Development and validation of a mortality predicting scoring system for severe aplastic anaemia patients receiving haploidentical allogeneic transplantation

Haploidentical allogeneic haematopoietic stem cell transplantation (haplo-HSCT) is a significant alternative treatment for severe aplastic anaemia (SAA). To improve this process by modifying the risk stratification system, we conducted a retrospective study using our database. 432 SAA patients who received haplo-HSCT between 2006 and 2020 were enrolled. These patients were divided into a training (n = 288) and a validation (n = 144) subset randomly. In the training cohort, longer time from diagnosis to transplantation, poorer Eastern Cooperative Oncology Group (ECOG) status and higher haematopoietic cell transplantation-specific comorbidity index (HCT-CI) score were independent risk factors for worse treatment-related mortality (TRM) in the final multivariable model. The haplo-HSCT scoring system was developed by these three parameters. Three-year TRM after haplo-HSCT were 6% [95% confidence interval (CI), 1-21%], 21% (95% CI, 7-40%), and 47% (95% CI, 20-70%) for the low-, intermediate-, and high-risk group, respectively (P < 0 center dot 0001). In the validation cohort, the haplo-HSCT scoring system also separated patients into three risk groups with increasing risk of TRM: intermediate-risk [hazard ratio (HR) 2 center dot 45, 95% CI, 0 center dot 92-6 center dot 53] and high-risk (HR 11 center dot 74, 95% CI, 3 center dot 07-44 center dot 89) compared with the low-risk group (P = 0 center dot 001). In conclusion, the haplo-HSCT scoring system could effectively predict TRM after transplantation.