eMedicine Specialties > Rheumatology > Vasculitis

Microscopic Polyangiitis

Author: Mehran Farid-Moayer, MD, Adjunct Clinical Faculty, Department of Psychiatry, Sleep Disorders Clinic, Stanford Medical Center
Coauthor(s): Spencer T Lowe, MD, Rheumatologist, Private Practice, Peninsula Medical Group, Burlingame, CA
Contributor Information and Disclosures

Updated: Jan 20, 2010

Introduction

Background

Microscopic polyangiitis (MPA) is vasculitis of small vessels. It was initially considered as a microscopic form of polyarteritis nodosa (PAN). In 1990, the American College of Rheumatology developed classification criteria for several types of systemic vasculitis but did not distinguish between polyarteritis nodosa and microscopic polyarteritis nodosa.1 In 1994, a group of experts held an international consensus conference in Chapel Hill, North Carolina, to attempt to redefine the classification of small vessel vasculitides.2,3

Vasculitis in small vessels, including arterioles, capillaries, and venules, a characteristic of MPA, is absent in polyarteritis nodosa. This absence is the proposed distinguishing feature between MPA and PAN. Wegener granulomatosis, MPA, and Churg-Strauss syndrome comprise a category of small vessel vasculitis related to antineutrophil cytoplasmic antibodies (ANCAs) and are characterized by a paucity of immune deposits. MPA and Wegener granulomatosis seem to be part of a clinical spectrum. However, an absence of granuloma formation and sparing of the upper respiratory tract are features of MPA. These features help to distinguish MPA from Wegener granulomatosis, although the two conditions are occasionally difficult to distinguish.

Pathophysiology

Vasculitis is inflammation of the vessel walls. This may lead to necrosis and bleeding. MPA is characterized by pauci-immune, necrotizing, small vessel vasculitis without clinical or pathological evidence of granulomatous inflammation.

Frequency

United States

The annual incidence of MPA is 3.6 cases per million persons. Prevalence is 1-3 cases per 100,000 population.

International

Incidence is approximately 2 cases per 100,000 persons in the United Kingdom and approximately 1 case in 100,000 persons in Sweden.

Mortality/Morbidity

  • Renal failure and pulmonary involvement are the major causes of morbidity and mortality.
  • With treatment, Falk and Guillevin (1990) reported 2- and 5-year survival rates of 75% and 74%, respectively.4

Race

  • In the United States, MPA is more frequent among white persons than black persons.

Sex

  • Males are affected slightly more frequently than females.

Age

  • The age of onset is approximately 50 years.

Clinical

History

Symptoms of microscopic polyangiitis (MPA) include the following:

  • Constitutional symptoms
    • Fever (55%)
    • Malaise, fatigue, flulike syndrome
    • Myalgia (48%)
    • Weight loss (72%)
  • Skin manifestations - Skin rash (50%)
  • Pulmonary manifestations
    • Hemoptysis (11%)
    • Dyspnea
    • Cough
  • Cardiovascular manifestations – Chest pain, symptoms of heart failure
  • Gastrointestinal involvement
    • Gastrointestinal bleeding
    • Abdominal pain
  • Nervous system manifestations
    • More commonly, peripheral nervous system involvement manifesting as mononeuritis multiplex (57%)
    • CNS involvement manifesting as seizures (11%)
  • Arthralgias (10-50%)
  • Myalgias (40%)
  • Testicular pain (2%)
  • Ocular manifestations (1%)
    • Red eye
    • Ocular pain
    • Decreased visual acuity
  • Symptoms of sinusitis (1%)

Physical

The physical examination findings include the manifestations of specific organ system involvement. A dermato-pulmonary-renal syndrome is the feature of the disease.

  • Fever
  • Skin involvement
    • Leukocytoclastic angiitis and its palpable purpura (Leukocytoclastic purpura could be a manifestation of the systemic vasculitides or could be a stand-alone skin disorder (see image below.)

      • Leukocytoclastic angiitis.

        Leukocytoclastic angiitis.

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        Leukocytoclastic angiitis.

        Leukocytoclastic angiitis.

