The impact of hepatitis C virus infection on survival in dialysis patients: meta-analysis of observational studies

The impact of hepatitis C virus (HCV) infection on mortality of patients receiving regular dialysis remains unclear. The assessment of the natural history of HCV in dialysis population is difficult because of the low progression of HCV-related liver disease over time and the reduced life expectancy in patients with end-stage renal disease. The aim of the study was to conduct a systematic review of the published medical literature concerning the impact of HCV infection on the survival of patients undergoing maintenance dialysis. The relative risk of mortality was regarded as the most reliable outcome end-point. Study-specific relative risks were weighted by the inverse of their variance to obtain fixed- and random-effects pooled estimates for mortality with HCV across the published studies. We identified seven studies involving 11 589 unique patients on maintenance dialysis; two (29%) were case-control studies. Pooling of study results demonstrated that presence of anti-HCV antibody was an independent and significant risk factor for death in patients on maintenance dialysis. The summary estimate for adjusted relative risk (aRR) (all-cause mortality) was 1.34 with a 95% confidence interval (CI) of 1.13-1.59. Heterogeneity statistics, R-i = 0.48 (P-value by Q-test = 0.13). In a sensitivity analysis including only (n = 5) cohort studies, the pooled aRR was 1.38 (95% CI, 1.20-1.59); heterogeneity statistics R-i = 0.46. As a cause of death, hepatocellular carcinoma and liver cirrhosis were significantly more frequent among anti-HCV-positive than -negative dialysis patients. Our meta-analysis indicates that anti-HCV-positive patients on dialysis have an increased risk of mortality compared with HCV-negative patients. The excess risk of death in HCV-positive patients may be at least partially attributed to chronic liver disease with its attendant complications.