Sheth Sujit, Tang Haiying, Jensen Jens H, Altmann Karen, Prakash Ashwin, Printz Beth F, Hordof Alan J, Tosti Christina L, Azabagic Andjela, Swaminathan Srirama, Brown Truman R, Olivieri Nancy F, Brittenham Gary M
Department of Pediatrics, Columbia University College of Physicians and Surgeons, Harkness Pavilion, Room HP5, 180 Fort Washington Avenue, New York, NY 10032, USA.
Ann N Y Acad Sci. 2005;1054:358-72. doi: 10.1196/annals.1345.044.
To examine the relationship between myocardial storage iron and body iron burden, as assessed by hepatic storage iron measurements, we studied 22 patients with transfusion-dependent thalassemia syndromes, all being treated with subcutaneous deferoxamine, and 6 healthy subjects. Study participants were examined with a Philips 1.5-T Intera scanner using three multiecho spin echo sequences with electrocardiographic triggering and respiratory navigator gating. Myocardial and hepatic storage iron concentrations were determined using a new magnetic resonance method that estimates total tissue iron stores by separately measuring the two principal forms of storage iron, ferritin and hemosiderin. In a subset of 10 patients with beta-thalassemia major, the hepatic storage iron concentration had been monitored repeatedly for 12-14 years by chemical analysis of tissue obtained by liver biopsy and by magnetic susceptometry. In this subset, we examine the relationship between hepatic iron concentration over time and our current magnetic resonance estimates of myocardial iron stores. No significant relationship was found between simultaneous estimates of myocardial and hepatic storage iron concentrations. By contrast, in the subset of 10 patients with beta-thalassemia major, the correlation between the 5-year average of hepatic iron concentration and the current myocardial storage iron was significant (R = .67, P = .03). In these patients, myocardial storage iron concentrations seem to reflect the control of body iron over a period of years. Magnetic resonance methods promise to provide more effective monitoring of iron deposition in vulnerable tissues, including the liver, heart, and endocrine organs, and could contribute to the development of iron-chelating regimens that more effectively prevent iron toxicity.
为了研究通过肝脏储存铁测量评估的心肌储存铁与机体铁负荷之间的关系，我们对22例依赖输血的地中海贫血综合征患者（均接受皮下去铁胺治疗）和6名健康受试者进行了研究。研究参与者使用飞利浦1.5-T Intera扫描仪，采用三个多回波自旋回波序列，并结合心电图触发和呼吸导航门控进行检查。使用一种新的磁共振方法测定心肌和肝脏储存铁浓度，该方法通过分别测量储存铁的两种主要形式，即铁蛋白和含铁血黄素，来估计组织总铁储存量。在10例重型β地中海贫血患者的亚组中，通过对肝活检获得的组织进行化学分析和磁测法，对肝脏储存铁浓度进行了12至14年的反复监测。在该亚组中，我们研究了随时间变化的肝脏铁浓度与我们目前对心肌铁储存的磁共振估计值之间的关系。心肌和肝脏储存铁浓度的同时估计值之间未发现显著关系。相比之下，在10例重型β地中海贫血患者的亚组中，肝脏铁浓度的5年平均值与当前心肌储存铁之间的相关性显著（R = 0.67，P = 0.03）。在这些患者中，心肌储存铁浓度似乎反映了数年期间机体铁的控制情况。磁共振方法有望为包括肝脏、心脏和内分泌器官在内的易损组织中的铁沉积提供更有效的监测，并有助于开发更有效地预防铁毒性的铁螯合方案。
