Main Disease Association
ANCA-associated vasculitis

Category
Antibody

When to Order
* Follow-up test for p-ANCA positivity since it is a type of p-ANCA antibody

What It Means If Positive
* Strong association with small vessel vasculitis, such as microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA)
* MPO antibody correlates with p-ANCA staining

What It Means If Negative
* Does NOT rule out vasculitides