Fluctuation of anti-A and anti-B histo-blood-group antibodies in a patient after liver transplantation.

The concentrations of anti-A and anti-B IgM and IgG antibodies have been studied in the serum of a patient with blood group AB who received a type A donor liver. A newly developed ABO-ELISA was used for this purpose and the values were compared to hemagglutination titers. During the postoperative study period over 8 weeks, the anti-A and anti-B levels showed a higher fluctuation than was measured in preoperative samples. Thus, in this AB-type patient, anti-A IgM varied 10-fold, anti-A IgG 20-fold and anti-B IgG 16-fold. Peak values corresponded to rejection episodes. Immunoactivation in the patient was further documented by the presence of abnormally high levels of soluble interleukin-2 receptors (sIL-2R) in serum samples. The study shows that monitoring of anti-A/B antibodies may represent a further criterion to follow-up transplanted patients during the critical postoperative graft acceptance period.