IL18 and chronic obstructive pulmonary disease: Activation of inflammasomes and alterations of their responses linked to the development of airway inflammation may also be seen in COPD.243 A comparison of COPD with smoking revealed elevated levels of NLRP3, Caspase-1, ASC, IL-1β, and IL-18 mRNA in peripheral blood mononuclear cells and bronchial tissues.244 However, the mRNA levels of NLRP3, Caspase-1, ASC, IL-1β, and IL-18 mRNA were higher in acute exacerbation of COPD (AECOPD) than those in COPD patients in the stable stage, suggesting a greater involvement of the NLRP3 inflammasome in AECOPD.