Abstract
Alanine aminotransferase (ALT) measurements in blood donors has been advocated as a surrogate test for non-A, non-B hepatitis. Use of the recommended single cutoff value for all donors resulted in disqualifying four times as many males as females in a group of 4712 donors. Separate cutoff values were calculated for male and female donors. The use of these separate cutoff values resulted in disqualifying equal numbers of males and famales.