Patients with severe aplastic anemia (SAA) are at high risk for morbidity and mortality due to severe infections. We aimed to characterize the role of granulocyte transfusion (GT) in SAA. Primary outcomes were survival from first GT, including overall survival (OS) at last follow up, survival to discharge, and receipt of HSCT. Secondary outcomes included evaluation of clinical response at 7 and 30 days after GT initiation based on a clinical scoring system incorporating microbiological and radiographic response. Twenty-eight SAA patients underwent 30 GT courses with a per-dose median of 1.28 x 109 granulocyte cells/kilogram (range 0.45-4.52 x 109). OS from initial GT to median last follow up (551 days) was 50%, with 39% (11/28) alive at last follow up. Sixty-four percent (18/28) of all patients survived to hospital discharge. Patients with complete, partial, or stable response at 30 days had significantly improved OS compared to non-responders (p=0.0004). Eighty-six percent (18/21) of patients awaiting HSCT during GT underwent transplant and 62% (13/21) survived to post-HSCT discharge. Sex, type of infection, or percentage of days with absolute neutrophil count > 0.2x109/L during GT course were not predictive of survival (p=0.52, p=0.7, p=0.28). Nine of 28 (32%) patients developed new or increased human leukocyte antigen (HLA) alloimmunization during their GT course. GTs in SAA may impact survival in those with improvement or stabilization of their underlying infection. Alloimmunization can occur and OS in this population remains poor, but GTs may be a useful tool to bridge patients to curative treatment with HSCT.
