LONG-TERM FOLLOW-UP OF AND INFECTIVITY IN BLOOD-DONORS WITH HEPATITIS-C ANTIBODIES AND PERSISTENTLY NORMAL ALANINE AMINOTRANSFERASE LEVELS

Background: Little is known about the prevalence of serum hepatitis C virus (HCV) RNA In blood donors with HCV antibodies and persistently n ormal alanine aminotransferase (ALT) levels. Study Design and Methods: Thirty-nine anti-HCV-positive donors with normal ALT on four determin ations at 3-month intervals were further tested monthly for 6 months, and they had normal ALT values. The presence of HCV RNA was determined in these 39 donors. Results: Serum HCV RNA was detected in 16 of 39 d onors, 14 of 14 who reacted on second-generation recombinant immunoblo t assay (RIBA-2) and 2 of 15 who were indeterminate. None of the 10 RI BA-2-nonreactive donors had evidence of viremia. The 15 RIBA-2-indeter minate samples were tested with third-generation RIBA (RIBA-3); the re sults showed reactivity in 5 (including the 2 HCV RNA positive), an in determinate pattern in 7, and nonreactivity in 3 (all RNA negative). A mong HCV RNA-positive subjects, mean age (p<0.05), mean ALT (p<0.01), signal-to-cutoff (S:CO) ratio on second-generation enzyme-linked immun osorbent assay(p<0.001), and gamma globulin levels (p<0.05) were highe r than those among HCV RNA-negative subjects. During 6 additional mont hs of ALT monitoring, completed by 36 of 39 donors, Increased values w ere detected in 6 (5 HCV RNA positive). In 4 of those 6, however, ALT levels were less than 1.5-fold the upper normal limit. HCV RNA results were unchanged at the end of 1-year follow-up. Conclusion: Forty-one percent of anti-HCV-positive donors with persistently normal ALT had a ctive HCV infection. Long-term ALT monitoring allowed the detection of significantly increased enzyme values in only 2 of 16 viremic donors. Reactivity on RIBA-2 or -3, greater age, mean ALT levels In the upper range of normal, higher S:CO ratio on second-generation enzyme-linked immunosorbent assay, and higher gamma globulin levels were predictive of viremia.