Sarcoidosis

About

• Non caseating granulomatous lung disease
• Protean manifestations affecting many organs
• Commoner in Blacks/Females >Males only slightly more/Irish/Scandinavians Age 20-40

Aetiology

• Cutaneous anergy - lack of a skin reaction to various antigens eg tuberculin
• Diminished cell mediate immune response to antigens
• Reduced lymphocytes and low circulating T cells as they are sequestered in lungs
• Mildly increased B cells in peripheral blood and increased bronchial CD4 cells

Clinical - There are broadly 2 different presentations

• 1. Acute Disease with a good prognosis with Erythema nodosum, Arthralgia, Bilateral hilar lymphadenopathy
• 2. Chronic - worse prognosis - Gradual increasing dyspnoea, Pulmonary fibrosis

Other findings

• Arthritis is common usually involving feet and hands and large joints may be affected too
• Hypercalcaemia in less than 10% can lead to Kidney stones
• Eye : Early on - Anterior uveitis, Later - Posterior uveitis → blindness
• Cardiac - Heart block, VT and Abnormal ECG, Cardiomyopathy (v rare)
• Uveoparotid fever - Heerfordt's syndrome - Uveitis + Parotids enlarged + VIIth palsy + Fever
• Lofgren's syndrome - BHL + EN + arthritis/arthralgia + fever
• Skin - Erythema nodosum, Lupus pernio (red/blue nose), Nodules, scar infiltration
• CNS - Chronic granulomatous meningitis, Fits, Peripheral/cranial neuropathy
• Endocrine : Hypothalamic lesions - cranial diabetes insipidus
• Haematological - Generalised lymphadenopathy, low CD4 count
• Liver involvement with granulomas on biopsy and mild deranged LFT's
• Often the patients are female of childbearing age and pregnancy usually improves symptoms.

Differentials

• Tuberculosis - check smear for open TB and tuberculin testing
• Lymphoma - do HRCT
• Lung cancer with localised spread

Investigations

• The ESR and inflammatory markers are elevated with active disease
• Raised serum ACE - non specific
• Raised 1,25(OH)2 D3
• The Calcium (Blood and urine) is elevated in only 10%
• Tuberculin tests are usually negative
• Bronchoscopy - Cobble stoning of mucosa and lavage shows an increased CD4:CD8 T cell ratio
• Transbronchial Biopsies - Non-caseating granulomata on biopsy
• Kveim test was formerly used and was an injection of splenic extract from a sarcoid patient injected intradermally and then biopsied but now cannot be done with risks of infections.
• Hypergammaglobulinaemia
• Exclude open (smear positive) TB before formal lung function tests or risks contaminating the equipment. Reduced transfer factor, Restrictive (small lung) PFT's and reduced DLCO
• Histology by trans bronchial biopsy is useful in selected cases
• High resolution CT can show the extend of the fibrosis - ground glass appearance suggests active disease which may be steroid responsive
• Gallium-67 scan: The “panda” sign (localization in the lacrimal and salivary glands, giving a “panda” appearance to the face) is suggestive of sarcoidosis

Staging is really all based on the CXR findings

• Stage 0 - CXR normal
• Stage 1 - BHL 80% resolve
• Stage 2 - BHL + pulmonary infiltrate 50% resolve
• Stage 3 - Pulmonary infiltrate with no BHL 25% resolve
• Stage 4 - Advanced fibrosis with evidence of honey-combing, hilar retraction, bullae, cysts, and Emphysema.

Poor prognostic indicators

• Age > 40
• Afro-Caribbean
• Continuous symptoms over 6 months
• Lupus pernio
• Involvement of over 3 organs

Management

• No treatment is needed for simple BHL except NSAID's as analgesia for joint involvement
• Steroids are given for active disease eg Prednisolone 30 mg od for 6 weeks and then a reducing dose
• Topical steroids for uveitis
• Chloroquine is used in skin and progressive lung disease
• Lung transplantation in severe cases