Genotypic antiretroviral resistance testing (GRT) in HIV infection with drug resistant virus is recommended to optimize antiretroviral therapy, in particular in patients with virological failure. We estimated the clinical effect, cost and cost-effectiveness of using GRT as compared to expert opinion in patients with antiretroviral treatment failure.We developed a mathematical model of HIV disease to describe disease progression in HIV-infected patients with treatment failure and compared the incremental impact of GRT versus expert opinion to guide antiretroviral therapy. The analysis was conducted from the health care (discount rate 4%) and societal (discount rate 2%) perspective. Outcome measures included life-expectancy, quality-adjusted life-expectancy, health care costs, productivity costs and cost-effectiveness in US Dollars per quality-adjusted life-year (QALY) gained. Clinical and economic data were extracted from the large Swiss HIV Cohort Study and clinical trials.Patients whose treatment was optimized with GRT versus expert opinion had an increase in discounted life-expectancy and quality-adjusted life-expectancy of three and two weeks, respectively. Health care costs with and without GRT were $US 421,000 and $US 419,000, leading to an incremental cost-effectiveness ratio of $US 35,000 per QALY gained. In the analysis from the societal perspective, GRT versus expert opinion led to an increase in discounted life-expectancy and quality-adjusted life-expectancy of three and four weeks, respectively. Health care costs with and without GRT were $US 551,000 and $US 549,000, respectively. When productivity changes were included in the analysis, GRT was cost-saving.GRT for treatment optimization in HIV-infected patients with treatment failure is a cost-effective use of scarce health care resources and beneficial to the society at large. The advent of potent antiretroviral therapies (ART) a decade ago has led to a substantial decline of morbidity and mortality in HIV infected patients It has been documented in randomized controlled trials that GRT based treatment optimization leads to a higher viral load reduction than standard care alone in treatment-experienced patients Early and more recent cost-effectiveness studies suggested that antiretroviral treatment optimization using GRT is cost-effective We developed a mathematical model of HIV disease to assess the incremental impact of antiretroviral therapy guided by genotypic antiretroviral resistance testing versus expert opinion alone in patients presenting with treatment failure defined as i) a viral log reduction of <1 log HIV RNA copies/ml during the first six months after initiation of antiretroviral therapy (ART), ii) a viral load increase of >1 log HIV RNA copies/ml within two months of ART, or iii) two consecutive viral load assessments >200 copies/ml after reaching undetectable plasma HIV RNA levels (<50 copies/ml) 3, 201–500 cells/mm3, >500 cells/mm3) and viral load , and in patients who experienced an AIDS-indicator disease by CD4 cell count only . Patients are always at risk of dying due to an HIV-related or unrelated cause and were modeled until death. The disease model was populated with data extracted from the SHCS; the starting age of patients is 33 years, the average age of patients enrolled in the SHCS, and 80% of patients are male A state transition model of HIV disease with mutually exclusive health states was developed to describe the course of HIV disease after antiretroviral treatment failure, the starting state of patients entering the model The probability of maintaining the failing antiretroviral regimen or switching to a new regimen with or without information available from GRT was derived from Haupts et al. www.statistik.admin.ch).HIV disease progression was modeled by means of a transition probability matrix derived from the SHCS using the dataset from the period 1996–2004 before GRT became widely available. The probability of transitions to a health state with a viral load above or below 1000 copies/ml, a different CD4 cell stratum, the risk of developing an AIDS-indicator disease and dying was extracted from the SHCS database by pooling observations from patients on highly active antiretroviral therapy over consecutive six-month periods HIV disease may not only affect survival but may also substantially affect the patient's wellbeing st, 2005 .In the analysis from the health care perspective we only included costs due to health care resource consumption . We usedwww.statistik.admin.ch) to estimate productivity changes over a patient's simulated lifetime  or the benefit of Hepatitis B vaccination in newborn babies whose mothers have Hepatitis B (gain in life-expectancy 2 weeks) M. avium complex infection in patients with AIDS ($US 80'000 per QALY gained) However, when only health care costs are considered, the cost-effectiveness ratio of GRT is $US 35'000 per QALY gained, which is similar to the cost-effectiveness ratio of implantable cardioverter-defibrillators ($US 35'000 per QALY gained) In a previous study we have shown that GRT reduces health care costs over a two-year follow-up period due to the reduction of ambulatory and in-patient costs and a reduced consumption of non-HIV medication In the present paper we also considered the most recent methodological developments with respect to the inclusion of productivity costs in economic evaluation to avoid a biased cost-effectiveness ratio Our study has several limitations. We used a mathematical model to approximate the real-world and project long-term costs and outcomes of GRT. However, we used best available evidence from one of the largest cohort studies on HIV disease to reflect a real-world setting Our study has been conducted in Switzerland where health insurance is compulsory by law for all patients. However, our results are equally relevant for other countries such as the USA where health insurance is often funded by employers. The inclusion of GRT in health insurance plans not only leads to a benefit to the patient but also to the employer by increasing job productivity. Public health insurance coverage in the USA, on the other hand, is tied to disability status. Patients with disability status on public health insurance may also benefit from GRT based treatment optimization, as a better health state may increase the likelihood to return to work. Our results suggest that GRT represents high value for money and should be offered to all patients who can benefit from it. Table S1Transition probability matrix for HIV disease progression generated by pooling consecutive six-month observations from patients on HAART enrolled in the SHCS between 1996–2004. Numbers indicate observations, the likelihood is shown in brackets. To calculate the posterior probability with a non-informative prior, the number of observations in each cell with an allowed transition is increased by one.(0.05 MB DOC)Click here for additional data file.


Mycobacterium tuberculosis (MTB)-specific antigens are contradictory. Differences in technical aspects of the assays used to detect this response and populations studied might explain some of these discrepancies. In an attempt to find surrogate markers of the effect of LTBI treatment, it would be important to determine whether, among contacts of patients with contagious tuberculosis, therapy for LTBI could cause changes in MTB-specific immune responses to a variety of RD1-antigens.Existing data on the effect of treatment of latent tuberculosis infection (LTBI) on T-cell responses to + recent contacts were followed over a 6-month period and divided according to previous exposure to MTB and LTBI treatment. The following tests which evaluate IFN-gamma responses to RD1 antigens were performed: QuantiFERON TB Gold, RD1 intact protein- and selected peptide-based assays. Among the 24 contacts without previous exposure that completed therapy, we showed a significant decrease of IFN-gamma response in all tests employed. The response to RD1 selected peptides was found to be more markedly decreased compared to that to other RD1 antigens. Conversely, no significant changes in the response to RD1 reagents were found in 9 treated subjects with a known previous exposure to MTB and in 11 untreated controls.In a longitudinal study, 44 tuberculin skin testThese data suggest that the effect of INH prophylaxis on RD1-specific T-cell responses may be different based on the population of subjects enrolled (recent infection versus re-infection) and, to a minor extent, on the reagents used. Mycobacterium tuberculosis (MTB) in an asymptomatic, latent form (latent tuberculosis [TB] infection [LTBI]) but retains a lifelong risk of future disease. The control and elimination process of the global TB epidemic could be enhanced by identification and treatment of individuals with LTBI, in particular of individuals who recently acquired the infection as the risk of developing active disease is higher in the first 2 years after exposure  and culture filtrate protein 10 [CFP-10]) encoded by the RD1 (region of difference) genomic segment, which is absent from most non-pathogenic mycobacteria, including Bacillus Calmette Guerin (BCG)  on initial screening. Patients were not included in the analysis if they were at risk for Human Immunodeficiency Virus infection (HIV), or if they reported having had active TB in the past, or having previously received treatment for LTBI. Upon enrolment demographic and epidemiological information were collected, including information about BCG vaccination. Data were collected by the physician through a structured questionnaire.In a one-year period we enrolled close contacts of infectious TB patients in 2 outpatient services in Rome, Italy . We included in the present analysis individuals who tested TSTIndividuals included in the analysis were classified into four groups based on the history of past exposure to a patient with contagious TB, and on whether or not they were receiving treatment for LTBI. The study was approved by the ethics committee at our institution and all enrolled individuals provided written informed consent prior to screening procedures, as did the parents of the children included in the study.TST was administered by the Mantoux procedure using 5 IU of purified protein derivative (PPD) . Results were read after 72 hours. Induration of at least 5 mm was considered a positive response ,27.6–28, 67–79 and CFP-10 18–31, 41–68, 74–86.Selection of Human Leukocyte Aplotype (HLA)-class II-restricted epitopes of ESAT-6 and CFP-10 proteins was performed by quantitative implemented HLA peptide-binding motifs analysis . PeptideAll samples were analyzed by WBE assays, as previously described . BrieflyResults are presented as IU/ml for ELISA after subtraction of the appropriate control according to the described criteria . Cut-offQTF-G  was performed and its results were scored as indicated by the manufacturer . For IFN-gamma values above 10 IU/ml serial dilutions of plasma were performed.The main outcome of the study was the effect of treatment in terms of IFN-gamma production in response to antigenic stimulation in the QTF-G and WBE, expressed as dichotomous (positive/negative) and continuous (IU/mL) measures. IFN-gamma mean ± SE was calculated. The Mann-Whitney U test was used to compare continuous variables, and Chi square or McNemar tests were used for categorical variables. Analysis was carried out with SPSS v 14 for Windows .