The Hematopoietic Cell Transplant Comorbidity Index predicts survival after allogeneic transplant for nonmalignant...

Area of Science:

• Hematology
• Transplantation Medicine
• Clinical Outcomes Research

Background:

• Mortality after allogeneic hematopoietic cell transplantation (HCT) for nonmalignant conditions remains a challenge.
• Pre-transplant patient conditions can significantly impact post-transplant survival outcomes.

Purpose of the Study:

• To evaluate the predictive value of the HCT Comorbidity Index (HCT-CI) for post-transplant survival in patients with nonmalignant diseases.
• To identify specific nonmalignant disease indications where HCT-CI may influence mortality risk.

Main Methods:

• Analysis of 4083 patients with nonmalignant diseases undergoing HCT between 2007-2014 from the Center for International Blood and Marrow Transplant Research database.
• Kaplan-Meier method for overall survival (OS) and multivariable Cox regression models to estimate hazard ratios (HRs) for HCT-CI scores.
• Stratification of analysis by disease indication to assess differential impact of HCT-CI on mortality.

Main Results:

• Increasing HCT-CI scores correlated with decreased 2-year OS: 82.7% (score 0), 80.3% (scores 1-2), 74% (scores 3-4), and 55.8% (score ≥5).
• HCT-CI scores of 3-4 (HR 1.33) and ≥5 (HR 2.31) significantly increased mortality risk compared to scores of 0-1.
• The HCT-CI's impact on mortality varied by disease: increased risk for aplastic anemia, immune deficiencies, and bone marrow failure syndromes, but not for hemoglobinopathies.

Conclusions:

• This large-scale study confirms that HCT-CI scores ≥3 are associated with inferior survival after HCT for most nonmalignant diseases, with hemoglobinopathies as a notable exception.
• The HCT-CI, alongside disease-specific factors, can aid in developing personalized treatment strategies and risk stratification for patients undergoing HCT for nonmalignant conditions.