Interleukin-1 and Interleukin-8 are Prominent Inflammatory Markers in Patients with Cystic Fibrosis and Non-Cystic...

Bronchiectasis is characterized by pathological inflammation and infection that cause thickening and dilation of the airways. It is categorized into cystic fibrosis (CF) and non-cystic fibrosis bronchiectasis (NCFB). Given the disease's inflammatory nature, this study aimed to assess the levels of interleukin-1 (IL-1), IL-8, and tumor necrosis factor-alpha (TNF-α) in CF and NCFB patients compared to a healthy control (HC) group.

A total of 35 bronchiectasis patients (18 with CF and 16 with NCFB) and 18 individuals in the HC group were selected based on specific inclusion and exclusion criteria. After receiving informed consent, the levels of IL-1, IL-8, and TNF-α in serum and broncho-alveolar lavage (BAL) fluid were measured using ELISA. Additionally, spirometry results for the study participants were recorded before and after bronchoscopy.

Significant differences were observed in serum IL-8 (p = 0.018) and in BAL IL-1 and IL-8 levels (p = 0.018 and p < 0.0001, respectively). A notable positive correlation was found between serum IL-1 and both serum and BAL IL-8 (p < 0.0001). Similarly, serum IL-8 showed a significant positive correlation with its BAL levels (p = 0.007).

Findings from this study suggest that elevated IL-1 in the lungs is a key factor in bronchiectasis-related inflammation, and the increase in IL-8 may occur via an IL-1-dependent pathway. The heightened levels of IL-8 in BAL and serum among bronchiectasis patients align with known neutrophilia in these cases. Spirometry results showed no significant association with these cytokine increases, indicating that relying solely on spirometry may be insufficient for monitoring inflammation in bronchiectasis patients.