Chronic bronchitis is defined as a persistent cough with mucus production for at least three months in a year for two consecutive years. It is primarily caused by long-term irritation and inflammation of the airways due to cigarette smoke or other inhaled chemicals. Chronic bronchitis can progress to more severe lung diseases like COPD or lung cancer and, if left untreated, may result in heart failure or respiratory infections. The pathology involves damage to the airways, thickening of the mucus membranes, and increased mucus production.

1. CHRONIC
BRONCHITIS
Dr.CSBR.Prasad, M.D.
CSBRP-Nov-2012

2. Chronic Bronchitis - gist
 Damage to air ways caused mainly by
chemicals
 Sources: Cigarette smoke, Industrial gases,
Motor vehicle exhaust et.c.
Definition: Persistent productive cough for
at least 3 months in at least 2
consecutive years with out any identifiable
cause.
CSBRP-Nov-2012

3. Chronic Bronchitis
 Damage to air ways caused mainly by
chemicals
 Sources: Cigarette smoke, Industrial gases,
Motor vehicle exhaust et.c.
CSBRP-Nov-2012

4. Chronic Bronchitis
Importance:
 CB may progress to COLD
 Result in cor pulmonale & heart failure
 Result in metaplasia / dysplasia > Carcinoma
CSBRP-Nov-2012

5. CHRONIC BRONCHITIS
DEFINITION:
 Persistent productive cough for at least 3
months in at least 2 consecutive years
with out any identifiable cause.
 Chronic asthmatic bronchitis – intermittent
bronchospasm and wheezing.
CSBRP-Nov-2012

6. CHRONIC BRONCHITIS
Pathogenesis:
 Chronic irritation by inhaled substances
(Tobacco smoke-90%, grain, cotton, Si dust)
 Microbiologic infections – trigger exacerbations
 Middle-aged men – more common
 Smokers – 4 to 10x more common
CSBRP-Nov-2012

7. CHRONIC BRONCHITIS
Features of CB:
Initially:
 Hypersecretion of mucus (Proteases from PMNs)
 Hypertrophy of submucosal glands in trachea and bronchi
With chronicity:
 Marked increase in goblet cells of small airways
Increase in globlet cells and hypertrophy of submucosal glands are of
protective metaplastic reaction against the irritants
Irritants > EGF receptor stimulation > up regulation of MUC 5AC
gene (a mucin gene)
CSBRP-Nov-2012

8. CHRONIC BRONCHITIS
Hypersecretion of mucus is the basis
for smaller air way obstruction
CSBRP-Nov-2012

9. CHRONIC BRONCHITIS
Cigarette smoke: Plays primary initiating role
Role of infection: Plays a secondary role
CSBRP-Nov-2012

10. CHRONIC BRONCHITIS
Action of Cigarette smoke:
1. Interferes with ciliary motility
2. Direct damage to epithelium
3. Inhibits alveolar leucocytes to clear bacteria
CSBRP-Nov-2012

11. Figure 15-9
Schematic
representation of
evolution of chronic
bronchitis (left) and
emphysema (right).
CSBRP-Nov-2012

12. CHRONIC BRONCHITIS
Morphology:
 Hyperemia and edema of mucus membranes
 Excessive mucus / mucopurulent secretion
layers the epithelial surfaces
CSBRP-Nov-2012

13. CHRONIC BRONCHITIS
SMALL AIRWAYS SHOW:
 Goblet cell metaplasia with mucous plugging
 Clustering of pigmented alveolar MØ
 Inflammatory cell infiltration
 Fibrosis of the bronchiolar wall
 Bronchiolitis obliterans
 Bronchial epithelium may exhibit squamous metaplasia
and dysplasia
CSBRP-Nov-2012

14. CHRONIC BRONCHITIS
Characteristic histological feature:
 Lymphocytic infiltration
 Enlargement of mucin secreting glands of trachea and
bronchi i.e. Increased size of mucous glands
 REID Index: Normal is 0.4
Ratio of the thickness of the mucous gland layer to the
thickness of the wall between the epithelium and the
cartilage
CSBRP-Nov-2012

15. CSBRP-Nov-2012
Chronic inflammatory cells infiltration in submucosa of bronchus

16. CSBRP-Nov-2012

17. CSBRP-Nov-2012

18. Reid’s Index
REID Index
bc/ad
CSBRP-Nov-2012

19. CSBRP-Nov-2012

20. CSBRP-Nov-2012

21. CSBRP-Nov-2012

22. CHRONIC BRONCHITIS
Clinical feature:
 Persistent productive cough
 Over the period the patient develops dyspnea on
exertion
 With further progression – patient develops
hypercapnea, hypoxemia and mild cyanosis
 They may land in emphysema
 Long standing cases – cor pulmonale and cardiac
failure
 Death may occur due to respiratory infections
CSBRP-Nov-2012

23. E N D
goto Bronchiectsis
CSBRP-Nov-2012