Silent Restrictive Lung Disease is Common Among Children with ß-thalassemia: A Single Center Study

Abstract

Background: β-thalassemia syndromes are a group of hereditary blood diseases characterized by reduced or absent β-globin chain synthesis, resulting in reduced hemoglobin in red blood cells. Pulmonary dysfunction ranging from restrictive to obstructive was reported among those with β- thalassemia. Aim of the work: to evaluate the pulmonary functions in patients with β-thalassemia. Patients and Methods: We conducted a cross-sectional study that included 60 ß-thalassemia patients following up at the Hematology Outpatient Clinic of Cairo University Children’s Hospital. They all underwent assessment of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), maximal expiratory flow (MEF) and peak expiratory flow (PEF) using spirometry and assessment of resistance (R) and reactance (Z) to different frequencies by impulse oscillometry (IOS). Results: The mean ± SD age of the studied group was 10.63 ± 3.53 years. Of them, 32 (53.3%) were females and 28 (46.7%) were males. 39 (65%) were transfusion dependent, 23 (38.3%) were compliant to chelation therapy and only 8 (13.3%) did not need chelation therapy. 30 (50%) patients showed restrictive pattern in spirometry (FVC80%”) and 15 (50%) of them also showed abnormal high impulse IOS to 5 and 20HZ (readings above 150%). The non-compliant patients had airway obstructive pattern by spirometry MEF50 (p=0.075), and higher IOS resistance pattern to R5Hz (p= 0.007), R20Hz (p=0.007) and X5Hz (p= 0.003). Higher airway resistance on IOS (0.0001) was associated with transfusion dependency, and need for chelation therapy (p=0.039). Poor compliance to chelation therapy correlated with spirometry restrictive pattern (p=0.0006). Conclusion: Restrictive lung disease is a common pulmonary dysfunction among children with ß-thalassemia. Compliance to adequate chelation therapy decreases the incidence of pulmonary dysfunction.

Keywords

• pediatric
• ß-thalassemia
• spirometry
• impulse oscillometry
• pulmonary functions
• chelation therapy