Effect of interferon-alpha-based antiviral therapy on hepatitis C virus-associated glomerulonephritis: a meta-analysis.

BACKGROUND Hepatitis C virus (HCV) is associated with various glomerulopathies, in which HCV is responsible not only for the onset of glomerulopathy but also for its progressive loss of kidney function. The effect of antiviral treatment on the glomerular lesions and subsequent course of kidney disease remains controversial. Therefore, we performed a systematic analysis of the available evidence on the effect of interferon (IFN)-α-based therapy on HCV-associated chronic kidney disease. METHODS A meta-analysis was performed of controlled and uncontrolled clinical studies related to IFNα-based antiviral therapy and its impact on kidney function in HCV-associated glomerulonephritis. Improvement of proteinuria and serum creatinine levels after antiviral therapy was taken as the end points of interest. Data from eligible studies selected according to protocols were analysed using Review Manager 5.0. RESULTS Eleven clinical trials involving 225 patients were included in our meta-analysis. At the end of antiviral therapy, the summary estimate of the mean decrease in proteinuria was 2.71 g/24 h [95% confidence interval (CI) 1.38-4.04, P < 0.0001], P-value for heterogeneity 0.05 (I(2) = 53%). The pooled decrease in mean serum creatinine levels was 0.23 mg/dL (95% CI 0.02-0.44, P = 0.03), P-value for heterogeneity 0.30 (I(2) = 17%). Comparison of non-sustained virological response (SVR) to SVR groups demonstrated a mean difference of proteinuria decrease in the SVR group of 1.04 g/24 h (95% CI 0.20-1.89, P = 0.02), P-value for heterogeneity 0.21 (I(2) = 36%) and of serum creatinine decrease of 0.05 mg/dL (95% CI -0.33 to 0.43, P = 0.80), P-value for heterogeneity 0.70 (I(2) = 0%). CONCLUSION Antiviral therapy based on IFNα can significantly decrease proteinuria and stabilize serum creatitine, and therefore, should be undertaken in patients with HCV-associated glomerulonephritis. The improvement in protein excretion is greater in those who achieve HCV RNA clearance, a finding in line with a causal role for HCV in glomerulonephritis.