sarcoidosis Flashcards
what is the definition of sarcoidosis?
Granulomatous inflammation in lungs and other parts of body
what is the epidemiology of sarcoidosis?
diagnosis of exclusion
what are the risk factors for sarcoidosis?
age 20 to 40 years
FHx sarcoidosis
female gender
non-smokers
what is the pathophysiology of sarcoidosis?
The characteristic finding is the presence of non-caseating granulomas with multinucleated giant cells in the centre. CD4 lymphocytes are spread out through the granuloma, and CD8 cells cluster around the periphery. The CD4 lymphocyte and associated cytokines, such as interferon gamma, interleukin (IL)-2, and IL-12, promote and maintain the granulomas.
Alveolar macrophages behave as versatile secretory cells that release a variety of cytokines, including TNF-alpha, IL-12, IL-15, and growth factors. The immunological pattern of cells in the sarcoid infiltrate suggests that sarcoid granulomas are formed in response to a persistent and probably poorly degradable antigenic stimulus that induces a local T-cell-mediated immune response with an oligoclonal pattern. As a consequence of their chronic stimulation, macrophages release mediators of inflammation locally, leading to accumulation of T-helper type 1 cells at sites of ongoing inflammation and contributing to the development of the granuloma structure.
what are the key presentations of sarcoidosis?
cough dyspnoea chronic fatigue arthralgia painful shin lesions, bilateral hilar lymphadenopathy elevated ACE levels
what are the first line and gold standard investigations for sarcoidosis?
Typical history and biopsy from affected organs are essential for the diagnosis.
Lung biopsy - non-caseating granulomas
CXR - hilar and/or paratracheal adenopathy with upper lobe predominant, bilateral infiltrates; pleural effusions (rare) and egg shell calcifications (very rare) may be seen
FBC
what are the differential diagnoses for sarcoidosis?
TB
Histoplasmosis
Non-small cell lung cancer
how is sarcoidosis managed?
Treated with topical corticosteroids for mild local cutaneous disease.
Systemic corticosteroids are the mainstay of treatment for severe disease.
IV corticosteroid for acute resp failure
how is sarcoidosis monitored?
Spontaneous remissions occur in 55% to 90% of patients with stage I, 40% to 70% of patients with stage II, and about 20% of patients with stage III disease, but no remissions are expected in stage IV.
what are the complications of sarcoidosis?
Server haemoptysis
Corticosteroid related hyperglycemia
Primary arterial hypertension
what is the prognosis of sarcoidosis?
Carries a mortality of 1% to 6%.
Poorer prognosis if black ancestry, chronic pulmonary involvement, lupus pernio, or chronic hypercalcaemia.
Lung fibrosis caused by sarcoidosis typically affects the:
upper lobes
how is hypercalcaemia caused by sarcoidosis?
macrophages cause an increased conversion of vitamin D to its active form (1,25-dihydroxycholecalciferol)
what is a stereotypical history of sarcoidosis?
A 30-year-old man of African origin presents with a non-productive cough and dyspnoea. He also complains of multiple joint pains. A chest x-ray shows bilateral hilar lymphadenopathy
