Outcome of hematopoietic stem cell transplantation is similar for patients with a partial in vitro T-cell-depleted graft compared with a non-T-cell-depleted graft when stratified by the refined disease risk index.

Comparisons of hematopoietic stem cell transplantation (HSCT) methods in retrospective studies are often hampered by the heterogeneity of comparison groups. The refined disease risk index (DRI) is a potentially interesting tool to compare HSCT protocols as it is based on the disease type and burden at transplant and stratifies patients into four prognostic groups for overall survival (OS). We included 265 patients with partial T-cell-depleted graft (TDEP) and 163 non-TDEP patients in a retrospective study and compared outcomes following stratification using the refined DRI. The 2-year OS rate for TDEP patients was 81.6, 60.9 and 43.3% for the low-, intermediate- and high-risk groups, respectively (P<0.001). For non-TDEP patients, the 2-year OS rate was 62.9, 48.8, 44.2 and 7.6% for the low-, intermediate-, high- and very-high-risk groups, respectively (P<0.001). There was no significant difference when comparing OS between TDEP and non-TDEP for the low-, intermediate- and high-risk groups, but TDEP patients had less acute GvHD grades II-IV. In conclusion, we confirm that the refined DRI is a valuable tool to compare the outcomes of different HSCT protocols. We demonstrate also that TDEP did not impact on the outcome of HSCT, but it did reduce the incidence of acute GvHD.