Anti-Neutrophil Cytoplasmic Antibody

Test Description
The anti-neutrophil cytoplasmic antibody test (ANCA) is used primarily in the diagnosis
and monitoring of patients with Wegener’s granulomatosis (WG). WG is an
autoimmune disease, which is characterized by inflammation in many tissues of the
body, including the upper and lower respiratory system, the kidneys, eyes, ears, and
skin. The blood vessels in these areas become inflamed, a condition known as vasculitis,
and granulomas develop. Once the diagnosis is confirmed, treatment with
cytotoxic agents is usually needed.

Normal Values                      

ANCA by immunofluorescence: Negative
ANCA by EIA: Negative: <21 Units
Weak Positive: 21–30 Units
Positive: >30 Units

Possible Meanings of Abnormal Values
Increased
Glomerulonephritis
Inflammatory bowel disease
Polyarthritis nodosa
Systemic arthritis
Wegener’s granulomatosis

Interventions/Implications

Pretest
• Explain to the patient the purpose of the test and the need for a blood sample to be drawn.
• No fasting is required before the test.
Procedure
• A 7-mL blood sample is drawn in a gold-top (serum separator) collection tube.
• Gloves are worn throughout the procedure.
Posttest
• Apply pressure at venipuncture site. Apply dressing, periodically assessing for continued
  bleeding.
• Label the specimen and transport it to the laboratory.
• Report abnormal findings to the primary care provider.
 skin. The blood vessels in these areas become inflamed, a condition known as vasculitis,
  and granulomas develop. Once the diagnosis is confirmed, treatment with
  cytotoxic agents is usually needed.