Predictive Factors of Fatal Bleeding in Pediatric Acute Promyelocytic Leukemia (APL)

Background: Pediatric APL has a higher bleeding risk but better outcomes. This study aimed to identify predictors of fatal bleeding in pediatric APL to optimize early interventions and improve survival in Pakistan. Methods: A retrospective study was conducted at the Department of Pediatric Oncology, Combined Military Hospital, Rawalpindi, from January 2013 to December 2023, using census sampling to analyze data from 51 pediatric APL patients (≤18 years) diagnosed and treated during this period. The severity and type of bleeding were classified using standardized bleeding severity scores. The patients were classified into standard or high-risk categories as per total leucocyte count (TLC). The bleeding events and risk factors to fatal bleeding were noted and compared between the two groups using Independent samplest, Mann-Whitney U, and chi-square tests. Data analysis was performed using SPSS version 25, and a p-value ≤ 0.05 was considered statistically significant. Results: Fifty-one pediatric APL patients were included with a median age of 4.75 (4.00) years in a high-risk group and 10.0 (6.00) years in the low-risk group (p<0.001). Mortality and fatal bleeding incidence were found to be higher in the high-risk group. Fatal bleeding occurred in 8 (28.57%) high-risk patients and 6 (26.08%) low-risk risk group, which contributed to mortality. Higher median TLC, Partial Thromboplastin Time (PTT), and activated PTT were noticed in patients who suffered from fatal bleeding. Sixteen (31.37%) patients couldn’t survive, with 6 (37.5%) patients suffering a fatal bleeding event, which led to death. Conclusion: Higher WBCs, lower platelets, and prolonged PT / aPTT are potential risk factors of fatal bleeding and mortality in APL patients.