The CC16 A38G polymorphism is associated with the development of asthma in children with allergic rhinitis

Background Although asthma and allergic rhinitis (AR) are considered to be one syndrome, many questions remain unanswered. Why do some AR patients develop asthma but others do not, and which factors play a role in the development of asthma that have so far not been clearly elucidated. Objective We hypothesize that children with AR who have the Clara cell secretory protein (CC16, secretoglobin 1A1) 38A/38A genotype (rs3741240) have an increased likelihood of developing asthma. Methods The study sample included 117 children, with AR, but no asthma diagnosed within the following 5 years, as the control group. Cases group (n=202) included age- and gender-matched children with AR first, and asthma developed 3-5 years later, as the study group. The CC16 genotype was determined by PCR and Sau96I restriction digestion of PCR products. The serum CC16 levels were measured by ELISA. Total serum IgE, allergen specific IgE, eosinophil count and pulmonary function were also measured. Results In children with rhinitis who develop asthma, the frequencies of the AA genotype were significantly higher than those who did not develop asthma [odds ratio (OR)=2.527; 95% confidence interval (CI)=1.571-4.065; P<0.01]. Serum CC16 levels in the children with rhinitis who develop asthma and carry the AA genotype were significantly lower than those who carry the non-AA genotype and those who did not develop asthma. Conclusions and Clinical Relevance Results of this study suggest that CC16 38A/38A genotype plays a role in the development of early asthma in children with AR. Early identification of rhinitis children at risk may assist in designing preventative approach to asthma development.