Sarcoidosis Flashcards
sarcoidosis
multi-system disorder of unknown cause
commonly affects young to middle-aged adults
usually characterized by interstitial lung disease and hilar/mediastinal lymphadenopathy
commonly affects eyes, skin, and othe rorgans
noncaseating granulomatous inflammation on biopsy without evidence that granuloma formation was triggered by infection or foreign bodies
decreased cutaneous delayed-type hypersensitivity and increased Th1 inflammatory response at sites of disease activity
epidemiology of sarcoidosis
African Americans more at risk
age of diagnosis 20-40
slight female predominance
polygenic, complex, non-medelian inheritance
pathogenesis of sarcoidosis
initiation of granuloma formation
deposition of poorly soluble antigenic material
oligoclonal expansion of T cells at sites of disease
Th-1 polarized cytokine response
release of TNF by T cells and macrophages
presence of circulating immune complexes
recent evidence suggests presence of mycobacterial antigens
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pathology of sarcoidosis
discreet, compact, non-caseating granuloma
highly differentiated macrophages - epithelioid histiocytes and multinucleated giant cells
lymphocytes also present
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organ distribution of sarcoid granulomas
lung, lymph nodes, liver, spleen, skin
lung distribution of non-caseating granulomas
peribronchovascular, perilobular, subpleural
end-stage pulmonary sarcoidosis - parenchymal fibrosis and honeycombing
clinical manifestations of sarcoidosis
pulmonary involvement in 90-95%
asymptomatic hilar lymphadenopathy
cough, dyspnea, chest pain
chest physical exam usually normal - clubbing is rare
constitutional symptoms of sarcoidosis
fever, fatigue, malaise, wieght loss in 30% of patients
mostly in African Americans
skin manifestations of sarcoidosis
erythema nodosum - good prognosis, raise, tender on anterior shin, no granulomas underneath
hyperpigmented plaques - granulomatous lesion underneath
lupus pernio - difficult to treat, associated with poor prognosis
Stage I sarcoidosis CXR
bilateral hilar lymphadenopathy without interstitial pulmonary infiltrates
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Stage II sarcoidosis CXR
bilateral hilar lymphadenopatyh with intersitial infiltrates
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Stage III sarcoidosis CXR
parynchymal infiltrate without bilateral hilar lymphadenopathy
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Stage IV CXR and CT
end-stage fibrosis
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HRCT patterns suggestive of sarcoidosis
nodular opacities typically peribronchovascular in location
often with a “tree-in-bud” appearance, distributed in the upper and middle lung zones
subpleural nodules also seen
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pulmonary function tests for sarcoidosis
restrictive defect is characteristic
airflow obstruction seen in up to 20%
decreased DLCO is common
correlation of PFTs with pathology and CXR or CT is poor
do not predict response to therapy well