Vasculitis

Etiology

Classification of Vasculitis (Based on Clinicopathologic Features): 1994 Chapel Hill Classification

Primary Idiopathic Vasculitis

Primary Small-Vessel, Immune Complex-Mediated Vasculitis

Secondary Vasculitis


Classification of Vasculitis (Based on Site of Vascular Involvement)

(Note: there can be some overlap between the site of vascular involvement in these disorders -> while small and medium-vessel vasculitides may also involve the medium-sized arteries, large-vessel vasculitides do not usually involve vessels smaller than arteries)

Large Vessel Vasculitis (involving aorta and arteries)

Medium-Vessel Vasculitis (involving arteries and arterioles)

Small-Vessel Vasculitis (involving arterioles, capillaries, venules, and veins)


Clinical Features

Features of Large Vessel Vasculitis

  • Limb Claudication
  • Asymmetric BP’s
  • Absence of Pulses
  • Bruits
  • Aortic Dilation

Features of Medium-Vessel Vasculitis

Features of Small-Vessel Vasculitis


Differentiating Features of Vasculitis Syndromes

Wegener’s Granulomatosis (see Wegeners Granulomatosis)

  • Pathology
    • Site: small-medium arterioles to venules (sometimes arteries and veins) -> necrotizing
    • Capillaritis
    • Immunofluorescence: granular or negative
  • Serology
    • c-ANCA: positive (>1:20) in 80-90% of cases (high titers correlate well with active granulomatous vasculitis)
      • c-ANCA (anti-proteinase 3 = anti-PR3) ELISA positive in >85% of cases with generalized active disease
    • ANA: variable
    • RF: variable
    • Complement: normal
  • Clinical
    • Constitutional: fatigue, weight loss, malaise, fevers
    • Upper Respiratory Tract (70-95% of cases): destructive or ulcerating lesions -> nasal septal perforation, saddle-nose deformity, subglottic stenosis
    • Lung (70-95% of cases): lung nodules, cavitary lesions, DAH, trachebronchial disease (10-50% of cases)
      • Chest imaging is abnormal in 80% of cases: alveolar, interstitial, mixed alveolar-interstitial, nodules, cavitary disease, tracheobronchial lesions
    • Renal (50-90% of cases): necrotizing crescentic GLN, occasional granulomatous features, absence of HTN
    • GI (<10% of cases):
    • Rheum (80% of cases): arthritis, arthralgias, myalgias, synovitis
    • Derm (60% of cases): skin vasculitis with palpable purpura, ulcers, nodules, vesicles
    • Neuro (may be involved): mononeuritis multiplex, CNS involvement
    • Ocular (20-60% of cases): uveitis, ocular ulcers
    • Cardiac (5-30% of cases):
    • Vascular: microaneurysms are rare
  • Distinguishing Features
    • Destructive upper airway disease
    • Granulomatous inflammation

Microscopic Polyangiitis (see Microscopic Polyangiitis)

  • Epidemiology
    • Most common cause of pulm-renal syndromes (several times more common than Goodpasture’s)
  • Pathology
    • Site: small-medium arterioles to venules (sometimes arteries and veins) -> necrotizing
    • Capillaritis
    • Immunofluorescence: negative
  • Serology
    • p-ANCA (anti-myeloperoxidase = anti-MPO) : ANCA positive in 50-75% of cases
    • ANA: variable
    • RF: variable
    • Complement: normal
  • Clinical
    • Constitutional: very common (generally precedes renal disease by months)
    • Upper Respiratory Tract (5-30% of cases): usually mild involvement -> sinus disease
    • Lung (25-55% of cases)
      • DAH (10-30% of cases)
      • Pulmonary fibrosis
      • Focal infiltrates (10-30% of cases)
      • Pleural effusion (5-20% of cases)
      • Renal: necrotizing crescentic GLN, absence of HTN -> rapidly progresive glomerulonephritis (almost universal)
    • GI (35-55% of cases): abdominal pain, GI bleeding, ischemia/infarction, visceral aneurysms (rare)
    • Rheum (50% of cases): arthritis, arthralgias, myalgias
    • Derm (35-60% of cases): skin vasculitis with purpura
    • Neuro: mononeuritis multiplex (common): mononeuritis multiplex in 10-50% of cases
    • Ocular (0-30% of cases): may be clinically silent
    • Cardiac (10-15% of cases): CHF, pericarditis
    • Vascular: microaneurysms are rare
  • Distinguishing Features
    • Absence of granulomatous inflammation

Churg-Strauss Syndrome (see Churg-Strauss Syndrome)