+ and 44 of them accepted to be followed over time and were included in the analysis. The study group was divided into those who did not report having had any previous exposure to a smear positive TB case (30), and those who did (14). Among the former group, 6 patients did not receive therapy on the grounds that two were contacts of a patient with multidrug-resistant TB, two had chronic hepatitis C and two refused treatment; five subjects belonging to the latter group decided to not undergo INH therapy  table . Similar+ individuals that started therapy, and that did not report a previous exposure to MTB in the past, is shown in Figure The IFN-gamma response to PPD, QTF-G, RD1 intact proteins and selected peptides of the 24 TSTIFN-gamma production in response to PPD was detected in all the individuals studied  and did not significantly change over time  with a 34% reduction over baseline, and a 70% reduction at time 3 (p = 0.0001 vs. time 1)  and 79% reduction at time 3 (p = 0.0002 vs. time 1)  with a 63% reduction over baseline, and a 91% reduction at time 3 (p = 0.0005 vs. time 1), as shown in figure Among these same individuals TST cuticonversion was observed in 9/24. However no differences were observed in the trends of RD1 responses when the results from these individuals were compared with those from the remaining 15 subjects in whom a cuticonversion was not observed (data not shown).It is interesting to note that in the group of the 9 individuals that reported an exposure to MTB in the past and started INH therapy at the time of the present study, the IFN-gamma response to PPD, QTF-G, RD1 intact proteins and selected peptides did not significantly change over time Figure . In partin vitro RD1 responses in individuals with LTBI with a recent exposure to MTB, who did not report any exposure in the past. This decrease was observed, although to a different extent, with all RD1 antigen reagents used. It is important to note that the trend of decrease of the test using RD1 selected peptides was particularly marked after 1–2 months of therapy and that the response of the majority became undetectable after six months, while the response to the other RD1 products (overlapping peptides of the QTF-G and RD1 intact proteins) decreased more slowly and fewer negative results were observed after six months of therapy. These differences may be related to the amount and the composition of epitopes covered by the peptides and intact proteins. For example, the peptides employed in the QTF-G cover the whole CFP-10 and ESAT-6 intact proteins (in addition to having a peptide from TB7.7) [+. Further investigations are needed to clarify the meaning of these differences. In contrast, no significant variation was observed in individuals with LTBI who, in addition to a recent exposure, had also a past exposure to contagious TB patients. Altogether, these data suggest that RD1-based assays may be a tool to monitor therapy-related changes of MTB-specific immune responses not only in patients with active disease, as previously demonstrated by us and others [In this pilot study, we show that INH preventive therapy is associated with a significant decrease of the m TB7.7)  whereas m TB7.7) . Based od others ,19-21, bA few studies have been previously published on the effect of LTBI therapy on T-cell responses. Decreasing responses to CFP-10 overlapping peptides, and not to ESAT-6, were found after INH therapy in recently exposed contacts  that arein vivo, and can therefore rapidly release IFN-gamma when stimulated in vitro. This suggests a correlation between the measure of this response and antigen load [The reasons for the different effect of therapy in modulating RD1 responses in recently infected patients vs. those potentially reinfected, observed in the present study, are currently unclear. In several models of infectious diseases it has been shown that the immune response is strictly dependent on pathogen replication and antigenic load -31. In sgen load ,11,12. Agen load . This pogen load . Howevergen load , our datgen load ,22-25.Some potential limitations of the present study should be considered. Firstly, we were able to document only 9 cuticonversions among the 24 individuals who did not report a previous exposure to MTB. This limit however is common to previous studies ,25, and In conclusion, our preliminary data suggest the possibility of using RD1 immune responses as surrogate markers of efficacy during LTBI treatment. A larger study is needed to better evaluate the difference in kinetics of the T-cell response after exposure to MTB in those with an already established LTBI vs. those recently infected.• BCG: Bacillus Calmette Guerin• CFP: culture filtrate protein• ESAT: early secreted antigenic target• HIV: Human Immunodeficiency Virus infection• IFN: interferon• INH: isoniazid• IU: international unit• LTBI: Latent tuberculosis infectionMycobacterium tuberculosis• MTB: • PHA: Phytohemagglutinin• PPD: purified protein derivative• QFT-G: QuantiFERON TB Gold• RD: region of difference• RD1: CFP-10 and ESAT-6• TST: tuberculin skin test• TB: Tuberculosis• WBE: whole blood ELISADG, RC, FP and EG have a patent pending on T cell assay based on RD1 selected peptides.DG designed the study and recruited the adult patients and performed data analysis and wrote the draft of the manuscript, MPP carried out the data base of collected data and helped in the data and statistical analysis, OB and FB and RC carried out the immunological assays, DD and GA helped in the recruitment of adults and children respectively and in the design of the study, CN helped in writing the draft and did the editing and performed data analysis, GI and FP helped in writing the draft of the paper and in the design of the study, EG conceived of the study and participated in its design and performed the statistical analysis and helped to draft the manuscript. The article has not been submitted elsewhere and all co-authors have read and approved the final manuscript with its conclusions.


Evidence of PI activity was observed in plasma virus as early as 72 hours post treatment-initiation and was predictive of plasma viral RNA decrease at 4 weeks.Protease inhibitors (PIs) block HIV-1 maturation into an infectious virus particle by inhibiting the protease processing of gag and gag-pol precursor proteins. We have used a simple anti-HIV-1 p24 Western blot to monitor the processing of p55 This processing step likely requires the dimerization of two gag-pol precursors (at least in the region of protease) that permits a low-efficiency cleavage of the precursor proteins and release of fully active protease (PR) homodimers [Assembly and transport of the 55 kDa gag  could support any HIV-1 infection of PHA/IL-2 treated PBMC regardless of the patients treatment status (data not shown). Concentrating the virus by ultracentrifugation did little to increase infectious titer of virus from plasma.The first assay involved measurement of infectious virus potential. We serially diluted cell-free culture supernatants from chronically HIV-infected U87.CD4.CCR5 cells treated with PIs. This diluted and undiluted plasma was then added to uninfected peripheral blood mononuclear cells (PBMC). Although this assay could be used to measure infectious potential of high titer viruses in tissue culture, only plasma containing extremely high viral loads (> 103–4 RNA copies/ml).The second assay involved PCR amplification of strong-stop viral DNA found in cell-free virus. Previous reports have shown that viral DNA is found HIV-1 particles ,17 but t50 values (i.e. lower concentrations of each drug) [In contrast to the assays described above, an anti-p24 Western blot was successful in measuring both in vitro and in vivo PI effects and was the simplest in design and application. To initially test this assay we infected U87.CD4.CXCR4 cells with a wild type HXB2 virus or the protease inhibitor resistant virus, RF (containing PR mutations V82F and I84V) . Followich drug) ,14,15. Cgag. We observed minute amounts of partly cleaved gag product containing the matrix (MA) p17 and CA p24, i.e. 41 kDa. In these experiments, the HXB2 p55:p24 is increasing over the first 72 hours of 20 nM LPV treatment indicating an inhibition of gag processing. In contrast, there was no evidence of decreased gag precursor processing with the RF virus treated with 20 nM LPV as indicated by a constant p55:p24 ratio of 0.1 during the 72 h of treatment. Treatment with a lower concentration of LPV (0.2 nM) or with NVP (2 or 200 nM) did not result in a significant difference in the HXB2 or RF p55:p24 ratios over time (data not shown). In tissue culture, longer incubation times with LPV (20 nM) reduced virus production to levels at which the quantities of p55 and p24 products were difficult to detect by Western blot analyses.Fig. To test the utility of this simple Western blot assay to monitor initial PI treatment, nine patients were enrolled into the A5036s Substudy of the ACTG Clinical Trial Substudy A5014 . All of 4 copies/ml at initiation of treatment. The level of virus production or success of PBMC infections did not increase if the virus was concentrated from plasma by ultracentrifugation. This concentration step would also remove any residual drug in plasma that might affect infectivity of virus in plasma after