vasculitis

VASCULITISVASCULITIS

FERDA ÖZKAN M.D.

YEDITEPE UNIVERSITY MEDICAL FACULTY

OBJECTIVESOBJECTIVES

Review vessel structure

Explain inflammatory processes of vessels

Describe types of vasculitis

The basic constituents of the walls of blood vessels are endothelial cells and smooth muscle cells, and extracellular matrix (ECM), including elastin, collagen, and glycosoaminoglycans.

The three concentric layers: -intima, -media, -adventitia are most clearly defined in the larger

vessels, particularly arteries.

In normal arteries, the intima consists of a single layer of endothelial cells with minimal underlying subendothelial connective tissue.

It is separated from the media by a dense elastic membrane called the internal elastic lamina.

The smooth muscle cell layers of the media near the vessel lumen receive oxygen and nutrients by direct diffusion from the vessel lumen, facilitated by holes in the internal elastic membrane

However, diffusion from the lumen is inadequate for the outer portions of the media in large and medium-sized vessels, therefore these areas are nourished by small arterioles arising from outside the vessel (called vasa vasorum, literally "vessels of the vessels") coursing into the outer one half to two thirds of the media.

The outer limit of the media of most arteries is a well-defined external elastic lamina. External to the media is the adventitia, consisting of connective tissue with nerve fibers and the vasa vasorum

ARTERIESARTERIES

Arteries are divided into three types:

(1) large or elastic arteries, including the aorta,

(2) medium-sized or muscular arteries,

(3) small arteries

Large or elastic arteries, including the aorta, its large branches (particularly the innominate, subclavian, common carotid, and iliac), and pulmonary arteries;

2-medium-sized or muscular arteries, comprising other branches of the aorta (e.g., coronary and renal arteries); and

3- small arteries (less than approximately 2 mm in diameter) and arterioles (20 to 100 μm in diameter), within the substance of tissues and organs.

Capillaries, approximately the diameter of a red blood cell (7 to 8 μm), have an endothelial cell lining but no media.

VEINSVEINS

Veins have larger diameters, larger lumens, and thinner and less well organized walls

Thus, because of their poor support, veins are predisposed to irregular dilation, compression, and easy penetration by tumors and inflammatory processes.

VEINSVEINS

The venous system collectively has a large capacity; approximately two thirds of all the blood is in veins. Reverse flow is prevented by venous valves in the extremities, where blood flows against gravity.


Vasculitis is a general term for vessel wall inflammation.

The clinical features of the various vasculitides are diverse and largely depend on the vascular bed affected (e.g., central nervous system vs. heart vs. small bowel).


This is a heterogenous group of disorders characterized by inflammation & damage of blood vessels followed by thrombosis & ischemic manifestations in the tissues supplied by the blood vessels.


Besides the findings referable to the specific tissue(s) involved, the clinical manifestations typically include constitutional signs and symptoms such as fever, myalgias, arthralgias, and malaise.

INFECTIOUS VASCULITISINFECTIOUS VASCULITIS

Localized arteritis may be caused by the direct invasion of infectious agents, usually bacteria or fungi, and in particular Aspergillus and Mucor species.

INFECTIOUS VASCULITISINFECTIOUS VASCULITIS

Vascular invasion can be part of a localized tissue infection (e.g., bacterial pneumonia or adjacent to abscesses), or

less commonly-it can arise from hematogenous seeding of bacteria during septicemia or embolization from sepsis of infective endocarditis.

NONINFECTIOUS NONINFECTIOUS VASCULITISVASCULITIS

The main immunological mechanisms that initiate noninfectious vasculitis are:

(1) immune complex deposition, (2) antineutrophil cytoplasmic

antibodies, and (3) anti-endothelial cell

antibodies.

Immune Complex-Immune Complex-Associated VasculitisAssociated Vasculitis The lesions resemble those found in

experimental immune complex-mediated conditions such as the Arthus reaction and serum sickness Many systemic immunological diseases, such as systemic lupus erythematosus (SLE) and polyarteritis nodosa, manifest as immune complex-mediated vasculitis.

Immune Complex-Immune Complex-Associated VasculitisAssociated VasculitisAntibody and complement are

typically detected in vasculitic lesions, although the nature of the antigens responsible for their deposition cannot usually be determined.

