Study on sputum differential counts in asthmatics controlled & uncontrolled on inhaled corticosteroids

Introduction: Asthma is characterized by a combination of three features: airway obstruction with spontaneous and or pharmacological reversibility, bronchial responsiveness and airway inflammation. A lot of interest has developed over last few years on markers inflammation eg feno, sputum differential counts. Aims and Objectives: 1)To study pattern of differential cell count in sputum of asthmatics on treatment with inhaled corticosteroids (ICS)2)To compare differential cell counts in asthmatics controlled & uncontrolled on ICS. Methods: This study is the first of its kind done in India. This involved setting up a sputum processing laboratory at an approximate cost of 8,000 EUR supported by our Hospital grant.Inclusion: asthmatics in the age group of 15 to 70 years,on ICS.Exclusion: smokers,recent exacerbation (last 3 months) requiring hospitalization, oral or intravenous steroids ,mixed and restrictive pattern of lung function in spirometry.115 asthma patients visiting chest OPD in Bombay Hospital were interviewed from January to December 2013. Patients were divided in two groups based on ACT. After sputum induction,serial processing was done followed by staining of the slides which were read under the microscope. Results: Mean neutrophil % count in uncontrolled group was74.5 +/- 18.8%, and in controlled group was 68.5 +/-23.9% (p=0.04).Mean Eosinophil % count in uncontrolled group was 12.1 +/- 15.9% and in controlled group was 14.6 +/-19.5%(p=0.95). Conclusion: Our results provide support for the presence of distinct asthma phenotypes-neutrophilic, eosionphilic & mixed granulocytic. We observed significantly impaired response to ICS in the subjects with neutrophilic phenotypes.