3.1b Blood Vessels 2 Flashcards
Mechanisms of vasculitis (2)
- Direct injury to vessels (invasion of vascular walls by infectious pathogens)
- Immune-mediate inflammation
What is vasculitis?
Vessel wall inflammation
Classification of vasculitis acc to size of blood vessels (4)
- Large vessel vasculitis: aorta, large branches to extremities, head, neck
- Medium vessel vasculitis: main visceral arteries and their branches
- Small vessel vasculitis (ANCA +)
- Small vessel vasculitis (ANCA -)
Examples (diseases) of large vessel vasculitis (2)
Giant cell arteritis
Takayasu arteritis
Examples (diseases) of medium vessel vasculitis (2)
- Polyarteritis nodosa
2. Kawasaki disease
Examples (diseases) of small vessel vasculitis ANCA+ (3)
- Wegener’s granulomatosis
- Microscopic polyangitis
- Churg Strauss syndrome
Examples (diseases) of small vessel vasculitis ANCA- (4)
- Henoch Schonlein purpura
- Cryglobulinaemic vasculitis
- Cutaneous leukocytoclastic vasculitis
- Anti-GBM disease
Classification of vasculitis based on Pathogenesis of blood vessels (3)
- Direct infection (ie. fungal infection of vessel wall)
- Immunologic (more common)
- Idiopathic (ie. giant cell arteritis)
Example of immunologic vasculitis (4)
- Immune-complex mediated: SLE, drug induced
- ANCA-mediated: Wegener’s granulomatosis
- Direct Ab attack: Goodpasture syndrome, Kawasaki disease
- Cell-mediated: organ rejection
What are the main mechanisms that initiate noninfectious vasculitis? (3)
- Immune complex deposition
- ANCA (antineutrophil cytoplasmic antibodies)
- Anti-endothelial cell antibodies
This immunological mechanism induces in-situ vasculitis formation due to Ab-Ag complex
Immune complex deposition
This immunological mechanism is a heterogenous group of autoantibodies directed against constituents of neutrophil primary granules, monocytes, lysosomes, endothelial cells
ANCA
What are the staining patterns of ANCA? Describe each (2)
- c-ANCA: cytoplasmic location of immunofluorescence stain
2. p-ANCA: perinuclear location of IF stain
This immunological mechanism that initiate noninfectious vasculitis states that antibodies to endothelial cells may predispose certain vasculitides
Anti-endothelial cell antibodies
Name the common types of vasculitis (7)
- Giant cell/Temporal arteritis
- Takayasu arteritis
- Polyarteritis nodosa (PAN)
- Microscopic polyangitis
- Kawasaki disease
- Wegener granulomatosis
- Thromboangitis obliterans (Buerger Disease)
Chronic granulomatous inflammation of SMALL and MEDIUM sized arteries in head and neck, especially TEMPORAL arteries
Giant-cell/Temporal Arteritis
Giant-cell/Temporal arteritis also affects which arteries? (2)
- Vertebral arteries
2. Ophthalmic arteries –> may lead to permanent blindness
Giant-cell arteritis sad a therapeutic response to what?
Corticosteroids (may help prevent blindness)
Diagnostic procedure for Giant-cell arteritis
Temporal artery biopsy (2-3cm of artery is needed)
Pathogenesis of Giant-cell arteritis (3)
- T-cell mediated immunologic reaction: Ab are directed vs unknown Ag
- Pro-inflammatory cytokines (TNF)
- Anti-endothelial cells
Predilection of Giant-cell arteritis (3)
- Elderly
- Females
- Single vascular site
The ff are clinical features of?
1. Headaches, facial pain, ocular symptoms (range from diplopia to complete loss of vision)
- Unilateral throbbing headache (esp. Along superficial temporal artery - painful with palpation)
- Temporal ophthalmic arteries most commonly affected
- Systemic manifestations: joint pains, myalgia, muscle pains
Giant-cell/Temporal arteritis
Which disease is characterize by the ff:
- Granulomatous thickening of inner portions of ECA
- Tender temporal arteries
- Physical exam and labs are nonrevealing
Giant-cell/Temporal arteritis
What is the gross morphology of Giant-cell/Temporal arteritis?
Nodular intimal thickening of the artery upon palpation
- diameter of lumen is reduced
- rope-y consistency (looks like a worm on your temples)
What are the histologic feature of Giant-cell/Temporal arteritis? (3)
- Granulomatous inflammation with giant cells, T-cells, macrophages –> elastic lamina fragmentation
- Thromboses may be present
- Nonspecific mononuclear inflammation
Describe the old lesions seen in Giant-cell/Temporal arteritis? (2)
- Fibrosis
2. Thickening
Describe the healing stage in Giant-cell/Temporal arteritis (3)
- Medial scarring
- Intimal thickening
- Residual elastic tissue fragmentation
What is the defining diagnostic finding in Giant-cell/Temporal arteritis?
