Effective engraftment via granulocyte transfusion in pre-engraftment febrile neutropenia following allogeneic hematopoietic stem cell transplantation: granulocyte transfusion as bridge therapy.

Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is crucial for treating high-risk hematological cancers. Posttransplant infections are a leading cause of mortality and morbidity, especially before engraftment. This study evaluated the effects of granulocyte transfusion (GT) therapy on neutrophil and platelet (PLT) engraftment in patients with febrile neutropenia during the pre-engraftment phase following allo-HSCT with a control group.

Methods: We retrospectively analyzed 56 patients who underwent allo-HSCT from January 2019 to January 2024, dividing them into two groups: those who received GT (GTG) and those who did not (non-GTG).

Results: A total of 76 GTs were administered to 28 patients with febrile neutropenia during the pre-engraftment period. The median granulocyte dose was 5.4 × 10⁸/kg. Median engraftment times in the GTG were 13 days for both PLT and neutrophil engraftment, compared to 15.5 days (PLT) and 19 days (neutrophil) in the non-GTG (p < 0.001 for neutrophil and p = 0.007 for PLT). Additionally, 89.3% of patients in the GTG showed improved infection status. Overall survival (OS) at 2 year was 61.4% for GTG and 73.2% for non-GTG, respectively. No significant difference in OS between the groups (p > 0.05). In the non-GTG, the OS rate was 47.5%, with no significant difference in OS and mortality rates between the groups. GT did not affect the incidence of graft-versus-host disease or cytomegalovirus infection.

Conclusion: This study is the first to include a control group and demonstrate a statistically significant association between GT therapy in the pre-engraftment period and shortened engraftment times in allo-HSCT recipients.