ANTI-MPO ANTIBODIES (ANTI-MYLEOPEROXIDASE ANTIBODIES) - PANCA

The Anti-MPO Antibodies (Anti-Myeloperoxidase Antibodies) – pANCA Test is a specialized blood test used to detect autoantibodies against myeloperoxidase (MPO), an enzyme found within neutrophils, a type of white blood cell. These antibodies are commonly associated with Perinuclear Anti-Neutrophil Cytoplasmic Antibodies (pANCA) and are an important marker for diagnosing ANCA-associated vasculitis (AAV) and other autoimmune inflammatory disorders.

ANCA-associated vasculitis is a group of autoimmune diseases in which the immune system attacks small blood vessels, leading to inflammation and damage in organs such as the kidneys, lungs, skin, nerves, and joints. The Anti-MPO antibody test is particularly useful in diagnosing Microscopic Polyangiitis (MPA), Eosinophilic Granulomatosis with Polyangiitis (EGPA) (formerly Churg-Strauss syndrome), and certain cases of pauci-immune crescentic glomerulonephritis.

The Anti-MPO (pANCA) Test is often performed together with PR3-ANCA (cANCA) testing to help classify different forms of ANCA-associated vasculitis. Early diagnosis allows prompt treatment with immunosuppressive therapy, helping prevent irreversible organ damage and improving long-term outcomes.

Benefits of the Test

• Detects Anti-Myeloperoxidase (MPO) autoantibodies
• Supports diagnosis of ANCA-associated vasculitis
• Helps diagnose Microscopic Polyangiitis (MPA)
• Assists in evaluating autoimmune kidney and lung disorders
• Helps differentiate autoimmune vasculitis from other inflammatory diseases
• Supports treatment planning and disease monitoring
• Requires only a peripheral blood sample

Why Doctors Recommend This Test

Doctors may recommend this test if a patient has:

• Persistent unexplained inflammation
• Blood in the urine (hematuria)
• Protein in the urine (proteinuria)
• Rapid decline in kidney function
• Chronic sinus inflammation
• Persistent cough or coughing up blood
• Shortness of breath
• Skin rashes or purpura
• Peripheral neuropathy
• Suspected ANCA-associated vasculitis

Preparation Before Test

Sample Required

• Peripheral venous blood sample (Serum)

Preparation Guidelines

• No fasting is generally required.
• Continue medications unless advised otherwise by your physician.
• Inform your healthcare provider about autoimmune diseases, infections, and current medications.
• Follow laboratory instructions before sample collection.

Reporting Time

Results are generally available within 3–7 working days, depending on laboratory methodology.

Who Should Take This Test?

This test is recommended for:

• Individuals with suspected ANCA-associated vasculitis
• Patients with unexplained kidney inflammation
• Individuals with suspected Microscopic Polyangiitis (MPA)
• Patients with unexplained lung inflammation or pulmonary hemorrhage
• Individuals with autoimmune inflammatory disorders
• Patients referred by nephrologists, rheumatologists, pulmonologists, or immunologists

Clinical Significance

A positive Anti-MPO (pANCA) antibody result may indicate:

• Microscopic Polyangiitis (MPA)
• ANCA-Associated Vasculitis (AAV)
• Eosinophilic Granulomatosis with Polyangiitis (EGPA)
• Pauci-Immune Crescentic Glomerulonephritis
• Autoimmune Small Vessel Vasculitis

Common symptoms associated with these conditions include:

• Fatigue
• Fever
• Weight loss
• Joint pain
• Muscle pain
• Blood in urine
• Kidney dysfunction
• Persistent cough
• Shortness of breath
• Skin rash or purpura
• Numbness or weakness due to nerve involvement

A positive Anti-MPO antibody result strongly supports the diagnosis of ANCA-associated vasculitis but should always be interpreted together with clinical findings, PR3-ANCA testing, inflammatory markers, kidney function tests, imaging studies, and tissue biopsy when appropriate.