prospective analysis of a cohort of 9040 HIV-infected adults who were initiated on HAART at the Themba Lethu Clinic (TLC) in Johannesburg between April 1, 2004 to December 31, 2007, and followed up until June 30, 2008.3 (IQR 29-149). Median follow up on HAART was 19 months (IQR: 9.1-31.6). The proportion of HAART-related side effects for stavudine compared to non-stavudine containing regimens were, respectively: peripheral neuropathy,17.1% vs. 11.2% (p < 0.001); symptomatic hyperlactataemia, 5.7% vs. 2.2% (p < 0.0005); lactic acidosis, 2.5 vs. 1.3% (p = 0.072); lipoatrophy, 7.3% vs. 4.6% (p < 0.05). Among those on stavudine-based regimens, incidence rates for peripheral neuropathy were 12.1 cases/100 person-years (95%CI 7.0-19.5), symptomatic hyperlactataemia 3.6 cases/100 person-years (95%CI 1.2-7.5), lactic acidosis 1.6 cases/100 person-years (95%CI 0.4-5.2) and lipoatrophy 4.6 cases/100 person-years (95%CI 2.1-9.6). Females experienced more toxicity when compared to males in terms of symptomatic hyperlactataemia (p < 0.0001), lactic acidosis (p < 0.0001), lipoatrophy (p < 0.0001) and hypertension (p < 0.05).Amongst the 9040 study subjects, 8497(94%) were on stavudine based therapy and 5962 (66%) were women. The median baseline CD4 count was 81 cells/mmWe demonstrate significant morbidity associated with stavudine. These data support the latest WHO guidelines, and provide additional evidence for other resource limited HAART rollout programs considering the implementation of non-stavudine based regimens as first line therapy. By the end of 2008, an estimated 33.4 million people worldwide were living with human immunodeficiency virus (HIV) infection . SoutherThere has been an increase in the provision of highly active antiretroviral therapy (HAART), with up to 44% of adults and children estimated to be receiving therapy with a profound reduction in mortality  and, witHowever, some of the anti-retroviral agents used in HAART regimens have severe side effects. Prominent amongst these drugs is stavudine, the use of which is associated with lactic acidosis/symptomatic hyperlactataemia, lipoatrophy, and peripheral neuropathy . Other sThe aim of this study was to make use of a large (N = 9040) clinic-based survey of HIV-positive patients newly initiated onto HAART over a period of three years, to compare and describe the effect of stavudine based therapy on acute and chronic toxicities after initiation of HAART. We present baseline data gathered before the initiation of HAART and data collected for three years with each patient having a minimum of six months of follow-up. This is the largest study of the side effects of stavudine therapy conducted to date in a South African HIV-positive population.The study population included HIV-1 infected individuals attending the Themba Lethu Clinic, a public sector HAART rollout facility based at the Helen Joseph Hospital, a teaching hospital attached to the University of the Witwatersrand, Johannesburg, South Africa. This clinic provides free antiretroviral therapy and other specialized services, and is one of the largest HAART rollout clinics in Africa. The program is funded by the South African National and Gauteng Departments of Health, with support from Right to Care funded by USAID and PEPFAR.3 or WHO stage 4 AIDS defining illness irrespective of CD4 count  compared to those on other regimens , symptomatic hyperlactataemia , lactic acidosis  and diabetes mellitus  though some of these estimates lacked precision  and those with a BMI of > 30 kg/m2 . The same was seen with lactic acidosis, where an increased risk was seen for those with a BMI of 25-30 kg/m2  and those with a BMI of > 30 kg/m2  when compared to subjects with a BMI of < 25 kg/m2.Age, CD4 counts and WHO staging at baseline did not appear to increase the risk of any adverse events after HAART initiation; however, BMIs at baseline did significantly increase the risk of both symptomatic hyperlactataemia and lactic acidosis. Relative to a baseline BMI of < 25 kg/mThis study describes data of three years of follow up of 9040 HIV-infected adults initiated on anti-retroviral treatment at the Themba Lethu Clinic, Johannesburg, South Africa. This high number of patients demonstrates the ability of rolling out a successful HAART programme despite being in a resource limited environment, and this, at a rapidity and scale that compares with reports from other African countries ,11,12.Despite the fact