Correlation of Serum IL-17 with Level of Vitamin D and IgE in Asthmatic Patients

Background: Allergic asthma is a chronic inflammatory disorder of the airways caused by hypersensitivity and characterized by Th2 cytokine i.e. IL-4, that contribute to enhanced proliferation and differentiation of Th2 cells and switch of B cells from IgM to IgE production. Vitamin D also has a role in proliferation, differentiation, apoptosis of cells of the immune system, production of cytokines, and immunoglobulins. Elevated levels of IL-17 have been documented in bronchial submucosa and relationship of IL-17 and severe hyper responsiveness of airways have been established. Therefore, a study was conducted to determine serum level of vitamin D, IgE and IL-17 in patients of bronchial asthma.

Methodology: It was a comparative study, which included 82 subjects i.e. Group-I (41 subjects without asthma), and group-II (41 asthmatic patients). Serum levels of IL-17, IgE and vitamin D were determined by ELISA technique and the results were analyzed by using SPSS-20.0. Mann-Whitney-U, Chi-square and Pearson’s correlation tests were used for data analysis.

Results: Mean ± SD of total serum IgE level of bronchial asthma patients was high (861.6±559.2 IU/ml) compared to controls (204.7±237 IU/ml) and on comparison there was statistically significant difference (p value 0.000). Mean ± SD of serum vitamin D level in asthmatics was 28.04±17.67 ng/ml while in non-asthmatics it was 27.27±17.01 ng/ml and on comparison the difference was not statistical significant (p=0.915). Mean ± SD of serum level of IL-17 was high in asthmatics (920.08±732 pg/ml) as compared to non-asthmatics (767.71±811 pg/ml) and on comparison the difference was not statistically significant (p=0.108). In asthmatics, there was positive correlation of serum level of vitamin D and IL-17 (r=0.101) and there was an association (p=0.001) of family history with asthma.

Conclusion: Asthmatics had raised serum level of IgE, vitamin D and IL-17 as compared to controls and on comparison only the difference of IgE was statistically significant. Further, an association of family history of asthma was observed in asthmatic patients.