Efficacy of vitamin D plus calcium with/without alendronate on bone metabolism in immunologic thrombocytopenic purpura patients with steroid treatment: Nine-month results of a randomized, double-blinded, controlled trial.

Bone loss is a prominent complication in immunologic thrombocytopenic purpura (ITP) patients with steroid treatment. Anti-osteoporotic medications are applied as a therapeutic strategy to prevent bone deterioration in ITP patients. However, the skeletal protective effect of alendronate (ALN) in ITP patients has been rarely reported. The present study was performed to determine whether ALN reduces bone loss in ITP patients. A total of 40 ITP patients with steroid treatment were randomized into a placebo group [n=20; caltrate D (CalD)] and an ALN (10 mg/day) + CalD group (n=20). The patients received CalD or CalD + ALN treatment for 9 months. The primary outcomes were bone mineral density (BMD) in the lumbar vertebrae (L1-L4), femoral neck and total hip, as well as bone metabolism markers. The results indicated that the BMD of the lumbar vertebrae (L1-L4), femoral neck and total hip was significantly increased after ALN + CalD treatment for at 6 and 9 months compared with the baseline. Compared with CalD treatment alone, CalD combined with ALN significantly elevated the BMD at the three skeletal sites at 9 months. Compared with the baseline levels or CalD treatment alone, ALN together with CalD treatment markedly reduced urinary Ca excretion and the serum levels of the bone resorption markers tartrate resistant acid phosphatase 5b and C-terminal telopeptides of type 1 collagen, at 9 months. In conclusion, treatment with ALN together with CalD significantly elevated the BMD at three skeletal sites, and inhibited urinary Ca excretion and the activity of bone resorption markers in patients with ITP.