Vascular Pathology 2 Flashcards
Vasculitis
Inflammation of vessels
Clinical presentation: depend on location affected and often have nonspecific S/S:
Fever, malaise, arthralgias, myalgias
Infectious vs noninfectious vasculitis
Noninfectious vasculitis: immunologic injury - immune complex deposition or autoantibodies; indicates immunosuppressive therapy
Infectious vasculitis - pathogenic organisms invading vessel wall
Immune complex vasculitis
Deposition of antigen-antibody complexes in vascular walls
◦ Incites an inflammatory reaction within the wall
◦ Antigen is often unidentified
May be seen in
◦ Systemic immunologic diseases (eg, SLE)
◦ Drug hypersensitivity
◦ Secondary to exposure to infectious agent
Antineutrophil cytoplasmic antibodies
Heterogeneous group of antibodies reactant with cytoplasmic enzymes in neutrophil granules, monocytes, and endothelial cells
◦ Anti-proteinase-3 (previously c-ANCA)
◦ Anti-myeloperoxidase (previously p-ANCA)
ANCA titers generally follow disease severity
ANCAs activate neutrophils, which then release reactive oxygen species
Giant cell (temporal) arteritis
Most common vasculitis in older patients, may present with constitutional symptoms
Chronic (T cell mediated) inflammation of arteries in the head, especially the temporal arteries
◦ Medial granulomatous inflammation, often with multinucleated giant cells
◦ Fragmentation of the elastic lamina
◦ Sites of involvement within an artery may be patchy and focal
◦ Healed sites of inflammation show scarring of the media and intimal thickening
Involvement of the ophthalmic artery may lead to vision loss
Takayasu arteritis
Similar histologic findings as those seen in giant cell arteritis, except ◦ Involves the aortic arch and major branch vessels (“pulseless disease”)
◦ Pulmonary, coronary and renal arteries may be involved
◦ Younger age group (<50)
May present with weak pulse and low blood pressure in the upper extremities
Polyarteritis nodosa (PAN) incidence
Systemic vasculitis, likely immune complex mediated
Involves (decreasing order of frequency)
◦ Renal vessels, heart, liver, GI tract
◦ Pulmonary vessels are spared
May affect any age group, but classically young adult
Almost 1/3 of patients have chronic hepatitis B
◦ HBsAg-HBsAb complexes are found in the involved vessels
Polyarteritis nodosa (PAN) characteristics
Transmural necrotizing inflammation, containing neutrophils, eosinophils, lymphocytes and macrophages
Fibrinoid necrosis of the vessel wall
Sites of inflammation are typically not circumferential
The inflamed vessel wall my become susceptible to ◦ Thrombus formation/occlusion
◦ Aneurysm
◦ Rupture
Immunosuppressive therapy usually effective
Kawasaki disease
Acute arteritis of infants and small children (80% ≤ 4 years)
Often involves the coronary arteries
◦ Affected sites may form aneurysms → thrombosis or rupture → acute MI
Presenting picture is usually erythema of the conjunctiva, oral mucosa, palms and soles; rash, and cervical lymph node enlargement
◦ “Mucocutaneous lymph node syndrome”
Usually self-limited, but IV Ig and aspirin are indicated to lower the risk of a coronary event
Microscopic polyangiitis
Necrotizing vasculitis involving arterioles, capillaries and venules
Affects vessels of many organ systems
◦ Renal glomeruli and lung capillaries most common
Most cases associated with MPO-ANCA
Segmental necrotizing inflammation with fibrinoid necrosis
◦ Many apoptotic neutrophils are usually seen
◦ “leukocytoclastic vasculitis”
Churg-Strauss Syndrome
Small vessel necrotizing vasculitis, associated with
◦ Asthma, allergic rhinitis, hypereosinophilia, lung infiltrates, extravascular granulomas
Inflammation may resemble PAN or m. polyangiitis, with the addition of eosinophils and granulomas
Less than half show ANCA positivity
Many organ systems may be involved.
Behcet disease
Vasculitis of small to medium vessels with the following additional findings:
◦ Aphthous ulcers of the oral cavity
◦ Genital ulcers
◦ uveitis
The vessel inflammation is neutrophilic and morphologically nonspecific, may involve visceral organ systems with subsequent aneurysm formation
Associated with HLA-B51
Granulomatosis with polyangiitis features
Necrotizing vasculitis featuring:
◦ Necrotizing granulomas of the upper and/or lower respiratory tracts
◦ Necrotizing or granulomatous vasculitis, most prominently in the respiratory tract
◦ Focal necrotizing, often crescentic, glomerulonephritis
Associated with PR3-ANCA (up to 95% of cases)
◦ Upper respiratory tract: sinonasal and pharyngeal inflammation with granulomas and vasculitis
◦ Lower respiratory tract: multiple necrotizing granulomas, which may coalesce and cavitate
Immunosuppressive therapy is usually successful (untreated, 80% mortality in one year)
Clinical features of Granulomatosis with polyangiitis
◦ M >F
◦ Avg age of 40
◦ Most patients have persistent pneumonitis and sinusitis, renal disease, and nasopharyngeal ulceration
Thromboangiitis obliterans
Acute and chronic thrombosing vasculitis of small and medium vessels, especially
◦ Tibial arteries
◦ Radial arteries
May lead to vascular insufficiency of the extremities
Patients are almost always smokers, and young adults
Inflammation may extend to involve adjacent veins and nerves (leading to pain)
Chronic ulcerations, which may lead to gangrene
