Microscopic polyangiitis

Microscopic polyangiitis
Classification and external resources
ICD-10	M31.7
DiseasesDB	8193
eMedicine	med/2931

Microscopic polyangiitis (also known as "Microscopic polyarteritis,"^[1] "Microscopic polyarteritis nodosa,"^[1] "MPA"^[2]) is an ill-defined autoimmune disease characterized by pauci-immune, necrotizing, small-vessel vasculitis without clinical or pathological evidence of necrotizing granulomatous inflammation.

Presentation

Because many different organ systems may be involved, a wide range of symptoms is possible in MPA.

Purpura and livedo may be present.^[3]

Diagnosis

Laboratory tests show an increased sedimentation rate, reduced red blood count, perinuclear antineutrophil cytoplasmic antibodies (p-ANCA) directed against myeloperoxidase^[4] (a constituent of neutrophil granules), and protein and red blood cells in the urine.

The test for anti-glomerular basement membrane antibody (GBM), which is positive in Goodpasture's syndrome, is negative.

Cause

This condition, the clinical picture of which may include many features of systemic lupus erythematosis, has been reported. While the mechanism of disease has yet to be fully elucidated, the leading hypothesis is that the process is begun with an autoimmune process of unknown etiology that triggers production of p-ANCA. These antibodies will circulate at low levels until a pro-inflammatory trigger - such as infection, malignancy, or drug therapy. The trigger upregulates production of p-ANCA. Then, the large number of antibodies make it more likely that they will bind a neutrophil. Once bound, the neutrophil degranulates. The degranulation releases toxins that cause endothelial injury, that is, damage to vessels of glomeruli.^[5]

Treatment

The customary treatment involves long term dosage of prednisone, alternated or combined with cytotoxic drugs, such as cyclophosphamide or azathioprine.

Plasmapheresis may also be indicated in the acute setting to remove ANCA antibodies.

Rituximab has been investigated,^[6] and in April 2011 approved by the FDA when used in combination with glucocorticoids.^[2]

See also

• ANCA-associated vasculitides
• Polyarteritis nodosa
• List of cutaneous conditions

References

1. ^ ^{a b} Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. ISBN 1-4160-2999-0. 
2. ^ ^{a b} "FDA approves Rituxan to treat two rare disorders" (Press release). Food and Drug Administration. 19 April 2011. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm251946.htm. Retrieved 20 April 2011. 
3. ^ Nagai Y, Hasegawa M, Igarashi N, Tanaka S, Yamanaka M, Ishikawa O (December 2008). "Cutaneous manifestations and histological features of microscopic polyangiitis". Eur J Dermatol 19 (1): 57–60. doi:10.1684/ejd.2008.0566. PMID 19059827. http://www.john-libbey-eurotext.fr/medline.md?issn=1167-1122&vol=&iss=&page=. ^{[dead link]}
4. ^ Seishima M, Oyama Z, Oda M (2004). "Skin eruptions associated with microscopic polyangiitis". Eur J Dermatol 14 (4): 255–8. PMID 15319159. http://www.john-libbey-eurotext.fr/medline.md?issn=1167-1122&vol=14&iss=4&page=255. 
5. ^ Xiao H, Heeringa P, Hu P, et al. (October 2002). "Antineutrophil cytoplasmic autoantibodies specific for myeloperoxidase cause glomerulonephritis and vasculitis in mice". J. Clin. Invest. 110 (7): 955–63. doi:10.1172/JCI15918. PMC 151154. PMID 12370273. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=151154. 
6. ^ Jayne D (January 2008). "Challenges in the management of microscopic polyangiitis: past, present and future". Curr Opin Rheumatol 20 (1): 3–9. doi:10.1097/BOR.0b013e3282f370d1. PMID 18281850. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?an=00002281-200801000-00003. 

External links

• Overview at Johns Hopkins
• Overview at Cleveland Clinic

This cutaneous condition article is a stub. You can help Wikipedia by expanding it.v · Categories: Vascular-related cutaneous conditions Systemic connective tissue disorders Cutaneous condition stubs Wikimedia Foundation. 2010. Игры ⚽ Поможем сделать НИР John Bamford Anthony Hamilton Look at other dictionaries: microscopic polyangiitis — a type of small vessel vasculitis, usually in the kidneys but sometimes also in the lungs, skin, and nervous system; characteristics are similar to those of polyarteritis nodosa with focal segmental glomerulosclerosis and presence of… …   Medical dictionary polyangiitis — Inflammation of multiple blood vessel s involving more than one type of vessel, e.g., arteries and veins, or arterioles and capillaries. microscopic p. systemic, nongranulomatous small vessel vasculitis, associated with glomerulonephritis,… …   Medical dictionary microscopic polyarteritis — see under polyangiitis …   Medical dictionary Microhematuria — Microscopic hematuria is a medical condition in which urine contains small amounts of blood. Blood quantity is too low to change the color of the urine (otherwise, it is known as gross hematuria). While not dangerous in itself, it maybe a symptom …   Wikipedia Systemic vasculitis — Classification and external resources ICD 10 M30 M31 ICD 9 …   Wikipedia Wegener's granulomatosis — Classification and external resources Micrograph showing features characteristic of Wegener s granulomatosis a vasculitis and granulomas with multi nucleated giant cells …   Wikipedia Polyarteritis nodosa — Classification and external resources ICD 10 M30.0 ICD 9 446.0 …   Wikipedia Rapidly progressive glomerulonephritis — Classification and external resources Histopathological image of crescentic glomerulonephritis in a patient with MPO ANCA positive rapid progressive glomerulonephritis. Hematoxylin eosin stain …   Wikipedia P-ANCA — Perinuclear staining typical of p ANCA p ANCA, or Perinuclear Anti Neutrophil Cytoplasmic Antibodies, show a perinuclear staining pattern. This pattern occurs because the vast majority of the antigens targeted by ANCAs are highly cationic… …   Wikipedia Kawasaki disease — Classification and external resources A child showing characteristic strawberry tongue seen in Kawasaki disease ICD 10 M …   Wikipedia 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”