the initial treatment.In addition to the Western blot analyses, the sub-study also called for a measure of infectious potential by HIV-1 found in plasma. For these tests we exposed HIV-negative peripheral blood mononuclear cells to plasma samples obtained prior to and immediately following treatment with the PI- or non PI-containing HAART regimen. Only plasma samples of one patient (of 9) resulted in productive infection of PHA/IL-2 treated PBMC cultures suggesting that this not a sensitive assay. Unfortunately, no assessment of PI activity could be evaluated using this infectious assay since this patient was treated with NVP and the three NRTIs. It is unlikely that viral levels in plasma is the sole factor contributing to the ability of plasma virus to infect PBMC cultures since all patients in this substudy had viral RNA loads approximately 10gag considering the anti-p24 antibody should bind at least as efficiently to CA p24 than to the unprocessed p55gag. It is also possible that background p55 is due to the rapid turnover, and therefore that nascent virions make up a large fraction of the total. These virions could be more infectious than the fully processed ones seen in cell culture, since they would be rapidly processed in the course of the assay.Preliminary data indicated that plasma protein concentrations were too high to efficiently concentrate virus and resulted in excessive background on the Western blot for HIV-1 gag proteins. Thus, 1.5 ml of each plasma sample was diluted with 3.5 ml of phosphate-buffered saline (PBS) prior to concentrating the virus by ultracentrifugation. The procedures for the Western blot analyses are described above. Fig. gag or gag-pol precursors.We predicted that the p55:p24 ratio would increase during first three days of PI treatment with the possible dips in this ratio between PI dosages every 12 h). Preliminary data with patients starting a PI-containing treatment regimen suggest a PI-mediated inhibition of p55 processing within 8–12 h of treatment (data not shown). However, these studies were performed with patients starting RIT+SAQ or IND-containing treatment regimens and not with patients treated with LPV. As indicated by the results of tissue culture infection experiments shown in Fig. 2 h. PrelAlthough only one example of these analyses is shown Fig. . This inNearly all antiretroviral drug-naïve patients recruited into AACTG 5014 demonstrate a drop in viral RNA load to undetectable levels after 8 weeks of treatment with either regimen. This viral load decrease was associated with an increase in CD4 cell counts. In patients B, C, and D, the drop in viral load was likely mediated by both NVP and LPV but the initial viral RNA load decrease (within one week) could be more of a measure of NVP than LPV inhibitory activity Fig. . Within gag and p160gag-pol precursor proteins during virus budding or following virus release. However, the protease inhibitor does not impede incorporation of genomic HIV-1 RNA into the virus particle. Thus, following PI treatment, viral load assays based on detection of viral RNA measure both noninfectious, immature virus particles and virions found in plasma. We have developed a method to measure the anti-HIV activity of a protease inhibitor using a simple approach. In three patients treated with LPV+NVP, the ratio of unprocessed p55:processed p24 increased at 72 hours and over the next four weeks of treatment. In contrast, the ratio of HIV-1 p55:p24 did not change over the four weeks of study in patients treated with an NNRTI-containing regimen (NVP+3TC+D4T+ABV). This pilot study, though limited in patient number, has provided evidence that an HIV-1 p24 Western blot can be used to immediately measure the antiviral activity of protease inhibitors. Preliminary in vitro data also suggests that inability of PIs to block PI-resistant HIV-1 in patients could be assessed within 3 days of treatment. Based on these findings we are now testing the utility of this assay in highly PI experienced patients to predict the success of a new PI-containing treatment regimen within 3 days of starting this therapy. In addition, this study indicates that western blot is an excellent tool for the evaluation of the activity of protease inhibitors in vitro, and may be useful in evaluating new drugs putatively active against isolates resistant to current agents, or to evaluate the activity of different combinations of protease inhibitors using a more insightful measure than viral infectivity.In summary HIV protease inhibitors block the processing of p55The author(s) declare that they have no competing interests.H.B. and A.J.M. performed the laboratory work presented in this paper. E.J.A. supervised the laboratory work. M.M.L. and A.L. were the PI's of the parent study A5014. D.M. was the statistician for A5014 and 5036. D.R.K. was the protocol virologist for A5014.


Therapeutic drug monitoring (TDM) of the protease inhibitors administered in doses recommended for nonpregnant adults resulted in below-target concentrations in 29%, 35%, and 44% of 1st, 2nd, and 3rd trimester measurements, respectively, but low drug concentrations did not correlate with virologic failure. Demographic characteristics, antiretroviral experience prior to pregnancy, baseline VL, or use of specific antiretrovirals did not affect the virologic response. Adherence to ≥95% of prescribed doses and utilization of psychosocial services were associated with undetectable plasma HIV RNA at delivery. In conclusion, the virologic responses of pregnant and nonpregnant adults share similar charactersitics.HIV-infected pregnant women with undetectable plasma HIV RNA concentrations at delivery pose a minimal risk of vertical transmission. We studied the kinetics and the determinants of the virologic response to antiretroviral therapy in 117 consecutive pregnancies. Patients who initiated therapy during pregnancy had a VL decrease of 2 and 2.5 log Highly active antiretroviral (ARV) therapy (HAART) has decreased HIV mother-to-child transmission (MTCT) to <2% in the US and other countries where ARVs are readily available –5. This The dominant risk factor for MTCT is high maternal viral load at delivery . In nonpAnother important issue for prevention of MTCT (PMTCT) is optimization of drug regimens during pregnancy, which typically include 2 nucleoside reverse transcriptase inhibitors (NRTI) and a protease inhibitor (PI). Pharmacokinetics and therapeutic drug monitoring (TDM) studies during pregnancy showed that absorption and distribution of PIs differ in 3rd trimester pregnant women compared with nonpregnant adults, such that dose adjustments may be warranted –13. HoweTo address these issues, we conducted a retrospective chart review of pregnancies managed by the Children's Human Immunodeficiency Program (CHIP) in Denver. In August 1997, CHIP became the reference center for the care of HIV-infected pregnant women in Colorado and neighboring states. These women come from a relatively broad patient population that is highly representative of the HIV epidemic in the Southwestern US.Patients were cared for by a multidisciplinary team, comprising specialists in adult and pediatric infectious diseases, obstetrics and maternal-fetal medicine, nursing, social work, mental health, and nutrition. Basic HIV-specific treatment consisted of ≥3 ARV including ≥2 classes of ARV. HIV genotype was determined before treatment initiation in patients with plasma HIV RNA ≥1000 copies/mL. Adherence was facilitated by distributing pill boxes, watches, and pagers, office counseling or home visits, and direct observed therapy. Plasma HIV RNA and CD4+ cells were measured at 2–6 week intervals. PI plasma concentrations were assessed using high-pressure liquid chromatography assays performed at the National Jewish Hospital pharmacology laboratory, certified by the AIDS Clinical Trials Group and compliant with the Clinical Laboratory Improvements Amendments. For TDM, drugs were administered in clinic with or without food, as indicated. Trough concentrations were obtained immediately before the dose. Peak concentrations of lopinavir (LPV) were measured 4 hours after administration of LPV/ritonavir (LPVr) and of other PIs 2 hours after administration of the drug.Treatment was modified based on drug levels, virologic response, safety, and tolerability. Centralized treatment decisions were made by the physician in charge of the maternal care of the PMTCT program in consultation with the primary infectious diseases provider of the patient, if different from the PMTCT physician.The HIV-specific obstetrical plan included intravenous zidovudine (AZT) administration during delivery except for patients on stavudine, who continued their oral medications. Cesarean sections were scheduled at 38 weeks of gestation for consenting patients with VL > 1000 copies/mL at ≥34 weeks gestation, as indicated by other medical obstetrical conditions or patients' choice.Infants were treated during the first 6 weeks of life with AZT. When the maternal VL at the last visit prior to delivery was ≥5,000 copies/mL or >1000 copies/mL with vaginal delivery, the neonate received 2 additional drugs from 2 ARV classes for the first 4 weeks of life.This study was reviewed by the local IRB and deemed exempt from IRB approval due to the retrospective nature of the study and absence of disclosure of any personal information. Pregnancies with delivery between Aug. 1997 (inception of the CHIP PMTCT program) and Dec. 2005 (initiation of chart review) were identified in the CHIP database. Information was abstracted for pregnancies with ≥16-week duration and ≥2 visits at CHIP, using study-specific forms.Analyses assumed a two-sided test of hypothesis with a 0.05 significance level. Associations between categorical variables were determined using Fisher's exact test. Wilcoxon rank-sum test was used for comparisons of continuous variables between two groups. Changes in VL and CD4+ T-cell counts were tested using a signed-rank test. 10 VL was modeled as smooth functions of time on treatment using a natural cubic B-spline transformation on time [ns command in Splus v8.0 (Insightful Corp). A random intercept was included in all models and a random slope was modeled using natural cubic B-splines. Akaike's Information Criterion was used to determine the final model [To determine the kinetics of the virologic response, log on