Atopy prevalance in children with cystic fibrosis

Purpose: It is known that genetic and geographic factors have significant roles in the expression of the clinical phenotype in cystic fibrosis. Another factor which may also be significant in determination of phenotype is coexistence of atopy. We aimed to investigate the frequency of atopy in children with cystic fibrosis who have been regularly followed up in our department. Methods: Total IgE, CAP-System FEIA (fluoroenzyme immunosorbent assay) and skin prick tests to common allergens were performed in children with cystic fibrosis who have symptoms of disease and whose sweat chloride level has been found greater than 60 mmol/L in two different times. FEV1 (forced expiratory volume in one second) values with spirometry and Shwachman-Kulczycki score were also recorded. Results: Forty patients aged between 1 and 20 years; mean 11 years were included to the study. Total IgE levels were between 17.6-2225 (median 376.7) IU/ml. CAP-System FEIA was found positive in five patients. One or more skin prick test results to common allergens were positive in four (10%) patients. All four patients with positive skin prick tests had also positive results for CAP-System FEIA. Only one patient with positive IgE-FEIA, did not show any positive reaction to skin prick tests. Mean Shwachman-Kulczycki score was 73.2 ± 11.0. There was no statistically significant difference between mean values of Shwachman-Kulczycki score of atopic and nonatopic patients. Conclusion: Atopy prevalance of Turkish children with cystic fibrosis as 10% is no more than the general population. Additionally, there is no correlation between the existence of atopy and Shwachman-Kulczycki score or FEV1 measurements. Further studies with larger series and follow up are needed to determine the role of atopy in the expression of the phenotype in cystic fibrosis