The IL6R gene polymorphisms are associated with sIL-6R, IgE and lung function in Chinese patients with asthma

• Serum sIL-6R increased in serum of patients with asthma, the elevated sIL6R correlated with higher IgE and lower FEV1
• IL6R polymorphism rs2228145 C allele related to higher sIL6R, higher serum IgE levels and lower lung functions in patients with asthma
• IL6R polymorphism rs12083537 G allele associated with lower lung functions in patients with asthma

Background: sIL-6R is involved in a variety of inflammatory diseases. The present study analyzed the potential associations between two IL6R gene polymorphisms (rs2228145 and rs12083537) and asthma in a Han Chinese population. Methods: A cohort of 394 patients and 395 healthy controls were genotyped to detect the two polymorphisms using SNaPshot. In 66 asthma patients and 49 controls, peripheral eosinophil and serum immunoglobulin E (IgE) levels were determined using a routine blood test, and sIL-6R levels were measured by ELISA. Results: No statistically significant differences were detected between the patients and controls in the distribution of the two independent IL6R polymorphisms (p > 0.05). However, rs2228145 C and rs12083537 G were significantly associated with decreased lung function in patients with asthma; the rs2228145 A–C variant was also associated with increased sIL-6R and IgE levels. In addition, sIL-6R levels were positively associated with IgE and inversely associated with lung function in patients with asthma. Conclusions: Our results provide evidence that rs2228145 C and rs12083537 G are associated with poor lung function in patients with asthma. Furthermore, the rs2228145 A–C variant is associated with levels of sIL-6R and IgE.