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Perinuclear staining typical of p-ANCA

p-ANCA, or MPO-ANCA, or perinuclear anti-neutrophil cytoplasmic antibodies, are antibodies that stain the material around the nucleus of a neutrophil. They are a special class of anti-neutrophil cytoplasmic antibodies.

This pattern occurs because the vast majority of the antigens targeted by ANCAs are highly cationic (positively charged) at pH 7.00. During ethanol (pH ~7.0 in water) fixation, antigens which are more cationic migrate and localize around the nucleus, attracted by its negatively charged DNA content. Antibody staining therefore results in fluorescence of the region around the nucleus.


p-ANCAs stain the perinuclear region by binding to specific targets. By far the most common p-ANCA target is myeloperoxidase (MPO), a neutrophil granule protein whose primary role in normal metabolic processes is generation of oxygen radicals.

ANCA will less commonly form against alternative antigens that may also result in a p-ANCA pattern. These include lactoferrin, elastase, and cathepsin G.

When the condition is a vasculitis, the target is usually MPO.[1] However, the proportion of p-ANCA sera with anti-MPO antibodies has been reported to be as low as 12%.[2]

Medical conditions[edit]

p-ANCA is associated with several medical conditions:[3]

See also[edit]


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  2. ^ Yehuda Shoenfeld; M. Eric Gershwin; Pier-Luigi Meroni (2007). Autoantibodies. Elsevier. pp. 98–. ISBN 978-0-444-52763-9. Retrieved 1 November 2010.
  3. ^ Mary Lee (10 March 2009). Basic Skills in Interpreting Laboratory Data. ASHP. pp. 455–. ISBN 978-1-58528-180-0. Retrieved 15 November 2010.
  4. ^ Shepherd B, et al. (2005). "Inflammatory Bowel Disease: Diagnostic and Treatment Options". Hospital Physician: 11–19.
  5. ^ [1] Walker, D. G.; Bancil, A. S.; Williams, H. R.; Bunn, C.; Orchard, T. R. (2011). "How helpful are serological markers in differentiating crohn's disease from ulcerative colitis in indian asian inflammatory bowel disease patients?". Gut. 60: A222–A223. doi:10.1136/gut.2011.239301.469.
  6. ^ Thomas M. Habermann; Mayo Clinic (1 November 2007). Mayo Clinic Internal Medicine Concise Textbook. CRC Press. pp. 775–. ISBN 978-1-4200-6749-1. Retrieved 15 November 2010.