Transfusion regimens in thalassemia intermedia

Abstract

Thalassemia intermedia (TI) is a heterogeneous disease, in terms of both clinical manifestations and underlying molecular defects. Some TI patients are asymptomatic until adult life, whereas others are symptomatic from early childhood. In contrast with patients with Thalassemia major (TM), the severity of anemia is less and the patients do not require transfusions during at least the first few years of life. Many patients with TI, especially older ones, have been exposed to the multiple long-term effects of chronic anemia and tissue hypoxia and their compensatory reactions, including enhanced erythropoiesis and increased iron absorption. Bone marrow expansion and extramedullary hematopoiesis lead to bone deformities and liver and spleen enlargement. Therapeutic strategies in TI are not clear and different criteria are used to decide the initiation of transfusion and chelation therapy, modulation of fetal hemoglobin production, and hematopoietic stem cell transplantation on an individual basis. The clinical picture of well-treated TM patients with regular transfusionchelation therapy is better from TI patients who have not received adequate transfusion therapy. There is a significant role of early blood transfusion to prevent and treat complications commonly associated with TI, such as extramedullary erythropoiesis and bone deformities, autoimmune hemolytic anemia, leg ulcers, gallstones, pseudoxantoma elasticum, hyperuricosuria, gout and pulmonary hypertension, which are rarely seen in thalassemia major. Nowadays, indications of transfusion in patients with TI are chronic anemia (Hb < 7 g/dL), bone deformities, growth failure, extramedullary erythropoiesis, heart failure, pregnancy and preparation for surgical procedures. Conclusion: Adequate (regular or tailored) transfusion therapy is an important treatment modality for increasing the quality of life in patients with thalassemia intermedia during childhood. 就临床表象和潜在的分子缺陷而言，中间型地中海贫血(TI) 是一种混杂疾病。 有些中间型地中海贫血患者为无症状，直到成年，而其他的患者则是在儿童早期就表现出症状。 和重型地中海贫血患者相比，贫血的严重程度更低，至少在生命最初的几年，患者不需要输血。 患中间型地中海贫血的患者，尤其是年龄较大的患者，受到慢性贫血和组织缺氧以及其代偿反应的多次长期影响，代偿反应包括增强的红血球生成和增加的铁吸收。 骨髓扩张和髓外造血导致骨畸形和肝脾肿大。 中间型地中海贫血的治疗方法还不清楚，不同的标准用于决定启动输血和螯合治疗、调制生产胎儿血红蛋白和基于个别基础上移植造血干细胞。 受到良好的常规输血螯合治疗的重型地中海贫血患者临床表现要好于没有接受到足够的输血治疗的中型地中海贫血患者。 早期输血对阻止和治疗中型地中海贫血并发症具有重要作用，如：髓外血红球生成与骨畸形、自身免疫性溶血性贫血、腿部溃疡、胆结石、弹性假黄色瘤、高尿酸血、痛风和肺动脉高血压，这些在重型地中海贫血中极为罕见。 如今，中间型地中海贫血患者输血的适应症为慢性贫血（血红蛋白< 7 g/dL）、骨畸形、成长失败、髓外红血球生成、心脏衰竭、妊娠、以及外科手术准备。 结论： 充足的（常规的或定制的）输血治疗是提高中间型地中海贫血患者童年时期生命质量的重要治疗方法。

Keywords

• thalassemia intermedia, transfusion.