This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Reid index is useful in - \nSelect and explain. \nA. Glomerulonephritis, B. Chronic bronchitis, C. Cirrhosis, D. MI', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Reid index is used to assess the increase in the size of the submucous gland in chronic bronchitis.\nChronic bronchitis \n\nChronic bronchitis is defined as a persistent cough with sputum production for at least 3 months in at least 2 consecutive years, in the absence of any other identifiable cause.\nIt is strongly associated with smoking.\nMorphological changes in chronic bronchitis\nThe earliest feature of chronic bronchitis is hypersecretion of mucus in the larger airways, associated with hypertrophy of submucosal gland of trachea and bronchi.\nAlthough the numbers of glands increase slightly, the major increase is in the size of mucous glands.\nThis increase can be assessed by Reid index which is the ratio of between the thickness of the submucosal glands to that of the bronchial wall. The Reid index (normal 0.4) is increased in chronic bronchitis.\nLater, small airways (small bronchi and bronchioles) are also involved and show goblet cell hyperplasia, and intraluminal and peribronchial fibrosis.\nIn most severe cases, there may be obliteration of lumen due to fibrosis → Bronchiolitis obliterans.\nThe bronchial epithelium may undergo squamous metaplasia and dysplasia.', 'role': 'assistant'}]