  • Pathology
    • Site: systemic necrotizing vasculitis
  • Serology
    • p-ANCA (anti-myeloperoxidase = anti-MPO) : ANCA positive in 40-70% of cases
  • Clinical
    • Constitutional: common
    • Upper Respiratory Tract (20-70% of cases): usually non-destructive -> sinusitis, nasal polyps, allergic rhinitis
    • Lung: asthma (universally present), obstructive airways disease (airway wall thickening, hyperinflation), eosinophilic fleeting infiltrates (30-50% of cases), DAH (0-20% of cases)
      • Chest imaging: opacities in 40-75% of cases
    • Renal (20-60% of cases): necrotizing crescentic GLN (severe renal disease is unusual)
    • GI (15-60% of cases, major cause of morbidity and mortality): GI bleed, abdomnal pain, ischemia/infarction, perforation
    • Rheum (50% of cases): arthritis, arthralgias, myalgias
    • Derm (50-70% of cases): nodules, papules, leukocytoclastic vasculitis with or without eosinophils
    • Neuro: mononeuritis multiplex in 50-75% of cases, CNS involvement in 5-40% of cases
    • Ocular (<5% of cases):
    • Cardiac (15-50% of cases): conduction delays, EKG abnormalities, systolic or diatolic CHF, pericarditis, coronary artery vasculitis
  • Distinguishing Features
    • Allergy
    • Eosinophilia

Polyarteritis Nodosa (see Polyarteritis Nodosa)

  • Pathology
    • Site: medium muscular arteries -> necrotizing
  • Serology
    • ANCA: negative
  • Clinical
    • Lung: absence of involvement
    • Renal: absence of glomerulonephritis, presence of HTN
    • GI: presence of GI symptoms
    • Derm: involved
    • Neuro: mononeuritis multiplex (common)
    • Ocular: absence of symptoms
    • Vascular: microaneurysms are common
  • Distinguishing Features
    • Absence of granulomatous inflammation

Systemic Lupus Erythematosus (SLE) (see Systemic Lupus Erythematosus)

  • Pathology
    • Bland or capillaritis
    • Immunofluorescence: granular IgG
  • Serology
    • ANCA: negative
    • ANA: positive (>1:160 titer) in 95% of cases
    • Anti-DNA: positive
    • RF: positive
    • Complement: decreased
  • Clinical
    • Lung: DAH
    • Renal: involved
    • Rheum: arthritis
    • Derm: skin vasculitis (variable)

Goodpasture’s Syndrome (see Goodpasture’s Syndrome)

  • Pathology
    • Bland or capillaritis
    • Immunofluorescence: linear IgG
  • Serology
    • ANCA: negative
    • ANA: negative
    • RF: negative
    • Complement: normal
    • Anti-Basement Membrane: positive
  • Clinical
    • Lung: DAH
    • Renal: involved

Idiopathic Pulmonary Hemosiderosis (see Idiopathic Pulmonary Hemosiderosis)

  • Pathology
    • Bland
    • Immunofluorescence: negative
  • Serology
    • ANCA: negative
    • ANA: negative
    • RF: negative
    • Complement: normal
  • Clinical
    • Lung: DAH
    • Heme: anemia

Isolated Pulmonary Capillaritis (see Isolated Pulmonary Capillaritis)

  • Pathology
    • Capillaritis
    • Immunofluorescence: negative
  • Serology
    • ANCA: usually negative (occasionally p-ANCA positive)
    • ANA: negative
    • RF: negative
    • Complement: normal
  • Clinical
    • Lung: DAH
    • Heme: anemia

Henoch-Schonlein Purpura (see Henoch-Schonlein Purpura)

  • Pathology
    • Immunofluorescence: granular IgA
  • Serology
    • ANCA: variable
    • ANA: negative
    • RF: negative
    • Complement: normal
    • IgA Immune Complexes: positive
  • Clinical
    • Lung: DAH
    • Renal: involved
    • Rheum: arthritis
    • Derm: skin vasculitis

Type II or III Mixed Cryoglobulinemia (see Cryoglobulinemia)

  • Clinical
    • Renal: glomerulonephritis
    • Neuro: peripheral neuropathy
    • Derm: purpura
  • Distinguishing Features
    • Most type II and III cases are associated with HCV infection -> antiviral therapy can cause remission in some patients

Rheumatoid Vasculitis (see Rheumatoid Arthritis)

  • Clinical
    • Cardiac: pericarditis
    • Lung: pleuritis
    • Renal:
    • Derm: skin vasculitis
    • Vascular: digital ischemia
    • Neuro: peripheral neuropathy
    • Ocular: scleritis

References

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