Hepatitis C infects 2-3% of the world's population, over 180 million persons, and is a cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma(1). The current standard of care, pegylated interferon plus ribavirin (pegIFN/Riba) combination therapy, is both expensive and poorly tolerated. Treatment efficacy is approximately 50%. Telaprevir and boceprevir, two direct acting antiviral (DAA) protease inhibitors, have recently been approved for clinical use in the US (2). Addition of either of these new agents has the potential to improve sustained virological response in hepatitis C to 65-75%. However, the addition of a DAA to the current standard of care introduces the risk of side effects, including anemia and rash, and failure to achieve Sustained viral response may pose an increased risk of accumulation protease inhibitor-resistant viral strains that may carry over resistance problems to future treatments. None of these current or future treatments appear to provide any benefit to the patient beyond suppression of the virus. Specifically, the liver is not healed even when viral counts are very low, the damage either ceases at the point of suppression, or inflammation and fibrosis may even progress slowly in the presence of a small number of residual viral particles. Hepatic steatosis, the primary accompanying condition of most patients with hepatitis C, continues and may progress even with complete viral suppression, and it is now time to propose that hepatic steatosis must be managed in lock step with the specific anti-viral treatments.
Hepatic steatosis is a common diagnosis in populations as a whole, often as frequent as 25% (3). There is no drug therapy for hepatic steatosis at the present time (4), most experts rely on lifestyle counseling alone. Of great concern, hepatic steatosis is a histologic feature in approximately two thirds of liver biopsies of patients with chronic hepatitis C. Until recently, this common finding was not carefully documented, and there were no large longitudinal studies describing the progression of steatosis in chronic hepatitis C or even hepatitis B. In 2009, Lok and colleagues examined changes in steatosis on serial biopsies among chronic hepatitis C patients participating in the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) trial(5). All 1050 patients in this trial had advanced fibrosis at baseline biopsy and were documented not to have had a sustained virological response to pegIFN/Riba. Most (94%) of these patients had genotype 1 infection. At least one protocol follow-up biopsy was read on 892 patients, and 699 had the last biopsy performed 3.5 years after randomization. Hepatic damage was well advanced at enrollment, as 39% had cirrhosis and 61% had bridging fibrosis; 18%, 41%, 31%, and 10% had steatosis scores of 0, 1, 2, and 3 or 4, respectively. The mean steatosis score decreased in the follow-up biopsies in both the pegIFN/Riba-treated patients and controls with no effect of treatment assignment (P=0.66). A decrease in steatosis score by > or =1 point was observed in 30% of patients and was associated with both progression to cirrhosis and continued presence of cirrhosis (P=0.02). Compared to patients without a decrease in steatosis, those with a decrease in steatosis had worse metabolic parameters at enrollment, and were more likely to have a decrease in alcohol intake, improvement in metabolic parameters, and worsening liver disease (cirrhosis, esophageal varices, and deterioration in liver function). Lok and colleagues (5) concluded that hepatic steatosis recedes during progression from advanced fibrosis to cirrhosis. However, there was no available means to produce a decline in hepatic steatosis in most patients, which then became the primary motivation to discover a means of treating hepatic steatosis as an integral part of treatment of hepatitis C patients.
In a further definitive examination of the role of hepatic steatosis on the course of hepatitis C therapy, Briceno and colleagues (2009) examined livers that were to be transplanted into patients with hepatitis C that had already destroyed the original liver (6). The aim of this study was to determine the influence of donor graft steatosis on overall outcome, viral recurrence, and fibrosis progression in orthotopic liver transplantation for hepatitis C virus cirrhosis. One hundred twenty patients who underwent OLT for HCV cirrhosis between 1995 and 2005 were included in the study. Donor steatosis was categorized as absent (0%-10%; n=40), mild (10%-30%; n=32), moderate (30%-60%; n=29), or severe (>60%; n=19). A Cox multivariate analysis for marginal donor variables and a Model for End-Stage Liver Disease index were performed. Fibrosis evolution was analyzed in liver biopsies (fibrosis <2 or > or =2) 3, 6, and 12 months post-OLT and in the late post-OLT period. Fifty-six grafts were lost (46%). The survival of the grafts was inversely proportional to donor liver steatosis: 82%, 72%, and 72% at 1, 2, and 3 years post-OLT in the absence of steatosis; 73%, 63%, and 58% with mild steatosis; 74%, 62%, and 43% with moderate steatosis; and 62%, 49%, and 42% with severe steatosis (P=0.012). HCV recurrence was earlier and more frequent in recipients with steatosis >30% (46% versus 32% at 3 months, P=0.017; 58% versus 43% at 6 months, P=0.020; 70% versus 56% at 12 months, P=0.058; and 95% versus 69% at 3 years post-OLT, P=0.0001). (6). Graft survival was lower in alcoholic liver disease recipients versus HCV recipients when steatosis was >30% at 3, 6, and 12 months post-OLT (P=0.042) but not when steatosis was <30% (P=0.53). A higher fibrosis score was obtained 3 months post-OLT (P=0.033), 6 months post-OLT (P=0.306), 12 months post-OLT (P=0.035), and in the late post-OLT period (P=0.009). The authors concluded that the degree of hepatic steatosis in the new liver greatly influences the recurrence of hepatitis C and its progression in the new liver. In fact, Steatosis affects the success of treatment the second time. Hepatitis C recurrence was more frequent and earlier in recipients of moderately and severely steatotic livers. Fibrosis evolution is more rapid and severe when graft steatosis is >30% (6). As pointed out by Lok as well, there is a need to manage the hepatic steatosis in order to optimize the outcome of antiviral therapy for hepatitis C.
