Objective: The aim of this retrospective study was to assess platelet transfusion needs and the kinetics and predictive factors for platelet recovery after reduced-intensity conditioning (RIC) allogeneic hematopoietic stem cell transplantation (HSCT).
Materials and methods: The profile of platelet recovery and transfusion needs in the first 100 days after RIC allo-SCT from a human leukocyte antigen-identical sibling donor was analyzed in a single-center series of 166 consecutive patients.
Results: Platelet recovery (>20g/L) was observed at a median of 9 days (range, 0-99 days) after allo-SCT. One-hundred forty-five patients could be assessed for platelet recovery at day +100, of which 99 (68%) had a platelet count >99g/L. In the multivariate analysis, a lower platelet counts before the start of conditioning, and occurrence of grade III to IV acute graft-vs-host disease significantly influenced day-100 platelet recovery >100 x 10(9)/L (odds ratio [OR] = 2.51; 95% confidence interval [CI], 1.13-5.61; p = 0.025; and OR = 7.6; 95% CI, 3.0-19.29; p = 0.00002, respectively). Eighty-three patients (50%) did not require any platelet transfusion during follow-up. Multivariate analysis found the following parameters to be significantly associated with platelet transfusion needs: conditioning regimen type (use of antithymoglobulin: OR = 3.96; 95% CI, 1.77-8.89; p = 0.008), platelet count prior to RIC administration (>144g/L; OR = 0.18; 95% CI, 0.08-0.39; p = 0.00001) and occurrence of grade III to IV acute GVHD (OR = 11.62; 95% CI, 4.01-33.66; p = 0.000006).
Conclusions: Overall, these observations show a lower rate of platelet transfusion and faster platelet recovery kinetics after RIC HSCT, but also highlight the negative effect of severe acute GVHD as a risk factor for increased need for platelet transfusions.