Quantitation and genotyping of hepatitis C virus RNA in sera of hemodialysis and AIDS patients

Background: Hepatitis C virus (HCV) infection is highly prevalent in hemodialysis and AIDS patients. Little information exists about the viral load in those patients. Objective: To characterize HCV infection in hemodialysis and AIDS patients, the viral load in the sera was measured. Results were compared with genotypes, gender of the patients, and biochemical markers of active hepatitis. Study design: Sera from a total of 442 patients were screened with a third-generation EIA, and anti-HCV immunoreactivity was confirmed with the Wellcozyme HCV Western Blot. After qualitative PCR with the Amplicor PCR Test, positives were genotyped using a reverse hybridization test. Determination of HCV levels was done with the Amplicor HCV Monitor assay. Results: HCV RNA was detected in the sera of 95 (74.8%) EIA-positive patients. HCV RNA levels ranged from 1 x 10(4) to 1.4 x 10(6) molecules of HCV RNA/ml. Median HCV RNA levels of AIDS patients were slightly higher than those of hemodialysis patients. Male patients had higher median HCV RNA levels compared with female patients. No association between HCV RNA levels and both alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels was found. The most common genotypes were type 1b and type 1a, followed by type 3, type 4, and type 2a. There were no significant differences in HCV RNA levels among patients with genotypes 1a, 1b, and 2a. Patients infected with types 3 and 4, respectively, had significantly lower HCV RNA levels compared with other genotypes. Conclusion: Because the Amplicor HCV Monitor assay allows quantitation of low-titer viremic patients, HCV RNA levels were distinctly lower compared with previous reports. HCV RNA levels of males did not differ significantly from those of females. ALT and AST are very poor indicators of ongoing HCV infection. Patients with chronic type 3 or type 4 HCV infection tended to have lower HCV RNA levels.