Testino and colleagues (2009) examined the influence of improvement in metabolic syndrome (typically associated with steatosis) biomarkers on the response of patients with hepatitis C to pegIFN/Riba (7). They examined baseline biomarkers such as Body Mass Index (BMI), cholesterol, triglycerides (TGs) and hepatic percentage of steatosis in the response to therapy with pegIFN/Riba in patients with recurrent hepatitis C (genotype 1). In this study, 30 consecutive prospectively followed patients diagnosed with recurrent hepatitis C were considered candidates for antiviral therapy. The observed distribution of BMI, cholesterol, TGs and steatosis were confirmed to be normally distributed by the one-sample Kolmogorov-Smirnov Goodness of fit test procedure. Comparison of BMI, cholesterol, TGs and steatosis between non responders (NR), sustained virological responders (SVR) and sustained biochemical responders (SBR) groups were analyzed by ANOVA with a post hoc Bonferroni test and correlation between variables was tested by Pearson test. The multivariate analysis was performed to estimate the chance of response on basis of the above mentioned variables. In patients with abnormal results in at least two out of four steatosis associated variables the chance of no-response was 40 times higher than that of SBR and 96 times than that of SVR (7). On the basis of these epidemiological studies, they argued that diet and exercise therapy should improve BMI, liver histology and, therefore, the response to pegIFN/Riba (7). Indeed this study provides further justification for concomitant use of a treatment for hepatic steatosis in conjunction with a treatment for the hepatitis C virus itself.
There is also evidence that management of hepatic steatosis in patients with hepatitis C would be of value in the prevention of hepatocellular carcinoma (HCC). For example, Pekow and colleagues (2007) (8) retrospectively identified 94 consecutive patients with hepatitis C cirrhosis who underwent liver transplantation from 1992 to 2005 and had pathology available for review. Of these, 32 had evidence of HCC, and 62 had no HCC on explant histology. All explant specimens were then graded for steatosis by a single, blinded pathologist. Next, hepatic steatosis, age, sex, BMI, HCV RNA, HCV genotype, Model for End-Stage Liver Disease (MELD) score, chronic alcohol use, and diabetes were examined in univariate and multivariate analyses for association with HCC. In total, 69% of patients in the HCC group and 50% of patients in the control group had evidence of hepatic steatosis (1+) on histology. Odds ratios for the development of HCC for each grade of steatosis compared with grade 0 were as follows: grade 1 (1.61 [0.6-4.3]), grade 2 (3.68 [1.1-12.8]), and grade 3 or 4 (8.02 [0.6-108.3]) (P=0.03 for the trend). In univariate analyses, there was a significant association between increasing steatosis grade (P=0.03), older age (56 years vs. 49 years; P<0.02), higher ALT aspartate aminotransferase (122.5 U/L vs. 91.5 U/L; P=0.005), higher AST alanine aminotransferase (95.8 U/L vs. 57.2 U/L; P=0.002), higher alpha-fetoprotein (113.5 ng/mL vs. 17.8 ng/mL; P<0.001), lower median HCV RNA (239,000 IU/mL vs. 496,500 IU/mL; P=0.02), higher biologic MELD score (21.8 vs. 20.3; P=0.03), and risk of HCC. In multivariate analysis, age (P=0.02), alpha-fetoprotein (P=0.007), and hepatic steatosis (P=0.045) were significantly associated with HCC (8). These authors concluded that in patients with Hepatitis C-related cirrhosis, the presence of hepatic steatosis is independently associated with the development of hepatocellular carcinoma (8). Clearly if the steatosis could be reversed, there is plausible evidence that HCC might be prevented or at least there would be fewer cases that progress to this deadly complication of the combined problem of hepatitis C and hepatic steatosis.