Core-antigen and RNA of hepatitis C virus in sera samples of patients with antibodies to virus Core-antigen
The expediency of studying a direct marker of infection, caused by hepatitis C virus (HCV), Core antigen (Ag-Core), as well as the importance of only detecting antibodies to Ag-Core (Ab-Core) antigen, is just being studied at the present time. The aim of this study was to identify Ag-Core and HCV RNA in blood sera samples obtained from patients with Ab-Core which are found in enzyme-linked immunosorbent assay (ELISA) with different optical density (OD). Materials and methods. Separate and joint Ab-HCV and Ag-Core identification in patients’ blood sera samples was carried out with ELISA test systems. The positivity coefficient (PC), also known as S/Co, was calculated as the ratio of a sample OD to the cut-off OD. HCV RNA was determined by using PCR with both electrophoretic and real-time detection of reaction products. In some samples HCV genotype has been defined. Results and conclusions. In our study the joint research of Ag-Core and Ab-HCV hasn 't improved the laboratory diagnostics of HCV infection compared with ELISA screening intended only for Ab-HCV identification. Contrary to this, Ag-Core identification has proved to be expedient in sera samples groups with different Ab-Core HCV S/Co. In a group of samples with Ab-Core S/Co > 15 Ag-Core is found 7 times as often as in those with low (< 6.5) Ab-Core S/Co (66.6 and 8.82 % respectively; p < 0.005). HCV RNA with a concentration higher than 3.8 * 10<sup>5</sup> ME/ml is found in 75 % of samples with high Ag-Core (> 11) and AT-Core (> 15) S/Co. HCV RNA with a low concentration (< 300 ME/ml) is found in 20 % of samples with low Ab-Core S/Co (< 6.5) which also contain Ag-Core with low S/Co (< 3). Apparently, patients with Ag-Core as the only marker of HCV infection need to be under dynamic laboratory and clinical observation.