time . This anal model . We allo10 transformation was conducted after the imputation.As VL was measured using different assays, the lower limit of detection varied. Six limits exist in our data: <20, 20–50, <50, <200, 200–400, and <400. In preparation for the B-spline analyses, we imputed plasma HIV RNA copies/mL such that those with (a) <20 were set to 10, (b) 20–50 to 35, (c) <50 to the mean of all values <50 , (d) <200 to the mean of all values below 200 , (e) 200–400 to 300, and (f) <400 to the mean of all values <400 . The logMedical records were available for 117 of 123 pregnancies that met inclusion criteria. These involved 12 women with 2 pregnancies . The medThe most common risk factor for HIV acquisition was heterosexual intercourse, reported by 97 patients (92%). In 70 patients (67%), the diagnosis of HIV infection was established before pregnancy. Of the 35 patients diagnosed with HIV during pregnancy, 11 (34%) were diagnosed during the first trimester, 16 (50%) during the second trimester, and 5 (16%) during the third trimester. μL; 13 women (12%) had <200 cells/μL. In 51 pregnancies (44%), the women were ARV naϊve and in 59 (50%) ARV experienced, including 29 patients who became pregnant on therapy.At the first pregnancy visit, the median VL was 2657 copies/mL including 78 (72%) with >400 copies/mL. The median CD4+ T-cells was 450 cells/Median gestational age at delivery was 38 weeks (interquartile range (IQR) = 37–40 weeks). Thirty-six women (31%) delivered by scheduled Cesarean section. The 114 single and 3 twin pregnancies resulted in, 117 infants without HIV infection, 1 fetal demise, 1 stillbirth and 1 neonate who died of sepsis at 1 day of life. Of the 117 neonates who lived >1 day, 98 (84%) received AZT and 19 (16%) HAART. These infants were not infected with HIV. The incidence of MTCT was 0 with a 95% confidence interval = 0% to 3%.N = 89), lamivudine (N = 108), stavudine (N = 22), nevirapine , nelfinavir , and LPVr (N = 25).At delivery, 106/114 (94%) pregnant women were on HAART (≥3 drugs from ≥2 classes); 7 women (4%), who did not tolerate PIs or NNRTIs, were on 2 or 3 NRTIs; and 1 woman, who delivered shortly after referral precluding a change in therapy, was on AZT monotherapy. The most common drugs at delivery were AZT (The median duration of continuous therapy up to delivery was 22 weeks (IQR of 15 to 35 weeks). Among 84 women who started ARV during pregnancy after being off therapy for several months or never being on therapy, the median duration of therapy during pregnancy was 20 weeks (IQR of 11 to 25 weeks). Of these, 77 (92%) received ARV for ≥4 weeks and 61 (73%) for ≥12 weeks.Adherence was measured by pill counts, pharmacy refill histories, MEMS caps, and detailed interviews in 44 pregnancies. Of these, 36 women (82%) took ≥95% doses of the prescribed medication, 7 (16%) took 50% doses–95%, and 1 took <50% doses. The analysis of adherence by ARV regimen  did not N = 59), referrals to housing agencies (N = 31) and peer advocacy groups (N = 30), food (N = 59) and financial (N = 56) assistance, and psychoeducational group activities (N = 37).This was provided in 76 of 117 pregnancies. A median of 7 support interventions per pregnancy took place (IQR = 4 to 13). These included case management visits (N = 95), which represented a significant decrease compared with the first pregnancy visit median of 2657 copies/mL (P < .0001). At the last visit before delivery, 80 women (82%) had plasma HIV RNA <400 copies/mL and 53 women (56%) had < 50 HIV RNA copies/mL. For all study participants, the median VL at delivery was 51 copies/mL  had <100 copies/mL; at 12 weeks of HAART, 11 of 26 women (42%) had <50 copies/mL; and at 24 weeks of HAART, 9 of 16 women (56%) had <50 copies/mL. These data confirmed the predictions of the model.To determine the kinetics of the virologic response to HAART during pregnancy, we applied a mixed-model analysis to data from 76 of 84 patients who initiated or reinitiated HAART during pregnancy and had multiple tests during pregnancy . The modμL : 92% of values >200 cells/μL. The median CD4+ T-cell increase between first pregnancy visit and delivery was 88 cells/μL . At delivery, the median CD4+ T-cell number was 540 cells/P = .29).In the mixed-model analysis used to elucidate the kinetics of CD4+ T-cells during pregnancy, we set the reference time at delivery to take into account the upward effect of ARV and the downward effect of pregnancy on the CD4+ T-cells. The model indicated that the CD4+ T-cells started to increase at 6 weeks prior to delivery and peaked at approximately 8 weeks after delivery in all subjects  and in tThirty-two pregnant women had ≥1 PI TDM for a total of 92 measurements. TDM was performed at a median of 5.5 weeks after initiation or change in therapy (IQR of 3.5 to 30 weeks). Eighty-two TDM assays were performed in women taking PI doses recommended for nonpregnant adults (regular) and 10 in women taking increased doses. P = .70).The analysis of the plasma concentrations achieved by the most commonly used PI in this study, LPVr, NFV, and saquinavir (SAQr), showed that 75% of all LPV measurements were normal and 25% were low across all trimesters; 20% to 59% of the NFV levels were normal with a trend of decreasing concentrations from 1st to 3rd trimester; and 30 to 50% of SAQ concentrations were normal. There were 10 PI TDM results during the 2nd or 3rd trimester in women who received increased PI doses (6 received LPVr 533/133 mg bid and 3 NFV 1500 mg bid). Of these, 3 measurements (30%) were below target.10 VL described above (Virologic response to therapy) was used to compare NFV- (N = 49) versus LPVr-containing HAART (N = 20). Differences in estimated log10 VL between the regimens, calculated as NFV estimate minus LPVr estimate, were 0.01 (P = .96), 0.44 (P = .10), 0.39 (P = .12), and 0.09 (P = .78) at 4, 8, 12, and 24 weeks on treatment, respectively.To evaluate potential differences between HAART regimens with respect to VL decay during pregnancy, the mixed-model analysis of logP = .006) and psychosocial support (P = .010).An analysis of the factors that could potentially affect the response to therapy defined by undetectable VL at delivery, including race, ethnicity, country of origin (as a surrogate of HIV-1 clade), magnitude of VL before initiation of therapy, ARV experience, HIV drug resistance (data presented elsewhere) , adherenTo determine what length of HAART administration during pregnancy was needed to achieve undetectable VL, we analyzed the kinetics of the virologic response in women who started HAART during pregnancy. The time to undetectable VL did not differ from that previously reported in HIV-infected nonpregnant adults , 18, witIn our patient population, the rate of Cesarean section was similar to that reported for other areas in the US and lower than that reported in Europe, where the use of scheduled Cesarean section is twice as common as in the US , 19. HowThe analysis of the kinetics of CD4+ T-cells in pregnancy revealed a delay in the response to HAART compared with the kinetics of VL. In pregnancy, the most significant increases in CD4+ T-cell numbers occurred in the last 6 weeks of pregnancy and first 6 weeks of postpartum. This pattern was observed in women who started HAART before or during pregnancy and was independent of continuing HAART post-partum. This pattern is most likely due to physiologic changes of pregnancy, including the increased volume of distribution of white blood cells and/or hormonal changes depressing CD4+ T-cells. The implication of this observation is that a lack of increase of CD4+ T-cells in pregnant women may not indicate virologic failure.An important question in the care of HIV-infected pregnant women is whether there is an ARV regimen more likely than others to rapidly decrease the VL in women diagnosed with HIV late in pregnancy. We did not find any significant differences in the kfinetics of VL as a function of the PI used in HAART. Previous studies showed that nonpregnant HIV-infected adults on NFV-containing regimens were less likely to achieve or maintain viral suppression compared with individuals receiving LPVr-containing regimens . HoweverWith respect to plasma concentrations achieved by various PIs during pregnancy, we found that LPVr levels were below target in 20% to 25% of pregnant women on adult recommended doses across all trimesters, whereas for another PI, 35% to 80% of the levels were below target. Others have shown that up to 72% of women on LPVr do not reach target concentrations of LPV during the 3rd trimester , 12, 21.The use of TDM did not significantly affect the virologic response to therapy in this study. Some studies in nonpregnant HIV-infected adults showed improved virologic response to PI-containing regimens in subjects whose doses were adjusted based on TDM results –26, but Among multiple factors that could potentially affect virologic response to therapy, suppression of viral replication at delivery was positively associated with adherence, confirming previous observations . We did Utilization of psychosocial support services was significantly associated with virologic response to therapy during pregnancy, which makes intuitive sense, but has not been previously demonstrated in a formal analysis. Although the association between utilization of psychosocial services and virologic success may indicate that women who are committed to medical treatment for PMTCT are also likely to seek resources to improve other aspects of their lives, it may also indicate that support services facilitate adherence to therapy –32. In summary, undetectable VL at delivery was associated with lack of vertical transmission of HIV in this group of women who predominantly delivered by vaginal route. Undetectable VL was achieved as soon as 4 weeks after initiation of HAART in 50% of the patients and at 12 weeks in the vast majority. Achieving undetectable VL at delivery did not depend on the specific PIs or NNRTIs included in the treatment regimen. Adherence, which was important to reach undetectable VL at delivery, did not vary with the drugs included in the treatment regimen, either. The pattern that emerges is that critical factors for PMTCT without high utilization of Cesarean sections are initiating therapy ≥12 weeks prior to delivery with a regimen that is well tolerated and conducive to ≥95% adherence.


