Vasculitis
Approach to a suspected vasculitis:
· the term “vasculitis” refers to a heterogeneous group of disorders linked by the primary finding of inflammation within blood vessel walls
- common complaints and signs of vasculitis include: fatigue, weakness, fever, arthralgias, abdominal pain, hypertension, renal insufficiency (with an active urine sediment), and neurologic dysfunction
- as the symptoms are nonspecific, the clinical manifestations of vasculitis can be mimicked by a number of other disorders
- some findings that can be somewhat specific for vasculitis include: mononeuritis multiplex (PAN), palpable purpura (HSP and microscopic polyangitis) and a pulmonary/renal syndrome (Wegner’s and anti-GBM)
· Additional considerations in classification include:
o patient demographics (age, gender ethnicity)
o organ tropism
o presence or absence of granulomatous inflammation
o presence (or lack) of immune complexes
o presence of autoantibodies
o detection of infections associated with some vasculitides
- A general approach includes a detailed history, including any new medications (which can cause a hypersensitivity vasculitis), history of Hep B or C and any previous diagnosis of a disorder known to be associated with a vasculitis (such as SLE)
- Physical exam helps to determine the extent of vascular lesions and possible distribution of affected organs. Specific findings such as palpable purpura or mononeuritis multiplex are highly suggestive of an underlying vasculitis
- A basic laboratory workup should include: serum creatinine, CK, LFTs, ESR, hepatitis serologies, UA, CXR, and EKG. More specific tests include ANA, ANCA and complement levels.
Classification of vasculitis:
· vasculitides are classified first by the size of blood vessel involved:
o small (capillaries and postcapillary venules)
o medium (muscular arteries and arterioles)
o large (the aorta and its major branches), see below for more infomation
o there are over 20 forms of systemic vasculitis
· Within small/medium vessel vasculitides, there are 2 main categories:
o Immune complex deposition: immune complex–mediated tissue injury applies to many forms of vasculitis and overlaps with injuries caused by other immune mechanisms. Examples include:
§ IgA in Henoch-Schonlein purpura
§ IgG, IgM and complement in mixed cryoglobulinemia
§ HBV surface antigen/antibody complexes in HBV-associated PAN
§ Rheumatoid factor and complement in rheumatoid vasculitis
§ Anti-GBM disease (Goodpasture's disease) is a unique form of immune complex disease in which the immune complexes form in situ rather than in the circulation
o “Pauci-immune” inflammation: “Pauci-immune” refers not to a lack of immunologic involvement in these disorders, but rather to the absence of significant immunoglobulin or complement deposition within diseased tissues. Many (but not all) patients with pauci-immune forms of vasculitis have ANCA in their serum. Examples include:
§ Wegener's granulomatosis
§ Microscopic polyangiitis
§ Churg-Strauss syndrome
Large Vessel Vasculitis
Polymyalgia rheumatica: click here to learn more
Giant Cell Arteritis: granulomatous vasculitis typically involving extracranial branches of the carotids (temporal artery, ophthalmic artery, posterior ciliary common).
Epidemiology: Elderly with female predominance. 30-40% of patients with GCA have PMR.
Pathophysiology: transluminal inflammation of the arteries induces luminal occlusion through intimal hyperplasia.
Symptoms: usually related to end organ ischemia:
Blindness, HA, scalp tenderness, jaw claudication, stroke, TIA, vertigo, dizziness (vertebral artery involvement)
Nonspecific inflammation: malaise, anorexia, weight loss, fever, night sweats, depression
Less common: aortitis leading to aneurysm formation, dissection, hemorrhage, rupture.
Physical findings: temporal artery beading, prominence, tenderness
Treatment:
Prednisone – usually 60mg daily as initial dose. If presenting symptom is visual disturbance then methylprednisolone 1gm IV daily. Steroids should be tapered by 10% q1-2 weeks
No proven adjunctive steroid sparing agents
Takayasu arteritis – aka Pulseless disease: Arteritis of large, elastic arteries.
Epidemiology: younger/adolescent females, often of Japanese, Southeast Asia, Indian, Mexican descent.
Pathophysiology: panarteritic inflammatory infiltrates leads to marked thickening of the involved artery. Result is occlusion, luminal narrowing, diffuse dilation à aneurysm, thrombosis
Symptoms:
Inflammatory phase: fever, myalgia, arthralgia, malaise, weight loss
Pulseless phase: arm/leg claudication, hypertension secondary to renal artery stenosis, great vessel narrowing, AR from dilation of the ascending aorta, abdominal aneurysms
Physical findings: differential blood pressure in arms, diminished or absent pulses.
Treatment: 45-60 mg prednisone/day.
Approximately 50% of patients have chronic active disease on prednisone and do not go into sustained remission. Methotrexate and TNF alpha inhibitors used as adjunctive therapy.
Aspirin is usually added to prevent ischemic complications from vessel narrowing.
(Meghan Ramsey MD, 6/8/11)
(Victoria Kelly MD, 12/7/10)