Department of Internal Medicine, Division of Hematology & Oncology, American University of Beirut Medical Center, Beirut, Lebanon.
Haematologica. 2011 Nov;96(11):1605-12. doi: 10.3324/haematol.2011.047852. Epub 2011 Jul 26.
Patients with β thalassemia intermedia can have substantial iron overload, irrespectively of their transfusion status, secondary to increased intestinal iron absorption. This study evaluates whether iron overload in patients with β thalassemia intermedia is associated with morbidity.
This was a cross-sectional study of 168 patients with β thalassemia intermedia treated at two centers in Lebanon and Italy. Data on demographics, splenectomy status, transfusion status, and presence of co-morbidities were retrieved. Laboratory values of serum ferritin, fetal and total hemoglobin levels, as well as platelet and nucleated red blood cell counts were also obtained. Iron burden was determined directly by measuring liver iron concentration using magnetic resonance imaging. Patients were subdivided according to transfusion and splenectomy status into groups with phenotypes of different severity.
The mean age of the patients was 35.2 ± 12.6 years and 42.9% of them were male. The mean liver iron concentration was 8.4 ± 6.7 mg Fe/g dry weight. On multivariate logistic regression analysis, after adjusting for age, gender, splenectomy status, transfusion status, and laboratory indices, an increase in 1 mg Fe/g dry weight liver iron concentration was independently and significantly associated with higher odds of thrombosis, pulmonary hypertension, hypothyroidism, osteoporosis, and hypogonadism. A liver iron concentration of at least 7 and at least 6 mg Fe/g dry weight were the best thresholds for discriminating the presence and absence of vascular and endocrine/bone morbidities, respectively (area under the receiver-operating characteristic curve: 0.72, P<0.001). Elevated liver iron concentration was associated with an increased rate of morbidity in patients with phenotypes of all severity, with a steeper increase in the rate of vascular morbidity being attributed to aging, and an earlier appearance of endocrine and bone disease.
Elevated liver iron concentration in patients with β thalassemia intermedia is a marker of increased vascular, endocrine, and bone disease.
β 中间型地中海贫血患者无论其输血状态如何，由于肠道铁吸收增加，均可发生大量铁过载。本研究评估了β 中间型地中海贫血患者的铁过载是否与发病率有关。
这是一项在黎巴嫩和意大利的两个中心治疗的 168 例β 中间型地中海贫血患者的横断面研究。检索了人口统计学、脾切除术状态、输血状态和合并症的存在情况。还获得了血清铁蛋白、胎儿和总血红蛋白水平以及血小板和有核红细胞计数的实验室值。使用磁共振成像直接测量肝脏铁浓度来确定铁负荷。根据输血和脾切除术状态将患者分为不同严重程度表型的组。
患者的平均年龄为 35.2±12.6 岁，其中 42.9%为男性。平均肝脏铁浓度为 8.4±6.7mgFe/g 干重。在多变量逻辑回归分析中，在校正年龄、性别、脾切除术状态、输血状态和实验室指标后，肝脏铁浓度每增加 1mgFe/g 干重与血栓形成、肺动脉高压、甲状腺功能减退症、骨质疏松症和性腺功能减退症的几率增加独立相关。肝脏铁浓度至少为 7 和至少 6mgFe/g 干重分别是区分血管和内分泌/骨骼疾病存在与否的最佳阈值（受试者工作特征曲线下面积：0.72，P<0.001）。升高的肝脏铁浓度与所有严重程度表型患者的发病率增加相关，血管发病率的增加归因于年龄增长，而内分泌和骨骼疾病的出现更早。
β 中间型地中海贫血患者肝脏铁浓度升高是血管、内分泌和骨骼疾病增加的标志。
