Sputum Eosinophil Level among Healthy Individuals Visiting Medicine Outpatient Department of a Tertiary Care Centre: A Descriptive Cross-sectional Study

Abstract

Introduction: Sputum differential is the most comprehensive, and non-invasive investigation for evaluating airway inflammation because of its reliability, reproducibility and responsiveness. The interpretation of the results of induced sputum examination depends on knowledge of normal values from a healthy population. So far, the reference values of sputum differential cells in Nepalese population are not reported. Neutrophil and eosinophil are used to assess the inflammatory response of the airway. The aim of our study was to detect the eosinophil level in the sputum of healthy individuals with normal pulmonary function.

Methods: A descriptive cross-sectional study was conducted in a tertiary care hospital, from November 1, 2021 to December 31, 2021 after taking ethical clearance from Institutional Review Board (Reference number: 1507202106). Convenience sampling was done. Collected data was entered and analysed using Statistical Package for the Social Sciences version 24.0. Point estimate at 95% was calculated along with mean and standard deviation for continuous data.

Results: Among 139 induced sputum samples, 7 (5.03%) had eosinophils present in their sputum (1.40 to 8.67 at 95% Confidence Interval). The age range of the participants was 18 years to 79 years with mean age of 39.5 ± 15.06. Prevalence of eosinophilia (percentage of eosinophil ≥3) was 4 (2.88%).

Conclusions: The prevalence of eosinophilia in our study was found to be similar to published literature. The results of the present study show that there is a paucity of eosinophils with predominance of neutrophils, macrophages and lymphocytes in induced sputum samples of healthy non-smoker adults with normal pulmonary function test.