Disease Risk Comorbidity Index for Patients Receiving Haploidentical Allogeneic Hematopoietic Transplantation

Purpose or Background:

We aimed to develop a disease risk comorbidity index (DRCI) based on Disease Risk Index (DRI) and Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) in patients receiving haploidentical hematopoietic stem cell transplantation (haplo-HSCT).

Method or Case:

We examined 889 patients undergoing haplo-HSCT from 2015 to 2016. We used a Cox multivariable model to identify factors prognostic of disease-free survival (DFS) in a training subset (n = 593). A weighted score using these factors was assigned to the remaining patients (validation cohort; n = 296). This work was supported by the Capital's Funds for Health Improvement and Research (grant number 2018-4-4089).

Results or Progress:

The multivariable model identified two independent predictors of DFS: DRI and HCT-CI before HSCT. A weighted score of 2 was assigned to very high risk DRI, and a weighted score of 1 was assigned to high-risk DRI and intermediate- and high-risk HCT-CI in the scoring system (i.e., haplo-HSCT). In the validation cohort, the 3-year DFS was 65.2% (95% CI, 58.2-72.2%), 55.8% (95% CI, 44.9-66.7%), and 32.0% (95% CI, 5.8-58.2%) for the low-, intermediate- and high-risk group, respectively (P=0.005). Haplo-DRCI can predict relapse (P<0.001), non-relapse mortality (NRM, P<0.001), DFS (P<0.001), and overall survival (OS, P<0.001) in total population and in disease-specific subgroups, particularly in acute leukemia patients. Increasing score was also significantly predictive of increased relapse (P<0.001), increased NRM (P=0.001), decreased DFS (P<0.001), and decreased OS (P<0.001) in an independent historical cohort (n=526).

Conclusion or Discussion:

These data confirmed that haplo-DRCI can effectively risk stratifies haplo-HSCT recipients and provide the tool to better predict who will best benefit from haplo-HSCT.