Immune Complex-Immune Complex-Associated VasculitisAssociated VasculitisCirculating antigen-antibody

complexes may also be seen (e.g., DNA-anti-DNA complexes in SLE-associated vasculitis.

Antineutrophil Antineutrophil Cytoplasmic Antibodies Cytoplasmic Antibodies Patients with vasculitis have

circulating antibodies that react with neutrophil cytoplasmic antigens, so-called antineutrophil cytoplasmic antibodies (ANCAs).

Antineutrophil Antineutrophil Cytoplasmic Antibodies Cytoplasmic Antibodies ANCAs are a heterogeneous

group of autoantibodies directed against constituents (mainly enzymes) of neutrophil primary granules, monocyte lysosomes, and endothelial cells

Antineutrophil Antineutrophil Cytoplasmic Antibodies Cytoplasmic Antibodies These were previously

classified according to their intracellular distribution, either cytoplasmic (c-ANCA) or perinuclear (p-ANCA).

ANCASANCAS

They are discriminated based on their target antigens:

Anti-myeloperoxidase (MPO-ANCA): MPO is a lysosomal granule constituent normally involved in generating oxygen free radicals. MPO-ANCAs can be induced by a variety of therapeutic agents, in particular propylthiouracil. These have been called p-ANCA.

ANCASANCAS

Anti-proteinase-3 (PR3-ANCA): PR3 is also a neutrophil azurophilic granule constituent.

That it shares homology with numerous microbial peptides may explain how PR3-ANCAs develop.

These have been called c-ANCA.

Mechanism for ANCA Mechanism for ANCA vasculitisvasculitis- Drugs or cross-reactive

microbial antigens induce ANCAs; alternatively, neutrophil surface expression or release of PR3 and MPO (e.g., in the setting of infections) incites ANCA formation in a susceptible host.

Mechanism for ANCA Mechanism for ANCA vasculitisvasculitis Subsequent infection,

endotoxin exposure, or other inflammatory stimuli elicit cytokines such as TNF that cause surface expression of PR3 and MPO on neutrophils and other cell types.

Mechanism for ANCA Mechanism for ANCA vasculitisvasculitis ANCAs react with these cytokine-

activated cells and either cause direct injury (e.g., to endothelial cells) or induce further activation (e.g., in neutrophils).

ANCA-activated neutrophils degranulate and also cause injury by releasing reactive oxygen species, engendering endothelial cell toxicity and other indirect tissue injury.

Mechanism for ANCA Mechanism for ANCA vasculitisvasculitis ANCAs directed against

constituents other than PR3 and MPO are also found in some patients with inflammatory disorders that do not involve vasculitis (e.g., inflammatory bowel disease, primary sclerosing cholangitis, rheumatoid arthritis

ANCA stainingANCA staining

c-ANCA p-ANCA

Anti-Endothelial Cell Anti-Endothelial Cell Antibodies Antibodies Antibodies to endothelial cells

may predispose to certain vasculitides, for example, Kawasaki disease

form of hypersensitivity vasculitis in kids, young adults

clinical:purpura on buttocks, arms, legs

– necrotizing vasculitis involving small dermal vesselsarthritisabdominal pain – often with bloody diarrhea/other evidence of intestinal bleeding, due to mucosal/submucosal vasculitiskidney involvement in 1/3 – proteinuria, nephrotic syndrome, gross/microscopic hematuria.

Pathology: glomerulonephritis is often focal, mesangial

proliferative in type; often self-limiting IgA is predominant Ab in glomerular and skin

lesions.

PathologyPathology:: Small vesselsSmall vesselsHenoch-Schönlein PurpuraHenoch-Schönlein Purpura

Clinical:widespread small vessel vasculitis, often associated with severe glomerulonephritispurpuraarthralgia or arthritis

– cryoglobulinsreversibly precipitatie in the coldconsist of IgM rheumatoid factorsmost seen in patients with HCV

PathologyPathology:: Small vesselsSmall vessels

Mixed Cryoglobulinemia Mixed Cryoglobulinemia syndromesyndrome

Pathology:– vessels show deposits

containing cryoglobulins and complementleukocytoclastic vasculitis.

40-50s, May be life threatenting; fever, myalgia, weight loss, foot drop,

weakness, abdominal pain, hypertension from renal arteriole involvementmononeuritis complex - asymmetric peripheral neuropathy with sudden or subacute onset due to nerve infarction; many modalities lost in one nervelocal ischemia, inflammation of affected organskidney, GI tract, joints/muscles, heart, nervous system, skin, lungs may be affected.

