Bone loss following hematopoietic stem cell transplantation: a long-term follow-up

Transplantation-associated bone loss is a well-known phenomenon, however, effects of hematopoietic stem cell transplantation are insufficiently characterized. We conducted a prospective, unicentric, long-term follow-up in 280 patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Bone mineral density (BMD) was measured before transplantation and then yearly for at least 4 years. Patients received vitamin D plus calcium until steroid withdrawal. Mean baseline BMD was normal. We demonstrated significant bone loss with nadir BMD at month 6 for the spine and at month 24 for total body and femoral neck. Average annual bone loss was 0.6% for spine, 0.4% for total body, 2.3% for femoral neck, and 3.5% for Ward triangle. While spine and total body BMD returned to baseline, bone loss at femoral neck sites was attenuated, but BMD did not return to baseline until month 48 (P <.0001 for femoral neck and Ward triangle). Univariate factor analysis of 15 potential risk factors for rapid bone loss revealed a positive correlation of bone loss with steroid and cyclosporine A use, baseline BMD, and loss of muscle mass (overwhelming power of steroid use in multifactor analysis). Such rapid BMD changes probably increase fracture risk consecutive to irreversible microarchitectural changes even if osteodensitometry shows long-term recovery.