Myeloperoxidase (MPO) Antibodies

Immunology

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Description

P-ANCA are principally directed against myeloperoxidase ( MPO ), which is found in azurophil granules in the cytoplasm of human neutrophils. Other P-ANCA antigen specificities are for elastase and lactoferrin. P-ANCA is associated with microscopic polyangitis ( MPA ) and in some cases of Granulomatosis with Polyangiitis ( GPA )( formerly known as Wegener's granulomatosis ) and Eosinophilic Granulomatosis with Polyangiitis ( EGPA ) ( formerly known as Churg-Strauss syndrome ). Although can also be seen in inflammatory bowel disease and other autoimmune diseases [2]. ANCA measurements are not closely associated with disease activity and should therefore not determine treatment increases or decreases [1]. However treatment withdrawal in patients with a persistently positive ANCA is associated with relapse [1].

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Indications

Confirmatory test for the presence of anti-MPO antibodies in ANCA positive samples. Please note the Protein Reference Unit does not provide out of hours service for these tests. Our working hours are Monday to Friday from 9:00 to 17:00 (excluding bank Holidays). For any out of hours clinical queries, suggest discuss with relevant specialities e.g. renal/ Rheumatology.

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Sample Type

2mL Serum ( Gel 5mL Yellow tube ). Requests from outside Sheffield: Transport at ambient temperature via Royal Mail or Courier.

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Reference Range

<5 IU/mL = Negative
Reference range established by manufacturer and verified in-house.

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Turnaround Time

Within 3 days

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Testing Frequency

Daily

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References

Guilpain P, et al. Natural and disease associated anti-myeloperoxidase ( MPO ) antibodies. Autoimmunity Reviews. 2008. 7( 6 ):421-425.
Lapraik C, et al. BSR and BHPR guidelines for the management of adults with ANCA associated vasculitis. Rheumatology. 2007. 46( 10 ): 1615-1616. [Ref 1]
Bosch X, Guilabert A and Font J. Antineutrophil cytoplasmic antibodies. Lancet. 2006. 368( 9533 ):404-418.
Seo P and Stone J. The Antineutrophil cytoplasmic antibody-associated vasculitides. Am J Med. 2004. 117:39-50.
Reumaux D, Duthilleul P, Roos D. Pathogenesis of diseases associated with antineutrophil cytoplasm autoantibodies. Hum Immunol. 2004. 65( 1 ):1-12.
Savige J, et al. Addendum to the International Consensus Statement on testing and reporting of antineutrophil cytoplasmic antibodies. Quality control guidelines, comments, and recommendations for testing in other autoimmune diseases. Am J Clin Pathol. 2003. 120( 3 ):312-318. Review. [Ref 2]
Bossuyt X, et al. Revised 2017 international consensus on testing of ANCAs in granulomatosis with polyangitis and microscopic polyangitis. Nature Reviews Rheumatology. 2017. 13; 683-692.

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See Also

ANCA; PR3

Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.