Clinical significance of BPI-ANCA detecting in COPD patients with Pseudomonas aeruginosa colonization

Background Antineutrophil cytoplasmic autoantibodies against neutrophil granule bactericidal/permeability-increasing protein (BPI-ANCA) has been found in many inflammatory diseases, such as COPD, which can reduce the killing effect of BPI on Gram-negative bacteria. This study was aimed to assess the clinical significance of BPI-ANCA detecting in COPD patients with Pseudomonas aeruginosa (P aeruginosa) colonization. Methods A total of 216 COPD patients with lung P aeruginosa colonization, 244 patients with P aeruginosa infection from June 2015 to June 2018, and 100 healthy individuals were included. Serum BPI-ANCA, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6 and IL-1 beta levels were detected by ELISA, and the lung function of the patients was measured at stable clinical stages. Patients with COPD were grouped according to BPI-ANCA detection and GOLD criteria, and serum TNF-alpha, IL-6, and IL-1 beta levels and indices reflecting lung function were compared and analyzed between groups. Results Positive rate of BPI-ANCA in COPD patients with P aeruginosa colonization was 48.15%; and compared with BPI-ANCA(-) group, FEV1%pred and FEV1/FVC(%) in BPI-ANCA(+) patients were significantly decreased, while TNF-alpha, IL-6, and IL-1 beta levels were elevated. There were 31.73% and 36.54% BPI-ANCA(+) patients with severe and very severe airflow limitation, respectively, which was significantly higher than that in the BPI-ANCA(-) group. FEV1%pred and FEV1/FVC(%) were negatively correlated with TNF-alpha, IL-6, IL-1 beta, and NEU%. C-reactive protein (CRP) was negatively correlated with FEV1%pred, yet not significantly correlated with FEV1/FVC(%). Conclusion BPI-ANCA positivity is associated with inflammatory status in COPD patients with pulmonary P aeruginosa colonization and can be used as a potential biomarker assessing disease severity.