Impact Of Red Blood Cell And Platelet Transfusions At Early After Engraftment On Outcome Of Allogeneic Hematopoietic Stem Cell Transplantation

Abstract Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is often associated with comorbidity or mortality, due to graft-versus-host disease (GVHD), opportunistic infections, and regimen-related toxicities. Recently, several studies have shown that pre-transplant red blood cell (RBC) transfusions may increase risks of such allo-HSCT-related complications, possibly due to iron overload caused by pre-transplant RBC transfusions. However, it is unknown how post-transplant RBC and platelet (PLT) transfusions influence the long-term outcome of allo-HSCT. In this study, to clarify impact of RBC and PLT transfusions at early after engraftment of allo-HSCT, we investigated the clinical and laboratory findings and long-term outcomes of 71 recipients of allo-HSCT including 48 bone marrow transplantation and 23 peripheral blood stem cell transplantation who received leukoreduced and irradiated RBC and/or PLT from days 31 to 50, after exclusion of patients who did not achieve complete chimera (>90% donor cells) before day 30 or engraftment (neutrophil count > 0.5 x 109 /L) up to day 35; whose disease relapsed until day 60; and who did not survive until day 100. In these 71 patients, 33 (46.5%) patients received RBC and/or PLT transfusion, while 38 (53.5%) received no transfusion from days 31 to 50. Among groups of those patients who received RBC (RBC-transfused patients), PLT (PLT-transfused patients), and both (RBC/PLT-transfused patients) transfusions, pre-transplant findings, including age, sex, sources, serum ferritin (Ft) levels, conditioning regimens, and blood group and HLA compatibilities were not significantly different. However, even at day 100, significant decreases of both Hb concentrations and platelet counts, but not leukocyte counts, were observed in RBC-transfused patients, PLT-transfused patients, and RBC/PLT-transfused patients (Table 1), although vast majority of them no longer required transfusion after day 50. Moreover, serum Ft and C-reactive protein (CRP) levels were higher at day 100 in RBC-, PLT-, and RBC/PLT-transfused patients versus other patients (Table 1). Risk of clinically significant chronic GVHD (cGVHD) by transfusions of both RBC and PLT from days 31 to 50 did not reach statistical significance [hazard risk (HR) = 2.75, p = 0.06], but cumulative incidence of cGVHD was significantly greater in RBC/PLT-transfused patients compared with other patients (p = 0.03). Risk of cGVHD was also correlated with elevated CRP levels (HR = 3.28, p = 0.02) rather than serum Ft levels (HR = 1.40, p = 0.6) at day 100 in univariable analysis, although multivariable analysis did not show significant differences in CRP levels (p=0.07). Moreover, non-relapse mortality was greater in patients who received RBC transfusion compared other patients (p = 0.02), although overall survival (p=0.1) and cumulative incidence of relapse (p=0.4) were not different. In conclusion, both RBC and PLT transfusions early after engraftment of allo-HSCT may be correlated with following elevations of CRP and serum Ft levels and contribute to adverse long-term outcomes of allo-HSCT with an increase of cGVHD. Disclosures No relevant conflicts of interest to declare.