Increased serum soluble ST2 in asthmatic children and recurrent early wheezers

ABSTRACT

PURPOSE: Soluble ST2 (sST2) has been reported to regulate Th2 response. In this study, serum levels of sST2 and other cytokines were measured in recurrent early wheezers and asthmatic children. We aimed to investigate if there are any differences or similarities in Th1 or Th2 response between those two patient groups. METHODS: Fifty-nine patients admitted with exacerbation of wheezing or asthma were enrolled. Two patient groups were defined children with atopic asthma (> or =6 years, n=21) and recurrent early wheezers (< or =2 years, n=38). Recurrent early wheezers were divided based on their atopic status 19 were atopic and 19 were nonatopic. sST2, interleukin (IL) 33, IL-5, and interferon (IFN)-gamma were measured in serum samples collected on admission. Cytokine levels in both patient groups were compared with their age-matched controls and evaluated the relationship with blood eosinophils, serum IgE levels, and also with the severity of symptom. RESULTS: sST2 and IL-5 were significantly increased both in asthmatic children (P=0.02, P=0.004) and recurrent early wheezers (P=0.01, P=0.001) compared to their age-matched controls. IL-5 was significantly higher in atopic wheezers compared with non-atopic wheezers (P=0.04). Severity score showed a positive correlation with sST2 and IFN-gamma in asthmatic children, but only with IFN-gamma in early wheezers. There was an inverse correlation between sST2 and blood eosinophil counts both in asthmatic children and atopic recurrent wheezers. CONCLUSION: Our study suggests that sST2 might regulate allergic inflammation by suppressing eosinophilia and play an important role in pathophysiology of acute exacerbation of wheezing or asthma both in asthmatic children and early wheezers.