IL1B and chronic obstructive pulmonary disease: The resultsshowed that the plasma levels of the pro-inflammatory cytokine IL-1β did notsignificantly differ between COPD patients and healthy controls (0.005±0.004vs0.004±0.002 ng/mL; P>0.05) nor among COPD patients withdifferent disease severity according to the GOLD criteria (P>0.05; Table 2).