Clinical, Physiological and Radiological features of poorly reversible obstructive airway diseases - a cross sectional study

Poorlyreversible obstructive airway disease means Post Bronchodilator FEV1/FVC<0.7 and Post bronchodilator reversibility of FEV1 <12% OR 400ML. Patientswith poorly reversible obstructive airway disease can be ashtmatic orReversible Chronic obstructive pulmonary disease(COPD). In Asthmatic patientmay be poorly reversible due to improper treatment, due to exposure to Noxiousparticles, Smoking , Biomass Exposure. Reversible COPD may be COPD in non smokers,may be due to significant eosinophilia (>3%) or concomitant for asthma. Theyall exhibit more or less similar clinical presentation. There are differentphenotypes which include poorly controlled Asthma, Asthma with exposure toSmoking and biomass fuel. The Phenotypes in COPD includes COPD inNonsmokers,COPD with eosinophilia, COPD concomitant with Bronchial Asthma. Obstructive airway disease (OAD)includes mainly Asthma, Chronic obstructive airway disease(COPD) or Asthmachronic obstructive pulmonary disease overlap (ACO)

Asthma is defined as a “heterogeneousdisease characterized by chronic airway inflammation with history of respiratorysymptoms like wheeze, shortness of breath, chest tightness and cough that varyfor a period in severity, along with changing expiratory airflow limitation1.

Chronic obstructive pulmonary disease isa common, preventable and treatable disease. It is characterized by persistentrespiratory symptoms and airflow limitation which is caused due to airway and /or alveolar abnormalities caused by significant exposure to harmful particlesor gases*.*

When patients possess characteristicfeatures of both asthma and COPD, they are often thought to have asthma-Chronicobstructive pulmonary disease overlap (ACO)2.

— Airwaydiseases are caused mostly by inflammation and its nature differs in asthma andalso in chronic obstructive airway disease (COPD). It is eosinophilic andCD4-driven in asthma, where as in chronic obstructive pulmonary disease (COPD)neutrophilic and CD8-driven inflammation.

— Patientswith Asthma chronic obstructive pulmonary disease overlap(ACO) have anasthmatic factor and therefore may exhibit the same characteristics to someextent as patients with asthma. Therefore, studying the clinical andpathological differences between Asthma chronic obstructive pulmonary diseaseoverlap(ACO )and Chronic obstructive pulmonary disease (COPD )patients isessential.

— Thisstudy is conducted to study the differences in the respiratory physiology ofpatients with chronic obstructive pulmonary disease (COPD), asthma-COPDoverlap  (ACO), and asthma with airflowlimitation (asthma FL+).