DECLINING VALUE OF ALANINE AMINOTRANSFERASE IN SCREENING OF BLOOD-DONORS TO PREVENT POSTTRANSFUSION HEPATITIS-B AND HEPATITIS-C VIRUS-INFECTION

Background: Since the mid-1980s, blood banks in the United States have screened donors for elevated alanine aminotransferase (ALT) in an eff ort to prevent posttransfusion hepatitis. The present study was design ed to quantitate the residual value of ALT screening following the imp lementation of hepatitis C virus (HCV) assays. Study Design and Method s: Two approaches were used. First, a database of 2.3 million donation s made by 586,507 volunteer blood donors between 1991 and 1993 was use d to compare the incidence of seroconversion to hepatitis B virus (HBV ) and HCV marker positivity in donors with elevated ALT values and wit h normal ALT values. Second, the duration of ALT elevation prior to HB V and HCV seroconversion was determined from 34 well-documented cases of posttransfusion HBV and HCV; elevated-ALT window periods were multi plied by rates of HBV and HCV incidence in donors to project the yield of ALT screening. Predictive value and cost-effectiveness analyses we re also performed to compare the value of ALT screening before and aft er HCV screening was implemented. Results: Both approaches indicate th at ALT testing does not detect HBV in the window phase but does curren tly identify approximately 3 HCV window-phase donations per 1 million donations; this contrasts with ALT detection of approximately 1800 HCV -infectious units per 1 million donations prior to anti-HCV screening. Currently, only 8 in 10,000 donated units with elevated ALT (negative anti-HCV) are infected with HCV. The cost of continued ALT screening was estimated at $7,931,000 per quality-adjusted year of life saved. C onclusion: The yield, predictive value, and cost-effectiveness of ALT screening of blood donors have declined dramatically with the implemen tation of progressively improved anti-HCV assays. ALT screening of vol unteer blood donors should be discontinued.