COPD: an autoimmune disease?

Diagnosis and management of stable chronic obstructive pulmonary disease: a clinical practice guideline from the American College of Physicians. The ratio of forced expiratory volume in 1-second to forced vital capacity as a basis for establishing chronic obstructive pulmonary disease. Evaluating respiratory impairment in middle-aged persons using lambda-mu-sigma derived z-scores. Interpreting lung function data using 80% predicted and fixed thresholds mis-classifies more than 20% of patients. HEMMINKI et al. [1] report an increased prevalence of chronic obstructive pulmonary disease (COPD) in patients with auto-immune disease and suggest the presence of autoimmunity is a risk factor for the development of COPD. We have previously reported an increased prevalence of autoimmune disease in patients with COPD who have never smoked [2]. These patients tended to be elderly females and many had a blood lympho-penia, positive autoantibodies and airway inflammation. We have also reported a four-fold increase in the prevalence of COPD in patients with autoimmune bowel disease [3, 4]. The association with autoimmune disease is not limited to COPD; patients with unexplained chronic cough (UCC) are eight times more likely to have autoimmune disease compared to matched controls [5]. Patients with UCC are largely middle-aged females and have evidence of lymphocytic airway inflammation [6]. The mechanism for the association of cough with airway lympho-cytosis may be homing of inflammation from the primary site of autoimmune disease to the airways [7]. A recent study has reported that patients with UCC have an increased decline in lung function, which raises the possibility that some patients with UCC may develop COPD [8]. It is likely that the presence of factors other than smoking is necessary for the development of COPD since most smokers do not develop COPD [9]. Examples of co-factors include autoimmunity and chronic airway infection. Further studies should investigate whether therapy targeting co-factors could prevent or treat COPD. Subsequent COPD and lung cancer in patients with autoimmune disease. induced sputum features of chronic obstructive pulmonary disease in nonsmokers: a descriptive study. Idiopathic chronic cough and organ-specific autoimmune diseases: a case-control study. Airway function and markers of airway inflammation in patients with treated hypothyroidism.