that stavudine is associated with significant complications, a large proportion of low and middle-income countries still use stavudine based HAART as first line therapy ,9, mainlThis study provides estimates of the pattern of toxicities, the predominant ones being peripheral neuropathy, symptomatic hyperlactataemia, and lipoatrophy. Our incidence rates of peripheral neuropathy (12.1/100 person-years) were much higher compared to other African studies: 5.2/100 person-years in Rwanda  and 2.8/In terms of the chronic toxicities, incidence rates of lipoatrophy were 4.6/100 person-years on stavudine based therapy and 3.0/100 person-years on the non-stavudine based therapy. One study from Rwanda , where pA very small number of patients presented with diabetes (0.3%) and dyslipidaemias (1.3%). However, this could be because lipid or glucose levels were only tested when clinically suspected due to cost implications, therefore probably underestimating the true prevalence of dyslipidaemia and diabetes.The major strength of this study is the large sample size. This cohort is similar to many other resource-limited settings where there is rapid scaling-up of comprehensive HIV care and HAART. It allowed for a relatively long duration of follow up of up to three years and a fairly high retention rate of 70%, with all clinicians working on common protocols for defining the various HAART-associated toxicities. However, despite this, these findings must be considered in the light of potential limitations. It is possible that only severe toxicities that warranted a change in regimen may have been reported and this may have led to an underestimation of the rates of some of the HAART-related toxicities, particularly lipoatrophy. Also, plasma glucose and serum lipid levels were not routinely measured and thus the true rates for glucose intolerance, diabetes and dyslipidemia were not attained. Lower reported rates of the chronic toxicities could also be related to the rates of death (5%) and loss to follow up (24%), the majority of which occurred within the first six months on treatment as described in a previous report .These results support the move away from stavudine based regimens towards less toxic combination regimens as advocated by the World Health Organisation ,20. SoutThe authors declare that they have no competing interests.Study concept and design: CNM, MM, IS. Acquisition and analysis of data: MM. Interpretation of data: CNM, MM. Drafting of manuscript: CNM. Critical revisions for important intellectual content: CNM, MM, NJC, IS, FJR. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2334/11/244/prepub


Health beliefs are an important factor in the maintenance of an adherent behaviour. However, specific interventions based on the modification of health beliefs to promote adherence have not been applied in naïve HIV-infected subjects.Prospective randomized 48-week study to evaluate the efficacy of a psychoeducative intervention based on health beliefs to promote adherence in a sample of naïve HIV-1-infected men who started antiretroviral therapy. Participants were randomized to follow three intervention visits to promote adherence with the use of projective drawing techniques, Life-steps and Motivational interview  or to continue with the routine care . Adherence was assessed through self-report and drug plasma levels. Mann-Whitney nonparametric test, w2 or Fisher exact test were used to compare variables.3 and HIV-RNA VL of 65.000 (22.500–250.000) copies. The infection route had been mainly MSM (90%). QD and BID ARV therapy was prescribed in 29 (72.5%) and 11 (27.5%) subjects. Seven patients  were lost to follow-up. At week 48, 100% of subjects in GI and 60% in GC had 100% adherence (p=0.01). In GC, 26% and 14% of subjects had ≥95% and <95% adherence, respectively. No differences were found in adherence regarding QD or BID therapy. All subjects except for 3 had VL <25 copies at week 48.Participants were 40 men with a median (IQ) age of 35.2 (30.2–44.8) years, CD4 cell count at the study entry of 316 (229–539) cells/mmHigh adherence was observed in the majority of this group of naïve HIV-infected men who initiated their first antiretroviral therapy. However, all subjects following the intervention had 100% adherence after one year of follow-up. A psychoeducative intervention based on the modification of health beliefs may be a useful strategy to promote adherence in naïve HIV-infected patients.