Tipranavir (TPV) is a recently approved nonpeptidic protease inhibitor (PI) of HIV-1 and has been indicated for those infected with PIs-resistant HIV-1. However, in clinical practice, whether the HIV-1 from the patients with virological failure to the regimens containing first-line PIs remains susceptible to TPV/r may be questionable.To assess the resistance levels to TPV of HIV-1 from patients with treatment failure to first-line PIs, patients who experienced virological failure were tested for genotypic resistance of HIV-1 since August 2006 in National Taiwan University Hospital. Patients were enrolled for this analysis if their failed regimens contained > 12 weeks of atazanavir or lopinavir/ritonavir , but were excluded if they experienced both or other PIs. The levels of genotypic resistance to TPV/r were determined by TPV mutation score.Till May 2008, 21 subjects in ATV group and 20 subjects in LPV/r group were enrolled. The TPV mutation scores in subjects in LPV/r group were significantly higher than these in ATV group . 95.2% subjects in ATV group and only 45% subjects in LPV/r group had an estimated maximal virological response to TPV/r (P < 0.001). The resistance levels to TPV/r correlated with the duration of exposure to first-line PIs, whether in ATV or LPV/r group.Cross-resistance from first-line PIs may impede the effectiveness of TPV/r-containing salvage therapy. TPV/r should be used cautiously for patients with virological failure to LPV/r especially long duration of exposure. Tipranavir (TPV) is a recently approved nonpeptidic protease inhibitor (PI) of HIV-1 and ritonavir (RTV)-boosted tipranavir (TPV/r) has been indicated for treatment-experienced patients or those infected with PIs-resistant HIV-1  thus TPVHowever, TPV shares some resistance-associated mutations  with other PIs [Since August 2006, HIV-1-infected patients who experienced virological failure were tested for genotypic resistance of HIV-1 in National Taiwan University Hospital, the major referral center for HIV/AIDS and reference laboratory for HIV-1 resistance testing in Taiwan. Virological failure was defined if a confirmed HIV RNA level > 400 copies/mL after 24 weeks of antiretroviral treatment, or > 50 copies/mL after 48 weeks, or repeated detectable HIV RNA level after prior suppression of viremia. Resistance testing was performed while the patients were taking or immediately (< 4 weeks) after discontinuation of the failed regimen. Patients were enrolled for this analysis if their failed regimens contained > 12 weeks of LPV/r or ATV , and were excluded from the analysis if they experienced both of LPV and ATV, or using any antiretrovirals more than 12 weeks prior to the first-line PIs, or if they had a plasma HIV RNA < 1000 copies/mL. Low-dose RTV was not counted as a separate drug. This study has been approved by the Institutional Review Board of the hospital and informed consents have been obtained from all of the subjects before analysis. Initiating LPV/r or ATV depends on doctors' choice.2, 0.2 mM each deoxynucleoside triphosphate, 0.2 μM of each specific primer, 2.5 U of platinum Taq DNA polymerase . Population-based nucleotide sequence analysis of the PCR fragments was conducted using an automatic sequencer .This assay has been described previously . BrieflyWe assessed the genotypic susceptibility of TPV/r by using a unweighted tipranavir mutation score as described by Baxter et al. in 2006 . The scoU test) to compare the duration of exposure to PI, and using Fisher exact test or Chi-square test for categorical variables. Linear correlation was evaluated by Pearson's correlation coefficient. P < 0.05 was considered statistically significant.Statistical significance was determined using a non-parametric test  and 20 subjects with virological failure to LPV/r-containing regimens (LPV/r group). The CD4+ cell counts, plasma HIV RNA, and the total duration of PI exposure at the time of genotypic testing are similar in ATV group vs. LPV/r group . Based on the study of Baxter et al, TPV mutation scores of ≤ 1 were associated with < 1 median fold change (FC) of IC50 from the wild-type susceptibility, the scores of 4~ 7 were associated with a median FC of 2 ~ 3.9, and the scores of > 8 were associated with a dramatic increase in median FC (> 14.7) [Based on the Virco's algorithms, the lower and higher clinical cut-offs  of FC from the wild-type susceptibility to TPV/r are 1.2 and 5.4, respectively -10. FC ≤To know whether longer durations of exposure to PIs are associated with higher levels of resistance to TPV/r, we assessed the relationship between the TPV mutation scores and the duration of exposure to first-line PIs in these subjects with virological failure to regimens containing first-line PIs. The data showed that the TPV mutation scores had a linear correlation with the duration of exposure to first-line PIs, especially in subjects in LPV/r group Figure .in vivo, extensive levels of resistance-associated mutations in HIV-1 protease gene could be identified [This study showed the HIV-1 derived from the subjects after virological failure with LPV/r-containing regimens had a significantly higher genotypic resistance to TPV/r, than that from the subjects after virological failure with ATV-containing regimens, under the similar duration of PI exposure. Furthermore, in these subjects with virological failure to regimens containing first-line PIs, the TPV resistance levels had a linear correlation with the duration of exposure to ATV or LPV/r, indicating accumulation of mutations through time. The results may indicate that the subjects with virological failure with LPV/r-containing regimens may less likely respond to TPV/r-containing regimens, thus TPV/r may not be an ideal empirical choice for patients with virological failure with LPV/r-containing regimens, especially in a long duration of exposure. The mechanisms remain to be investigated. The possible explanation is that LPV/r has a high genetic barrier for HIV-1 resistance; once HIV-1 develops resistance to LPV/r entified .Only three subjects had a TPV mutation score of ≥ 6 in LPV/r group. This could mean that most patients on a failing LPV/r-containing regimens may just have a reduced virological response but not necessarily virological failure when shifted to TPV-containing salvage regimens. The clinical success may still possibly be achieved by maximizing the number of active drugs in the background regimens and improving the adherence of patients.The study has several limitations. The reason to explain why such high levels of resistance to TPV could be identified after virological failure to PI-containing regimens in a short duration of PI exposure in these subjects may include inadequate adherence or high baseline resistance. However, the impact of medication adherence on the resistance emergence, that may bias the interpretation for the results, could not be quantitatively assessed in this study. Though the resistance rate to PIs in treatment-naïve patients has been documented to have a significant increase in recent years in Taiwan , our datThe subjects with virological failure to LPV/r-containing regimens may less likely respond to TPV/r-containing salvage regimens than these with virological failure to ATV/r-containing regimens, especially in a long duration of exposure. Even the feasibility of resistance testing is limited, the empirical use of TPV/r should be very cautiously in subjects with virological failure to LPV/r-containing regimens unless resistance assay showed no or few mutations associated with TPV resistance.The authors declare that they have no competing interests.SMH and SYC participated in its design and coordination and drafted the manuscript. CCH and WHS made substantial contributions to conception and design and acquisition of data and analysis and interpretation of data. MYC and SCC involved in drafting the manuscript and revised it critically for important intellectual content. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2334/9/154/prepub


This study compares the costs and effects of a regimen with ritonavir-boosted tipranavir (TPV/r) to a physician-selected genotypically-defined standard-of-care comparator protease inhibitor regimen boosted with ritonavir (CPI/r) in HIV infected patients that were previously exposed to antiretroviral therapy in the Netherlands.We compared the projected lifetime costs and effects of two theoretical groups of 1000 patients, one receiving a standard of care regimen with TPV/r as a component and the other receiving a standard of care regimen with CPI/r. A 3-stage Markov model was formulated to represent three different consecutive HAART regimens. The model uses 12 health states based on viral load and CD4+ count to simulate disease progression. The transition probabilities for the Markov model were derived from a United States cohort of treatment experienced HIV patients. Furthermore, the study design was based on 48-week data from the RESIST-2 clinical trial and local Dutch costing data. Cost and health effects were discounted at 4% and 1.5% respectively according to the Dutch guideline. The analysis was conducted from the Dutch healthcare perspective using 2006 unit cost prices.Our model projects an accumulated discounted cost to the Dutch healthcare system per patient receiving the TPV/r regimen of €167,200 compared to €145,400 for the CPI/r regimen. This results in an incremental cost of €21,800 per patient. The accumulated discounted effect is 7.43 life years or 6.31 quality adjusted life years (QALYs) per patient receiving TPV/r, compared to 6.91 life years or 5.80 QALYs per patient receiving CPI/r. This translates into an incremental effect of TPV/r over CPI/r of 0.52 life years gained (LYG) or 0.51 QALYs gained. The corresponding incremental cost effectiveness ratios (iCERs) are €41,600 per LYG and €42,500 per QALY.We estimated the iCER for TPV/r compared to CPI/r at approximately €40,000 in