Granulomatous inflammation with giant cells
Granulomatous vasculitis of MEDIUM and LARGE arteries (aorta)
Takayasu arteritis
It is associated wit
- Fibrous thickening and obliteration of the aorta (aortic arch, great vessels)
- Luminal narrowing of major branch vessels
Characterized by
- Ocular disturbances
- Marked weakening of pulses in upper extremities :. aka Pulseless Disease
Takayasu arteritis
It is aka Pulseless Disease
Takayasu arteritis
It has a predilection for female, younger than 50 years old
Takayasu arteritis
The ff are clinical features of which disease?
- If brachiocephalic is affected –> secondary head disturbances, headache, pain
- Ocular disturbance
- Weakened pulses in upper extremities (UL: feeble, LL: full, bounding)
- Neurological deficits
- Pulmonary HPN
Takayasu arteritis
What are the gross characteristics of Takayasu arteritis? (3)
- Irregularly thickened intima (hyperplasia)
- Fibrous aortic wall
- Narrowed lumen
= weakened peripheral pulses
What are the histologic characteristics of Takayasu arteritis? (4)
- Adventitial and medial mononuclear inflammation
- Granuloma with giant cell (similar to temporal arteritis but involves aorta and its branches)
- Perivascular cuffing of vasa vasorum
- Necrosis of media of aorta
SYSTEMIC vasculitis of SMALL/MEDIUM muscular arteries (but not arterioles, capillaries, venues) typically involving RENAL and VISCERAL vessels
Polyarteritis Nodosa (PAN)
- It is 30% associated with positive Hepa B antigen
2. Part of connective tissue disease
Polyarteritis Nodosa (PAN)
It has a predilection for males, young adult, branch point of vessels
Polyarteritis Nodosa (PAN)
Its clinical feature include the ff:
- Fever of unknown origin
- Peripheral neuritis
- Malignant HPN - important clinical feature
- Renal arterial involvement - prominent; major cause of death
Polyarteritis Nodosa (PAN)
What is the histology of Polyarteritis Nodosa (PAN)? (4)
- Segmented transmural necrotizing inflammation
- Involves full thickness inflammation –> weakened arterial wall –> rupture/aneurysm
- Sharply segmental in distribution (affected and unaffected blood vessels may be seen together)
- Blood vessel involvement: kidneys > heart > liver > GIT
What treatment is give on for Polyarteritis Nodosa (PAN)? (2)
Corticosteroids
Cyclophosphamide
What are the stages in Polyarteritis Nodosa (PAN)? (3)
- Acute: transmural neutrophilic inflammation with fibrinoid necrosis, mixed infiltrate (neu, eosi, mononuclear cells)
- Healing (late stage): start of fibrous thickening of vessel wall, mononuclear inflammation, nodular thickening of vessels (rosary bead)
- Healed: marked fibrosis, obstruction to blood flow may lead to scarring
T/F: all stages in Polyarteritis Nodosa (PAN) can co-exist in differ vessels or same vessels, suggesting ongoing and recurrent insults
True
What happens in the acute stage of PAN? (2)
- Transmural neutrophilic inflammation with fibrinoid necrosis
- Mixed infiltrate (neu, eosi, mononuclear cells)
What happens in the healing stage ore PAN? (3)
- Start of fibrous thickening of vessel wall
- Mononuclear inflammation
- Nodular thickening of vessels (rosary bead)
What happens in the healed stage of PAN? (2)
- Marked fibrosis
2. Obstruction to blood flow may lead to scarring
- It is also called hypersensitivity vasculitis or leukocytoclastic vasculitis
- It’s usual manifestation in post-capillary venues is infiltrating and fragmenting neutrophils
- Necrotizing vasculitis
- ANCA+ in most cases
- Necrotizing glomerulonephritis and pulmonary capilliritis are common
- Associated with drug hypersensitivity
Microscopic polyangitis
What are the distinguishing features of Microscopic polyangitis vs. PAN? (2)
- Vessels affected: arterioles, capillaries, venules
(PAN: small to medium sized arteries) - All lesions are of the same histologic age
(PAN: multiple stages at the same time)
Pathogenesis of Microscopic polyangitis (2)
- Antibody response to antigens such as:
- drugs (ie. penicillin)
- microorganisms (ie. strep)
- heterologous proteins
- tumor proteins
–> immune complex deposition / tigger secondary immune response
- Pauci-immune (devoid of immune complexes): recruitment and activation of neutrophils –> disease manifestations
The ff are clinical features of?
- Hemoptysis
- Hematuria
- Proteinuria
- Bowel pain or bleeding
- Muscle pain or weakness
- Palpable cutaneous purpura
Microscopic polyangitis