Interleukins in induced sputum and plasma of COPD and asthma patients in indian population: Correlation with respiratory indices and cell counts

Background: Inflammation of airways is a hallmark of COPDand Asthma. Inflammatory cells secrete interleukins with an important role in airway inflammation and VEGF an important angiogenic factor which can be analysed in sputum. Aim: To evaluate IL-6, Il-8 and VEGF in the plasma and sputumof asthma and COPDpatients and theircorrelation with cell counts and spirometric indices. Methods: Blood and induced sputumsamples were collected from COPD(n=7) and Asthma (n=11) subjects. Cell pellet was used for analysis of total and differential counts. IL-6, IL-8 and VEGF levels were measured in supernatant and Plasma by ELISA and correlated with the cell counts and spirometric parameters. Results: There were statistically significant differences in TLC (p=0.02) in COPDand Asthmatics. Mean eosinophil count was significantly higher in asthmatics (p=0.0023). Mean IL-6 levels in Plasma (p=0.013) and supernatant (p=0.043) were significantly higher in COPD. Mean IL-8, VEGF level in Supernatant and Plasma of COPDand Asthma were not significantly different. IL-6 in supernatant correlated with Lymphocytes (p=0.009, r= 0.769). IL-8 in supernatant was negatively correlated with eosinophils in COPD(p=0.033, r=-0.885), in Asthma, IL-8 Plasma was negatively correlated with eosinophils (p=0.046, r= -0.640). Supernatant VEGF was negatively correlated with neutrophils in both COPD(p=0.034,r=-0.821) and Asthma. Conclusion: Neutrophils were predominant in COPDwhile eosinophils were primarily seen in asthma reflecting severity of disease. Correlations of cytokines with cell types need further investigations for any probable role in disease pathogenesis.