Antinuclear antibodies and rheumatoid factor are associated with blood eosinophils in asthma and COPD

Background: Autoimmune involvement in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD) has been proposed, and autoantibodies are a hallmark of autoimmunity. Autoantibody assessment may help to better characterize asthma and COPD. Aims: Determine autoantibody profiles, and the relationship between autoantibodies and features of asthma and COPD. Methods: We recruited 102 asthma patients and 88 COPD patients prospectively. Six autoantibody types were evaluated: antinuclear antibody (ANA), anti-cytoplasmic antibodies, rheumatoid factor (RF); anti-cyclic citrullinated peptide (CCP) antibody; myeloperoxidase-anti-neutrophil cytoplasmic autoantibody (ANCA); proteinase 3–ANCA. Results: ANA prevalence was significantly higher in asthma than in COPD (24% vs . 10%, p=0.01). Low eosinophil counts in blood (ECB) were related to positive ANA in asthma and COPD. Conversely, high ECB and high levels of immunoglobulin-E were associated with RF in asthma but not in COPD. There was no relationship between ANA or RF and disease severity, including asthma control test, COPD assessment test, exacerbations in 1 % predicted. Prevalence of anti-cytoplasmic antibodies and anti-CCP antibody was low, and no patient harbored ANCA. Conclusions: It is possible asthma tends to involve autoimmunity more frequently than COPD because the prevalence of ANA is higher in asthma than in COPD. ANA and RF are associated with eosinophilic responses, but they do not work as biomarkers for disease severity.