Related Experiment Video
Updated: May 10, 2026

Methodology for Sputum Induction and Laboratory Processing
Published on: December 17, 2017
Value of sputum differential count in chronic obstructive airway disease
1Department of Medicine, Kathmandu Medical College Teaching Hospital, Sinamangal, Kathmandu, Nepal. arpana.neopane@ gmail.com
Background:
Sputum differential count is a useful tool to evaluate airway inflammation in chronic airway diseases. Since COPD (chronic obstructive airway disease) is so common in our setting this simple tool can be used to initiate and follow up treatment and progression of disease process.
Methods:
A prospective cross sectional study was done in Department of Medicine, in a Teaching Hospital from June 2011 to June 2012. All patients admitted with acute exacerbation of chronic airway disease to the Department of Medicine were included in the study and their sputum was sent for differential count.
Results:
Predominant cause of chronic airway disease was COPD 61 (85.9%). The sputum of these patients predominantly showed neutrophilia in the differential count with a mean neutrophil count of 82.06%. This was significantly high than the stated 60% in stable COPD. None of the COPD patients had eosinophilia or lymphocytosis. One patient with asthma showed eosinophil count of 12%. In these patients the peripheral blood smear differential did not show correlation with sputum neutrophilia (r2≥002, p≥0.05).
Conclusions:
Sputum differential has an important role in management of chronic airway diseases.
Related Concept Videos
Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies
Medical History
Sputum Studies I: Gram Stain, cytology, and Acid-fast smear and culture
Gram Stain
The Gram Stain is an integral part of sputum studies. It involves the staining of sputum, which permits...
Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features
Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...
Chronic Obstructive Pulmonary Disease
Smoking is a primary risk factor for COPD, with over 80% of patients having a history of it. Patients typically experience progressive dyspnea or labored breathing, frequent coughing, and recurrent pulmonary infections. Many eventually succumb to respiratory failure, characterized by...
Chronic Obstructive Pulmonary Disease-I: Introduction

