Microbial Translocation in Patients with Inflammatory Lung Diseases

Introduction Many lung diseases, such as chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF) or lung cancer (LC). are associated with local and systemic inflammation. In addition, these diseases are associated with pulmonary colonization with microbial pathogens and a dysbiosis of the lung microbiome. The aim of this study was to determine if translocation of microbial molecules can be detected in these disease areas.
Methods Within the PULMOHOM study, a prospective, observational study on inflammatory lung diseases, a total of 493 patients with different lung diseases, were recruited and the serum levels of lipopolysaccharide (LPS) were analyzed with a modified, commercially available Limulus Amebocyte assey (Genscript). The study group comprised COPD (99), lung cancer (111), CF (32) and 62 lung transplantation.
Results The analysis shows significantly increased LPS levels in almost all patients with lung diseases as compared to the healthy controls: (0.8713 vs. 0.1003 EU/ml, p = 0.0001 for COPD vs. healthy controls [hc]) (2.165 vs. 0.1003 EU/ml, p = 0.0001 for acute exacerbation of COPD vs. hc) (0.8044 vs. 0.1003 EU/ml, p = 0.0001 for CF vs. hc) (6.380 vs. 0.1003 EU/ml, p = 0.0001 for LC vs. hc) (1.949 vs. 0.1003 EU/ml, p = 0.0001 for LTX vs. hc) Also patients with AECOPD had significantly more LPS in their serum as compared to patients with stable COPD.
Conclusion LPS levels were significantly increased in patients with COPD, AECOPD, LC, LTX and CF. The results of this study underscope the connection of microbial colonization and pulmonary disease and indicate that translocation of microbial molecules might be a mechanistic link between organs and systemic.