Amyloidosis & Sarcoidosis Flashcards
What is amyloidosis?
Multisystem disorder caused by abnormal folding of proteins and their deposition as amyloid fibrils in tissues, disrupting their normal function
What is sarcoidosis?
Multisystem disorder of unknown aetiology, commonly affecting young adults, and characterised by non-caseating granulomas in many tissues
State at least 3 types of amyloidosis
AL amyloidosis (primary), AA amyloidosis (secondary), haemodialysis-associated amyloidosis, familial amyloidosis
Describe the histology of sarcoidosis
Non-caseating granulomas, Schaumann bodies, asteroid bodies (inclusions of protein and calcium)
Define secondary amyloidosis
Deposition of amyloid formed from serum amyloid A, an acute phase protein, secondary to chronic infection or inflammation
Name two conditions associated with AL amyloidosis
Plasma cell dyscrasias, paraproteinaemias (e.g. monoclonal gammopathy of unknown significance, multiple myeloma, CLL)
Describe the investigation results in AL amyloidosis
Monoclonal immunoglobulin, free light chains in serum and urine (Bence Jones proteins), increased bone marrow plasma cells
Name at least two autoimmune and two other causes of AA amyloidosis
Autoimmune: rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease
Other: TB, osteomyelitis, renal cell carcinoma, Hodgkin’s lymphoma
What is deposited in haemodialysis-associated amyloidosis?
Beta-2-microglobulin
State the most common type of familial amyloidosis and its inheritance pattern
Familial Mediterranean Fever (autosomal recessive)
Describe the histology of amyloidosis
Apple green birefringence when stained with Congo Red and viewed under polarised light (due to beta pleated sheet configuration)
In which group is sarcoidosis most severe?
Those of Afro-Caribbean descent
Which organ is most commonly affected by sarcoidosis?
Lungs
Describe the appearance of sarcoidosis on chest x-ray
Bilateral hilar lymphadenopathy, fine nodular shadowing in mid zones (pulmonary infiltrates)
Describe the typical clinical symptoms of sarcoidosis
Insidious-onset of dyspnoea, cough, chest pain, and night sweats
Describe the clinical features of amyloidosis on the heart
Conduction defects, heart failure, cardiomegaly
Describe the clinical features of amyloidosis on the liver and kidneys
Nephrotic syndrome, hepatosplenomegaly
What is the most common presentation of amyloidosis?
Nephrotic syndrome
What % of patients with amyloidosis get macroglossia?
10%
Describe the pathophysiology of familial Mediterranean fever
Abnormalities in pyrin lead to increased production of IL-1, causing attacks of fever and inflammation of serosal surfaces (pleura, peritoneum, synovium) with predominantly renal deposition of AA amyloid
State the dermatological manifestations of sarcoidosis
Erythema nodosum, lupus pernio, skin nodules
State the bone and joint manifestations of sarcoidosis
Arthritis, bone cysts
State the ocular manifestations of sarcoidosis
Anterior uveitis, posterior uveitis, uveoparotid fever, parotid enlargement (may cause facial nerve palsy), keratoconjunctivitis, lacrimal gland enlargement
Describe the symptoms of anterior and posterior uveitis
Anterior: painful red eye, misting of vision
Posterior: progressive visual loss
Describe the haematological manifestations of sarcoidosis
Leukopaenia, anaemia
Describe the cardiac manifestations of sarcoidosis
Arrhythmias, cardiomyopathy, conduction defects
Describe the metabolic manifestations of sarcoidosis
Hypercalcaemia, hypercalciuria -> renal calculi and nephrocalcinosis
State the constitutional symptoms of sarcoidosis
Malaise, fever, weight loss, night sweats
Describe the investigation results in sarcoidosis
Hypercalcaemia, raised ESR, raised ACE. Transbronchial biopsy shows non-caseating granulomas
