IL-6 and TIMP-1 Correlated to Airway Pathogen Colonization and Predict Disease Severity in Patients with Non-Cystic Fibrosis Bronchiectasis

Background: Non-cystic fibrosis bronchiectasis is associated with airway pathogen colonization. We planned to investigate the inflammatory markers in patients with different airway pathogens and their correlation with disease severity. Methods: We enrolled patients aged between 20 and 75 from October 2021 to August 2022. All patients had sputum evaluation for bacterial and fungal cultures before enrollment, and were classified into four groups according to the culture results. Results: Forty-four patients with non-CF bronchiectasis and six controls were enrolled and categorized as follows: Group 1, no pathogens identified in sputum cultures (n = 14); Group 2, positive fungal culture results (n = 18); Group 3, positive P. aeruginosa culture results (n = 7); and Group 4, positive culture results for both fungi and P. aeruginosa (n = 5). Group 4 had significantly higher serum defensin α1, IL-6 and tissue inhibitors of MMP (TIMP)-1 levels than group 1 patients. The serum levels of IL-6 and TIMP-1 were positively correlated with the FACED score and negatively correlated with distance-saturation product. Conclusion: Significantly higher levels of serum IL-6 and TIMP-1 were found in the patients who had concomitant fungal and P. aeruginosa colonization, and were closely related to clinical severity and may have important roles in disease monitoring.