Impact of age on graft-versus-host disease and overall survival in pediatric hematopoietic cell transplant recipients.

abstractAdvances in graft-versus-host disease (GVHD) prevention and treatment have resulted in expanded donor options and improvement in treatment-related mortality (TRM). This analysis aimed to compare the incidence of acute and chronic GVHD (aGVHD and cGVHD, respectively) in pediatric patients by recipient age and to evaluate the impact of GVHD on overall survival (OS) and TRM. We included 14 099 patients aged ≤21 years who received their first allogeneic hematopoietic cell transplantation from 2002 to 2020, categorizing recipient age as 0 to 2 years (infants/toddlers), 3 to 12 years (school-aged), and 13 to 21 years (adolescent/young adult). There was no difference in grade 2 to 4 and 3 to 4 aGVHD by day 100 among age groups, except among patients with nonmalignant disease (NMD), among whom there was a small increase in incidence of severe aGVHD in older patients. Incidence of moderate/severe cGVHD by 1 year was higher with age. A similar impact of age was observed after adjusting for patient, donor, and transplant characteristics. Risk of severe aGVHD was higher in older children with NMD. Severe aGVHD and moderate/severe cGVHD were independently associated with inferior OS. In patients with malignant disease, both severe aGVHD and moderate/severe cGVHD were associated with increased risk of TRM. In conclusion, risk of moderate/severe cGVHD increases with recipient age, and risk of severe aGVHD is increased among older patients with nonmalignant conditions. Despite the low overall incidence of aGVHD and cGVHD in children, both are associated with significantly worse survival. These data highlight the need to consider GVHD outcomes at time of consultation and for improved prevention and treatment approaches.