The Role of C-Kit Receptor Level as a Serological Marker for Predicting the Extent of Upper and Lower Airway Inflammation in Patients Sensitized to House Dust Mites

Abstract

Background: Allergic rhinitis can progress to asthma. Both allergic rhinitis and asthma are characterized by Th2-dependent inflammation due to activated mast cells and eosinophils. Mast cells are dependent on kit-mediated activation, and the stem cell factor (SCF)/c-kit pathway leads to eosinophil infiltration. We investigated whether inflammation through the SCF/c-kit pathway would be associated with upper and lower airway inflammation. Methods: We enrolled 71 allergic asthma patients with rhinitis (group I) and 47 patients with allergic rhinitis alone (group II), and 59 non-atopic healthy controls (group III). Groups I and II showed positive responses to house dust mites in skin prick tests. The serum concentrations of c-kit receptor and SCF were measured by using ELISA. Eosinophil cationic protein (ECP) levels were measured by using the CAP system. Other clinical parameters were analyzed. Results: There were significant differences in the mean values of c-kit receptor levels between the 3 groups (117.27± 41.05 vs. 93.13±37.21 vs. 88.45±24.32 ng/mL, P＜0.001). The c-kit receptor level was the highest in group I. However, no significant differences were found in SCF levels between the 3 groups. A positive correlation was found between c-kit receptor and ECP levels in groups I and II (r=0.31, P=0.016). Moreover, a positive correlation was found between c-kit receptor levels and total eosinophil counts in groups I and II (r=0.34, P＜0.001). However, there were no significant associations between c-kit receptor levels and clinical parameters, such as forced expiratory volume 1% predicted value in group I. Conclusion: Serum c-kit receptor levels can be a useful serologic marker for predicting the extent of eosinophilic inflammation in upper and lower airway inflammation.