Hematopoietic Cell Transplantation-Comorbidity Index Score Is Correlated with Treatment-Related Mortality and Overall Survival following Second Allogeneic Hematopoietic Cell Transplantation in Children

• Published in: Transplantation and cellular therapy Vol. 28; no. 3; pp. 155.e1 - 155.e8
• Main Authors: Forlanini, Federica, Zinter, Matt S., Dvorak, Christopher C., Bailey-Olson, Mara, Winestone, Lena E., Shimano, Kristin A., Higham, Christine S., Melton, Alexis, Chu, Julia, Kharbanda, Sandhya
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2022
• Subjects: Adult; Child; Cohort Studies; Comorbidity; HCT-CI; Hematopoietic cell transplantation; Hematopoietic Stem Cell Transplantation - adverse effects; Humans; Retrospective Studies; Survival; Transplantation, Homologous - adverse effects; Treatment-related mortality; United States; Young Adult; United States; HCT-CI; Hematopoietic cell transplantation; Comorbidity; Treatment-related mortality; Survival
• ISSN: 2666-6367; 2666-6367
• DOI: 10.1016/j.jtct.2021.11.015

•This is the first study to focus on the importance of the Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) in second allogeneic HCT.•The study cohort was composed entirely of pediatric HCT recipients.•HCT-CI is the predominant factor associated with both treatment-related mortality and overall survival.•Pulmonary dysfunction was the most frequently reported comorbidity, occurring in 12% of patients. Allogeneic hematopoietic cell transplantation (HCT) can lead to considerable complications and treatment-related mortality (TRM); therefore, a detailed assessment of risks is essential. The Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI) can predict both TRM and overall survival (OS). Although the HCT-CI has been validated as a useful tool for first HCT, its potential utility for second HCT has not yet been investigated. Here we aimed to evaluate the utility of the HCT-CI score in assessing the risk of TRM and OS in the setting of a second allogeneic HCT. This was a retrospective analysis of all pediatric patients (age <21 years) who underwent a second allogeneic HCT at UCSF Benioff Children's Hospital San Francisco between 2008 and 2019. According to their HCT-CI, patients were classified as “low risk” with an HCT-CI of 0 or “intermediate-high risk” with an HCT-CI ≥1. A total of 59 patients were included in the study. Our primary endpoint was TRM, observed at 100 days, 180 days, 1 year, and last follow-up following HCT, and our secondary endpoint was OS at 1 year and at 5 years or last follow-up. We also evaluated outcomes of patients admitted to the pediatric intensive care unit based on the HCT-CI score. Seventy-six percent of patients had an HCT-CI of 0. The most frequent comorbidities were pulmonary, seen in 7 patients (12%; 95% CI, 5% to 23%), including 5 (71%) with moderate and 2 (29%) with severe comorbidities. The OS and the cumulative incidence of TRM at 1 year for the entire cohort were 81% (95% CI, 69% to 90%) and 12% (95% CI, 5% to 22%), respectively. The cumulative incidence of TRM and OS at 1 year showed a significant correlation with HCT-CI score; TRM was 4% (95% CI, 1% to 13%) for an HCT-CI of 0 versus 36% (95% CI, 13% to 60%) for an HCT-CI ≥1 (P < .001), and OS was 89% (95% CI, 75% to 99%) for an HCT-CI of 0 versus 57% (95% CI, 28% to 78%) for an HCT-CI ≥1 (P = .003). After adjusting for covariates, HCT-CI continued to be associated with both TRM (P = .004) and OS (P = .003). In addition, comparing patients with malignancies and nonmalignant disorders, disease-free-survival at last follow-up was higher in the nonmalignant disorder group and also was influenced by the HCT-CI score in each group (P = .0035). There also was a significant difference in outcomes of patients admitted to the pediatric intensive care unit; 15 patients (68%) with an HCT-CI of 0 were alive at last follow-up, compared with only two (22%) with an HCT-CI ≥1 (P = .016). HCT-CI has an impact on TRM and OS and may serve as a predictor of outcomes of second allogeneic transplantation. Although this study was conducted in a relatively small sample, it is the first to investigate the utility of the HCT-CI score in predicting outcomes after a second allogeneic HCT in pediatric recipients. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.