Severe combined immunodeficiency disease. Characterization of the disease and results of transplantation.

Pretransplant and posttransplant data for 69 patients with severe combined immunodeficiency disease are presented. Both B and T lymphocyte functions were absent in approximately 80% of the children and markedly depressed in the remainder. Transplantation of marrow from HLA genotypically identical donors provided the highest six-month survival rate (63%); six-month survival rates for patients who received fetal tissue transplants (43%) or marrow from mixed leukocyte culture (MLC) negative donors (38%) were significantly higher (P less than .05) than for patients treated with marrow from MLC positive donors (5%). Additional factors appeared to influence survival and the severity of graft-vs-host (GVH) disease. Patients more than 6 months of age had more intense GVH disease than younger patients. Survival rates were lower and GVH disease more intense when boys received transplants from girl donors than the reverse.