Donor alloreactivity may predict acute graft-versus-host disease in HLA-matched bone marrow transplantation for leukemia in early remission.

The pretransplant alloantigen-dependent responding and stimulating capacity of donors and of recipients was studied retrospectively, in a study of prediction of acute graft-versus-host disease. Donor responding capacity (DRC) and host stimulating capacity (HSC) were defined by mixed lymphocyte culture (MLC) and normalized by help of the pool response. High and low DRC and strong and weak HSC was defined by distribution plots. Kaplan-Meier estimates of the risk of developing Grade II or higher aGvHD showed that first remission patients (N = 125) had a significantly different risk if transplanted with marrow from a donor with high (N = 54) or low (N = 71) DRC (chi 2 = 9.49; d.f. = 1; p less than 0.002). This was not the case for patients transplanted in later remissions. Host SC status had no significant influence on the aGvHD status (chi 2 = 1.75 and 2.40; d.f. = 1; p = 0.19 and 0.12, defined by normal controls A and B respectively). In conclusion, the results indicate that pretransplant donor alloreactivity may predict aGvHD, confirming the results from a Scandinavian study. The results need to be confirmed in prospective studies of alloreactivity as risk factor for aGvHD.