FREQUENT DETECTION OF HEPATITIS-A VIRAL-RNA IN SERUM DURING THE EARLYCONVALESCENT PHASE OF ACUTE HEPATITIS-A

The diagnosis of type A hepatitis is :performed mainly by immunoglobul in M (IgM) anti-hepatitis A antibody assay, but it has not been establ ished whether there is a correlation between changes in viremia and th e clinical course of type A hepatitis. We examined hepatitis A virus ( HAV) RNA in the sera from type A and non-A, non-B, non-C acute hepatit is and analyzed the relation of HAV viremia with alanine aminotransfer ase (ALT) and IgM-HA levels. Two hundred sera from 38 patients with ty pe A acute hepatitis and 20 patients with non-A, non-B, non-C acute he patitis were examined for the presence of HAV RNA. HAV RNA was detecte d by nested reverse transcription-polymerase chain reaction (RT-PCR) w ith primers located at the 5' non-translated region of HAV. HAV RNA wa s detected in 35 of 38 (92%) type A hepatitis patients and in 60 of 15 6 (38%) serum samples. In contrast, it was detected in none of 44 seru m specimens from 20 non-A, non-B, non-C acute hepatitis patients. In t ype A hepatitis, the mean ALT level in HAV RNA positive specimens was 1,481 +/- 2,042 (range, 20-10,370) IU/L and that in HAV RNA negative s pecimens 186 +/- 330 (range, 8-1,698). The positivity of HAV RNA was c orrelated with the Level of transaminase at the time of sample collect ion. The mean duration from the onset of symptoms to disappearance of HAV RNA was 18 +/- 14 days. The mean titer of IgM-HA. in HAV RNA posit ive cases was 5.0 +/- 1.4, in negative cases 5.7 +/- 1.1, with no stat istical difference. Our results indicate that HAV RNA in serum is dete ctable in the majority of type A hepatitis cases in their early conval escent phase by nested RT-PCR.