Investigations for polyarteritis nodosa
Investigations commonly performed for most systemic vasculitides (including polyarteritis nodosa) are outlined in Investigations for systemic vasculitides. Investigations that may support the diagnosis of polyarteritis nodosa include:
- inflammatory markers—serum C-reactive protein (CRP) concentration and erythrocyte sedimentation rate (ESR) are usually raised in people with active disease
- organ-specific investigations—for example, kidney function tests and liver biochemistry.
Classic polyarteritis nodosa is antineutrophil cytoplasmic antibody (ANCA)–negative.
Diagnosis of polyarteritis nodosa is based on biopsy of affected tissues. Typical sites for biopsy include:
- sural nerve—particularly if nerve conduction studies demonstrate involvement
- symptomatic muscle
- affected skin
- kidney—may reveal arteritis (rather than glomerulonephritis in microscopic polyangiitis).
Specialised vascular imaging, including mesenteric or renal angiography, may be useful if no tissue is available for biopsy. Specialised vascular imaging improves diagnostic yield in people with abdominal symptoms or abnormal liver biochemistry. Typical features seen on angiography may include aneurysms and vascular irregularity with occlusion of penetrating (organ) arteries.
People with polyarteritis nodosa should have viral hepatitis serology performed because polyarteritis nodosa is commonly associated with active hepatitis B and C infections. For advice about viral hepatitis serology testing, see: