Gm allotyping to determine the origin of red cell antibodies in recipients of solid organ transplants.

Alloantibodies of A and B specificity were detected in the serum and on the red cells of 4 non-0 recipients of group 0 solid organ transplants. The antibodies were assumed to be produced by 'passenger' lymphocytes introduced at the time of transplant. Gm allotyping of donor serums, recipient serums and the unexpected antibodies was done. Gm typing was informative in 1 case, when the anti-A1 found in the serum of a liver transplant recipient was shown to be of phenotype Gm(fb) and the Gm phenotype of the recipient to be Gm(axg). Gm allotyping was not informative in the other 3 cases.