Specimen Collection Manual and Test Catalog

0.5 mL serum; minimum 0.2 mL

Allow to clot. Centrifuge and submit 0.5 mL serum.

Refrigerated (preferred). Room temperature (stable 8 hours) and frozen specimens also acceptable.

Room temperature: 8 hours. 2-8°C: 48 hours. Frozen: 6 months.

Specimen stability exceeded; specimen grossly hemolyzed.

C-ANCA negative, P-ANCA negative.

A sample is considered negative if specific neutrophil staining is equivalent to or less than the negative control well. A sample is considered positive if cytoplasmic or perinuclear staining is observed.

C-ANCA, P-ANCA antibody detection.

ANCA, Anti-neutrophil cytoplasmic antibody

For initial evaluation of suspected autoimmune vasculitis, Systemic Vasculitis Screen (LAB5191) should be used. In rare cases, ANCA-associated vasculitides (AAV) such as Microscopic Polyangiitis, Granulomatosis with Polyantiitis, pauciimmune-necrotizing crescentic glomerulonephritis, and Churg-Strauss syndrome, may present with positive ANCA testing by immunofluorescence (ANCA-IFA) and negative anti-MPO/PR3 antibodies. ANCA-IFA may be useful in conjunction with other tests and clinical findings in the evaluation of patients where anti-MPO/PR3 are negative but strong clinical suspicion of autoimmune vasculitis remains, or follow-up of known MPO/PR3-negative, ANCA-positive vasculitis. ANCA-IFA positivity is also seen in some patients with other autoimmune conditions such as IBD, PSC, and RA.