Determining the Activity of Periostin and Interleukin-13 among Asthmatics in Compared to Healthy People in Southern India

This chapter assess to obtain the reference value of serum Periostin and IL-13 levels in healthy south Indian adult population and to compare the reference range of Periostin and IL-13 with that of the asthmatics on inhalational corticosteroids. Asthma is described as a chronic inflammatory condition affecting the airways consisting of a cellular component resulting in airway inflammation, and smooth muscle hyper-responsiveness in response to direct or indirect stimuli leading to bronchoconstriction. Indirect stimuli, such as that of exercise, result in the release of inflammatory mediators from cells present in the airway contributing to airflow obstruction. This prospective cohort study was conducted among individuals aged 25 to 65 years. The sample size was calculated considering alpha – 5%; power – 80%; Since it was a follow up study, the attrition rate was kept at 20%. Based on this, 50 healthy individuals and 50 asthmatics were enrolled in this study, The study subjects were categorized into two groups, viz asthmatics and healthy controls by subjecting them to pulmonary function test and by following the GINA guidelines. . The median (IQR) baseline level of Serum Periostin among control group and in asthmatics was 13.2 (8.8-28.1) ng/ml and 16.7 (10.9-20.7) respectively. Also, the median (IQR) baseline level of Serum IL-13 among healthy individuals and among asthmatics was 42.9 (37.8-52.4) pg/ml and 73.5 (60.0-91.1) pg/ml respectively, which was statistically significant. There was significant difference between the serum IL-13 levels between both the groups. Various studies that have been attempted to find the link between the IL-13 and asthma have yielded conflicting results. Few studies have shown IL-13 as a molecule that is responsible for the raised IgE levels and hyperreactivity whereas few studies have shown IL-13 to have either a protective role or no association in the pathogenesis of asthma. The obtained baseline values of Serum IL-13 and Periostin could be of clinical utility in asthmatics. The validity of the data obtained from this study can be tested out on larger study populations. The study can be conducted on a large scale and values, thus obtained could be clinically utilized in targeting refractory asthma and thus change the management strategy.