Pretransplant helper T-lymphocyte determination in bone marrow donors: acute graft-versus-host disease prediction and relation with long-term survival.

Helper T-lymphocyte precursor (HTLp) frequency from 19 allogeneic bone marrow donors was tested to detect weak antigenic differences with the recipient, and then compared to the outcome. HTLp frequency was estimated in limiting dilution cultures, and HLA-DR and CD 80 expression by stimulating cells was measured by flow cytometry. 12/19 patients experienced acute graft-versus-host disease (aGVHD) grade II-IV. A good correlation was found between high pretransplant HTLp frequency and grade II-IV aGVHD (median: 1/55848 PBMNC for II-IV GVHD versus 1/184346 for 0-I GVHD; P = 0.008). Sensitivity was 82%, specificity 63%, negative predictive value 71% and positive predictive value 75%. Long-term survivors also had a lower HTLp median frequency (1/143354) when compared with patients who died as a result of the transplant procedure (1/22100, P < 0.001). No correlation was found between HTLp frequency and HLA-DR or CD80 expression by patient's cells. We conclude that HTLp frequency estimation can predict, although poorly, acute GVHD risk and long-term survival.