EFFECT OF FRESH VERSUS CRYOPRESERVED GRAFTS ON FEBRILE NEUTROPENIA AND INFECTIONS IN ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION: FACTORS DETERMINING MORTALITY.

Background: The study aimed to compare the incidence and course of febrile neutropenia (FN) and factors affecting mortality in hematologic patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) with either fresh or cryopreserved grafts. Methods: The clinical data of 155 patients who underwent allo-HSCT at our hematology clinic between 2010 and 2023 were retrospectively analyzed. The incidence of bloodstream infection (BSI) and FN-related mortality were analyzed in these patients. Factors affecting FN-related mortality were examined using a Cox regression model. Results: A total of 143 patients who developed FN were included in the study. Ninety-eight patients underwent transplantation with fresh stem cells and 45 patients with cryopreserved stem cells. The duration of FN episodes was similar between groups (p = 0.077); however, the duration of deep neutropenia (neutrophils < 100/mm³) was significantly longer in the cryopreserved group (11.56 ± 4.84 vs. 7.78 ± 3.03; p < 0.001). GNB infections and invasive fungal infections were more frequent in the cryopreserved group (p = 0.009 and p < 0.001, respectively). In the Cox regression model, the most important determinants of FN-related mortality were duration of the FN episode (HR 1.18; 95% CI 0.99–1.41; p = 0.046) and higher hematopoietic cell transplantation comorbidity index (HCT-CI) score (score 1; p = 0.014 and score 2; p = 0.039). Conclusions: This study demonstrated that irrespective of the graft type, prolonged FN duration and high HCT-CI score are the primary determinants of mortality. Therefore, clinical management of patients should also address these risk factors.