Quantitative assessment of HCV load in chronic hemodialysis patients: A cross-sectional survey

Recent evidence has been accumulated showing that chronic hemodialysis (HD) patients have a very high prevalence of antibodies to hepatitis C virus (HCV). In contrast, there is little information addressing the virological characteristics of HCV infection in this population. Aim: To measure HCV viral load and to correlate this with demographic, biochemical, and clinical features of a large cohort of HCV-infected patients on chronic HD. Methods: 394 chronic HD patients were tested by branched-DNA signal amplification assay, anti-HCV enzyme-linked immunosorbent assay 2.0, and on the basis of the aspartate aminotransferase/alanine aminotransferase (AST/ALT) activity. Multivariate analysis by ordinal logistic regression model was performed: age, gender, race, time on HD, allocation of the patients among the HD units, etiology of end-stage renal disease, HBsAg status, anti-HCV positivity, HCV genotype, and AST/ALT levels were independent factors, and viremic levels of HCV in serum were assumed as dependent variables. Results: 88 (22.3%) patients showed serological and/or virological signs of HCV infection, 59 (15%) out of 394 had detectable HCV RNA in serum, the mean HCV load was 19.4 x 10⁵ (95% CI, 6.06 x 10⁷ to 6.2 x 10⁴) Eq/ml. According to the criteria suggested by others, there were 8 (13.5%) individuals with high-titer viremia (> 1 x 10⁷ Eq/ml) in the subset of viremic patients, A small subset (8/394 or 2%) of individuals was seronegative, but viremic; 29 (7%) out of 394 were seropositive without detectable HCV RNA in serum. Univariate analysis showed that the frequency of anti-HCV positivity was significantly higher in viremic patients as compared with individuals with no detectable HCV viremia: 51/59 (86%) vs, 29/335 (8.6%), p = 0.0001, Serum AST and ALT levels were significantly higher in viremic patients than in individuals with no detectable HCV RNA in serum: 23.8 (95% CI 60, 8-9.3) vs. 17.1 (95% CI 50.4-5.8) U/1 (p = 0.009) and 14.4 (95% CI 48.9-4.3) vs, 9.8 (95% CI, 37.3-2.5) U/1 (p = 0.009), Logistic regression analysis showed an association between HCV viremia and anti-HCV positivity (p = 0.00001) and ALT activity (p = 0.01), Conclusions: Hepatitis C virus infection is highly prevalent in the HD population; the viral load is relatively low, and it was associated with elevated hepatic enzyme levels and anti-HCV positivity, No other clinical characteristics were associated with HCV RNA levels. Seronegative but viremic patients were also found, Longitudinal studies with long follow-up periods are necessary to evaluate the course of HCV load overtime in this population.