Immunologic reactivity in marrow graft recipients receiving cyclosporine to prevent graft-versus-host disease.

In vitro and in vivo immunologic parameters were determined in 26 patients treated continuously with cyclosporine to prevent graft-versus-host-disease (GVHD) after allogeneic bone marrow transplantation (BMT) for acute and chronic leukemia and for aplastic anemia. A group of 18 patients was tested 6 months after BMT and another group of 10 patients was tested after one year. At 6 months after BMT, 94% of the patients had normal serum IgG and IgM levels, whereas at one year 29% of them had low IgA levels. The proportion of patients with normal lymphocyte responses in vitro at 6 months after BMT was 69% and 76% for the responses to concanavalin A and to soluble antigens; 75% and 53% for the responses to allogeneic cells and pokeweed mitogen, respectively; and 89% for the response to phytohemagglutinin. All but one were able to generate suppressor cells upon con A stimulation. At one year after the graft, only one patient had demonstrable multiple abnormalities in in vitro tests. Skin test reactivity at one year was comparable to pre-graft reactivity. After BMT a lymphopenia persisted for 6 months. The rate of infectious complications was high during the first 3 months after BMT, and it diminished progressively as immune functions returned to normal. Infection was the cause of death in two cases (one disseminated cytomegalovirus infection and one septicemia). GHVD occurred in 12 patients; in nine of them the disease was transient and mild, only 1 patient developed severe chronic GVHD. Acute GVHD did not influence the tempo of immunologic reconstitution. In comparison to other studies, it seems that cyclosporine does not delay immune restoration, or increase morbidity from infection, while preventing GVHD and its complications efficiently.