The hematopoietic cell transplantation-specific comorbidity index (HCT-CI) is an outcome predictor for partially matched related donor transplantation.

To validate the predictive ability of the Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) on the outcome of hematopoietic stem cell transplantation (HSCT) patients who received transplants from partially matched related donors (PMRD), a total of 526 patients who received PMRD HSCT between January 2006 and December 2009 at the Institute of Hematology, Peking University were enrolled. Patients were grouped according to their HCT-CI score; 31.0%, 31.4%, and 37.6% of patients had HCT-CI scores of 0, 1-2, and ≥3, respectively. Patients with HCT-CI scores of ≥3 had a significantly poorer 2-year overall survival (OS) than patients with HCT-CI scores of 0-2 (54.55% vs. 78.05%, P < 0.001). In addition, patients with HCT-CI scores of ≥3 had a significantly higher 2-year cumulative incidence of relapse and nonrelapse mortality (NRM) than patients with scores of 0-2 (relapse: 23.23% vs. 11.59%, P < 0.001; NRM: 34.30% vs. 15.93%, P < 0.001). HCT-CI scores of <3 were associated with better OS, less relapse, and lower NRM in multivariate analysis. Patients who had high comorbidity scores as well as high-risk disease had the poorest outcomes. Therefore, we found that HCT-CI is associated with the outcomes of PMRD HSCT and we should closely monitor patients with a high comorbidity burden.