Rheumatoid Lung Disease

Pathophysiology:  An immunologic inflammatory process involving alveolar walls, small vessels, and mesothelial or serosal linings (eg. synovium, pleural and pericardial linings).  The inflammatory response leads to granulomata, diffuse alveolar damage (DAD), vasculitis, fibrosis, exudative pleural and pericardial effusions, and lung fibrosis.

Clinical Clues:  Rheumatoid arthritis is more common in females, but rheumatoid lung disease is more common in males.

The pleural effusions are exudative with characteristically very LOW glucose content (TB effusion has low, but not as low a glucose concentration)

CXR/CT Findings:  There are many potential thoracic manifestations.  Listed in order of commonality:

1. pleural effusions

2. diffuse interstitial lung disease; reticular, with a lower lung predominance

3. progressive interstitial lower lung fibrosis and volume loss

4. end-stage lung disease with honeycombing in the lower peripheral lungs

5. pulmonary nodules including necrobiotic nodules

6. vasculitis, nodules and rarely, areas of hemorrhage

7. pericardial effusion

8. pulmonary arterial hypertension

9. cor pulmonale

10. Caplan’s syndrome: synergy between silicosis and rheumatoid lung disease with larger nodules

“Aunt Sophies”:  Many, usually consider a gamut of lower lung interstitial disease with volume loss.

1.      scleroderma

2.      dermatomyositis (rare)

3.      mixed collagen vascular disease (CREST syndrome)

4.      Idiopathic interstitial fibroisis (UIP, fibrosing alveolitis, cryptogenic fibrosing alveolitis)

5.      Chronic aspiration and lung fibrosis

6.      Drug reactions: rare to have basilar predilection.