Monitoring of bone metabolism after bone marrow transplantation by measuring two different markers of bone turnover.

Bone marrow transplant recipients may be at increased risk of osteoporosis. In a cross-sectional study we therefore measured two biochemical markers of bone turnover, bone alkaline phosphatase and the C-terminal propeptide of type I procollagen, in 22 serum samples from 9 patients before allogeneic bone marrow transplantation and 85 serum samples from 14 patients after allogeneic bone marrow transplantation. Following allogeneic bone marrow transplantation, female (but not male) patients showed elevated serum bone alkaline phosphatase values (p < 0.05). After bone marrow transplantation both female and male patients were characterized by elevated serum concentrations of the C-terminal propeptide (p < 0.01). Both the duration of cyclosporin A therapy (p < 0.05) and the time since transplantation (p < 0.01) were independent predictors of serum bone alkaline phosphatase values, whereas the duration of cyclosporin A therapy was the only independent predictor of C-terminal propeptide serum concentrations (p < 0.01). There was a correlation between bone alkaline phosphatase serum concentrations and C-terminal propeptide values in serum (p < 0.0001). These findings indicate an accelerated bone turnover in patients following bone marrow transplantation due to the stimulation of osteoblasts by cyclosporin A. In addition, oestrogen deficiency after total body irradiation may accelerate bone mass loss in female patients.