Voskaridou Ersi, Terpos Evangelos
Thalassaemia Center, Laikon General Hospital, Athens, Greece.
Pediatr Endocrinol Rev. 2008 Oct;6 Suppl 1:86-93.
Osteopenia and osteoporosis cause severe problems in thalassemic patients. The pathogenesis of bone loss in thalassemia is multifactorial. The delay in sexual maturation, the presence of diabetes and hypothyroidism, the parathyroid gland dysfunction, the accelerated hemopoiesis with progressive marrow expansion, the direct iron toxicity on osteoblasts, the iron chelators, the deficiency of growth hormone or insulin growth factors, all have been identified as major causes of osteoporosis in thalassemia. However, despite the normalization of hemoglobin levels, adequate hormone replacement and effective iron chelation, patients continue to show an unbalanced bone turnover with an increased resorptive phase resulting in seriously diminished bone mineral density (BMD). During the last decade bisphosphonates have been used for the management of osteoporosis in thalassemia. Alendronate, pamidronate and zoledronic acid have shown efficacy in increasing BMD in thalassemic patients. However, further trials must be conducted in order to clarify the exact role of each bisphosphonate, the long-term benefit and side-effects as well as the effects of the combination of bisphosphonates with other effective agents, such as hormonal replacement, on thalassemia osteoporosis.
骨质减少和骨质疏松在地中海贫血患者中会引发严重问题。地中海贫血中骨质流失的发病机制是多因素的。性成熟延迟、糖尿病和甲状腺功能减退的存在、甲状旁腺功能障碍、随着骨髓逐渐扩张而加速的造血作用、铁对成骨细胞的直接毒性、铁螯合剂、生长激素或胰岛素生长因子的缺乏，都已被确定为地中海贫血中骨质疏松的主要原因。然而，尽管血红蛋白水平恢复正常、进行了充分的激素替代治疗以及有效的铁螯合治疗，但患者仍表现出骨转换失衡，吸收期增加，导致骨矿物质密度（BMD）严重降低。在过去十年中，双膦酸盐已被用于治疗地中海贫血中的骨质疏松。阿仑膦酸盐、帕米膦酸盐和唑来膦酸已显示出对增加地中海贫血患者骨密度的疗效。然而，必须进行进一步试验，以明确每种双膦酸盐的确切作用、长期益处和副作用，以及双膦酸盐与其他有效药物（如激素替代药物）联合使用对地中海贫血骨质疏松的影响。
