Risk factors and outcome of graft failure after HLA matched and mismatched unrelated donor hematopoietic stem cell transplantation: a study on behalf of SFGM-TC and SFHI.

International audienceGraft failure remains a severe complication of hematopoietic stem cell transplantation (HSCT). Several risk factors have already beenpublished. In this study, we re-evaluated them in a large cohort who had the benefit of the recent experience in HSCT (2006–2012).Data from 4684 unrelated donor HSCT from 2006 to 2012 were retrospectively collected from centers belonging to the FrenchSociety for Stem Cell Transplantation. Among the 2716 patients for whom HLA typing was available, 103 did not engraft leading toa low rate of no engraftment at 3.8%. In univariate analysis, only type of disease and status of disease at transplant for malignantdiseases remained significant risk factors (P = 0.04 and Po0.0001, respectively). In multivariate analysis, only status of disease was asignificant risk factor (Po0.0001). Among the 61 patients who did not engraft and who were mismatched for 1 HLA class I and/orHLA-DP, 5 donor-specific antibodies (DSAs) were detected but only 1 was clearly involved in graft failure, for the others their rolewas more questionable. Second HSCT exhibited a protective although not statistically significant effect on OS (hazard ratio = 0.57[0.32–1.02]). In conclusion, only one parameter (disease status before graft) remains risk factor for graft failure in this recent cohort