Characterisation and Cluster Analysis of Adult Indian Asthmatics in Vellore District

BackgroundThere is a huge burden of asthma in India, with an estimated 34.3 million patients comprising 13% of the global burden. Little is known about asthma phenotypes, endotypes and clusters amongst native Indian patients.ObjectiveTo describe asthma phenotypes and clusters in a specialist outpatient service, Vellore, India.MethodsSystematic assessment was conducted as per GINA 2021 guidelines. Data on demographics, types of indoor pollution exposure, comorbidities, skin tests to aeroallergens (dust mite, pollens, cockroach, cat, dog, aspergillus and alternaria), spirometry, FeNO, blood eosinophils, total IgE, %sputum eosinophils and %sputum neutrophils were captured prospectively. Descriptive statistics were generated, and latent cluster analysis undertaken.ResultsN= 125; M=58 (47.6±15yrs; F=67 (42.8±11yrs) asthmatics were included, and 3 overlapping clusters identified. Cluster-1: Highest sensitisation to aeroallergens, lowest sputum %neutrophil pConclusionThere are overlapping asthma clusters in Vellore district based on clinical and physiological variables and biomarkers in peripheral blood and sputum. Large multicentre studies are needed to characterise asthma in India and shape national guidelines.Clinical Implications: Description of asthma clusters amongst Indian patients in resource-limited settings employing relatively simple clinical and physiological variables and biomarkers in sputum and blood may shape the development of national guidelines for asthma management.