057
Test #
ANCA Panel (Incudes ANCA, PR3 and MPO)
CPT Code(s) #
86036, 83516 x2
If Profile, Includes Tests:
N/A
Disease Name:
ANCA associated vasculits
Type of Study:
Serum Studies
Methodology:
Fluoroenzyme immunoassay (FEIA), Indirect Immunofluorescence (Human Neutrophil)
Substrate:
N/A
Reference Range:
Anti-Neutrophil Cytoplasmic Antibody (ANCA) (Titer)
• Negative <20
Myeloperoxidase (MPO) (U/mL)
• Negative <3.5
• Equivocal 3.5-5.0
• Positive >5.0
Proteinase 3 (PR3) (U/mL)
• Negative <2.0
• Equivocal 2.0-3.0
• Positive >3.0
Units:
ANCA: titer/pattern, MPO/PR3: U/mL (Units/mL)
Schedule:
Assay performed once every week. Report availability is within one week from the time of specimen receipt
Specimen Requirements:
Collect 5-10 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into red capped tube provided with Beutner Laboratories collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.
Sample Stability:
Sample is stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8ºC) up to five days and frozen (-20ºC or lower) up to one year
Clinical Relevance:
Antineutrophil cytoplasmic antibodies (ANCA) are the serological markers of some idiopathic systemic vasculitides predominantly afflicting small (medium)-sized blood vessels, such as granulomatosis with polyangiitis (GPA, previously called Wegener granulomatosis), microscopic polyangiitis (MPA) and, to a lesser extent eosinophilic granulomatosis with polyangiitis (EGPA, previously Churg-Strauss syndrome). These vasculitides, in which circulating ANCA are commonly found, are named “ANCA associated vasculitis” (AAV). ANCA are found in 70-95% of patients with GPA and MPA and their prevalence in EGPA is around 30%-40%. The main fluoroscopic patterns of ANCA by IIF are the diffuse, granular cytoplasmic (C-ANCA), and the perinuclear (P-ANCA). C-ANCA is due to the presence of autoantibodies targeting the serine protease proteinase-3 (PR-3). P-ANCA is caused by antibodies directed against multiple antigens, among which the myeloperoxidase (MPO-ANCA) is the most frequent one in AAV. The sensitivity of IIF to detect ANCA ranges from 80-90% and specificity is approximately 80%. P-ANCA and MPO prevalence is 65%-90% in MPA, 70%-90% in pauci-immune necrotizing crescentic glomerulonephritis, 25% in GPA and 30%-40% in EGPA. The disease associations of C-ANCA and PR3 antibodies include GPA (40%-90%), MPA (15-20%), pauci-immune necrotizing crescentic glomerulonephritis (NCGN, 10%), and EGPA (<10%). The definitive diagnosis should be based on clinical signs and symptoms and not on single diagnostic method results. ANCA can be deteced in other condiitons such as inflammaroty bowel disease (IBD), connective tissue disease, rheumatoid arthritis, infections, drug induced vasculitis and drug induced lupus.
