Background/Objectives: Chronic Obstructive Pulmonary Disease (COPD) is a disease of premature aging, characterized by airflow limitations in the lungs and systemic chronic inflammation. This systematic review aimed to provide a systematic overview of immunosenescence and inflammation in Chronic Obstructive Pulmonary Disease (COPD). Methods: The PubMed, Science Direct, Scopus, Cochrane Library, and Web of Science databases were searched for studies on markers of immunosenescence. Observational studies comparing patients with COPD to individuals without disease were evaluated, considering the following markers: inflammation and senescence in COPD, naïve, memory, and CD28^null T cells, and telomere length in leukocytes. Results: A total of 15 studies were included, eight of which were rated as high quality. IL-6 production, telomere shortening, and the higher frequencies of CD28^null T cells were more prominent findings in the COPD studies analyzed. Despite lung function severity being commonly investigated in the included studies, the importance of this clinical marker to immunosenescence remains inconclusive. Conclusions: The findings of this systematic review confirmed the presence of accelerated immunosenescence, in addition to systemic inflammation, in stable COPD patients. Further studies are necessary to more comprehensively evaluate the impact of immunosenescence on lung function in COPD.

Chronic Obstructive Pulmonary Disease (COPD) is a disease of the lungs characterized by chronic airflow obstruction. Individuals with preserved ratio impaired spirometry (PRISm) may be at risk for developing COPD. This study aimed to characterize PRISm and COPD patients in terms of their immune response and endocrine profile to identify differences extending beyond lung function. The participants performed the clinical assessment, pulmonary function test, and blood collection to determine serum hormone levels and concentrations of cytokine. Differences were observed in the nutritional status, lung function, and comorbidity. There were no differences in IL-6, IL-8, IL-10, IL-12, and TNF levels between PRISm and COPD groups. Both PRISm and COPD patients have lower dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) levels than controls. Correlation analysis of PRISm and COPD patients revealed positive correlations between serum levels of DHEA-S and DHEA, with forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC), which negatively correlated with IL-8 levels. The results indicated that despite differences in lung function parameters, the PRISm and COPD groups exhibited similarities in endocrine profile alterations. This study represents the first attempt to link endocrine with immune markers and lung function in individuals with PRISm.

The progression of chronic obstructive pulmonary disease (COPD) is characterized by functional changes in the airways. The lung–gut axis and gut microbiota (GM) have been linked to the pathophysiology of airway diseases. Regarding COPD, studies have shown that GM alterations could be related the stages of this disease. However, the relationship between GM and clinical, biochemical and immunological parameters in patients with COPD are not well understood. The aim of this study was to compare the relative abundance of specific groups of beneficial gut bacteria between COPD patients and healthy controls (CTLs) in order to evaluate relationships with metabolic and inflammatory markers in COPD. Methods: We included 16 stable COPD patients and 16 healthy volunteer CTLs. The relative abundances of Bifidobacterium spp. (Bf) and Akkermansia muciniphila (Akk) bacteria and the Bacteroidetes and Firmicutes phyla were assessed by qPCR. Pulmonary function was evaluated by spirometry, biochemical parameters by colorimetric methods and plasma cytokine levels by cytometric bead array analysis. Results: The Firmicutes/Bacteroides ratio was related to emergency hospital visits and six-minute walk test (6MWT) results. Furthermore, the relative abundance of Bf was associated with plasma concentrations of glucose, triglycerides, HDL-C and IL-10. In addition, Firmicutes levels and the Firmicutes/Bacteroidetes ratio were associated with the IL-12/IL-10 ratio, while Akk abundance was linked to IL-12 levels. Conclusions: The present findings suggest that the abundance of beneficial bacteria in the GM could influence clinical presentation and immunoregulation in COPD.

Introduction: studies have highlighted the importance of gut microbiota (GM) to the host immune defenses, influencing the hostdevelopment and physiology. Changes in the composition and diversity of GM have been detected in some disease and could beimplicated in the pathophysiological mechanisms of them. Objective: the purpose of this study was to show an overview of thecurrent knowledge about the GM of patients with airway diseases (AD). Methodology: the literature search was performed in fourdatabases, using a combination of the descriptors: “Gastrointestinal Microbiome”, “Gut Microbiome”, “Gut Microbiota”, “Cystic Fibrosis”(CF), “Asthma”, “Pulmonary Hypertension” (HP) and/or “Chronic Obstructive Pulmonary Disease” (COPD). Results: fifteen studieswere herein included: ten of CF and five of asthma. No study about other AD matched the inclusion criteria. In all studies about CF,changes were detected in GM, particularly quantitative and qualitative microbial changes. For asthma, data showed changes in GMalso including a reduction of microbial richness, evenness and diversity and in the Bacteroidetes/Firmicutes ratio. Conclusions: thecurrent data indicate the existence of GM changes in AD. However, due to the few studies for asthma and the lack of investigationson HP and COPD, it was not possible to confirm whether these GM changes are observed in other AD. Furthermore, this review showsthe necessity of more studies in this area to characterize dysbiosis and which alterations are more frequent observed in AD patients.