There are no specific lab tests for diagnosing polyarteritis nodosa. Diagnosis is generally based upon the physical examination and a few laboratory studies that help to confirm the diagnosis. Laboratory findings helpful in the diagnosis of polyarteritis nodosa include CBC, ESR, C-reactive protein, p-ANCA, Hepatitis B surface antigen and hepatitic C serologies, elevated levels of liver enzymes, elevated creatinine level and hypergammaglobulinemia.

• There are no specific lab tests for diagnosing polyarteritis nodosa.
• Diagnosis is generally based upon the physical examination and a few laboratory studies that help to confirm the diagnosis.
• Laboratory findings consistent with the diagnosis of polyarteritis nodosa include
  • CBC may show:
    • Leukocytosis
    • Normochromic anemia
    • thrombocytosis
  • ESR and C-reactive protein^[1]
    • These can be helpful to diagnose active disease.
  • Perinuclear pattern of antineutrophil cytoplasmic antibodies (p-ANCA) – not associated with “classic” polyarteritis nodosa, but is present in a form of the disease affecting smaller blood vessels, known as microscopic polyangiitis or leukocytoclastic angiitis.
  • Hepatitis B surface antigen and hepatitic C serologies
    • Patients with HBV related polyarteritis nodosa show:
      • Decreased levels of serum C3 and C4.
      • Circulating immune complexes
      • Cryoglobulins
  • Elevated levels of liver enzymes
  • Elevated creatinine level
  • Hypergammaglobulinemia
    • Seen in 30% patients with polyarteritis nodosa.