Prevalence fo HCV RNA in seronegative and seropositive blood donors by Nested-PCR and correlation to ALT level

Abstract

A Nested RT-PCR for detection of HCV RNA, using primers from the 5'non-coding region of the viral genome, was developed and shown to have a limit sensitivity of detecting 300 HCV RNA per ml, or 15 HCV RNA per assay. This sensitive and reliable technique was used to detect the presence of HCV RNA in blood donations with either positive or negative for anti-HCV by ELISA-2 (Abbott). None of the 314 donations with elevated ALT as well as the 100 donations with normal ALT but negative for anti-HCV had detectable serum HCV RNA. Of the 168 blood donations positive for anti-HCV, 104 (62.5%) had detectable HCV RNA. Among the anti-HCV positive donations, those with elevated ALT had significantly higher probability of detecting HCV RNA than those with normal ALT level. Also, HCV RNA was significantly detected in donations with high ELISA OD value compared to those with low ELISA OD value. Since all HCV RNA positive donations had anti-HCV, anti-HCV screening alone would be sufficient to detect HCV infection, even without ALT screening. The donations with elevated serum ALT but anti-HCV negative, none had detectable HCV RNA. Therefore, the second generation anti-HCV screening by abbott appeared efficient in preventing transfusion-related HCV transmissions, at least in this study. Routine ALT screening in addition to anti-HCV screening for further prevention of hepatitis C virus infection may be not necessary. In the absence of assays for viral antigens, the direct detection of HCV RNA by PCR could be useful as a confirmatory test to identify infectious carriers in blood donors.