NLRP3 is a BMI-independent mediator of stable COPD

The inflammatory response in animal models of chronic obstructive pulmonary disease (COPD) is activated by the NLR-family-pyrin-domain-containing-3 (NLRP3) inflammasome pathway, which is also known to play a role in obesity-related inflammation. The NLRP3/caspase-1/interleukin (IL)-1β pathway might be involved in the progression of COPD with increasing body mass index. To our knowledge, no previous studies have explored the role of NLRP3 inflammasome markers in linking COPD and obesity. Here, we aim to investigate this potential connection by examining levels of NLRP3, caspase-1, IL-1β, and IL-17A and to provide additional data on the expression of these molecules in relation to smoking status and COPD severity.

A case‒control study was conducted between July 2020 and March 2023. Peripheral blood mononuclear cells were isolated, and total RNA was extracted for real-time quantitative polymerase chain reaction (qPCR) analysis to measure the expression levels of inflammasome molecules.

29 subjects who were diagnosed with stable COPD and 32 controls were included in the data analysis. NLRP3 and IL-17A but not caspase-1 or IL-1β expression was significantly greater in the COPD group than in the control group. We detected a significant increase in NLRP3 levels in the smoker COPD group (p = 0.009) and nonsmoker COPD group (p = 0.045) compared with those in the nonsmoker control group. There was no significant correlation between BMI and the inflammasome markers.

As proinflammatory biomarkers, NLRP3 and IL-17A are prominent in stable COPD patients. Smoking may trigger NLRP3-mediated inflammation in stable COPD patients. The expression levels of NLRP3 inflammasome molecules did not differ in terms of disease severity or BMI.