A 55-year-old man with a long history of chronic bronchitis undergoes lung biopsy. The pathologist calculates the Reid index, which measures the ratio of the thickness of mucous glands to the total thickness of the bronchial wall. A Reid index greater than which value is diagnostic of chronic bronchitis?
- A 0.2
- B 0.3
- C 0.5 ✓
- D 0.7
Correct answer: C. 0.5
Explanation
The Reid index is the ratio of the thickness of the submucosal mucous glands to the total thickness of the bronchial wall (from epithelium to cartilage). The normal Reid index is 0.4 or less. A value greater than 0.4 to 0.5 is diagnostic of chronic bronchitis, reflecting hypertrophy and hyperplasia of mucus-secreting glands. Goblet cell hyperplasia is assessed separately by the Reid index does not measure it directly.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.