ACUTE EFFECTS OF HIGH-DOSE CHEMOTHERAPY FOLLOWED BY BONE-MARROW TRANSPLANTATION ON SERUM MARKERS OF BONE METABOLISM

There is an interplay between the cells in the bone marrow and the surrounding bone tissue, but little is known about the effects of myeloablative treatment followed by bone marrow transplantation on bone metabolism. We have therefore investigated 24 patients undergoing bone marrow transplantation (14 autologous, 10 allogeneic) for hematological malignancies. Serum concentrations of parathyroid hormone (PTH), albumin-modified calcium, and biomarkers for bone turnover-osteocalcin, bone alkaline phosphatase (B-ALP), and carboxyterminal cross-linked telopeptide of type I collagen (ICTP)-were measured. The samples were collected before myeloablative treatment, on the day of bone marrow infusion and 1, 2, 3, and 12 weeks thereafter. A serum PTH peak was consistently seen the day after total body irradiation, but no long-term effects on PTH/calcium homeostasis were observed. Bone formation as reflected by serum osteocalcin and B-ALP decreased, with nadir levels 2 to 3 weeks after marrow infusion. A simultaneous increase in bone resorption (increased S-ICTP) occurred. Pretreatment values were not completely regained 12 weeks after transplantation. The findings indicate that bone tissue is affected by myeloablative treatment, and the changes in biomarkers imply a net loss of bone over the study period.