16th January 2024

Berylliosis

Background

Berylliosis (also known as chronic beryllium disease) is a granulomatous lung disease caused by exposure to the alkaline earth metal beryllium. 

Pathophysiology

Beryllium exposure precipitates a delayed hypersensitivity cell-mediated immune response (Type IV hypersensitivity), which involves sensitisation to beryllium. Future exposure triggers proliferation of macrophages and CD4+ T lymphocytes, which aggregate in the lung. Over time, as this response progresses, these cells form noncaseating granulomas, which progress to fibrosis of the lung.

Presentation

• Predominantly a chronic disease, however, acute alveolitis secondary to beryllium exposure has been reported.
• Latency period between exposure and symptom onset varies from three months to thirty years.
• Common symptoms include dry cough, dyspnoea and, less often, constitutional symptoms such as weight loss, fatigue, and night sweats. 
• Physical examination findings include bi-basal crackles, rashes, cutaneous nodules, hepatosplenomegaly and clubbing in advanced disease.

Diagnosis

A definitive diagnosis of berylliosis requires all the following:

1. History of beryllium exposure
2. Beryllium lymphocyte proliferation test (BeLPT)
   • A positive blood or BAL test confirms sensitisation to beryllium
3. Tissue biopsy from bronchoscopy
   • This reveals non-caseating granulomas

Management

Corticosteroids are used in both acute and chronic berylliosis. In Chronic berylliosis, long-term glucocorticoid therapy is utilised with regular assessment (PFTs and imaging) to gauge response to treatment and plan future therapy. Immunosuppressants such as methotrexate and azathioprine are utilised in those who fail to respond to steroid therapy.