PathologyPathology:: Medium-sizedMedium-sized vessels vesselsPolyarteritis NodosaPolyarteritis Nodosa

Polyarteritis NodosaPolyarteritis Nodosa

Polyarteritis nodosa (PAN) is a systemic vasculitis of small or medium-sized muscular arteries (but not arterioles, capillaries, or venules), typically involving renal and visceral vessels but sparing the pulmonary circulation


There is no association with ANCAs, but about 30% of patients with PAN have chronic hepatitis B with HBsAg-HbsAb complexes in affected vessels, indicating an immune complex-mediated etiology


The cause remains unknown in the majority of cases; there may be etiologic and important clinical distinctions between classic idiopathic PAN, the cutaneous forms of PAN, and the PAN associated with chronic hepatitis. Clinical manifestations result from ischemia and infarction of affected tissues and organs.

Findings Digital gangrene, ulceration Renal - Hypertension,

hematuria, renal failurerenal failure GIS - hematemesis, melena RS - pneumonitis, pleural

effusion CNS - mononeuritis multiplexa Skin - urticaria, palpable

purpura, livedo reticularis.

Diagnosis:– microaneurysms on angiography if

medium vessels are target– segmental damage to artery walls;

present in up to 50% of cases– aneurysms or stenosis in

mesenteric vessels in absence of atherosclerosis is very helpful to make diagnosis.

Treatment: steroids, immunosuppressive drugs, some respond to bactrim.

PathologyAll stages of activity

may coexist in different vessels, even in one vessel.

Early: focal, fibrinoid necrosis of artery/arteriole wall; transmural inflammation – PMN, eosinophilic poly infiltrateIntermediate: mural/occlusive thrombiLate: aneurysms if segmental involvement

with healing, wall infiltrated by fibroblasts -> fibrous thickening of wall -> nodular appearance.

Mean age of onset 70 years; Commonly associated with clinical

syndrome polymyalgia rheumatica:opain, stiffness in shoulder & pelvic

girdles in absence of evidence of weakness or atrophy

ESRoresponse to low-moderate steroid

doses.Etiology: likely mediated by immune

reactions to elastin

PathologyPathology:: LargeLarge vessels vesselsGiant cell arteritis and temporal Giant cell arteritis and temporal arteritisarteritis

Granulomatous inflammatory process can affect any elastic and muscular artery:

most often seen in superficial temporal artery, other cranial arterieschief clinical risk is blindnessclinical presentation: headache, scalp tenderness, claudication of the jaw (tired jaw on chewing), transient visual disturbances, musculoskeletal symptoms (polymyalgia rheumatica) , fever, malaise, weight loss, anemia.

Extracranial disease in 10-15%:ointermittent claudication is commonoarterial bruits, blood pressure

abnormalities.Treatment: responds well to steroids.

Complicationscoronary artery involvement myocardial ischemiaaortic valve incompetenceaortic dissectionaortic aneurysm, may rupture.

PathologyInflammation confined to media; mixed cell infiltrate – lymphocytes, macrophagesGiant cells may be present at junction of intima and media (eating internal elastic lamina)Intimal proliferation.

Temporal (giant cell) arteritis. Temporal (giant cell) arteritis. A,A, H&E stain of section of H&E stain of section of temporal artery showing giant cells at the degenerated temporal artery showing giant cells at the degenerated internal elastic membrane in active arteritis (internal elastic membrane in active arteritis (arrowarrow ) )

Elastic tissue stain demonstrating focal destruction Elastic tissue stain demonstrating focal destruction of internal elastic membrane (of internal elastic membrane (arrowarrow) and intimal ) and intimal thickening (IT) characteristic of long-standing or thickening (IT) characteristic of long-standing or

healed arteritis.healed arteritis.

Cogan's diseaseCogan's disease

Cogan's disease is another rare disease usually affecting young adults.

It features abrupt onset of – nerve deafness, – interstitial keratitis, and/or – a systemic vasculitis often with – aortic aneurysm formation.

