Promising Outcome of Umbilical Cord Blood Transplantation in Patients with Multiple Comorbidities

The hematopoietic cell transplantation-specific comorbidity index (HCT-CI) has been recently proposed to predict the probability of nonrelapse mortality (NRM) and overall survival (OS) in allogeneic hematopoietic stem cell transplantation (HSCT). However, the usefulness of the HCT-CI in single-unit umbilical cord blood transplantation (UCBT) remains unclear. We investigated the impact of the HCT-CI on the clinical outcomes of allogeneic HSCT in a single-center retrospective study including 53 recipients of UCBT (UCBT group) and 90 recipients of other HSCT (non-UCBT group). In the non-UCBT group 2-year OS rates for HCT-CI score < 3 and ≥3 were 67% (n = 74; 95% confidence interval [CI], 54% to 78%) and 26% (n = 16; 95% CI, 7% to 51%), respectively (P = .001). In the UCBT group these rates were 66% (n = 39; 95% CI, 48% to 79%) and 69% (n = 14; 95% CI, 36% to 87%), respectively (P = .73). In the non-UCBT group 1-year NRM rates for HCT-CI score < 3 and ≥3 were 14% (95% CI, 6.4% to 22%) and 37% (95% CI, 14% to 61%), respectively (P = .02). In the UCBT group these rates were 6.1% (95% CI, 3.4% to 24%) and 7.7% (95% CI, .4% to 29%), respectively (P = .78). Using multivariate analysis we showed that HCT-CI score ≥ 3 was significantly associated with lower OS (hazard ratio, 3.06; 95% CI, 1.47 to 6.38; P = .003) and higher NRM (hazard ratio, 2.87; 95% CI, 1.18 to 6.96; P = .02) for the non-UCBT group. UCBT showed good OS with low incidence of NRM, even in patients with high HCT-CI scores. Altogether, we propose single-unit UCB to be a promising stem cell source for improving survival in patients with multiple comorbidities.