(P-BT-18) Engraftment Outcomes of Stem Cell Transplants

Background/Case Studies: Engraftment of neutrophils and platelets is a critical determinant of early post-transplant recovery in hematopoietic stem cell transplantation (HSCT). Clinical and biological variables that may influence engraftment remain poorly defined. This study evaluates neutrophil and platelet engraftment post HSCT at a single transplant center, examining patient- and treatment-related factors.

Study

Design/Methods: A retrospective cohort analysis was conducted on patients who underwent HSCT between 2018 and 2022. Data collected included recipient demographics, diagnoses, donor type, HLA/ABO Rh match, stem cell source, conditioning regimen and time to neutrophil and platelet recovery.

Neutrophil engraftment was defined as an absolute neutrophil count (ANC) ≥ 0.5 x 10⁹/L for three consecutive days. Platelet recovery was defined as a platelet count of ≥20×10^9/L for seven consecutive days without transfusion. Graft failure was defined as ANC < 0.5 x 10⁹/L by day +30, accompanied by pancytopenia.

Descriptive analysis, Chi-square & Mann-Whitney ‘U’ tests were performed using SPSS Statistics. A p-value < 0.05 was considered statistically significance. Institutional ethics approval was obtained.

Results/Findings: A total of 154 patients were included (median age 25.5 years, interquartile range (IQR) 12.2-38.6). Male donors accounted for 60% of the cohort, and 89.7% of transplants were allogenic, primarily from matched sibling donors (80.6%). The most common indication was acute leukemia (31.8%). Peripheral blood stem cells (PBSCs) were the predominant source for stem cells(76%). Bleeding and infectious complications occurred in 20.6% and 28.4% of patients respectively.

Neutrophil engraftment was achieved in 95% (n=146) with a median recovery time of 14 days (quartile range; QR 12,17). Platelet recovery occurred in 94.2%, with a median recovery time of 17 days (QR12, 23.5). Neutrophil engraftment was significantly associated with recipient age (p=0.029) and diagnosis (p=0.025) (Table 1). Platelet recovery was significantly associated with age (p=0.019), degree of HLA match (p=0.017) (Table 1), donor type (p=0.009), and conditioning regimen (p=0.015). The associations for all identified significant variables remained statistically significant (p < 0.05) in the subgroup analysis of allogeneic transplant recipients (n=138) for both platelet and neutrophil engraftment.

Conclusions: Neutrophil engraftment was significantly influenced by recipient age and diagnosis, while platelet recovery was associated with age, donor type, degree of HLA match, and conditioning regimen. the study’s findings can guide improved pre-transplant assessment and support tailored interventions to enhance hematopoietic recovery, especially in high-risk patients. Larger studies are warranted to confirm these findings.