Pulmonary functions in Egyptian children with transfusion‐dependent β‐thalassemia

Abstract

SUMMARY Background 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. Objectives To evaluate the pulmonary functions in asymptomatic beta thalassemic children on regular transfusion therapy and their relation to iron overload. Methods 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. Results 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−1 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−1 was the only predicting factor for diffusion impairment and the strongest predicting factor for restrictive dysfunction. Conclusion 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.

Race‐neutral equations for assessment of lung function in children with thalassemia

“…The weight and BMI z ‐scores were positively correlated to the FVC z ‐score and were among the factors contributing to the determination of vital capacity. This was in accordance with theories implicating short chest cage as a causative factor for restrictive impairment in children with TDT 9 and data suggesting the underweight status to be associated with reduced vital capacity 24 …”

“…Several studies have used spirometry to assess the possible effects of thalassemia on lung function, yet their results were conflicting 6–9 . This may be, in part, due to the divergence of reference equations used for interpretation of spirometry.…”

New Entity—Thalassemic Endocrine Disease: Major Beta-Thalassemia and Endocrine Involvement

“…Since the patients with intermediate BTH have different clinical presentations, EDs vary, and a subgroup of subjects was similar to patients with major BTH with regards to the profile of EDs [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ]. Overall, short stature affects both children and adults; GH/IG...…”

“…BTH persons might experience as a direct or indirect consequence of IO, EH, BME, and associated therapy: cardiac failure, pulmonary hypertension, pulmonary restrictive dysfunction, liver disease, renal dysfunction, leg ulcers, chronic pain, gallstones, thrombosis, psychiatric disorders, viral infections due to serial transfusions, and various skin manifestations, etc. [ 12 , 13 , 14 , 15 ]. Moreover, endocrine glands are particularly sensitive to iron deposits, hence the associated panel of hormonal imbalance is massive, representing a major challenge of the already complicated clinical course of the disease.…”

Pulmonary function in patients with transfusion-dependent thalassemia and its associations with iron overload

“…Up to 80% of patients with TDT were reported to have pulmonary dysfunction 9 , 10 . The pulmonary abnormalities identified in previous studies include restrictive lung function deficit (13.8–76.9%) 8 , 11 – 20 , obstructive pattern (3.2–32%) 9 , 16 – 18 , and decreased diffusion capacity for carbon dioxide (2.7–85.7%) 8 , 14 , 15 , 17 , 18 , 20 , 21 . Although the pathophysiology of pulmonary dysfunction is poorly defined, iron accumulation from repeated blood transfusions has been proposed as the likely cause 8 , 9 , 22 – 24 .…”