Continuous increase in erythropoietic activity despite the improvement in bone mineral density by zoledronic acid in patients with thalassemia intermedia-induced osteoporosis.

摘要

Treatment with transfusion program and chelation therapy has significantly prolonged survival in thalassemia patients, thus osteopenia and osteoporosis represent prominent causes of morbidity in adults of both genders with thalassemia major (TM) or thalassemia intermedia (TI). Patients with TI seem to have a more pronounced marrow erythropoiesis than TM patients , which leads to expansion of medullary cavities, pressure on cortical bone and subsequently bone loss, pain and skeletal abnormalities in several cases . Therefore, the pathogenesis of osteoporosis in TI is considered to be mainly due to ineffective hemopoiesis and progressive marrow expansion and seems to differ from the mechanisms of bone loss in TM that are very complicated and include several factors, such as endocrine dysfunction, iron overload, deferoxamine effect on osteoblasts, marrow expansion and genetic abnormalities [3, 4]. During the last years, increased osteoclast activity has been implicated in the pathogenesis of bone destruction in thalassemia . For that reason, bisphosphonates that are potent inhibitors of osteoclast function have been used in the management of osteoporosis in this cohort of patients [6, 7]. However, there is very limited information about their effect on patients with TI and osteopenia/osteoporosis and the possible correlations with marrow expansion and erythropoietic activity.