treatment experienced HIV-1 infected patients in the Netherlands. This ratio may well be in range of what is acceptable and warrants reimbursement for new drug treatments in the Netherlands, in particular in therapeutic areas as end-stage oncology and HIV and other last-resort health-care interventions. The human immunodeficiency virus (HIV) that causes acquired immunodeficiency syndrome (AIDS) confronts us with a pandemic that is one of the biggest health problems in the world today. The Netherlands is known as a low-prevalence country, where the HIV epidemic is mostly confined within risk-groups. In recent years however, the majority of new HIV infections have occurred in patients of the general population without obvious risk-factors. Heisterkamp et al.  estimate®, Boehringer Ingelheim) co-administrated with a low dose of ritonavir (TPV/r) provides an additional treatment option for highly treatment-experienced HIV-1 infected patients where the virus developed resistance during the course of previous treatments. TPV/r suppresses viral replication of HIV-1, in particular in isolates that are highly resistant to multiple PIs [The introduction of highly active antiretroviral therapy (HAART) has been one of the greatest therapeutic advances in slowing disease progression of HIV since the introduction of zidovudine in 1987. HAART consists of a combination of nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs) and/or a fusion inhibitor, acting at different stages of the replication cycle of the virus . These ciple PIs ,11.Two randomized open-label phase III clinical trials, RESIST-1  and RESIST-2, have demonstrated that patients treated with TPV/r were twice as likely to achieve a viral load of less than 50 copies per mL compared to investigator-selected genotypically-defined ritonavir-boosted standard-of-care comparator protease inhibitor (CPI/r) therapy at week 48 -14. TPV/Economic considerations are of increasing importance for the reimbursement of new therapeutics. In a number of countries , economics evaluations of pharmaceuticals are required for decisions on the reimbursement of such new pharmaceuticals. Several cost-effectiveness studies have been conducted comparing different antiretroviral combinations for HIV. However, in a recent review over 1994–2004 Harling et al. reported that the majority of these studies compare general regimen types  instead of specific therapeutics or combinations of brands [We compare the projected lifetime costs and effects in the Netherlands of a cohort receiving TPV/r as compared to CPI/r, both administered with an optimized background regimen including at least 2 non-PI antiretrovirals .To assess the life-time costs and effects of a TPV/r based regimen compared to CPI/r, we used two theoretical groups of 1000 HIV-1 infected patients in the Netherlands. One group was assumed to receive a regimen containing TPV/r and the other a CPI/r-containing regimen. All patients had previously been exposed to antiretroviral regimens. A 3-stage Markov model was formulated to simulate the costs and effects during the lifetime of this treatment experienced group of patients. A similar model was previously applied to evaluate the cost-effectiveness of lopinavir/ritonavir versus nelfinavir . A diagrPatients transit to a next model stage if their HAART regimen fails. This is determined by the patient's health state. Patients may transit both to more and less favorable health states. However, the main trend is progression to a less favorable health state. During all three model stages, if a patient reaches one of the treatment failure health states , the patient moves to the next Markov stage. Treatment failure is exactly defined as reaching a detectable viral load and a CD4+ count of <= 200. A patient moves to the next Markov stage through an intermediate period of improvement where the patient remains one Markov cycle. In this intermediate period, patients progress to a more favorable health state.As mentioned above, the analysis was conducted on a theoretical cohort provided with two alternative treatment regimens. The cohort was comparable to the study participants in the RESIST-2 trial with respect to viral load and CD4+ count  and viral load measurement (€209). Additional costs of switching to a different antiretroviral regimen were also assumed at €351. The extra costs of changes in HAART regimen due to toxicities and the treatment of toxicities were not included in the model.The resource utilization and associated costs for AIDS events (22 most common opportunistic infections and other HIV events) were based on data from the University Medical Centre Groningen (UMCG). The weighted average cost of the different types of AIDS events was estimated at €8,264, using a bottom-up approach using resource use data from the UMCG of the different types of AIDS events and their relative occurrence, shown in table We assessed the uncertainty in the model parameters through univariate sensitivity analysis. All cost parameters were varied in the univariate sensitivity analysis over a range of 75% to 125% of the base-case parameter value and the impact on the iCER per QALY was presented in a tornado diagram. The impact of the AIDS event rates were investigated by multiplying these rates by 0.75 and 1.25. Additionally, the discount rates were evaluated at values of 0% and 5%. To assess the impact of a slower or faster disease progression (that is reflected in the transition probabilities of the transition matrices), we varied the probability for each health state of a patient staying in that particular health state by 5%. Simultaneously, the probability of transiting to the other health states is proportionately increased or decreased. Utility weights were not included in the sensitivity analysis.The lifetime accumulated cost to the healthcare system per patient receiving the TPV/r regimen is estimated to be €167,200 compared to €145,400 for a patient receiving the CPI/r regimen. This results in an incremental cost per patient of €21,800 (including lifetime savings of €167 per patient due to the reduction in AIDS events). The accumulated effect is 7.43 life years or 6.31 QALYs per patient receiving TPV/r, compared to 6.91 life years or 5.80 QALYs per patient receiving CPI/r. This translates into an incremental effect per patient receiving TPV/r compared to CPI/r of 0.52 LYG or 0.51 QALYs gained per person. The equivalent incremental cost effectiveness ratios (iCERs) are €41,600 per LYG and €42,500 per QALY.The results of the univariate sensitivity analysis on cost parameters are presented in figure Our model generally shows that TPV/r versus CPI/r treatment in heavily treatment experienced HIV infected patients provides benefits regarding reductions in AIDS events and corresponding QALY gains and life years saved. This was achieved at a cost-effectiveness ratio of crudely €40,000 per LYG or QALY.rd year [Generally in the Netherlands drug interventions with an iCER below €20,000 per LYG are certainly considered cost-effective and are accepted for reimbursement . In partrd year .In the context of the international health economic literature for treatment of HIV disease, cost-effectiveness results vary significantly. These studies generally do however not directly compare two antiretroviral components in the context of HAART. In the UK, Miners et al. reported an iCER of UK £17,698 per QALY in 2000 for adding an unspecified PI to lamivudine and zidovudine . Anis etWe have used a Markov model to approximate the complexity of sequential antiretroviral regimens that are typical for treatment of HAART experienced patients. In the absence of transition probabilities for the Netherlands, our study is limited by the fact that the health state transition probabilities were based on a clinical trial with primarily non-Dutch participants and a large observational cohort in the United States. Also, the AIDS event rate for each health state was calculated from this cohort. However, transition probabilities and AIDS event rates found comparable to those derived from a cohort of 3000 US patients and 900 Dutch patients, published by Ghani and colleagues . AdditioWe did not specifically include the costs of adverse events in this model because inclusion of such costs in this same analysis for other countries (unpublished data) had shown that this inclusion had a very minor effect on the iCER. We note that our estimate for the cost of an AIDS event of €8,264 is substantially lower than the $30,291  reported by Simpson et al. for the United States in 2002 . This diIn conclusion, we estimated the iCER per QALY for TPV/r compared to CPI/r to be €42,500 in treatment experienced HIV-1 infected patients in the Netherlands. This ratio may well be in range of what is acceptable and warrants reimbursement for new drug treatments in the Netherlands, in particular in therapeutic areas as end-stage oncology and HIV and other last-resort healthcare interventions.This study was facilitated by an unrestricted grant from Boehringer-Ingelheim.GAAH is the main investigator of this study and corresponding author. JMB contributed to the manuscript and provided the sensitivity analysis. CAVS and SS performed the acquisition of data from the UMCG. HWF critically reviewed several versions of the manuscript. BSK and AT have provided information on the clinical aspects of HIV infection and have contributed to the manuscript. KNS is the designer of the mathematical model and provided all transition data. MJP has supervised this study.10 viral load reduction.The population of the randomized phase III efficacy and safety trial RESIST-2 consisted of HIV-1 positive patients in Europe and Latin America that have experienced previous treatment from all classes of antiretrovirals: Nucleoside Reverse Transcriptase Inhibitors, Non Nucleoside Reverse Transcriptase Inhibitors and at least two protease inhibitor based regimens for a period of minimum three