Pulmonary function tests in children with beta-thalassemia major

Abstract

Lung function abnormality is a known complication of thalassemia, but the results of studies in pulmonary function have been inconsistent. This study was conducted to describe the type of lung impairment in thalassemic children. Pulmonary function tests were conducted in 40 children with beta-thalassemia major, 23 males and 17 females. Tests included spirometry, total lung capacity (TLC), single breath diffusing capacity of the lung for carbon monoxide (DLCO) and arterial blood gases. Serum ferritin level was measured in all children to study its relationship to lung function impairment. A predominantly restrictive pattern was seen in 14 patients (35%). These patients had a significant reduction in RV, FVC, TLC and PEF with an FEV1/FVC ratio of more than 75%. Obstructive airway disease was found in six patients (15%), with an FEV1/FVC ratio less than 75%, increased RV and reduced FEF25%-75%. Impairment of diffusion was found in 10 patients (25%), with DLCO reduced to less than 80% of the predicted value. Arterial blood gases results showed that no patient was hypoxic. No correlation was found between the severity of restrictive or obstructive disease and the serum ferritin level. There was a significant linear correlation between age and serum ferritin level ( P < 0.019). Patients with thalassemia have a predominantly restrictive lung dysfunction pattern. This may be due to pulmonary parenchymal pathology, although the reason for the obstructive pattern seen in a small proportion of patients remains obscure.