Cardiovascular System

Vasculitis – Small Vessel

Anisha ValliLeave a comment

Key Points

  • Vasculitides are characterized by blood vessel inflammation with possible necrosis, ischemia, and organ damage.
  • The vessels and organs affected vary by the specific vasculitic disorder – the ones we’ll address in this tutorial affect the small arteries, veins, and capillaries.
  • General symptoms are due to systemic inflammation, and include fever, arthritis, arthralgia, fatigue, and weight loss.
  • Cutaneous manifestations can occur in isolation.
  • Treatments include corticosteroids and immunosuppressants.

ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODIES (ANCA) – ASSOCIATED VASCULITIDES

Granulomatosis with polyangiitis aka, Wegener’s

  • Characterized by necrotic granulomatous inflammation.
  • Granulomas comprise giant cells, plasma cells, lymphocytes, neutrophils, and eosinophils.
  • The respiratory tract is typically involved, which can lead to sinusitis, otitis media, rhinorrhea, and epistaxis; the mucosa can become granular and crusted.
    – Erosion and destruction of the nasal septum can case the nasal bridge to collapse.
    – Destruction of the tracheobronchial tree can lead to stenosis and airway obstruction.
    – When the lungs are involved, patients can develop a cough, difficulty breathing, hemoptysis, and hemorrhaging.
  • The kidneys are also commonly affected, leading to necrotizing crescent focal glomerulonephritis and thrombosis.
  • Cutaneous manifestations vary, and include palpable purpura, livedo reticularis, ulcers, and the formation of deep, tender nodules.
  • The eyes, nervous system, heart, and musculoskeletal system can also be involved.
  • Granulomatosis with polyangiitis most commonly occurs in Caucasians; the average age of onset is 40 years.

Eosinophilic granulomatosis with polyangiitis aka, Churg-Strauss

  • ANCA-associated disorder characterized by necrotizing granulomatous inflammation.
  • Manifests as both vascular and extravascular necrotizing granulomas with (as its name suggests) eosinophil blood and tissue infiltrations.
    Three stages of eosinophilc granulomatosis with polyangiitis:
  • The allergic stage is often marked by adult-onset asthma, which can develop years before full presentation of the disorder.
    – Patients may also develop sinusitis, hemoptysis, and pulmonary infiltrates as part of the allergic stage.
  • The eosinophilic stage is characterized by blood and tissue infiltration of eosinophils.
  • The vasculitic stage can affect multiple organ systems:
    – Nervous system involvement is associated with multiple mononeuropathy.
    – Cutaneous involvement manifests as nodules or papules on the extensor surfaces, especially around the elbows.
    – GI involvement can produce pain, diarrhea, and bleeding.
    – Cardiac involvement often leads to inflammation and/or cardiomyopathies.
  • Be aware that the kidneys are less commonly affected than in the other ANCA-associated vasculitides.
  • Disease onset is usually during the late 40s.

Microscopic polyangiitis

  • Characterized by necrotizing pauci-immune inflammation without granulomas.
  • Renal involvement is associated with glomerulonephritis and rapid progression to renal failure.
  • Purpuric rash is common.
  • The lungs are less commonly affected, but, when they are, alveolar hemorrhage and fibrosis can be serious.
  • Microscopic polyangiitis usually develops in patients 50-60 years old.

NON-ANCA-ASSOCIATED SMALL VESSEL VASCULITIDES

Immunoglobulin A-associated vasculitis aka, Henoch-Schonlein purpura

  • Occurs when IgA immune complexes are deposited in the small vessels.
  • Patients develop palpable purpura, especially on the lower extremities, arthralgias, abdominal pain, dark stools, and focal glomerulonephritis.
  • It’s common and self-limited in children, whereas, in adults, it often becomes chronic.

Cryoglobulinemia

  • Occurs when cryoglobulins in the blood clump at cold temperatures.
  • Patients experience notable fatigue, palpable purpura in the legs, arthralgias in the knees and hands, glomerulonephritis, and PNS disturbances.
  • Type I cryoglobulinemia is associated with B-cell lymphoproliferative disorder.
  • Types II and III (aka, mixed cryoglobulinemia) is assoc. with Hepatitis C virus.

Autoimmune Disorders

  • The autoimmune disorders systemic lupus erythematosus and rheumatoid arthritis are also associated with small-vessel vasculitis.

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