Evaluation of antibody test and quantitative RNA assay for accurate diagnosis of HCV infected Bangladeshi patients

Abstract

Viral hepatitis is a serious global public health problem affecting billions of people. Although therapies are available that can suppress or eliminate hepatitis C virus (HCV) infection yet identifring the person actively infected with HCV is challenging. Hundred (100) serum samples were collected from BIRDEM OPD, Chevron Clinical Laboratory (Pvt.) Ltd., Chittagong and Medinova Medical Services, Dhaka from suspected HCV patients. Selection of these patients was done according to the inclusion and exclusion criteria. All sera were tested for antibodies to HCV by enzyme linked immunosorbent assay (ELISA) and HCV-RNA quantification by real time polymerase chain reaction (rtPCR) assay to detect viral load. Among the 100 respondents, 63 (63%) were male and 37 (37%) were female. The mean age of enrolled subjects was 45.3±13.5 years. Of these, 86 patients were positive and 14 patients were negative for anti-HCV antibody detected by ELISA. Seventy one (71) patients were HCV-RNA positive by rtPCR. Among them, 56 patients had viral load of 103 -1071U/ml and rest 15 patients had 108-101010/ml. Viral load by rtPCR were not detected in 29 patients. The sensitivity of ELISA was 95.8% whereas the sensitivity of qPCR was 79.1% but the specificity of ELISA was 37.9% and the specificity of qPCR was 78.6%. The association between the ELISA and qPCR was highly significant at the level of 0.001. Positive predictive value (PPTO was 95.8% in case of rtPCR whereas it was 79.1% by ELISA. Combining the sensitivity and the specificity of rtPCR and ELISA, the quantitative PCR (qPCR) was more helpful and specific than antibody test (ELISA) for diagnosis of HCV infected patients of Bangladesh.