Background. HIV protease inhibitors exhibit concentration-dependent viral inhibition. Higher once daily doses of darunavir boosted with ritonavir (DRV/r) may achieve viral suppression in place of twice daily dosing. International antiretroviral adherence guidelines recommend once daily regimens whenever possible. We present data on virologic suppression achieved with DRV 1,200 mg and ritonavir 100 mg once daily compared to approved DRV regimens. Methods. This retrospective observational study included all patients treated with DRV after documented use of another protease inhibitor at an urban immunodeficiency clinic. Data collection from inception of DRV use in August 2006 through March 2012 included patient demographics, viral loads, CD4+ cell counts, and resistance test results. The primary outcome of virologic suppression was defined as <50 copies/mL at 24 weeks. Differences in baseline characteristics and virologic outcomes across dosing groups were analyzed via one-way analysis of variance. Results. One hundred and thirty-five patients were included in the ITT analysis. Most patients had no known DRV RAMs at baseline. Virologic suppression rate was not different among treatment groups: 53.6% of patients on 1,200 mg daily, 52.3% on 600 mg twice daily, and 42.9% on 800 mg daily (P = 0.568). Conclusions. Darunavir 1,200 mg daily should be investigated for use in protease inhibitor-experienced patients. Darunavir 600 mg with 100 mg of ritonavir (DRV/r) dosed twice daily is currently approved in treatment-experienced patients as part of combination antiretroviral therapy (cART) which effectively suppresses HIV in this patient population . DRV hasTreatment-experienced patients often have failed previous regimens due to poor adherence, adverse drug events, and the development of drug resistance. Therefore, the ideal regimen for treatment-experienced patients is well-tolerated, efficacious against drug-resistant virus, and convenient , 7. AddeThis retrospective cohort study screened all patients at our adult immunodeficiency clinic prescribed DRV since its initial use in August 2006 through March 2012. All patients with documented use of a protease inhibitor and subsequent therapy with DRV/r 1,200 mg daily, 600 mg twice daily, and 800 mg daily were included. Subjects who began DRV/r therapy <24 weeks before the study end date were excluded. The baseline and demographic data retrieved from the electronic medical record were age, sex, race/ethnicity, height, weight, start date of DRV/r therapy, CD4+ cell counts, viral loads (Roche COBAS AmpliPrep/Taqman HIV-1 test v1 and v2.0), and the number of concomitantly prescribed antiretrovirals. Protease inhibitor mutations were compiled from historical and on-treatment resistance tests . DRV RAMs were identified consistent with product labeling as determined from previous analyses , 16.Viral load at 24 weeks (±12 weeks) was evaluated for the primary endpoint of viral suppression (defined as <50 copies HIV RNA per mL) for the intention to treat-time to loss of virologic response (ITT-TLOVR) algorithm. Discontinuation of DRV prior to 12 weeks of therapy or the absence of a viral load in the 12–36 weeks window was considered treatment failure. Two viral loads >50 copies/mL after viral suppression also were identified as treatment failures. The secondary endpoint utilized the same ITT-TLOVR algorithm to determine the rate of viral suppression at 48 weeks (±12 weeks). One-way analysis of variance was used to determine the significance of differences in baseline factors and results.P = 0.197), lower CD4+ cell counts (P = 0.003), and a larger share of Caucasian and Hispanic subjects versus patients of African descent (P = 0.198).One hundred and eighty treatment-experienced patients started DRV/r of which 143 had previously documented use of another protease inhibitor. Of these, 135 subjects initiated DRV/r ≥24 weeks before the study end date and were included in the ITT analysis. Baseline patient data including resistance are presented in P = 0.568). This difference was equalized by 48 weeks . Of all subjects, 60.7% had their viral load suppressed to <200 copies/mL at 24 weeks . At 48 weeks, 54.1% of subjects were suppressed to <200 copies/mL . CD4+ cell counts increased slightly across groups , and all groups had an increase in CD4+ % . No new DRV RAMs were documented during therapy.A similar percentage of patients treated with 1,200 mg daily and 600 mg twice daily reached the primary endpoint of a suppressed viral load at 24 weeks, with a statistically insignificant trend toward viral suppression over the 800 mg daily group (53.6%, 52.3%, and 42.9%, resp., The groups had important baseline differences. The greater drug resistance, lower CD4+ count, and larger cART regimen seen with DRV/r 600 mg twice daily indicate a population more difficult to achieve viral suppression. The lack of DRV RAMs detected could be due to a sometimes distant history of protease inhibitor use, including use predating implementation of resistance testing. This study does not assess the effect of DRV dose on adherence and tolerability, important predictors of effectiveness. The inherent adherence advantage of once daily dosing could be lost to poorer tolerability of a larger DRV dose taken at a single time. Prospective adherence surveys and therapeutic drug monitoring could establish pharmacokinetic differences between DRV doses, especially since the DRV 1,200 mg dose has only been studied in HIV-negative healthy volunteers .Viral suppression rates appear low in this patient sample; however, effectiveness outcomes are less common and less favorable than clinical trial data which are affected by stricter exclusion criteria , 17. ProDRV/r 1,200 mg daily resulted in viral suppression in some protease inhibitor-experienced patients, though selection bias hinders comparisons with other dosing regimens in this study. A randomized controlled trial with safety, adherence, and therapeutic drug monitoring should be undertaken to elucidate the utility of this DRV dose.


