To the Editor.—
Silverstein et al1 advocate alanine aminotransferase (ALT) screening of donor blood because it will be cost-effective over a wide range of ALT levels.What the authors obviously did not take into consideration is that many chronic carriers of non-A, non-B hepatitis are asymptomatic with occasionally elevated ALT levels. The percentage of donors without transmissible liver disease in any donor population occasionally exhibiting elevated ALT levels is unknown. It therefore remains difficult to decide whether donors with previous ALT levels of 45 IU or higher should be accepted again as blood donors when their ALT levels have become lower than 45 IU, although transitory periods with normal ALT levels are typical for mild chronic non-A, non-B hepatitis, or whether such donors should be rejected once and for all. The latter course carries the risk of decimating the noninfectious part of the donor population as time goes on.
Fiedler H. Screening of Donor Blood for Alanine Aminotransferase. JAMA. 1985;254(24):3422. doi:10.1001/jama.1985.03360240034015