A review of donor alanine aminotransferase testing. Implications for the blood donor and practitioner.

To reduce the incidence of post-transfusion non-A, non-B hepatitis, the American Association of Blood Banks has required that serum alanine aminotransferase activity be used to screen blood donors. Consequently, approximately 2% to 3% of all blood donations will be discarded owing to an elevated alanine aminotransferase level. In addition, approximately 0.7% of blood donors will be notified of an abnormal alanine aminotransferase result. While some of these donors may have viral hepatitis, factors such as the donor's age, gender, body weight, ethnic background, alcohol intake, diet, and exercise must also be considered when interpreting an elevated alanine aminotransferase level. Donors with significant or persistently elevated alanine aminotransferase levels should have their conditions evaluated so that treatable diseases can be recognized and/or treated.