Evaluation of different methods for diagnosis of hepatitis C virus infection among haemodialysis patients

ABSTRACT

Haemodialysis [HD] patients are at high risk of hepatitis C virus infection. A comparative study was conducted to evaluate different methods for diagnosis of HCV infection. The study comprised 100 haemodialysis patients and 50 apparently healthy controls. All subjects were investigated for serum albumin, bilirubin, alanine aminotransferase [ALT] and aspartate aminotransferase [AST]. Serum HCV antibodies were detected by 2nd generation enzyme linked immunosorbent assay [ELISA II] and confirmed by recombinant immunoblot assay [RIBA II]. Serum HCV RNA was detected by reverse transcriptase [RT] polymerase chain reaction [nested PCR technique]. Out of 100 HD patients, 77 [77%] were found to be ELISA II positive and 38 [38%] were positive by RT-PCR. Out of 77 positive ELISA II, 68 were positive also by RIBA II and 8 were intermediate. The prevalence of HCV RNA positivity in ELISA II positive and in ELISA II negative groups were 31/77 [40.3%] and 7/23 [30.4%] respectively with no significant correlation. While in the control group, this correlation was highly significant [p=0.0004]. In normal population group [50] 13, 11,4 subjects were HCV positive by ELISA II, RIBA II and PCR respectively. A highly significant correlation [p=0.0008] was found between positive RIBA II and presence of HCV RNA by RT-PCR. In the HD group, compared to PCR results, the sensitivity of RIBA II was 68.4% and specificity was 32.3% versus 100% and 84.8% in the normal group. A highly significant correlation was found between ALT and AST levels in HCV RNA positive versus HCV RNA negative individuals in both groups. This finding was not verified with ELISA II or RIBA II in either groups. In conclusion, combined application of anti-HCV screening assay followed by a confirmatory RIBA assay and HCV RNA detection must be applied to establish HCV infection especially in immunocompromised patients undergoing dialysis. Serial ALT and AST testing must monitor those patients