BACKGROUNDThe prevalence of hepatitis C virus (HCV) infection among maintenance hemodialysis (MHD) patients varies among countries and among dialysis units within a single country. The present study aimed to investigate the prevalence and characteristics of HCV infection in MHD patients in a Chinese hemodialysis unit.

METHODSOne hundred and ninety-two patients on MHD for an average of (86.1 ± 30.0) months (range 6 - 181 months) were enrolled in this cross-sectional study. HCV antibody and HCV-RNA were measured in these MHD patients before hemodialysis by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) methods. According to the result, all the patients were then divided into two groups: Group I was positive for HCV antibody and/or HCV-RNA (n = 32), and Group II was negative for HCV antibody and HCV-RNA (n = 160). The following information was obtained for all the patients: socio-demographic data, history of blood transfusions and kidney transplantation, and some laboratory values. The MHD patients who were positive for HCV antibody and/or HCV-RNA were followed for more than three years. The disease activities were graded into "asymptomatic" if alanine aminotransferase (ALT) was less than 40 U/L, "low activities" if ALT was 40 - 79 U/L, and "high activities" if ALT was equal to or above 80 U/L.

RESULTSThe prevalence of HCV infection in MHD patients in our dialysis unit in May 2009 was 16.7%, which was significantly higher than in general population (3.2%). Among the 32 MHD patients with HCV positive, 20 patients were positive for HCV antibody but negative for HCV-RNA, eight patients were positive both for HCV antibody and HCV-RNA, four patients were negative for HCV antibody but positive for HCV-RNA. Eleven patients had a history of kidney transplantation and 12 had a history of blood transfusion, which were significantly more than among the MHD patients without HCV. Thirty of the 32 MHD patients were asymptomatic. There were no significant differences in age, aspartate aminotransferase (AST), ALT, or between HCV-RNA positive group and HCV-RNA negative group. But the dialysis duration in the HCV-RNA positive group was significantly longer than that in the HCV-RNA negative group. All the 20 HCV-RNA negative patients were asymptomatic. Two of the 12 HCV-RNA positive patients had low activity. None of the 32 cases with HCV positive markers had cirrhosis.

CONCLUSIONSA high prevalence of HCV infection in MHD patients is related to blood transfusion and kidney transplantation. Occult HCV infection is present in MHD patients. Chronic hepatitis C among MHD patients is mild in disease activity, and is not progressive, perhaps due to immunological abnormalities in these patients.