Hepatitis B virus (HBV) infection is still a worldwide disease, which may cause liver cirrhosis or even hepatocellular carcinoma. Telbivudine is a potent nucleoside analogue used in the treatment of chronic hepatitis B (CHB); however, drug resistance has remained a challenge. As early virological response can predict long-term efficacy of nucleotide analogue treatment, numerous studies have been conducted in this area.The aim of this study was to establish baseline prognostic factors and a statistical model to predict early virological response in telbivudine-treated CHB patients.One hundred and eight CHB patients without any experience of nucleotide analogue therapy were assigned to receive telbivudine  for at least 24 weeks, and then were followed up every two weeks. Cox proportional hazard regression model analyses were employed to evaluate baseline variables, and further developing a statistical model to predict early virological response.Negative family history of HBV infection (P = 0.000235), baseline higher serum TBIL (P = 0.038714) and AST (P = 0.020684) concentrations, and lower level of HBV-DNA (P = 0.0034784) were identified to be associated with higher possibility of early virological response. A model was established based on these variables to calculate the risk scores (R) for CHB patients. R > -0.38 suggested early virological response to telbivudine. The model was validated among an independent set of 20 patients.Family history as well as baseline bilirubin, AST and HBV DNA levels can predict early virological response. The model provides a better tool for response prediction based on the four prognostic factors. Chronic hepatitis B virus (HBV) infection is a major health problem -3. AboutTelbivudine is an orally bioavailable L-nucleoside with potent and specific anti-HBV activity . InitialTelbivudine had no mutagenic or carcinogenic effects, and no appreciable embryonic or fetal toxic effects, particularly important for men and women in their reproductive ages, according to many preclinical safety studies of the agent . A meta-Having so many distinct advantages, telbivudine has been widely used in clinical practice. Nonetheless, development of resistance mutations in the HBV polymerase-reverse transcriptase has limited its application. Therefore, it is very important to identify those who benefit most from this therapy.Studies have shown that early virological response predicts the long-term outcomes of nucleotide analogue treatment for patients with chronic HBV infection -20. HoweThe present study was an observational study, and ethical issues were considered during the data collection and preservation. The Ethics Committee of Infectious Disease Hospital, MengChao Hepatobiliary Hospital, Fujian Medical University approved the study; all patients gave an informed consent. One hundred and eight telbivudine-treated CHB patients  in Infectious Disease Hospital, MengChao Hepatobiliary Hospital, Fujian Medical University from January 2007 until April 2012 were recruited. Enrolled cases included some HBeAg-negative ones. All patients met the following diagnostic criteria for CHB, and had indications for telbivudine treatment:Patients with positive results for serum HBsAg for longer than six months; serum alanine aminotransferase (ALT) level, 2 to 10times of the upper limit of normal (ULN); or serum HBV DNA level more than 104 IU/mL.Exclusion criteria were as follows; coinfection with hepatitis C, hepatitis D, or the human immunodeficiency virus (HIV); evidence of hepatic decompensation, pancreatitis, or hepatocellular carcinoma; previous treatment for hepatitis B with nucleoside or nucleotide analogues or both; treatment with interferon or other immunomodulators within the previous 12 months; Other forms of liver disease， such as NAFLD, alcoholic hepatitis, and drug induced hepatitis; serum creatinine level > 1.5 mg per deciliter (133 μmol per liter); serum amylase or lipase level > 1.5 times the upper limit of normal; prothrombin time more than > 3 seconds; serum albumin level < 33 g/L; and bilirubin level > 2.0 mg/dL (50 μmol/L). Patients with serum alpha fetoprotein (AFP) levels > 50 ng/mL were enrolled only in case of excluding underlying hepatocellular carcinoma. Eligible subjects were assigned to receive telbivudine therapy  for at least 24 weeks. Primary data analyses were specified for a 24-week treatment period.Patient histories were obtained, physical examinations were conducted, and laboratory assessments were performed at baseline, and weeks 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24. Serum albumin, globulin, total bilirubin, direct/indirect bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamyltranspeptidase (GGT), HbeAg, creatinine, amylase, lipase, and prothrombin time were tested by standardized methods in Infectious Disease Hospital, MengChao Hepatobiliary Hospital, Fujian Medical University Clinical Laboratory. ABI 7500 Real-Time PCR was used to quantitatively detect serum HBV DNA levels using HBV PCR kit ; the detection limit was 420 IU/mL. Early virological response was defined as suppression of plasma HBV DNA to less than 420 IU/mL at week 24 according to the PCR analysis.In our study all telbivudine-treated patients were considered for the analyses. Enrolled patients were randomly assigned into two groups by using a table of random number with an allocation ratio of 85%:15%. Eighty five percent of patients were studied to determine predictors and establish a statistical model, and the rest for the model validation. 