Study of some Pulmonary Function Tests in Children with Sickle Cell Anemia: Correlation with Iron Overload

Abstract

Background: Sickle cell disease is hereditary hemoglobinopathy characterized by abnormal hemoglobin production, hemolytic anemia, and intermittent occlusion of small vessels, leading to acute and chronic tissue ischemia, and organ damage. Pulmonary function tests can differentiate between obstructive or restrictive lung diseases, assess the severity of the disease and evaluate the degree of efficacy of therapy in patients with sickle cell anemia. Objective: The aim of this study was to study pulmonary function tests in children with sickle cell anemia and its correlation with iron overload. Patients and methods: This study was carried out on 40 children with sickle cell anemia under follow up at Hematology unit, Pediatric Department, Tanta university hospital in the period between October 2012 and August 2014 including 24 males and 16 females with their age ranging from 9– 15 years and mean age value of 12.7+2.2 years and 40 healthy children as a control group including 22 males and 18 females with their age ranging from 7 – 15 years and mean age value of 10.3+2.36 years. All patients were subjected to the following investigations: Complete blood count, HB electrophoresis, serum ferritin, serum iron, total iron binding capacity and pulmonary function tests. Results: There were significantly higher serum ferritin, serum iron and lower TIBC in patients than controls, significantly lower Forced vital capacity (FVC), Forced expiratory volume in one second (FEV1), FEV1/FVC ratio, Peak expiratory flow rate, and Forced expiratory Flow in patients compared with controls, significant negative correlation between serum ferritin and both of FVC and FEV1 in studied patients. There were restrictive spirometric pattern in 30 patients with sickle cell anemia (75%) and mixed obstructive and restrictive pattern in 10 patients (25%) with highly significant differences between patients and controls regarding restrictive and mixed pattern of spirometry. Conclusion: Most SCD patients show abnormal pulmonary functions, predominantly of restrictive pattern. Recommendations: Patients with SCD should undergo pulmonary function tests to detect and confirm lung disease for early and proper therapeutic intervention.