ABSTRACT
BACKGROUND: Loss of bone mass is usually detected after BMT. The causes of bone loss are related with gonadal dysfunction and immunosuppressants. Cytokines, especially IL-6, play an important role in the pathogenesis of postmenopausal osteoporosis. However, the pathogenetic role of cytokines in post-BMT bone loss is unknown and data on the changes of cytokines in accordance with bone turnover markers are scarce. The aim of this study is to assess the relationship of bone turnover markers and cytokines of peripheral blood and bone marrow before and after allogeneic BMT. METHODS: This prospective study included two analyses. The first was a study of 46 BMT recipients, examining the relationship between bone turnover markers and cytokines of serum which were measured before and 1, 2, 3, 4 week and 3 months after BMT. The second was a study of 14 BMT patients, measuring bone marrow plasma cytokines such as IL-6 and TNF-alpha at post-BMT 3 week and bone turnover marker at the same time to assess the relationship between two parameters. RESULTS: Serum ICTP, bone resorption marker, increased progressively until 4 weeks (peak) after BMT and then decreased thereafter. Serum osteocalcin, bone formation marker, decreased progressively until 3 weeks after BMT and then increased thereafter. There was positive correlation between serum ICTP and bone marrow IL-6 levels at the post-BMT 3 week with a statistical significance, but the correlation between bone turnover markers and bone marrow TNF-alpha or peripheral blood cytokines was not found. CONCLUSION: Our data suggest that the progressive increase of bone resorption after BMT is related with the increase of bone marrow IL-6, which is a potent stimulator of bone resorption in vivo.