Older Age, Use Of Myeloablative Regimens For Malignant Diseases and Chronic Graft-Versus-Host Disease Are Risk Factors For Avascular Necrosis Of Bone After Allogeneic Hematopoietic Cell Transplantation In Children and Adolescents

Avascular necrosis (AVN) of the bone is a painful and debilitating complication of allogeneic hematopoietic cell transplantation (HCT) that is associated with significant morbidity and often requires surgery. Risk factors for its development in pediatric allogeneic HCT recipients are not well described. To assess risk factors for AVN in children and adolescents following allogeneic HCT, we conducted a nested case-control study with a matched cohort of 638 patients reported to the Center of International Blood and Marrow Transplant Research who were ≤ 21 years of age, received their first allogeneic transplant between 1990 to 2008 in the United States and had survived ≥ 6 months from HCT. Overall, 160 cases with AVN were identified. Each case was matched with up to 3 controls by same year of HCT, similar length of follow-up and by transplant center (478 controls). Cases and controls were confirmed via central review of radiology, pathology and/or surgical procedure reports. The median age for cases was 15 (range 2-21) years, 49% were male, 65% had acute leukemia, 65% had received high-dose total body irradiation (TBI) based conditioning regimen, and 65% had received unrelated donor HCT. Among cases, 18% had a history of acute graft-versus-host disease (GVHD) while 56% had a history of chronic GVHD prior to development of AVN. Median time from HCT to diagnosis of AVN was 14 (range Disclosures: No relevant conflicts of interest to declare.