Significance of serum hepatitis C virus RNA, IgM and IgG antibodies as markers of HCV infection

We investigated the significance of serum hepatitis C virus (HCV) RNA, immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies as markers of HCV infection in 91 HCV-IgG positive Saudi patients with liver diseases. HCV-RNA and IgM-HCV could be detected in 87.5% and 62.5% respectively of 16 patients with acute non-CMV, non-EBV, NANBH, HCV-RNA could be detected in 10 out of 12 (83.3%) in patients with chronic active hepatitis while HCV-IgM could be detected in only 25.0% of this group. In patients with live cirrhosis and hepatocellular carcinoma HCV-RNA could be detected in 100% while HCV-IgM were detectable in 25.0-30.0% of these patients. Only HCV-RNA could be detected in HCV-IgG-positive blood donors (22.2%) and neither HCV-RNA nor HCV-IgM were apparent in 22 patients with acute non A-E-hepatitis. These results show that testing for HCV-RNA could be essential in early diagnosis of acute HCV infection, and that the presence of HCV-IgG by third generation EIA test is a reliable indicator of HCV replication in chronic type C disease. They also indicate that the significance of HCV-IgM as a marker in diagnosing HCV infection is limited.