Description

The P-ANCA blood test measures perinuclear anti-neutrophil cytoplasmic antibodies, a specific type of autoantibody that targets components of white blood cells. These antibodies are commonly associated with certain autoimmune and inflammatory diseases, particularly vasculitis and inflammatory bowel disease (IBD).

This test is often used alongside C-ANCA testing and other autoimmune markers to help identify or rule out diseases like ulcerative colitis, primary sclerosing cholangitis, microscopic polyangiitis (MPA), and Churg-Strauss syndrome (EGPA).

What the P-ANCA Test Measures

  • Autoantibodies targeting white blood cell proteins that form a perinuclear (around the nucleus) staining pattern on testing.
  • Indicates potential immune system dysfunction, where the body mistakenly attacks its own tissues.
  • Used to differentiate between types of vasculitis and chronic inflammatory disorders.

Conditions Associated with Positive P-ANCA

A positive result may be seen in:

  • Ulcerative Colitis (UC)
  • Primary Sclerosing Cholangitis (PSC)
  • Microscopic Polyangiitis (MPA)
  • Churg-Strauss Syndrome (EGPA)
  • Autoimmune Hepatitis
  • Occasionally in systemic lupus erythematosus (SLE) or rheumatoid arthritis

Note: A positive P-ANCA alone is not diagnostic. Results must be interpreted in context with symptoms and other lab findings.

Why This Test May Be Ordered

Your provider may recommend a P-ANCA test if you have symptoms such as:

  • Chronic fatigue
  • Unexplained inflammation or joint pain
  • Bloody diarrhea or suspected IBD
  • Skin rashes, nerve pain, or sinus issues suggestive of vasculitis
  • Liver or bile duct abnormalities

Test Details

  • Sample Type: Blood
  • Fasting Required: No