Polyarteritis Nodosa

Polyarteritis Nodosa

Surya V. Seshan, MD

Kidney biopsy in polyarteritis nodosa (PAN) shows circumferential, transmural fibrinoid necrosis and active inflammatory infiltrate composed of neutrophils and lymphocytes.

Trichrome-stained kidney section shows a healing PAN of a medium-sized vessel with focal thrombosis and early microaneurysm formation. It is common to have both active and healed lesions in PAN.



  • Polyarteritis nodosa (PAN)


  • Macroscopic polyarteritis

  • Classic polyarteritis nodosa

  • Kussmaul and Maier periarteritis nodosa


  • Chapel Hill Consensus Conference criteria

    • Necrotizing inflammation of medium-sized or small arteries without glomerulonephritis or vasculitis in arterioles, capillaries, or venules

  • American College of Rheumatology criteria

    • Weight loss ≥ 4 kg, livedo reticularis, testicular pain or tenderness, myalgias, weakness or leg tenderness, mono- or polyneuropathy, diastolic BP > 90 mmHg, elevated BUN or creatinine, hepatitis B virus, biopsy diagnosis of small or medium-sized arteries, arteriography with aneurysms or occlusions in visceral arteries

    • 3 or more of the above criteria have high sensitivity and specificity for diagnosis

  • EULAR/PRINTO/PRES criteria for childhood PAN

    • Necrotizing vasculitis, angiographic abnormalities, and either skin involvement, myalgia/muscle tenderness, hypertension, peripheral neuropathy, or renal involvement


Infectious Agents

  • Hepatitis B virus (HBV)

    • Accounts for ˜ 36% of PAN cases

  • Possibly other bacterial and viral infections

    • Hepatitis C virus (HCV)

    • Rarely HIV, Epstein-Barr virus


  • HBV immunization

  • Exposure to silica-containing compounds

  • In majority, etiology is unknown


  • Immunologically mediated

    • Believed to be chronic immune-complex mediated disease

      • Resembles chronic serum sickness model

    • Probably a T-cell-mediated immune component

    • Antigen unknown

    • May be microbial or autoantigen in vessel wall

  • Participation of neutrophilic and mononuclear inflammatory infiltrate (T cells and macrophages)

    • Weakness in vessel wall leads to thrombosis or fibrosis and microaneurysm formation

  • Chronic, cyclic insults support presence of different stages of vasculitis



  • Incidence

    • 2-31/1,000,000 in Europe and USA

      • Some studies have included cases now classified as microscopic polyangiitis

    • Up to 77/1,000,000 in endemic areas for hepatitis B viral infection

  • Age

    • Adults: Peak at 5th to 7th decade

    • Children: 7-11 years

      • However, less common in children

  • Gender

    • Male predilection (M:F = 2:1)

  • Ethnicity

    • 2x higher prevalence in Europeans vs. others

    • Specific HLA haplotypes

    • Involves all ethnic groups


  • Multisystemic involvement

  • Clinical symptoms related to ischemia and are dependent on organ involved and disease severity

  • Constitutional symptoms: Fever, malaise, weight loss, myalgia, abdominal pain

  • Renal

    • Kidney frequently involved (70-80%)

      • Focal renal infarction (˜ 30%)

      • Microaneurysms (˜ 65%)

      • Hematuria, proteinuria (˜ 20%)

      • Loin pain

      • Acute renal failure

    • New onset hypertension, sometimes malignant range

    • Rare: Rupture of kidney with perirenal hematoma

    • Massive retroperitoneal and peritoneal hemorrhage following rupture of arterial aneurysm

  • Heart

    • Ischemic heart disease

  • Neurologic (10%)

    • Focal defects, hemiplegia, visual loss, mononeuritis multiplex

  • Skin

    • Varied lesions: Palpable purpura, necrotic with peripheral gangrene, livedo reticularis, ulcers

    • Subcutaneous nodules

  • Skeletal muscle and mesentery (30%)

  • Gastrointestinal, peripheral nerves, skin (50%)

Laboratory Tests

  • Anemia, leukocytosis, thrombocytosis

  • Elevation of ESR and C-reactive protein

  • Positive hepatitis B serology in some cases

  • No specific serologic tests

  • No significant association with ANCA

  • Rarely, ANCA positive (usually perinuclear) by indirect IF only, when overlap with microscopic polyangiitis


  • Steroid therapy is 1st line of therapy; remission in 50% of patients

  • Cyclophosphamide and steroids for severe cases; remission in 90%

  • Plasma exchange/plasmapheresis in refractory cases

  • HBV-associated PAN needs antiviral therapy


  • Fulminant disease with < 5-year survival

  • 40% of patients have relapse

  • 5 factor score (FFS) estimates prognosis

    • Scores renal (Cr > 1.6 mg/dL, proteinuria > 1 gm/24 hr), GI, cardiac, and CNS involvement

    • Lower score correlates with better 5-year survival


Ultrasonographic Findings

  • Pulsed and color Doppler ultrasonography

    • Localization of microaneurysm (seen in 50-60%)

Computed Tomography Angiography

  • Microaneurysms often seen at artery bifurcations

  • Tc-99m DMSA uptake scanning detects patchy renal parenchymal disease


Histologic Features

Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Polyarteritis Nodosa
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