For suspected COPD–CPA, base the diagnosis on Asp IgG (optimal ≥ 56.6 AU/mL; 77.8%, 63.9%; very high titers > 150 AU/mL achieve ≥ 95% specificity; COPD subgroup approximately 72 AU/mL yields 73%/72%) and incorporate IL-1β for activity and prognostic assessment; employ sequential retesting when clinically indicated. Here, IL1B is linked to chronic obstructive pulmonary disease.