Vasculitis | Cardiovascular system | Pathology

Vasculitis: Vasculitis is inflammation of blood vessels. Most types are caused due to immunological or autoimmune phenomena. Vascular damage in vasculitis results from immune complex deposition, T cell mediated granuloma formation or ANCA (anti-neutrophil cytoplasmic antibody) formation. End result is narrowing of vessels with ischemia of the territory supplied. Weakening of the vessel wall can lead to aneurysm formation and hemorrhages. Fever, rash, myalgia, malaise, arthralgia and weight loss are seen generally in most vasculitis. Characteristic presentations are seen in a few as below:

Types of vasculitis

Small vessel vasculitis
Types	Pathology	Presentation and laboratory characters
Churg-Strauss syndrome	Necrotizing vasculitis of vessels in the respiratory tract with eosinophil infiltration and granulomatous inflammation	Allergic rhinitis, asthma, eosinophilia, fever, anorexia, malaise
Cutaneous leukocytoclastic angiitis	Involves skin only	Palpable purpura, cutaneous infarcts and necrosis, urticaria
Essential cryoglobulinemia	Immune deposits in glomeruli and skin	Recurrent palpable purpura, polyarthralgia, glomerulonephritis; Cryoglobulins elevated in serum; may be seen in Hep C infection, multiple myeloma
Henoch-Schonlein purpura	IgA immune deposits in skin,joints, gut and glomeruli	Follows an URTI, recent viral or bacterial infections, food allergies, medications; Arthralgia, arthritis, abdominal pain, red or purple palpable purpura, headache, glomerulonephritis, typically in young children; normal coagulation studies
Microscopic polyangiitis	Necrotizing vasculitis with scanty immune deposits in microscopic vessels namely capillaries, venules or arterioles; lungs and kidneys involved	Palpable purpura, pulmonary hemorrhages, glomerulonephritis
Granulomatosis with polyangiitis (GPA) (formerly called Wegener’s granulomatosis)	Granulomatous inflammation of the upper and lower respiratory tract with glomerulonephritis	Nasopharyngeal ulcers, sinusitis, pneumonitis with bilateral nodular infiltrates, crescentic glomerulonephritis, otitis media, hemoptysis
Medium vessel vasculitis
Kawasaki disease or mucocutaneous lymph node syndrome	Coronary arteritis	Seen in young children, mostly in boys, fever, conjunctivitis, desquamation of fingers and toes, cervical lymphadenopathy, erythema of lips and oral mucosa, coronary aneurysms, most common acquired heart disease in children
Polyarteritis nodosa	Necrotizing inflammation of vessels; spares the lung; no glomerulonephritis but renal vessels may be stenosed causing renal ischemia	Fever, hypertension,weight loss, abdominal pain, melena, peripheral neuritis, renal and organ ischemia; can be seen in Hep B infection
Raynaud’s disease	Vasospasm only, no underlying cause; NO vasculitis; affects fingers, toes, ears, tip of nose; in response to cold exposure, stress	More common in women, typical changes of Raynaud’s phenomenon seen; no underlying disease; seen in healthy individuals
Raynaud’s phenomenon	Recurrent, reversible vasospasm of fingers and toes on cold exposure or stress; caused by underlying autoimmune disorder; vasculitis and fibrinoid changes in vessel walls	More common in women, seen in autoimmune disorders like systemic sclerosis, mixed connective tissue disease, SLE, frostbite, cryoglobulinemia, ergotamine; three color changes occur - initially white from vasospasm, then blue from cyanosis and finally red from hyperemia; affected areas are clearly demarcated from unaffected areas; seen in extremities, tip of the nose, ears.
Thromboangiitis obliterans or Buerger’s disease	Inflammation of peripheral arteries and veins leading to stenosis, thrombosis and decreased blood supply to extremities	Seen in young and middle-aged male, cigarette smokers; affects extremities, more commonly lower legs; extreme pain of the arms and legs while at rest, thrombophlebitis; Raynaud’s phenomenon; ulcers
Large vessel vasculitis
Giant cell or temporal arteritis	Granulomatous inflammation of aorta and branches especially temporal artery	Fever, facial pain , headache, tender scalp, Polymyalgia rheumatica, jaw claudication on chewing
Takayasu arteritis	Granulomatous inflammation of the aorta and major branches	More common in young Asian and Latin American women; lower BP and weaker pulses in the upper limbs, HT, cold and numb fingers, neurological deficit

Secondary causes of vasculitis are rheumatoid arthritis, systemic lupus erythematosus, scleroderma, hepatitis B and C infection, HIV, HTLV 1, CMV, VZV, Parvovirus B19, lymphoma, and solid organ malignancy.

Infectious vasculitis is seen in Rocky mountain spotted fever, Neisseria meningitidis septicaemia , syphilitic aortitis, by direct invasion of blood vessels or septic embolization.

Interpretations of lab findings in vasculitis

Lab finding	Interpretation
Eosinophilia	Churg-Strauss syndrome
Raised ESR	Any active vasculitis; Giant cell arteritis
Raised liver enzymes	Vasculitis affecting the liver e.g. polyarteritis nodosa
ANCA*	c-ANCA Wegener’s granulomatosis, p-ANCA microscopic polyangiitis and Churg-Strauss syndrome
X-ray Chest	Nonspecific patchy infiltrates and nodules; pleural effusion; cardiomegaly
Angiography	Vascular occlusion, aneurysms; seen in renal and mesenteric vessels in polyarteritis nodosa; in coronary arteries in Takayasu’s arteritis and Kawasaki disease
Echocardiography	Coronary artery aneurysms, coronary artery ectasia(Kawasaki disease)
CT scan	Nodules, ulcerations in nasal mucosa in Wegener’s granulomatosis

*Based on indirect immunofluorescence patterns, there are two types of ANCA - p-ANCA or perinuclear and c-ANCA or cytoplasmic. p-ANCA corresponds to myeloperoxidase , while c-ANCA corresponds to proteinase 3. Other disease conditions like infections, IBD or drug-induced vasculitis can also give a positive ANCA.