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.

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.

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.

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 10(5) (95% CI, 6.06 x 10(7) to 6.2 x 10(4)) Eq/ml. According to the criteria suggested by others [J Infect Dis 1994;169:1219-1225], there were 8 (13.5%) individuals with high-titer viremia (>1 x 10(7) 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/l (p = 0.009) and 14.4 (95% CI 48.9-4.3) vs. 9.8 (95% CI, 37.3- 2. 5) U/l (p = 0.008). Logistic regression analysis showed an association between HCV viremia and anti-HCV positivity (p = 0. 00001) and ALT activity (p = 0.01).

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 over time in this population.