Table 3.
Compares the characteristics of CBD with sarcoidosis across various clinical characteristics, lab abnormalities, and imaging studies.
| Sarcoidosis | Hypersensitivity pneumonitis (HP) | CBD | |
|---|---|---|---|
| Exposure history |
Unknown | May have a history of an allergen exposure | Exposure to beryllium; Occupational history |
| Age of diagnosis | Pea peak incidence at age of 20–39 years (49) | The median age of diagnosis 65 years | Mean age at time of diagnosis of CBD 43.9 (25–80) years (50) |
| Laboratory | ACE level elevated (>80%) | Serum IgG to potential antigens associated with HP (sensitivity and specificity of 83 and 68%) (48) | ACE may be elevated in 22% case (44, 51). BeLPT: abnormal (peripheral blood and/or BAL) (52) Patch testing (BeSO4 or BeF): abnormal (peripheral blood and/or BAL) |
| Radiological | - Symmetrical and bilateral Hilar LAD - Nodules and/or Reticulonodular opacities |
Features depend on subtype- non-fibrotic or fibrotic HP - GGO, mosaic attenuation, centrilobular nodules, fibrosis (irregular linear opacities; traction bronchiectasis and honeycombing) - Fibrosis is most severe in the mid or mid and lower lung zones or equally distributed in the three lung zones with relative basal sparing. Head cheese sign/three-density pattern (47) |
The most common radiographic abnormalities include diffuse small round and reticular opacities. Hilar adenopathy, linear scars, lung distortion, bullae, and pleural thickening are found less commonly associated (53) |
| Histopathology | Well-formed, non-necrotizing granulomas, showing a lymphangitic distribution. | Small and poorly formed granulomas, comprising loose, poorly circumscribed clusters of epithelioid and multinucleated cells (54). Bronchiolocentric inflammation In Fibrotic HP-subpleural and centriacinar fibrosis, with or without bridging fibrosis. May have features that overlap with a UIP pattern (55) |
Well-formed, non-necrotizing granulomas, and/or mononuclear cell interstitial cell infiltrates on endobronchial or transbronchial biopsy Calcific inclusions reported |
| BALF | Lymphocytic CD4+:CD8+ ratio >3.5 |
Lymphocytic (>30% for non- and ex-smokers and >20% for current smokers) (56) Low CD4+/CD8+ ratio (mean values of 0.5–1.5) Increased expression of CD80/CD86 (48, 57) |
Lymphocytosis 41–53% (44, 58) BeLPT BAL |
| Spontaneous resolution | Depends upon the stage | Rare | Rare |
| Treatment | Immunosuppressants (corticosteroids) | Removal from exposure - Corticosteroids (59) | Removal from further exposure. In symptomatic cases, corticosteroids/immunosuppressants |
ACE, angiotensin converting enzyme; BALF, bronchoalveolar fluid; BeLPT, beryllium lymphocyte proliferation assay; CBD, chronic beryllium disease.