MPO by EIA p-ANCA Test

Myeloperoxidase (MPO) enzyme is found in primary granules of neutrophil and monocyte lysosomes. Autoantibodies related to MPO (MPO antineutrophil cytoplasmic antibodies, i.e, ANCA) occur in several diseases and may be related to the pathogenesis of vascular inflammation in patients having microscopic polyangiitis (MPA).Patients with MPA often experience MPO ANCA and may also found with azotemia which is secondary to glomerulonephritis (pauci-immune necrotizing glomerulonephritis).MPO ANCA can also be seen in patients with:
1. Systemic lupus erythematosus(with or without lupus nephritis)
2. Goodpasture syndrome.
3. Churg-Strauss syndrome.

You don’t need to do any special preparation for this test.Make sure to wear a short-sleeved shirt or a shirt with sleeves that you can easily rollup.No special preparation needed for the Haematology test. There’s no need to adjust your diet. You can both eat and drink normally.However, your doctor may require that you fast for a specific amount of time before the test. That’s common if the blood sample will be used for additional testing. Your doctor will give you specific instructions.

A positive result has a high chances for microscopic polyangiitis (MPA) in patients with a: 1. negative test results for systemic lupus erythematosus (antinuclear antibodies) 2. Goodpasture syndrome (glomerular basement membrane antibody). Whereas a negative result shows that a patient doesn’t has MPA of any form. The results also helps in diagnosis of the forms of the autoimmune disorder systemic vasculitis(inflammation of blood vessels) The result also helps to distinguish between Crohn disease (CD) and ulcerative colitis (UC).

First, a lab assistant will cleanse your arm with an antiseptic. A needle will be inserted in one of your veins to draw a small sample of blood(few ml). An appropriate amount of blood will be collected.After that, the needle will be removed and a small bandage will be placed on your arm where the needle was inserted. MPO antigen is covalently coupled to polystyrene microsphere, that are later impregnated with fluorescent dyes creating a unique fluorescent signature. MPO antibodies bonds to the MPO antigen on the microspheres if present in diluted serum in any amount. The result is calculated by comparing the median fluorescence results for MPO microspheres to a four point calibration graph.