Serial evaluation of lymphocyte function in bone marrow-grafted patients.

Deficiencies in both cellular and humoral immunity follow human bone marrow transplantation, predisposing recipients to life-threatening infections. Peripheral blood mononuclear cells (cells of donor marrow origin) from nine patients were collected serially at 3-month intervals during the first year post transplant and evaluated for proliferation and lymphokine (gamma interferon and interleukin-2) production in vitro. Cultures of patient cells or those of normal adult volunteers were stimulated by phytohemagglutinin (PHA) in vitro, and lymphocyte blastogenesis was assayed by tritiated thymidine uptake on day 2. PHA blastogenesis for peripheral blood mononuclear cell cultures from patients post bone marrow transplant achieved normal levels 3-6 months post transplant. Supernatants produced by cells from marrow recipients (less than 12 months post transplant) had lower-than-normal IFN-gamma activity and decreased IL-2 activity. Two patients with acute graft-vs-host disease (GVHD) had persistently depressed PHA blastogenesis, IFN-gamma production, and IL-2 production at 12 months post transplant.