Clinical reactions and serologic changes after intramuscular administration of horse anti-human lymphocyte globulin (ALG) were studied in 53 human recipients of renal homografts. The ALG was used as an adjuvant immunosuppressive drug. In the usual case 47 injections were given over a 4-month period.
All patients had pain, tenderness, erythema, and swelling at the injection sites. Benign systemic side effects included fever in all cases, hives in eight cases, rash in five, pruritus in five, arthralgia in three, and periorbital edema in one. Anaphylactic reactions occurred in 11 cases. These were easily treated, and there was complete recovery in every instance within 90 min. In eight of these cases the ALG administration was discontinued. Subsequent injections were given in the other three.
Four of 11 patients tested had positive skin tests to ALG before therapy. Antibodies against sheep red blood cells developed during therapy in 39 of 40 patients; 10 reached titers as high as 1:128 to 1:512. Precipitin antibodies as measured with an electroimmunodiffusion technique developed in 36 of 40 patients. All three immunologic tests were of value in predicting the probability of an anaphylactic reaction, but the discrimination was imperfect
Immunoelectrophoretic studies of sera from 13 patients showed antibodies to horse beta globulins in all cases, to alpha globulins in 9 cases, and to gamma globulins in only 1. This finding indicates that a safer ALG could be made by removing the trace quantities of alpha and beta globulins from the immunologically more active gamma globulins.