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 marr ow donors was tested to detect weak antigenic differences with the recipien t, and then compared to the outcome. HTLp frequency was estimated in limiti ng dilution cultures, and HLA-DR and CD 80 expression by stimulating cells was measured by now cytometry. 12/19 patients experienced acute graft-versu s-host disease (aGVHD) grade II-IV. A good correlation was found between hi gh pretransplant HTLp frequency and grade II-IV aGVHD (median: 1/55848 PBMN C for IT-TV GVHD versus 1/ 184346 for 0-I GVHD; P=0.008). Sensitivity was 8 2%, specificity 63%, negative predictive value 71% and positive predictive value 75%. Long-term survivors also had a lower HTLp median frequency (1/14 3354) when compared with patients who died as a result of the transplant pr ocedure (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 fr equency estimation can predict, although poorly acute GVHD risk and long-te rm survival.