Pre-transfusion testing problems caused by anti-lymphocyte globulin and their solution.

Anti-lymphocyte globulin (ALG) is an antibody to human lymphocytes used to decrease T-cells in renal transplant patients. We recently encountered serologic problems in testing blood from patients treated with ALG. Thirty-nine patients undergoing acute kidney rejection developed positive direct and indirect antiglobulin tests following the administration of equine ALG. Sera from these patients reacted with all red cells (RBCs) tested using both polyspecific and monospecific anti-IgG anti-human sera. Eluates prepared from the patients' RBCs showed similar reactivity. The ALG panagglutinin did not react by manual hexadimethrine bromide (Polybrene) technique. The ALG panagglutinin could be neutralized by anti-human globulin. In our hands, these techniques were useful in distinguishing ALG panagglutinin from co-existing alloantibodies.