It's apparently caused by an autoantibody against inner ear and endothelium

can occur from teens to old age; peak at age 40,

slight male proponderance. 82% die in a year without

treatment

PathologyPathology:: Small to Small to Medium-sizedMedium-sized vessels vessels Wegener’s GranulomatosisWegener’s Granulomatosis

Wegener’s Wegener’s GranulomatosisGranulomatosis Wegener granulomatosis is a

necrotizing vasculitis characterized by a triad of:

Acute necrotizing granulomas of the upper respiratory tract (ear, nose, sinuses, throat) or the lower respiratory tract (lung) or both

Wegener’s Wegener’s GranulomatosisGranulomatosis Necrotizing or granulomatous

vasculitis affecting small to medium-sized vessels (e.g., capillaries, venules, arterioles, and arteries), most prominent in the lungs and upper airways but affecting other sites as well

Renal disease in the form of focal necrotizing, often crescentic, glomerulonephritis

Symptoms: – upper respiratory tract (sinusitis,

epistaxis, nasal obstruction, otitis media, deafness),

– lower respiratory tract (productive cough, hemoptysis, dyspnea),

– renal failure.

Clinical Findings

Respiratory System – upper respiratory tract infections, saddle nose deformity, pneumonitis, pleural effusion

Renal - hematuria, hypertension, renal failure

Ocular - conjunctivitis, uveitis Skin - urticaria, palpable purpura,

livedo reticularis.

Diagnosis: c-ANCA found in majority but not specificPathology: lung lesions are most diagnostic

lesions usually multiple, well circumscribed, variable sizecoagulative necrosis surrounded by granulation tissue; ghost outlines of vessels in necrotic zone, multinucleate giant cells may be present

– extrapulmonary lesions – same combo of granulomatous inflammation and vasculitis in upper respiratory tract, skin.

– Elsewhere vasculitis predominates.

predominates in young adult male (20-45) tobacco smokers; female smokers as well. Sligtly more common in Asians, Ashkenazi Jews.

clinical:ischemia, usually of lower limbs, progressing to gangreneabsence of atherosclerotic stigmata or risk factorsassociated with migratory thrombophlebitis

PathologyPathology:: Medium-sizedMedium-sized vessels vesselsBBüürger’s Diseaserger’s Disease ( (thromboangitis thromboangitis obliteransobliterans))

Pathology

sharply segmental, thrombosing acute and chronic inflammation of medium sized arteries with secondary spread to veins

thrombus may undergo organization and recanalization

improvement with smoking cessation.

Common in Far east; women 15-45 affected Chronic inflammatory disease involving both

systemic and pulmonary circulationsAorta & major branches most commonly affected – coronaries

Clinical: stenosis is characteristic Pathology: artery wall inflammation

fibromuscular intimal proliferation, mural thrombigranulomatous panarteritisvessel converted into rigid tube, associated with stenosis.

PathologyPathology:: LargeLarge vessels vesselsTakayasu Arteritis or AortitisTakayasu Arteritis or Aortitis

Aortitis is literally inflammation of the aorta, and it is representative of a cluster of large-vessel diseases that have various or unknown etiologies.

While inflammation can occur in response to any injury, including trauma, the most common known causes are infections or connective tissue disorders.

Infections can trigger a noninfectious vasculitis by generating immune complexes or by cross-reactivity.

The etiology is important because immunosuppressive therapy, the main treatment for vasculitis, could aggravate an active infectious process.

Inflammation of the aorta can cause aortic dilation, resulting in aortic insufficiency.

Also, it can cause fibrous thickening and ostial stenosis of major branches, resulting in reduced or absent pulses, low blood pressure in the arms, possibly with central hypertension due to renal artery stenosis.

Depending on what other vessels are involved, ocular disturbances, neurological deficits, claudication, and other manifestations of vascular impairment may accompany this disorder.

Infectious agents:

– Neisseria (eg, gonorrhea)– Rickettsia (eg, Rocky

Mountain spotted fever) species,

– spirochetes (eg, syphilis), – fungi (eg, aspergillosis,

mucormycosis), – viruses (eg, herpes, varicella-

zoster, hepatitis B and C).

Immune disorders:Immune disorders:

– serum sickness, – cryoglobulinemia, – SLE, – rheumatoid arthritis, – Henoch-Schönlein purpura, – postinfectious immune complex

disease,– drug-induced immune complex

disease.

– Anti-neutrophil cytoplasmic autoantibody (ANCA) can affect the large vessels, as in Wegener granulomatosis, polyangiitis, and Churg-Strauss syndrome.