months. The trial was conducted over the period 2003–2004. Patients had a viral load of >= 1000 with any CD4+ cell count, with at least one primary PI mutation. The baseline mean and standard deviation (between brackets) of CD4+ count was 219 (192) for the TPV/r arm and 217 (168) for the CPI/r arm. The overall aim of the study was to investigate whether TPV demonstrates similar or better efficacy and comparable safety as the drugs chosen in the active control group. The endpoint was the proportion of patients with a treatment response in terms of at least a 1 logAll patients received an optimized standard of care regimen selected by their physician. Patient were randomized to include in this regimen either TPV/r or a comparator PI/r.3 versus 1 cell/mm3), with similar counts at baseline (219 and 217). Co-administration of enfuvirtide increased the proportion of patients with a treatment response in both arms of the trial. The researchers summarize that: "the results of this 48-week interim summary show that the TPV regimen  was significantly more effective than the comparator regimen  in postponing treatment failure or achieving a treatment response in patients who had previously received multiple antiretroviral therapy". Benefits provided by the TPV regimen through 48 weeks were enhanced by co-administration of other active antiretroviral agents, including enfuvirtide. Adverse events (AEs) occurred more in the TPV arm of the trial . This resulted in discontinuation of study medication for 11% of TPV users and 6% for comparator drugs. There were no differences in overall serious AEs (both at 17%), however 3% of TPV users had serious AEs considered related to study medication, against 0.5% for comparator drugs.A total of 879 patients were randomized, with 863 being evaluable. Kaplan-Meier estimates of time to treatment failure indicated a significant difference in favor of TPV (p < 0.0001). Treatment response after 48 weeks was higher in the TPV group at 34% versus 15% in the active controls. Many active controls (57%) changed the drug or discontinued due to virologic failure (versus 18% in the TPV group). In the different strata defined by comparator drug  similar results were seen. Also, CD4+ counts increased more for TPV than for controls (26 cells/mm


Aims. To determine whether the erythrocyte phosphorylated ribavirin (RBV) level might be a useful index of EVR and risk of anemia and to determine the optimal dose of RBV in 24 patients with hepatitis C with pegylated interferon and RBV. Methodology. The RBV level was measured by a high-performance liquid chromatography. Results and Conclusion. In patients aged 50 years or over, a negative correlation  was observed between the RBV level at week 2 and rate of Hb reduction (ΔHb) at week 4. The ΔHb at week 4 was significantly greater in patients with RBV levels of ≥800 μM (−25.5 ± 10.1%) than in patients with RBV levels <800 μM (−15.6 ± 7.7%). None of the patients with RBV levels <600 μM at week 2 achieved EVR and SVR. Thus the optimal levels of erythrocyte phosphorylated RBV at week 2 of therapy in order to achieve EVR without anemia seemed to be 600–800 μM. The combination therapy with pegylated interferon (PEG-IFN) and ribavirin (RBV) has come to be established as the standard treatment for chronic hepatitis C. A sustained virological response (SVR) has been reported with this treatment in 30%–50% of patients with HCV genotype 1b infection, which accounts for 70% of all Japanese patients with chronic hepatitis C .RBV is incorporated into the cells via the equilibrative nucleoside transporter (ENT) and converted to phosphates within the cells. RBV monophosphate (RMP) and RBV triphosphate (RTP) are considered to have antiviral activity , 4. In nIn this study, with the objective of reducing the adverse effects and improving the treatment completion rate in patients receiving combined PEG-IFN and RBV therapy, we attempted to evaluate whether the erythrocyte phosphorylated RBV level might be useful as an index for the rate of Early Virological Response (EVR) and SVR, the risk of anemia.α2b and RBV therapy was started, 24 patients who provided written informed consent for participation in this study were enrolled. The dosage regimen for the combined PEG-IFN and RBV therapy was determined in accordance with the standard dosing recommended for Japanese HCV patients. RBV was started at the initial dose of 600 mg/day in patients with a body weight of ≤60 kg, 800 mg/day in those with a body weight of >60 kg and ≤80 kg, and 1,000 mg/day in those with a body weight of >80 kg. In patients with no cardiovascular disease, the RBV dosage of 600 mg/day was decreased to 400 mg/day, and 800 mg or 1000 mg/day was reduced to 600 mg/day, if hemoglobin (Hb) level decreased to less than 10 g/dL; permanently discontinued the drug if Hb decreased to less than 8.5 g/dL. In those with history of stable cardiovascular disease, the dosage of RBV was decreased to 400 mg or 600 mg if Hb decreased by 2 g/dL or more during any 4-week period; permanently discontinued the drug if Hb was less than 12 g/dL after 4weeks of a reduced RBV dosage. The patients were followed up until 48 weeks after the start of the combined IFN and RBV therapy, and Hb level and HCV RNA level were examined at week 12 after the start of treatment. Among the patients with chronic hepatitis C caused by genotype 1b infection in whom combined PEG-IFNSerum HCV RNA negativity until 12 week of the therapy was defined as EVR. Additionally, serum HCV RNA negativity until 24 weeks after the therapy was completed and was defined as SVR. This study was performed with the approval of the hospital research committee, in compliance with the ethical principles laid out in the Declaration of Helsinki.Ten-mL samples of venous blood were obtained at 2, 4, and 8 weeks after the start of the therapy, and the erythrocyte level of phosphorylated RBV was measured by the HPLC method described by Homma et al. . In thist-test, Pearson's correlation coefficient, χ2-test, and Fisher's exact probability test. P < .05 was regarded as denoting clinical significance.The changes in the Hb level were analyzed by repeated-measures ANOVA and Dunnett's test. The relationships of the RBV level to the risk of anemia and the drug efficacy were examined by Student's μg/kg in accordance with a standard regimen, and the conditions of IFN administration have not changed for 48 weeks after the combination therapy was started in the subjects except for 4 patients who discontinued the therapy.The subjects comprised 24 patients, and their demographic characteristics are indicated in P < .05). The Hb levels (11.0 ± 1.3 g/dL) were significantly lower at week 4 of therapy as compared with 13.6 ± 1.3 g/dL at the start. In addition, the rate of Hb reduction [(Hb level-Hb level before administration)/Hb level before administration] at week 4 of therapy was −12.4% in those aged less than 50 years, whereas it was −21.0% in those aged 50 years or over  between the RBV level at week 2 and the rate of Hb reduction (ΔHb) at week 4 in the subjects in whom the dose of RBV did not reduce or the combination therapy did not discontinue until week 4 (P < .05) in those with RBV level of ≥800 μM (−25.5 ± 10.1%) than in those with the level of <800 μM (−15.6 ± 7.7%).The relationship between the RBV level at week 2 and the rate of reduction of the Hb level was examined in the 19 patients aged 50 years or over. There was a negative correlation (l week 4 . As showP < .05) in the non-EVR patients (634.6 ± 236.6 μM) than the EVR patients (889.7 ± 210.6 μM).The relationship between the phosphorylated RBV level at week 2 and the EVR was evaluated in 20 of the 24 patients (Four cases were excluded because of the discontinuation of the therapy). The mean RBV level at week 2 was significantly lower  had EVR and 6 of 17 cases (35.3%) had SVR (P < .05). There were no EVR or SVR cases (0 of 7 cases) in patients with erythrocyte phosphorylated RBV levels <600 μM achieved EVR and 3 cases (42.9%) achieved SVR without development of marked anemia. None of those patients discontinued RBV due to development of anemia.Five of 7 cases (71.4%) with erythrocyte phosphorylated RBV level at week 2 of 600–800 In this study, combined PEG-IFN and RBV therapy needed to be discontinued, or the RBV dose needed to be reduced, in about 40% of the study subjects due to the development of hemolytic anemia (Hb ≤ 10 g/dL). None of the patients in whom the combined PEG-IFN and RBV therapy was discontinued by Week 12 showed SVR. However, no difference in the rate of SVR was noted between the subjects in whom the RBV dose was reduced and those in whom the treatment could be continued at the initial dose. This suggests that continuation of the combination therapy was the most important factor for achieving the desired clinical outcome. Clinically, the RBV dose reduction is performed based on the present Hb level. However, it has been noted that such dose adjustment does not effectively prevent the progression of anemia; that is, once a decrease of the Hb level has occurred, it is too late to stop the decline through RBV dose reduction, presumably because of erythropoietic delay.μM), implying gradual accumulation of phosphorylated RBV. Inoue et al. [μM and was well correlated with Hb reduction.In our subjects, the phosphorylated RBV level reached a steady-state by 4 weeks of RBV therapy  deficiency protects against clinically significant decline in Hb level induced by HCV antiviral treatment [In this study, the erythrocyte phosphorylated RBV level at week 2 was predictive of the EVR. Moreover, none of the patients in whom the phosphorylated RBV level at week 2 was <600 reatment . We shouIn this study, the erythrocyte phosphorylated RBV level at week 2 is proposed as a useful indicator to determine an optimal dosage of ribavirin in patients with chronic hepatitis C under treatment with combination therapy with pegylated interferon and RBV.


