Abd El Hakeem A A, Mousa S M O, AbdelFattah M T, AbdelAziz A O, Abd El Azeim S S
Pediatric Department, Faculty of Medicine, Minia University, El-Minya, Egypt.
Chest Diseases Department, Faculty of Medicine, Minia University, El-Minya, Egypt.
Transfus Med. 2019 Feb;29(1):55-60. doi: 10.1111/tme.12539. Epub 2019 Feb 18.
In β-thalassemia, there are varying degrees of ineffective haematopoiesis, intermittent haemolysis and iron overload. Excess iron is deposited in organs such as the heart, the liver, the endocrine glands and the lungs.
To evaluate the pulmonary functions in asymptomatic beta thalassemic children on regular transfusion therapy and their relation to iron overload.
The study included 50 transfusion-dependent β-thalassemic children and 50 apparently healthy children as control. All children had undergone pulmonary function tests (spirometry, lung volumes and diffusion capacities). In addition, test to determine the mean serum ferritin of the last 2 years and pre-transfusion haemoglobin and chest radiograph and echocardiography were performed for the thalassemic children only.
A total of 70% of the thalassemic children had diffusion impairment, whereas 34% of them had associated restrictive abnormality. Thalassemic children with serum ferritin >2500 ng mL had significantly lower values of forced vital capacity (FVC), forced expiratory volume at one second (FEV1), peak expiratory flow (PEFR), total lung capacity (TLC) and diffusing capacity of carbon monoxide (DLCO) (P < 0·05). Only diffusion impairment had a significant positive correlation with serum ferritin level. Restrictive impairment had significant positive correlations with age, duration of blood transfusion and serum ferritin level and a significant negative correlation with duration of chelation (P < 0·05). Having a serum ferritin >2500 ng mL was the only predicting factor for diffusion impairment and the strongest predicting factor for restrictive dysfunction.
Despite being asymptomatic, the majority of thalassemic children in this study suffered from diffusion impairment either alone or in combination with restrictive dysfunction. These pulmonary dysfunctions correlated significantly with body iron stores measured by serum ferritin.
在β地中海贫血中，存在不同程度的无效造血、间歇性溶血和铁过载。过量的铁沉积在心脏、肝脏、内分泌腺和肺等器官中。
评估接受定期输血治疗的无症状β地中海贫血儿童的肺功能及其与铁过载的关系。
本研究纳入50名依赖输血的β地中海贫血儿童和50名明显健康的儿童作为对照。所有儿童均接受了肺功能测试（肺活量测定、肺容积和弥散功能）。此外，仅对地中海贫血儿童进行了测定过去2年平均血清铁蛋白、输血前血红蛋白以及胸部X线片和超声心动图的检查。
共有70%的地中海贫血儿童存在弥散功能障碍，其中34%伴有限制性异常。血清铁蛋白>2500 ng/mL的地中海贫血儿童的用力肺活量（FVC）、一秒用力呼气容积（FEV1）、呼气峰值流速（PEFR）、肺总量（TLC）和一氧化碳弥散量（DLCO）值显著较低（P<0.05）。只有弥散功能障碍与血清铁蛋白水平呈显著正相关。限制性障碍与年龄、输血持续时间和血清铁蛋白水平呈显著正相关，与螯合治疗持续时间呈显著负相关（P<0.05）。血清铁蛋白>2500 ng/mL是弥散功能障碍的唯一预测因素，也是限制性功能障碍的最强预测因素。
尽管本研究中的大多数地中海贫血儿童无症状，但他们中的大多数单独或合并限制性功能障碍存在弥散功能障碍。这些肺功能障碍与通过血清铁蛋白测量的体内铁储存显著相关。
