الفهرس 
SICKLE CELL DISEASE
All included patients were subjected to the followingOnly 14 pages are availabe for public view
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Abstract
Background: Pulmonary involvement in sickle cell disease (SCD) is a source of acute morbidity and, in the long term, a major determinant of survival. Children with sickle cell disease have a significantly sharper decline in lung function with age when compared to other children of the same race and age. However, pulmonary function test (PFT) in children with SCD has shown conflicting evidences ranging from normal, obstructive and restrictive pattern of PFT. Aim: To evaluate pulmonary function test in children and adolescents with SCD and assess its possible relation to clinical characteristics, chest radiologic changes, markers of hemolysis, iron overload and surfactant protein-D (SP-D) levels. Methods: Fifty SCD patients in steady state were studied focusing on transfusion history, hydroxyurea therapy, hematological profile, serum ferritin, serum SP-D levels by enzyme linked immunosorbent assay. Patients were compared with 30 age- and sex-matched healthy subjects (17 males and 13 females) enrolled as controls. High-resolution computerized tomography (HRCT) of the chest was done. For pulmonary function test, spirometry was performed for all patients to assess forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEV1/FVC% and forced expiratory flow rate during 25 to 75% of expiration (FEF25-75%). Test results are given as percent’s of predicted values. SP-D levels were obtained from patients records. Results: HRCT of the chest revealed that 32 (%) of the studied patients had interstitial pulmonary fibrosis grades 1-3. The pulmonary function of the studied patients was classified into normal (50%), obstructive (10%), restrictive (26%), and mixed (14%). Comparison between SCD patients with normal and abnormal pulmonary function tests as regards clinical data showed older age, longer disease duration, higher incidence of acute chest syndrome and longer duration of chelation. Hemoglobin levels were lower among those with abnormal pulmonary function tests while serum ferritin was increased. Comparison between of different types of lung disease among SCD patients as regards clinical data revealed higher incidence of splenectomy and cough among patients with obstructive lung disease compared with restrictive type. The incidence of SCA was higher than sickle β-thalassemia among patients with restrictive lung disease compared with obstructive type, although the difference did not reach a significant level. SCD patients with restrictive lung disease had significantly higher levels of serum ferritin compared with restrictive type. FEV1, FVC, FEV1/FVC% and FEF25-75% were significantly decreased in relation to increased severity of interstitial pulmonary fibrosis grades reaching lowest levels in Grade 3. FEV1/FVC% was also significantly higher among patients on chelation as well as those on hydroxyurea therapy compared to untreated patients. Significant negative correlations were found between parameters of pulmonary function and each of age, disease duration, duration of chelation, WBC count and serum ferritin. SP-D levels were significantly associated with increasing severity of interstitial pulmonary fibrosis. The highest SP-D levels were observed among patients with restrictive lung disease followed by mixed type then obstructive lung disease. There were significant negative correlations between SP-D and parameters of pulmonary functions (FEV1, FVC, FEF25-75%). Conclusions: Abnormalities in lung function are common in pediatric patients with SCD and the type of lung disease varies, although restrictive pattern is more common than obstructive or mixed types. Age, disease duration, leucocytosis, hemolysis and iron overload are important determinants of lung function. The correlation between SP-D levels and parameters of pulmonary function suggests that it may be considered a promising biomarker for screening of SCD patients at risk of pulmonary complications. Periodical examination of lung function in pediatric patients with SCD is recommended, especially for patients with HbSS for early identification of lung disease.
Lung function abnormality is common in SCD, mostly restrictive type, SP-D could play a role in its pathophysiology and maybe considered as a promising biomarker for its survey.