2 test for dichotomous variables. Cox proportional-hazards regression was adopted to screen predictors from the baseline parameters and develop a model for early virological response. Receiver operating characteristic (ROC) curve and area under curve (AUC) were applied to assess the optimal cutoff values of the model through maximizing the Youden’s index. The demographics of patients in the model group and model validation group were compared by Student’s t test for continuous data, and xA P value < 0.05 was considered statistically significant. A 95% confidence interval accompanied all estimates when it was appropriate. All the analyses were performed by SPSS version 13.0 . One hundred and eight patients were recruited. Eighty-eight patients were studied to determine predictors of early virological response and to develop a prediction model. Cox Proportional Hazard Regression Model analyses were employed to evaluate baseline variables, including gender, age, family history of HBV infection, history of HBV infection, serum concentrations of ALB,GLB,TBIL,IBIL, ALT,AST, GGT, HBV DNA level, and HBeAg. The results showed that family history negative patients had a 3.18 time (P = 0.0002235) greater chance of early virological response. Patients with higher serum concentrations of TBIL (P = 0.038714) and AST (P = 0.020684) were more likely to achieve early virological response. On the contrary, lower level of HBV DNA (P = 0.0034784) suggested higher possibility of early virological response. Other factors had no predictive value . Risk scores (R) for individual patients were estimated by combining the four prognostic variables with the Partial Regression Coefficient reported in Twenty independent patients were studied to validate the model accuracy. Their risk scores (R) were calculated according to the equation mentioned above. The receiver operating characteristic (ROC) curve was drawn by combining the risk scores and the actual occurrence of early virological response at week 24. Actually there were 15 patients achieved early virological response at that time point. The area under the curve (AUC) was 73.3%, with a 95% confidence interval (CI) of 50.2% to 104.4% (P = 0.044). The optimal cutoff was determined through maximizing the Youden’s index (J), J = sensitivity + specificity-1. The optimal cutoff value was -0.38403, with a sensitivity of 100% and a specificity of 60%.Telbivudine is a safety oral drug with potent and specific anti-HBV activity. Telbivudine treatment reduces risks of end-stage disease manifestations such as cirrhosis and hepatocellular carcinoma. However, its use has been limited due to the development of resistance mutations in the HBV polymerase-reverse transcriptase. It was reported that 5.0% and 2.3% of HBeAg-positive and HBeAg-negative patients developed resistance to the drug at week 52, and at week 104 the resistance rates were 17.8% and 7.3% , 22. TelAs a useful predictor of prognosis, early virological response has been adopted to guide clinical practice. During telbivudine treatment, for example, we can decide whether to continue the therapy, or to add on or switch to another drug according to the response. However, if no response or incomplete response occurs at week 24, it indicates that resistance mutations may have happened or is more likely to happen in the future, subsequent therapy would be quite difficult. On this situation, early virological response is not an ideal predictor for nucleotide analogue treatment.It was reported that baseline ALT and HBV DNA predict the virological response of lamivudine treatment at weeks 52 and 156 . AnotherIn a word, baseline ALT, baseline HBV DNA and early virological response are not perfect predictors in the prediction of telbivudine treatment effect in clinical practice.As a main statistical tool for survival modeling, Cox proportional-hazards regression  was emplThe results showed that negative family history (P = 0.000235), higher serum TBIL (P = 0.038714), and AST (P = 0.020684) concentrations and lower level of HBV-DNA (P = 0.0034784) were predictive values of early virological response.Brook MG et al. studied 114 alpha-interferon treated CHB patients and found that loss of HBsAg in addition to HBeAg and hepatitis B virus DNA was more likely to occur in patients with chronic