Background: Despite major advances in the field of hematopoietic stem cell 
transplantation (HSCT), life-threatening complications still occur. Quantifying 
the risk of toxicity for individual patients is challenging, but essential for 
accurate pre-HSCT counseling. 
Aim: Validate 6 prognostic scoring systems for prediction of mortality risk in 
pediatrics post allogeneic HSCT [Hematopoietic cell transplantation 
comorbidity index (HCT-CI), Augmented HCT-CI, European Society for Blood 
and Marrow Transplantation score (EBMT), Pre-transplantation assessment of 
mortality score (PAM), disease risk index (DRI) and Endothelial Activation and 
Stress index (EASIx)]. 
Methods: We retrospectively analyzed 401 pediatric patients who underwent 
their first allogeneic HSCT in the period between January 2015 to December 
2019. Patients are stratified into different risk groups according to these 
prognostic indices. We assessed the validation of different risk groups of these 
systems in predicting OS of the patients. Many patients, transplant-related risk 
factors and different scoring systems were studied to detect predictors of OS. 
Results: 3-years Overall survival of benign group was 77%, where in malignant 
group was 73.2%. HCT-CI (AUC 53% & 61.8% in benign & malignant group 
respectively) and Augmented HCT-CI (AUC 52.3% in benign and 61.7% in 
malignant patients) were found to have most sensitive scores to predict 3-year 
OS in both disease groups. With comparing risk categories of each scoring 
system, we found that Augmented HCT-CI (P=0.039 & 0.03) in benign & 
malignant patients respectively) and EASIx (P=0.02 & 0.045 in benign and 
malignant groups respectively) had a significant power for prediction of 3-year 
OS in both disease groups where, PAM score (P=0.04) showed significance in 
benign group and DRI (P=0.023) in malignant group. After adjusting many 
patients and transplant related factors, Augmented HCT-CI showed the most 
significant score to predict the mortality risk in pediatrics (P=0.042). 
Conclusion: Augmented HCT-CI was found to have a strong power to predict 
mortality risk in pediatric patients post allo-HSCT. Female gender, older age 
and high ferritin level pre-transplant were associated with increased mortality 
risk in pediatrics post allo-HSCT.