Corticosteroid Dose as a Risk Factor for Avascular Necrosis of the Bone after Hematopoietic Cell Transplantation

Exposure to corticosteroids increases the risks of avascular necrosis (AVN) of the bone after hematopoietic cell transplantation (HCT). However, whether this effect is dependent on the dose of corticosteroids is not well known. We conducted a case-controlled study, which included 74 recipients of autologous or allogeneic HCT with AVN and 147 controls without AVN that were matched by age, sex, and year of HCT to cases. Cases with AVN included 8 autologous HCT recipients, 58 myeloablative allogeneic HCT recipients, and 8 recipients of nonmyeloabalative allogeneic HCT. Corticosteroid exposure was expressed as cumulative doses of prednisone. Cases received higher cumulative doses of prednisone than controls, and among allogeneic HCT recipients, cases were more likely to have developed acute and chronic graft-versus-host disease (aGVHD, cGVHD). Cumulative dose of prednisone was an independent risk factor for AVN. Compared to no corticosteroid exposure, exposure to <3870 mg cumulative dose of prednisone was associated with 4.0 (95% confidence intervals, 1.5-11.2) times higher risk, 3870-9735 mg with 5.6 (2.1-15.2) times higher risk and >9735 with 8.6 (3.2-23.5) times higher risk of AVN. Exposure to higher doses of corticosteroids increases the risk of AVN in HCT recipients.