infection of less than two years duration . It suppIt is known by liver biopsy that active CHB patients with higher level of viral replication are more likely to respond to alpha-interferon therapy. As serum concentrations of bilirubin and aspartate aminotransferase (AST) reflect the activity of chronic hepatitis B to a certain degree, it is easy to understand that the two factors were identified as predictors of the early virological response. However, alanine aminotransferase (ALT), which also reflects the grade of hepatitis activity on liver biopsy, was not found to be associated with early virological response in the present study. The possible explanation is that ALT is more susceptible than AST to be affected by some drugs. It was reported that CHB patients with lower level of HBV-DNA are more likely to respond to alpha-interferon and lamivudine therapy . Our stuFactors used to establish our model were baseline levels of bilirubin, AST, HBV-DNA and family history. All these are objective and relatively stable variables. By combining the four variables with the partial regression coefficient, we developed a model to predict early virological response. That is, R = 1.158*LN  + 0.055*LN (TBIL μmol/L) + 0.006*LN (ASTU/l) - 0.272*LN (log10HBVNDA IU/mL). The model was validated in an independent set of patients. The area under the ROC curve (AUC) was 73.3% (P = 0.044), and the optimal cut off value was -0.38403. It means that patients with R > -0.38 are most likely to achieve early virological response to telbivudine therapy, or good outcomes of the treatment. Patients with R > -0.38 are most suitable for telbivudine treatment in clinical practice.The model and optimal cutoff value were established from a short-term follow-up study of only telbivudine-treated CHB patients, which makes the conclusion a little weaker. Whether the model and cutoff value can be applied to other nucleos(t)ide analogs therapy for CHB needs to be determined. Furthermore, developing a more accurate model and cutoff values to predict the outcome of telbivudine treatment in CHB patients requires a large-scale, multicenter and long-term follow-up study. But, in the present study, the data were all from a single center, with a small sample size and a short follow-up period (only 24 weeks). Lastly, route of HBV transmission ，and the viral characteristics  could affect the predictive model. However, as the exact route of HBC transmission for each patient is rather difficult to determine, and also for economic reasons, these factors were not included in the study. Therefore, whether the model and optimal cutoff value can accurately predict the early virological response and long-term outcome of telbivudine treatment should be further studied.


In Mozambique, highly active antiretroviral treatment (HAART) was introduced in 2004 followed by decentralization and expansion, resulting in a more than 20-fold increase in coverage by 2009. Implementation of HIV drug resistance threshold surveys (HIVDR-TS) is crucial in order to monitor the emergence of transmitted viral resistance, and to produce evidence-based recommendations to support antiretroviral (ARV) policy in Mozambique.World Health Organization (WHO) methodology was used to evaluate transmitted drug resistance (TDR) in newly diagnosed HIV-1 infected pregnant women attending ante-natal clinics in Maputo and Beira to non-nucleoside reverse transcriptase inhibitors (NNRTI), nucleoside reverse transcriptase inhibitors (NRTI) and protease inhibitors (PI). Subtypes were assigned using REGA HIV-1 subtyping tool and phylogenetic trees constructed using MEGA version 5.Although mutations associated with resistance to all three drug were detected in these surveys, transmitted resistance was analyzed and classified as <5% in Maputo in both surveys for all three drug classes. Transmitted resistance to NNRTI in Beira in 2009 was classified between 5–15%, an increase from 2007 when no NNRTI mutations were found. All sequences clustered with subtype C.Our results show that the epidemic is dominated by subtype C, where the first-line option based on two NRTI and one NNRTI is still effective for treatment of HIV infection, but intermediate levels of TDR found in Beira reinforce the need for constant evaluation with continuing treatment expansion in Mozambique. The sub-Saharan region of Africa is the most severely HIV affected region of the globe, housing more than two thirds (69%) of the people living with HIV in the world and 70% of the AIDS related deaths in 2011 Before 2003, only people that could afford treatment abroad had access to antiretroviral (ARV) treatment in Mozambique. Since 2004, efforts have been made to provide free and universal access to highly active antiretroviral therapy (HAART) with massive service expansion and integration of health services. As a consequence, the number of people on treatment has increased dramatically, reaching 170,198 