Evaluation of inflammatory markers IL-6 and MMP-9 in asthma

Abstract

Introduction: Interleukin-6 (IL-6) and Matrix metalloproteinase-9(MMP-9) are associated with airway inflammation in asthma. There is paucity of data in Indian population. Objective: This study evaluated IL-6 and MMP-9 levels with asthma, its severity (GINA), clinical phenotypes and response to treatment. Methodology: The levels of IL-6 and MMP-9 were compared between Moderate persistent asthma (n=25), Severe persistent asthma (n=25) and normal controls (n=25). IL-6 and MMP-9 were measured by ELISA (R&D System, USA &Canada, Inc.) and compared to asthma and its severity, clinical variables, spirometry, allergen sensitization. Spirometry was repeated after two months of ICS + LABA to assess response to treatment in relation to baseline IL-6 and MMP-9 levels. Results: We observed a significant difference in both IL-6 and MMP-9 levels among asthmatics verses controls (p=0.000), moderate verses severe persistent asthma (p=0.000). A significant negative correlation was observed between MMP-9 and pre bronchodilator FEV1 and FVC, but not with IL-6. There was no association between IL-6 and MMP-9 with asthma duration, total IgE, AEC, number of allergens sensitized and degree of sensitization. No significant correlation (p>0.5) was observed with IL-6 and MMP-9 levels and FEV1 improvement after two months of ICS + LABA. Conclusion: Higher levels of IL-6 and MMP-9 were observed in asthmatics as compared to controls and in severe persistent asthma as compared to moderate persistent asthma, higher levels of MMP-9 was associated with lower lung functions.