– Other antibodies such as anti-glomerular basement membrane (ie, Goodpasture syndrome) and anti-endothelial (ie, Kawasaki disease) also can be culprits.

– Transplant rejection, inflammatory bowel diseases, and paraneoplastic vasculitis also may afflict the large vessels.

The disease has 3 phases:

–Phase I is (prepulseless inflammatory period)

–Phase II (vascular inflammation)

–Phase III (fibrosis stage)

•ischemic symptoms and signs secondary to dilation, narrowing, or occlusion of the proximal or distal branches of the aorta.

•Extremities become cool, and pain develops with use (ie, arm or leg claudication).

•In advanced cases, occlusion of the vessels to the extremities may result in ischemic ulcerations or gangrene, and with the involvement of cerebral arteries, strokes can occur.

Pathologic changes involved in Takayasu arteritis are the same as for giant cell arteritis. – Involved vessel walls develop irregular

thickening and intimal wrinkling. – Early in the disease, mononuclear

infiltration with perivascular cuffing is seen.

– That extends to the media, followed by granulomatous changes and patches of necrosis and scarring (fibrosis) of all layers, especially the intima.

– Late stages have lymphocytic infiltration.

Histologic Findings: Focal panarteritis:

– The intima is markedly thickened by accumulation of mucopolysaccharides.

– The media and adventitia demonstrate mixed cellular infiltration with granuloma and giant cells.

– The lesions usually are focal skip lesions rather than the diffuse involvement observed in patients with syphilitic aortitis.

When the abdominal aorta and its branches, eg, the renal arteries, are involved, central hypertension may develop. – Accurate blood pressure measurement may be

difficult because of arterial lesions affecting supply to the extremities.

Takayasu arteritis primarily involves the aorta, its main branches, and, in 50% of cases, the pulmonary artery.– The initial vascular lesions frequently occur in

or at the origin of the left subclavian artery, which can cause weakened radial pulse and easy fatigability in the left arm.

– As the disease progresses, the left common carotid, vertebral, brachiocephalic, right-middle or proximal subclavian, right carotid, and vertebral arteries, as well as the aorta, also are affected, as well as retinal vessels.

Complications:

Aortic insufficiency, angina pectoris, myocardial infarction, stroke, limb ischemia, renal artery hypertension, all consequences of vascular

diseases.

Kawasaki's diseaseKawasaki's disease

A febrile disease which resembles adult polyarteritis nodosa histologically but occurs in babies.

Need to see five of these six signs: o fever (will last more than five days)o non-purulent conjunctivitis in both eyeso rasho red cracked lips and/or strawberry tongue

and/or red oral mucosao red palms and soles (later they desquamate)o a big (1.5 cm or more) lymph node in the

neck.

Most patients are of Japanese of Korean ancestry, regardless of where they live, but no HLA links are found.

The most serious concern is coronary vasculitis, which causes myocardial infarcts. Healing can produce coronary aneurysms,

The cause remains obscure.

Raynaud's disease & Raynaud's disease & phenomenonphenomenon

Spasm and occlusion of the arteries supplying the fingers, which turn white, then red, then blue.

Triggered by cold weather, it's most often idiopathic; known causes range from vasculitis syndromes to operating jack-hammers.

Scleroderma patients and some others have this process greatly exacerbated by hyperplastic arteriolar sclerosis in the digital arteries.

Type of Type of vasculitisvasculitis

Aorta and its Aorta and its branchesbranches

Large and Large and medium-sized medium-sized

arteriesarteries

Medium-sized Medium-sized muscular muscular arteriesarteries

Small Small muscular muscular arteriesarteries

Venules, Venules, arteriolesarterioles

Takayasus Takayasus arteritisarteritis

++++++ ++

Giant cell Giant cell arteritisarteritis

++ ++++++ ++++++

PolyarteritisPolyarteritis ++++++ ++++++ ++

Wegeners Wegeners granulomatosisgranulomatosis

++++ ++++++ ++++++

Kawasaki Kawasaki diseasedisease

++++ ++

Vasculitis Vasculitis associated with associated with connective connective tissue diseasetissue disease

++++ ++++++

LeukocytoclastiLeukocytoclastic vasculitis: c vasculitis: Henoch-Henoch-Schönlein Schönlein purpura, purpura, hypersensitivity hypersensitivity vasculitis, othersvasculitis, others

++ ++++++

vasculitis

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