people on treatment in 2009, a figure that represents 38% of people in need of HAART in Mozambique In resource-constrained countries such as Mozambique, ensuring viral suppression in patients on treatment to avoid drug resistance development and consequently the transmission of drug resistant strains is a priority. Despite efforts to build more robust systems for tracking and retention of patients, treatment default is still common. Monitoring of patients in care is suboptimal due to the lack of adequate infrastructure and expensive CD4 and viral load tests. Recently published results have indicated that loss to follow up (71%) was the main cause of 12-month attrition. The same study revealed that the rate of regimen switch to second-line options remains low, with only 0.56% of patients in care currently on second-line regimens These problems of treatment default, poor monitoring of patients in care, and delayed or absent switches to second-line therapies cause concern over the possibility of rapid development of HIV drug resistance (HIVDR). Samples collected in 2002 from 75 drug-naïve HIV-positive women from the southern, central and northern regions of Mozambique revealed no circulation of HIV drug resistance WHO has developed a methodology for monitoring of TDR in resource-constrained countries that categorizes the level of resistance observed to each relevant drug class In Mozambique, HIV drug resistance threshold surveys (HIVDR-TS) were conducted in Maputo (southern region) and Beira , following WHO recommendations to conduct surveillance in capital cities where HAART has been available the longest and coverage is highest. Here we report the findings of two HIVDR-TS, conducted in 2007 and 2009 among pregnant women attending antenatal clinic (ANC).Two threshold surveys took place from March to June in 2007 and 2009 in Maputo (southern region) and Beira , cities where antiretroviral programs were first introduced and expanded rapidly with HAART coverage in 2007 of 23% and 54% and in 2009 of 38% and 77% for Beira and Maputo respectively. Two health units from each city were included to ensure timely collection of samples within the surveillance round. Consistent with WHO guidance, specimens from both units within the same geographic area were pooled prior to assessment of TDR. See .The population for this survey consisted of pregnant women participating in the biannual ANC-based HIV surveillance program at five of the 36 sentinel sites in Mozambique. The lot quality assurance sampling (LQAS) methodology was used to classify TDR separately for each of the three drug classes ANC-based HIV surveillance is unlinked and anonymous. Specimens are prepared from blood specimens collected for routine RPR testing. Prior to initiation of surveillance procedures, oral consent was obtained from each participating subject and documented in the ANC register. Pregnant women aged 15–17 years were treated as emancipated minors and parental consent was not sought, following Mozambique health services guidelines for treating pregnant minors. All participants, regardless of consent to participate in surveillance, were offered PMTCT services. Protocols for both ANC surveys, including consent procedures, were approved by the National Ethics Review Committee in Mozambique and by the US Centers for Disease Control and Prevention.1  were tested with Murex HIV 1–2–O2  to confirm positivity, whereas non-reactive specimens were considered HIV-negative. Specimens eligible for HIVDR testing were stored in a freezer at-20°C, then shipped on dry ice to the National HIV and Retrovirology Laboratories of the Public Health Agency of Canada for genotyping.Five milliliters of blood were drawn from each woman for routine RPR screening. For women who consented to participate in ANC surveillance, dried blood spots (DBS) were prepared on Whatman 903 filter paper . For each subject two DBS cards were prepared, dried overnight, and packed in a gas-impermeable zip-lock bag with five desiccant packs and one humidity indicator card, and stored in a refrigerator at 4–8°C before shipping to the reference laboratory in Mozambique. At the reference laboratory, two sequential ELISA tests were used to re-test the specimens. Specimens reactive to HIV antibodies on Vironostika HIV Uniform II plus Opol gene was performed using REGA and a phylogenetic tree constructed using neighbour-joining distance method Complete protease and part of reverse transcriptase were sequenced using the Big-Dye terminator Cycle Sequencing Kit  REGA HIV-1 subtyping tool version 2.0. Phylogenetic tree generation from complete PR (codons 1–99) and partial RT gene (codons 1–340) was conducted with MEGA 5 using Kimura’s two parameter model (2 K-P) neighbour-joining analysis with 1000 bootstraps Sequences were assembled, edited, aligned to a reference subtype B sequence (accession number NC_001802), trimmed to identical length  and had gaps