Salama Osama S, Al-Tonbary Youssef A, Shahin Rania A, Eldeen Omar A Sharaf
Clinical Pathology Department, Mansoura University, Mansoura, Egypt.
Hematology. 2006 Jun;11(3):197-202. doi: 10.1080/10245330600702851.
The life expectancy of patients with thalassemia has greatly improved over the last decade as a result of regular transfusions and increased compliance with iron chelation therapy, however, this improvement is often accompanied by a series of serious complications including osteopenia and osteoporosis. The pathogenesis of these skeletal disorders is multifactorial which may be due to hormonal deficiency, compromised nutritional status, bone marrow expansion due to erythroid hyperplasia, increased iron stores or desferrioxamine toxicity. The non invasive assessment of bone turnover has markedly improved with the development of specific and sensitive markers of bone formation. The aim of this work is to assess the value of bone formation markers in patients with beta-thalassemia. To achieve this goal, 36 patients with thalassemia were recruited in this study. There were 20 males (56.6%) and 16 females (44.4%) and their ages ranged from 3 to 18 years. A control group of 20 apparently healthy subjects of matched age and sex was used. The patients were selected from the outpatient clinic and inpatients of the Hematology/Oncology Unit of Mansoura University Children's Hospital (MUCH). The selected subjects were subjected to thorough history taking, clinical examination, radiological evaluation and laboratory investigations in the form of: complete blood count, serum iron, serum ferritin, total iron binding capacity, serum calcium, serum phosphorus and estimation of bone formation markers as alkaline phosphatase and osteocalcin. The results were as follows: serum calcium level was within normal range and showed no statistical significance (p = 0.176) when compared to the control group, while serum phosphorus level was significantly higher in thalassemic patients than the controls (p = 0.002); this may reflect hypoparathyroidism. Analysis of the level of bone formation markers showed serum alkaline phosphatase levels slightly higher in patients than controls but not significant (p = 0.055), and this elevation can be referred to associated liver disease in these patients. On the other hand, osteocalcin level was significantly lower in patients than controls (p = 0.011), and this may be due to osteoblast poisoning by iron overload. In conclusion, thalassemic patients have unbalanced bone turnover between the bone formation and resorption markers and this is evidenced by non significant changes or decreased levels of bone formation markers, while bone resorption is an active process.
在过去十年中，由于定期输血以及对铁螯合疗法的依从性提高，地中海贫血患者的预期寿命有了显著改善。然而，这种改善往往伴随着一系列严重并发症，包括骨质减少和骨质疏松。这些骨骼疾病的发病机制是多因素的，可能是由于激素缺乏、营养状况不佳、红系增生导致的骨髓扩张、铁储存增加或去铁胺毒性。随着骨形成特异性和敏感标志物的发展，骨转换的非侵入性评估有了显著改善。这项工作的目的是评估骨形成标志物在β地中海贫血患者中的价值。为实现这一目标，本研究招募了36例地中海贫血患者。其中男性20例（56.6%），女性16例（44.4%），年龄在3至18岁之间。使用了一组由20名年龄和性别匹配的明显健康受试者组成的对照组。患者选自曼苏拉大学儿童医院血液学/肿瘤学单元的门诊和住院患者。对选定的受试者进行了全面的病史采集、临床检查、放射学评估和实验室检查，包括：全血细胞计数、血清铁、血清铁蛋白、总铁结合力、血清钙、血清磷以及骨形成标志物碱性磷酸酶和骨钙素的测定。结果如下：血清钙水平在正常范围内，与对照组相比无统计学意义（p = 0.176），而地中海贫血患者的血清磷水平显著高于对照组（p = 0.002）；这可能反映了甲状旁腺功能减退。骨形成标志物水平分析显示，患者血清碱性磷酸酶水平略高于对照组，但无统计学意义（p = 0.055），这种升高可能与这些患者的相关肝病有关。另一方面，患者的骨钙素水平显著低于对照组（p = 0.011），这可能是由于铁过载导致成骨细胞中毒。总之，地中海贫血患者的骨形成和骨吸收标志物之间的骨转换不平衡，这表现为骨形成标志物无显著变化或水平降低，而骨吸收是一个活跃的过程。
