Antibodies of IgG, IgA and IgM against Human Bronchial Epithelial Cell in Patients with Chronic Obstructive Pulmonary Disease

Background: Recently, autoimmune mechanisms and pulmonary epithelial cells have attracted attention in chronic obstructive pulmonary disease (COPD). Circulating antibodies against human bronchial epithelial cells (anti-HBEC) bind to bronchial epithelial antigens and induce bronchial epithelial cell damage. This study aimed to detect the expression of IgG, IgM, and IgA anti-HBEC in patients with COPD. Methods: The association of gender, age, body mass index (BMI), and pulmonary function with the presence of IgG, IgA, and IgM anti-HBEC in the plasma was determined in 170 patients with COPD and 150 age-matched healthy controls. Circulating IgG, IgA, and IgM anti-HBEC were detected by indirect immunofluorescence (IIF). Results: Positive IgG anti-HBEC was seen in 34/170 (20.00%) COPD and 11/150 (7.33%) healthy controls (p < 0.001) (1:100 dilution); positive IgA anti-HBEC were presented in 50/170 (29.41%) COPD and 13/150 (8.67%) healthy controls (p < 0.0001) (1:40 dilution); 19/170 (11.18%) COPD and 10/150 (6.67%) healthy controls exhibited positive IgM anti-HBEC (p > 0.05) (1:40 dilution). The positive IgG and IgA anti-HBEC COPD patients were mostly classified as GOLD (Global Initiative for Chronic Obstructive Lung Disease) III and GOLD IV. The positive IgA anti-HBEC COPD patients had lower BMI than healthy controls (p < 0.05). Conclusions: Our results suggest that an autoimmune component associated with bronchial epithelial cell damage is possibly involved in COPD and the presence of IgG and IgA anti-HBEC correlated with the GOLD stage of COPD. Therefore, our studies indicate that IgG and IgA anti-HBEC may associate with the disease severity of COPD.