removed using BioEdit Software, version 7.0.9. Analysis of drug resistance mutations was performed using the Stanford Drug Resistance Database (http: //hivdb.stanford.edu/hiv). For complete sequences subtyping was performed using the In addition to reporting the type and frequency of drug mutations encountered, the LQAS method recommended by WHO for HIVDR surveillance was also applied for areas where the minimum required number of specimens were obtained and the SLQAS for areas where the minimum numbers could not be obtained due to low incidence or time constraints Due to quality problems in specimen collection one site from Maputo was excluded in 2007. The mean age of the participants was 20.3 years in 2007 and 20.9 in 2009. Summing across regions, 102 and 132 specimens were collected from 2007 and 2009 surveys, respectively. Serological confirmation followed by genotyping yielded 75 (73.5%) reportable sequences in 2007 and 114 (84.8%) reportable sequences in 2009 for the PR region and 64 (62.8%) reportable sequences in 2007 and 123 (93.2%) reportable sequences in 2009 for the RT region, reflecting an improvement in DBS quality and storage conditions in 2009 when compared to 2007.The SLQAS algorithm was used for analysis of TDR in Maputo for the 2007 survey. Maputo had 21 specimens available for classification of TDR for NRTI and NNRTI, and only 23 specimens were available for TDR classification for PI. Based on the 10% cutoff for the SLQAS algorithm, prevalence of TDR for all three drug classes was found to be <10%. Nonetheless one sequence carrying a PI mutation (M46L) was identified. Sequential analysis of the first 34 specimens from the same survey year from Beira for PI and NNRTI mutations did not show the occurrence of mutations, thus a prevalence of <5% for both PI and NNRTI drug classes was assigned. In contrast we found 2 NRTI mutations (M41L) conferring resistance to thymidine analogs in the first 34 specimens analyzed. Subsequential evaluation of four additional specimens revealed no drug resistance mutations, thus TDR was classified as intermediate to NRTI see .In 2009 the minimum sample size required for use with LQAS was attained for both regions. Consecutive analysis of 34 specimens from Maputo showed the absence of PI, NRTI and NNRTI relevant mutations, thus the prevalence was categorized as <5% for all drug classes. On the other hand analysis of the first 34 samples collected in Beira showed the presence of a NNRTI mutation at position K101E (n = 1) and K103N (n = 2) . Since tIn total, 112 specimens from the 2009 survey were analyzed for both geographic areas and the majority of PI mutations found could be classified as minor mutations with the exception of Q58E which can be a nonpolymorphic PI-selected mutation associated with decreased susceptibility to TPV/r . SimilarREGA, phylogenetic analysis of 112 sequences representing the 2009 survey in Maputo and Beira was performed and results are depicted in In order to confirm the subtype assignment done by In this study we report for the first time the occurrence of TDR in Mozambique using the WHO-recommended methodology for TDR surveillance among recently infected pregnant women. In a context of rapid scaling-up and decentralization of HAART services data generated from such studies are of extreme relevance to the country as these may be used by decision makers for choice of therapeutic options, improvement of prevention and treatment programs and treatment monitoring strategies. Analysis was performed based on the mutations list from WHO Of note, NRTI and NNRTI mutations were not identified in Maputo in contrast to Beira where NRTI mutation M41L was found in two sequences. This mutation confers resistance to stavudine (d4T) and zidovudine (AZT), antiretrovirals that compose the first-line backbone in Mozambique The prevalence of TDR found in Maputo is similar to prevalence found in threshold surveys performed in surrounding countries such as Swaziland, South Africa, Malawi and Tanzania Sample collection in ANC settings for HIVDR-TS presents challenges and difficulties with sample collection limited our ability to fully apply the LQAS algorithm in all regions for all drug classes in both surveys. However, application of the simplified LQAS algorithm allowed us to make full use of available specimens. Two consecutive surveys, in 2007 and 2009, have detected intermediate levels of TDR in Beira, thus revealing the need for intensification of prevention programs, along with the implementation of continued monitoring of drug resistance in other regions of the country. Moderate classification of TDR needs to be confirmed through repetition of the survey in this area and possibly in additional areas of the country. Furthermore work should be done to identify possible sources of HIVDR transmission, through evaluation of prevention programs and intensification of HIVDR early warning indicators monitoring.