🔬 What is this Test?
The Anti-Neutrophilic Cytoplasmic Antibody (ANCA) - Indirect Immunofluorescence Assay (IFA) Test detects autoantibodies against neutrophil cytoplasmic proteins. It is used to diagnose vasculitis-related autoimmune diseases, such as Granulomatosis with Polyangiitis (GPA) and Microscopic Polyangiitis (MPA).
📊 Normal Ranges:
✅ Negative: No detectable ANCA
⚠️ Low Positive: Borderline result, further testing required
❌ Positive: Suggestive of autoimmune vasculitis, subtyping (c-ANCA/p-ANCA) needed
🎯 Purpose of the Test:
✔️ Diagnose autoimmune vasculitis disorders (e.g., Granulomatosis with Polyangiitis, Microscopic Polyangiitis)
✔️ Differentiate between types of vasculitis based on ANCA patterns
✔️ Monitor disease progression and treatment response
🩺 Types of ANCA Patterns:
🔹 c-ANCA (Cytoplasmic ANCA) → Associated with Granulomatosis with Polyangiitis (GPA)
🔹 p-ANCA (Perinuclear ANCA) → Associated with Microscopic Polyangiitis (MPA) and Eosinophilic Granulomatosis with Polyangiitis (EGPA)
⚠️ Why Might You Need This Test?
Unexplained chronic sinusitis or lung infections
Blood in urine (hematuria) or kidney disease
Unusual skin rashes or ulcers
Chronic inflammation, fever, and weight loss
Neuropathy or unexplained nerve pain
📌 Understanding the Results:
Negative ANCA: No autoimmune vasculitis detected
Positive c-ANCA: Suggests Granulomatosis with Polyangiitis (GPA)
Positive p-ANCA: Suggests Microscopic Polyangiitis (MPA) or EGPA
🔬 Additional Notes:
IFA (Immunofluorescence Assay) is a standard method for detecting ANCA patterns
Further testing (ANCA ELISA) is needed to confirm the diagnosis
A positive result requires correlation with clinical symptoms and additional tests