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The Hematopoietic Cell Transplant Comorbidity Index predicts survival after allogeneic transplant for non-malignant diseases

Monica Thakar, Larisa Broglie, Brent Logan, Andrew Artz, Nancy Bunin, Lauri M. Burroughs, Caitrin Fretham, David A. Jacobsohn, Alison W. Loren, Joanne Kurtzberg, Caridad A. Martinez, Shin Mineishi, Adam S. Nelson, Ann Woolfrey, Marcelo C. Pasquini and Mohamed L. Sorror

Key points

  • HCT-CI scores of ≥3 are associated with inferior survival after allogeneic transplantation for non-malignant diseases.

  • The HCT-CI does not predict risk of mortality from transplantation for patients with hemoglobinopathies.

Abstract

Despite overall improvements, mortality after allogeneic hematopoietic cell transplantation (HCT) for non-malignant diseases remains a significant problem. We evaluated whether pre-HCT conditions defined by the HCT Comorbidity Index (HCT-CI), predicts probability of post-transplant survival in these patients. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we identified 4,083 patients with non-malignant diseases transplanted between 2007-2014. Primary outcome was overall survival (OS), estimated using the Kaplan-Meier method. Hazard ratios (HR) were estimated by multivariable Cox regression models. Increasing HCT-CI scores translated to decreased 2-year OS of 82.7%, 80.3%, 74%, 55.8% for patients with HCT-CI scores of 0, 1-2, 3-4, ≥5, respectively (log-rank p<0.001), regardless of conditioning intensity. HCT-CI scores of 1-2 did not differ relative to scores of 0, [HR 1.12 (0.93-1.34, p=0.218)], but HCT-CI of 3-4 and ≥5 posed significantly greater risks of mortality [HR 1.33 (95% CI 1.09-1.63), p=0.004; HR 2.31 (95% CI 1.79-2.96), p<0.0001, respectively). The impact of HCT-CI differed by disease indication. Patients with acquired aplastic anemia, primary immune deficiencies, and congenital bone marrow failure syndromes with scores of ≥3 had increased risk of death after HCT (p<0.001). However, higher HCT-CI scores among hemoglobinopathy patients did not increase mortality risk (p=0.11). In conclusion, this is the largest study to date reporting on patients with non-malignant diseases, demonstrating HCT-CI scores ≥ 3 had inferior survival after HCT, except for patients with hemoglobinopathies. Our findings suggest that using the HCT-CI score,in addition to disease-specific factors, could be useful when developing treatment plans for non-malignant diseases.

  • Submitted September 25, 2018.
  • Accepted November 20, 2018.