Bone turnover markers as an aid to monitor osteoporosis following allogeneic hematopoietic stem cell transplantation

Bone turnover markers (BTMs) are useful parameters for assessing fracture risk and unlike bone mineral density (BMD), can be measured at any institution. However, BTM values have not been established in patients post-allogeneic hematopoietic stem cell transplantation (allo-HSCT). We investigated the practicality of BTMs in patients who underwent allo-HSCT by measuring levels of the serum bone resorption marker, tartrate-resistant acid phosphatase-5b (TRACP-5b), and the bone formation marker, bone-specific alkaline phosphatase (BAP), together with BMD, 1 month before and 6 months after allo-HSCT. Patients were classified into either the alendronate group (n = 14) if alendronate treatment (35 mg orally per week) was administered before allo-HSCT or within 1 month after allo-HSCT, or the control group (n = 16), in which patients did not receive alendronate treatment. Despite the high frequency of corticosteroids users in the alendronate group (71.4 vs. 18.9%; p < 0.01), the mean percentage changes in BMD at the lumbar spine (− 2.9 vs. − 3.1%; p = 0.44) and femoral neck (− 3.2 vs. − 4.1%; p = 1.00), TRACP-5b levels (− 4.8 vs. 9.9%; p = 0.45), and BAP levels (6.9 vs. 1.0%; p = 0.85) during 6 months did not differ significantly between the alendronate and control groups. Additionally, the percentage changes in BMD at the lumbar spine were negatively associated with the TRACP-5b levels 6 months after allo-HSCT (p = 0.03, r = 0.40). Our results indicate the possible effectiveness of alendronate treatment in allo-HSCT patients. BTM levels could be useful to monitor the BMD changes.