Utility of HCV core antigen ELISA in the screening for hepatitis C virus infection in patients on hemodialysis.

An enzyme immuno assay for hepatitis C core antigen was recently developed and its performance was compared with that of the hepatitis C virus (HCV) RNA in the screening of HCV infection in patients on hemodialysis. One hundred and eleven chronic renal failure patients undergoing haemodialysis between May 2003 and October 2004 were included in the study. All the patients were tested for anti HCV antibody, core antigen and RNA. Fifteen patients were anti HCV antibody positive, three patients were positive for HCV core antigen and RNA, three patients were positive for HCV RNA, while two patients were positive only for core antigen but negative for RNA. In anti HCV antibody positive patients, the core antigen was negative while the viral RNA continued to be present. Hence, relying solely on a single HCV core antigen assay may not be useful for a definite diagnosis of early HCV infection. The sensitivity and specificity of the assay were 60% and 83% respectively, while the positive predictive value was 14.3%, negative predictive value was 97.7% and the efficiency was 81.9%.