Respiratory bronchiolitis interstitial lung disease
Respiratory bronchiolitis interstitial lung disease (RB-ILD) is a smoking related interstitial lung disease closely related to respiratory bronchiolitis, but demonstrating more severe histological, imaging and clinical findings.
In all cases RB-ILD is typically associated with heavy smoking (usually of 30 pack-years or more) and is usually seen in young middle aged patients (30-40 years of age).
Presentation tends to be with progressive shortness of breath and chronic cough 4. Inspiratory crackes are heard in up to half of patients. Clubbing is rare 1.
On lung biopsy pigment laden macrophages are found within alveoli and peribronchial inflammation noted. Unlike simple respiratory bronchiolitis, fibrosis extends beyond the tissues immediately adjacent to respiratory bronchioles and extends into alveolar septae.
Histologically RB-ILD is very similar to desquamative interstitial pneumonia (DIP) and many authors feel that the two conditions are closely related, or even variants of the same condition 3. It has even been suggested that DIP should be abolished altogether, and simply thought of as end-stage / severe RB-ILD 5.
- ground glass opacities
- poorly defined centrilobular nodules
- no particular distribution with both upper and lower zones potentially affected
- if advanced, fibrosis may be evident typically affecting the sub pleural regions and more so in the lower lung zones
- other changes related to smoking
- bronchial wall thickening
- centrilobular emphysema
Treatment and prognosis
Usually no treatment is required other than giving up smoking.
On HRCT appearances consider
- 1. Attili AK, Kazerooni EA, Gross BH et-al. Smoking-related interstitial lung disease: radiologic-clinical-pathologic correlation. Radiographics. 28 (5): 1383-96. doi:10.1148/rg.285075223 - Pubmed citation
- 2. Miller WT, Shah RM. Isolated diffuse ground-glass opacity in thoracic CT: causes and clinical presentations. AJR Am J Roentgenol. 2005;184 (2): 613-22. AJR Am J Roentgenol (full text) - Pubmed citation
- 3. Heyneman LE, Ward S, Lynch DA et-al. Respiratory bronchiolitis, respiratory bronchiolitis-associated interstitial lung disease, and desquamative interstitial pneumonia: different entities or part of the spectrum of the same disease process? AJR Am J Roentgenol. 1999;173 (6): 1617-22. AJR Am J Roentgenol (abstract) - Pubmed citation
- 4. Naidich DP, Srichai MB, Krinsky GA. Computed tomography and magnetic resonance of the thorax. Lippincott Williams & Wilkins. (2007) ISBN:0781757657. Read it at Google Books - Find it at Amazon
- 5. Katzenstein AL, Myers JL. Idiopathic pulmonary fibrosis: clinical relevance of pathologic classification. Am. J. Respir. Crit. Care Med. 1998;157 (4 Pt 1): 1301-15. Am. J. Respir. Crit. Care Med. (link) - Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Respiratory bronchiolitis ILD (RB-ILD)||✗|
|Respiratory bronchiolitis-interstitial lung disease (RB-ILD)||✗|
|Respiratory bronchiolitis-interstitial lung disease||✗|