Accelerated Bone Mineral Density Loss Occurs with Similar Incidence and Severity, But with Different Risk Factors, after Autologous versus Allogeneic Hematopoietic Cell Transplantation

Bone mineral density (BMD) loss occurs commonly in patients after allogeneic hematopoietic cell transplantation (HCT), primarily because of steroid use, but little is known about BMD change post-autologous HCT. In a prospective study of 206 consecutive first HCT patients, we measured acute BMD change at the lumbar spine and dual femur between baseline and day +100, and evaluated risk factors for bone loss. Accelerated BMD loss in this 4-month period occurred after both autologous and allogeneic HCT with similar severity (median, 0.03 g/cm 2 versus 0.03 g/cm 2 at the spine; 0.03 g/cm 2 versus 0.05 g/cm 2 at the femur, respectively). This is equivalent to 7 to 17 years' worth of bone loss by aging. Risk factors for BMD loss were different between autologous and allogeneic HCT patients: lymphoma was associated with greater bone loss after autologous HCT than myeloma, whereas higher steroid dose was the most significant risk factor after allogeneic HCT. Multivariable risk models explained 11% to 30% of the variation in HCT-related BMD change. Surprisingly, BMD loss post-autologous HCT occurred with similar incidence and severity to allogeneic HCT, even in the absence of steroid use. Evaluation of clinical strategies to prevent and reverse HCT-related BMD loss is necessary in both autologous and allogeneic HCT patients.