Saliva as a Non Invasive Specimen for Section Assessment of Chronic Obstructive Pulmonary Disease: A Cross-sectional Study

Abstract

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of morbidity and mortality worldwide. Impaired mucociliary clearance due to altered respiratory physiology in COPD presents an exceptional opportunity for bacterial proliferation. Sampling the respiratory tract using sputum or Bronchoalveolar Lavage (BAL) can be labourious and inconvenient, particularly in chronically debilitated patients. Saliva offers an interesting and non invasive method for assessing COPD patients and preventing exacerbations. Aim: To use saliva to analyse the association between the frequency of positive Potentially Pathological Bacterial Isolates (PPBI) and COPD exacerbations in relation to the frequency of exacerbations and the severity of the disease. Materials and Methods: This cross-sectional study was conducted over a period of one year (July 2022 to June 2023) among COPD patients attending the outpatient department at the Department of Respiratory Medicine, GMERS Medical College, Gotri, Vadodara, Gujarat, India. A total of 60 patients with COPD, diagnosed according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2021 guidelines, were included. The patients were categorised based on the severity of airflow limitation, GOLD “ABCD” assessment tool, and number of exacerbations. Salivary samples were collected and subjected to microbiological analysis using laboratory conventional culture techniques. Analysis of Variance (ANOVA) and t-tests were applied. Results: The mean age was 64±5.1 years. S. pneumoniae and H. influenza were common bacterial findings in all stages of COPD, while E. coli and A. baumannii were isolated in GOLD Group D patients. Disease severity also showed a significant association with oral bacterial composition (p=0.010) and the frequency of exacerbations (p=0.03). Conclusion: The current study demonstrates an association between oral bacteria and COPD, especially in patients with severe symptoms (GOLD Group D). Additionally, patients with repeated exacerbations exhibited a different oral bacterial composition, thus supporting the use of saliva as a non invasive specimen for assessing heterogeneous diseases like COPD and designing an empiric antibiotic regimen for those PPBI.