Consensus interferon (CIFN) is a newly developed type I interferon.This multicentre, controlled trial was conducted to determine the efficacy of CIFN and to compare it with alpha-1b-interferon (IFN-α1b) in the treatment of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B.144 Patients were randomly assigned to receive 9 μg CIFN (CIFN group) or 50 μg INF-α1b  subcutaneously 3 times weekly for 24 weeks, followed by 24 weeks of observation. Efficacy was assessed by normalization of serum alanine transaminase (ALT) levels and the non-detectability of serum hepatitis B virus DNA or HBeAg at the end of treatment and 24 weeks after stopping treatment.There was no statistically significant difference in the serological, virological and biochemical parameters between CIFN and IFN-α1b groups at the end of the therapy and follow-up period (p > 0.05). Overall, at the end of treatment, 7.0% (5/71) and 35.2% (25/71) of patients in the CIFN group showed a complete or partial response compared with 7.4% (5/68) and 33.8% (23/68) of the IFN-alpha group (p = 0.10). At 24 weeks after stopping treatment, 6.9% (5/72) and 37.5% (27/72) of patients in the CIFN group showed complete response or partial response compared with 7.1% (5/70) and 34.3% (24/70) of the IFN-alpha group (p = 0.10).These findings suggest that 9 μg CIFN is effective in the treatment of patients with HBeAg-positive chronic hepatitis B. It can gradually induce ALT normalization and HBV DNA clearance and HBeAg loss or HBeAg/HBeAb seroconversion. Hepatitis B, a serious liver disease caused by the hepatitis B virus, can develop into cirrhosis of the liver or liver cancer. ApproxiThere is no specific treatment for chronic HBV infection. Some drugs, including interferon and anti-viral agents , can helThe effectiveness of interferon for patients with hepatitis B has been widely recognized, but the effect is far from satisfactory . InterfeOn the basis of these observations, we conducted a multicentre, randomized controlled trial to compare the efficacy and safety of CIFN vs INF-λ1b therapy in patients with chronic hepatitis B.A total of 144 Chinese patients were enrolled in the study. All patients were outpatients from the West China Hospital of Sichuan University, the Second Affiliated Hospital of Chongqing Medical University, and Zhejiang Medical University Hospital. All patients signed informed consent and the Ethics Committee approved the protocol and minor changes in the program.5 copies/ml; (3) in the 35 days before treatment, patients must have had at least one occurrence of an ALT ≥ 2 times the upper limit of normal , but the highest ALT must have been ≤ 10 times ULM, and serum total bilirubin must have been lower than the ULM. Exclusion criteria included prior treatment for CHB with IFN-alpha or another antiviral or immunosuppressive drug; presence of antibodies to hepatitis A, C or D virus, or HIV; decompensated liver disease ; another cause of chronic liver disease; evidence of hepatocellular cancer or other tumors; history of alcoholism and drug abuse; history of a serious disease of the heart, brain, lung, kidney, thyroid or other important organ, the nervous system history, history of autoimmune disease or history of a blood disorder; allergy history; being pregnant, or breast-feeding if female; organ transplant history; any contraindication to the use of IFN-α; or lack of informed consent [Inclusion criteria:(1) age 18 to 65 years; (2) presence of HBsAg in serum for at least 6 months, and HBeAg-positive at least once during the screening of PCR HBV-DNA ≥ 10 consent .The study was a multicentre, randomized controlled trial that followed a detailed protocol. Statisticians calculated the number of samples in advance. Subject designer generated the allocation sequence according to a table of random numbers before recruiting the participants; 3 allocation sequence copies were sealed in opaque envelopes, which were kept confidential. The person who generated the allocation sequence did not recruit the participants. Both participants and results were masked during the treatment and follow-up . ConsecuAn analysis of efficacy was performed for all patients who completed the appropriate experimental project in a specified time. Serum complete blood count and biochemical profile, as well as hepatitis serology  was obtained at baseline and then every 4 weeks until the end of treatment, and 8, 16, and 24 weeks after treatment. These tests were conducted in a common centre. HBV-DNA was measured quantitatively by real-time polymerase chain reaction . Hepatitis serology was done using third-generation ELISA test kits .Virologic response was defined as HBeAg seroconversion, loss of HBeAg and non-detectable HBV-DNA level, and biochemical response as normalization of ALT level. The virologic and biochemical responses between the two groups were assessed at the end of treatment (at 24 weeks) and at 24 weeks after the end of treatment (at 48 weeks). Complete response was defined as HBeAg seroconversion, clearance of HBV DNA and normalization of ALT. Partial response was defined as normalization of ALT and no HBV DNA clearance but a reduction in hepatitis B virus deoxyribonucleic acid (HBV DNA) of ≥ log10 copies/mL or no HBeAg seroconversion. No response was defined as no ALT normalization, a decline of HBV-DNA less than 2 log10 copies/mL and no HBeAg seroconversion or no loss of HbeAg .Statistical Package for the Social Sciences (version 16.0) was used to conduct all statistical tests. Quantitative variables were expressed as mean and standard deviation. Hepatitis B virus DNA was logarithmically transformed for analysis. Quantitative and qualitative parameters were compared using the Mann-Whitney U test and Pearson chi squared tests or Fisher's exact test, respectively. A p value less than 0.05 was considered statistically significant. All statistical tests were 2-sided.8 (mean) ± 2.90*108 (S.D.) in the CIFN group and 0.70*108 ± 1.03*108 in the IFN-alpha group. ALT level was 194.18 ± 84.00 in the CIFN group and 191.61 ± 89.16 in the IFN-alpha group. Patients between the 2 groups had similar baseline characteristics with respect to age, gender, ALT and HBV DNA levels and Case history  patients in the CIFN group and 41 of 68 (60.3%) patients in the IFN-alpha group (p > 0.05). Loss of HBV-DNA was found in 25.4% (18 of 71) of the CIFN group patients and 20.6% (14 of 68) of the IFN-alpha group patients. Rates of HBeAg/anti-HBe seroconversion were 14.1% (10/71) in the CIFN group and 22.1% (15/68) in the IFN-alpha group at the end of therapy (p > 0.05). Loss of HBeAg was evident in 14.1% (10/71) of the CIFN group patients and 10.3% (7/68) of the IFN-alpha group patients  patients in the CIFN group and 37 of 70 (52.9%) patients in the IFN-alpha group (p > 0.05). Loss of HBV-DNA was found in 23.6% (17 of 72) of the CIFN group patients and 20.0% (14 of 70) of the IFN-alpha group patients. The rates of HBeAg/anti-HBe seroconversion at the end of the follow-up period were 16.7% (12/72) in the CIFN group and 17.1% (12/70) in the IFN-alpha group (p > 0.05). Loss of HBeAg was observed in 15.3% (11/72) of the CIFN group and 14.3% (10/70) of the IFN-alpha group  at the end of treatment. During the follow-up period, complete response was seen in 5 of 72 patients in the CIFN group and 5 of 70 patients in the IFN-alpha group. The rates of partial response between CIFN group and IFN-alpha group were 35.2% (25/71) and 33.8% (23/68) at the end of treatment. During the follow-up period, partial response was observed in 37.5% (27/72) of the CIFN group and 34.3% (24/70) of the IFN-alpha group.At the end of the treatment and follow-up periods, none of the patients had loss of HBsAg or appearance of anti-HBs.There is no specific treatment for hepatitis B, a serious and widely epidemic disease. Interferon has a double mechanism of anti-viral properties and immune regulation for viral hepatitis, therefore, it is widely used in the treatment of hepatitis B virus . CIFN haThe results revealed that CIFN is as effective as INF-α1b for HBeAg-positive chronic hepatitis B. No statistically significant difference existed in the serological, virological and biochemical parameters between the CIFN and IFN-α1b groups at the end of therapy or the follow-up period.The rates of complete or partial response between the CIFN group and the IFN-alpha group were 42.3% (30/71) and 41.2% (28/68) at the end of treatment, and 44.4% (32/72) and 41.4% (29/70) during the follow-up period, respectively (p > 0.05). A decrease in HBV-DNA was found in 42.3% of patients in the CIFN group compared with 41.2% of patients in the IFN-alpha group at the end of treatment. At the end of follow-up, 44.4% of patients in the CIFN group showed a decrease of HBV-DNA compared with 34.3% of the IFN-alpha group (p > 0.05).At the end of treatment, loss of HBeAg or HBeAg seroconversion was observed in 32.4% of patients in the IFN-alpha group and 28.2% of patients in the CIFN group. At 24 weeks after stopping treatment, 32.0% patients in the CIFN group had a loss of HBeAg or HBeAg seroconversion in comparison with 31.4% patients in the IFN-alpha group.Interferon is an important drug against the hepatitis B virus and its efficacy has been widely accepted. Many authors have had similar results with interferon as in our trial ,24. The Based on the aforementioned data, the dosage of alpha-1b interferon was about 5.6 times higher than CIFN. However, it is difficult to distinguish the difference in efficacy between the two agents. It was also confirmed by statistical analysis. On the one hand, the antiviral activity of the same dosage of CIFN was stronger than that of alpha-1b interferon; on the other hand, the necessary dose of CIFN was lower. Therefore, we assessed the safety of 15 μg CIFN for chronic hepatitis B in another trial. Preliminary results indicate that this dose of CIFN was safe and the efficacy of the high dose was superior to that of the low dose.According to the literature, CIFN has been used for hepatitis C. Treatment of chronic hepatitis C infection with CIFN in relapsers and non-responders to interferon-based therapy has achieved a certain efficacy -29. Our CIFN has been used for patients with not only hepatitis C but also hepatitis B. The disease burden of hepatitis B is more serious in Asian countries, particularly in China. Therefore, CIFN could be an alternative drug for hepatitis B infection in these areas.In conclusion, the results of this trial demonstrate that a 24-week course of CIFN therapy is effective for patients with HBeAg-positive chronic hepatitis B. Furthermore, it gradually induces sustained ALT normalization and HBV-DNA clearance and HBeAg loss or HBeAg/HBeAb seroconversion. The therapy was well tolerated by all volunteers who completed the treatment and follow-up periods. We will report its safety in another article in detail. We have observed the best indication and individual characteristics of CIFN. Further study of efficacy and safety will be performed after administration to patients in a large-scale trial, and advantages and disadvantages of CIFN will be compared with existing interferon.The authors declare that they have no competing interests.ZLS, ZYL and WTX were responsible for planning the study, analyzing the results and drafting the manuscript. ZYL wrote the manuscript. GSH, CYG, ZTY and ZYL collected the study material and coordinated the study. All authors have read and approved the manuscript.