Immunomodulatory Effects of Bacterial Lysates Combined  with Bronchoalveolar Lavage on Cytokine Regulation and T-cell  Responses in Pseudomonas aeruginosa–colonized Bronchiectasis

Shuke  Rao; Jiashun  Xu; Weixia  Xu; Yingjie  Chang; Lichong  Chen; Weiliang  Yuan; Jiamin  Xie; Huafeng  Li; Jinjian  Zhang; Ying  Xie; Guihua  Xu; Chenli  Xie

doi:10.18502/ijaai.v25i4.21737

Shuke Rao Department of Pulmonary and Critical Care Medicine, Binhaiwan Central Hospital of Dongguan, Dongguan, Guangdong, China
Jiashun Xu Department of Pulmonary and Critical Care Medicine, Qingxi Hospital of Dongguan, Dongguan, Guangdong, China
Weixia Xu Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital, Jinan University, Guangzhou, China
Yingjie Chang Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital, Jinan University, Guangzhou, China
Lichong Chen Department of Pulmonary and Critical Care Medicine, Binhaiwan Central Hospital of Dongguan, Dongguan, Guangdong, China
Weiliang Yuan Department of Pulmonary and Critical Care Medicine, Binhaiwan Central Hospital of Dongguan, Dongguan, Guangdong, China
Jiamin Xie Department of Pulmonary and Critical Care Medicine, Binhaiwan Central Hospital of Dongguan, Dongguan, Guangdong, China
Huafeng Li Department of Pulmonary and Critical Care Medicine, Binhaiwan Central Hospital of Dongguan, Dongguan, Guangdong, China
Jinjian Zhang Department of Pulmonary and Critical Care Medicine, Binhaiwan Central Hospital of Dongguan, Dongguan, Guangdong, China
Ying Xie Department of Pulmonary and Critical Care Medicine, Binhaiwan Central Hospital of Dongguan, Dongguan, Guangdong, China
Guihua Xu Department of Pulmonary and Critical Care Medicine, Binhaiwan Central Hospital of Dongguan, Dongguan, Guangdong, China
Chenli Xie Department of Pulmonary and Critical Care Medicine, Binhaiwan Central Hospital of Dongguan, Dongguan, Guangdong, China

DOI: https://doi.org/10.18502/ijaai.v25i4.21737

Keywords: Bacterial lysate; Bronchiectasis; Bronchoalveolar lavage; Cytokines; Immunomodulation; Pseudomonas aeruginosa; T lymphocytes

Abstract

We aimed to determine the impact of combined bacterial lysates (BLs) and bronchoalveolar lavage (BAL) therapy on specific immune biomarkers (interleukin [IL]-6, IL-17, CD4⁺, CD8⁺), lung function (forced expiratory volume in 1 second [FEV₁], forced vital capacity [FVC], maximal expiratory flow at 25% of FVC [MEF25]), and clinical symptoms in bronchiectasis patients with chronic P aeruginosa colonization.

Sixty-five stable bronchiectasis patients were randomized to receive BAL plus oral BLs (treatment group) or BAL alone (control group). After 3 months, IL-6 and IL-17 levels in BAL fluid and serum, peripheral blood T-lymphocyte subsets, lung function indices, clinical symptom scores (CSS), and reinfection rates were assessed.

Compared with BAL alone, the combination therapy significantly reduced IL-6 and IL-17 concentrations in both BAL fluid and serum. CD4⁺ and CD8⁺ T-cell counts increased markedly in the treatment group, correlating positively with improved lung function metrics (FEV₁, MEF75%, MEF50%, MEF25%, diffusion capacity). Elevated IL-6 and IL-17 were inversely correlated with pulmonary function and positively associated with symptom severity and reinfection risk. Clinically, the treatment group demonstrated improved CSS, enhanced lung function, and reduced reinfections.

BLs combined with BAL exert potent immunomodulatory effects by enhancing T-cell responses and downregulating pro-inflammatory cytokines, thereby improving both immune regulation and clinical outcomes in P aeruginosa–colonized bronchiectasis. These findings suggest BLs represent a promising adjunctive immunotherapy in chronic airway infections.