    • Palpable purpura (41%)
    • Livedo reticularis (12%)
    • Skin ulcerations
    • Necrosis and gangrene
    • Necrotizing nodules
    • Urticaria
    • Digital ischemia (7%)
    • Urticaria - Vasculitis-associated urticaria that lasts longer than 24 hours
  • Lower respiratory system
    • Pulmonary rales
    • Respiratory distress
  • Upper respiratory tract - Sinusitis less frequent than in Wegener granulomatosis
  • Cardiovascular system
    • Hypertension (34%)
    • Signs of cardiac failure (17%)
    • Myocardial infarction (2%)
    • Pericarditis (10%)
  • Gastrointestinal system
    • Gastrointestinal bleeding
    • Bowel ischemia and perforation
    • Pancreatitis
  • Ocular involvement (1%)
    • Retinal hemorrhage
    • Scleritis
    • Uveitis
  • Renal involvement - Signs of uremia in advanced renal failure (Eight percent of patients with MPA present with renal failure and require hemodialysis.)
  • Musculoskeletal system
    • Synovitis
    • Arthritis
  • Nervous system
    • Mononeuritis multiplex - Most frequent neurologic manifestation of the disease (57%)
    • CNS involvement - Includes meningeal vasculitis (11%)
  • Other organ vasculitis - Orchitis (2%)

Causes

  • Based on current understanding of the inflammatory response, cytokine-mediated changes in the expression and function of adhesion molecules coupled with inappropriate activation of leukocytes and endothelial cells are postulated to be the primary factors influencing the degree and location of vessel damage in the vasculitis syndromes. However, the stimuli that initiate these pathologic inflammatory changes are not well understood.
  • ANCA may play a role in the pathogenesis of MPA.
  • Case reports have described an association of MPA with medications such as propylthiouracil and with diseases such as primary biliary cirrhosis.5,6

More on Microscopic Polyangiitis

Overview: Microscopic Polyangiitis
Differential Diagnoses & Workup: Microscopic Polyangiitis
Treatment & Medication: Microscopic Polyangiitis
Follow-up: Microscopic Polyangiitis
Multimedia: Microscopic Polyangiitis
References
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References

  1. Fries JF, Hunder GG, Bloch DA, et al. The American College of Rheumatology 1990 criteria for the classification of vasculitis. Summary. Arthritis Rheum. Aug 1990;33(8):1135-6. [Medline].

  2. Jennette JC, Falk RJ, Andrassy K, et al. Nomenclature of systemic vasculitides. Proposal of an international consensus conference. Arthritis Rheum. Feb 1994;37(2):187-92. [Medline].

  3. Lightfoot RW, Michel BA, Bloch DA, et al. The American College of Rheumatology 1990 criteria for the classification of polyarteritis nodosa. Arthritis Rheum. Aug 1990;33(8):1088-93. [Medline].

  4. Falk RJ, Hogan S, Carey TS, Jennette JC. Clinical course of anti-neutrophil cytoplasmic autoantibody-associated glomerulonephritis and systemic vasculitis. The Glomerular Disease Collaborative Network. Ann Intern Med. Nov 1 1990;113(9):656-63. [Medline].

  5. Amezcua-Guerra LM, Prieto P, Bojalil R, Pineda C, Amigo MC. Microscopic polyangiitis associated with primary biliary cirrhosis: a causal or casual association?. J Rheumatol. Nov 2006;33(11):2351-3. [Medline].

  6. Seligman VA, Bolton PB, Sanchez HC, Fye KH. Propylthiouracil-induced microscopic polyangiitis. J Clin Rheumatol. Jun 2001;7(3):170-4. [Medline].

  7. Reinhold-Keller E, De Groot K, Rudert H, Nölle B, Heller M, Gross WL. Response to trimethoprim/sulfamethoxazole in Wegener's granulomatosis depends on the phase of disease. QJM. Jan 1996;89(1):15-23. [Medline].

  8. Stegeman CA, Tervaert JW, de Jong PE, Kallenberg CG. Trimethoprim-sulfamethoxazole (co-trimoxazole) for the prevention of relapses of Wegener's granulomatosis. Dutch Co-Trimoxazole Wegener Study Group. N Engl J Med. Jul 4 1996;335(1):16-20. [Medline].

  9. Langford CA, Talar-Williams C, Sneller MC. Mycophenolate mofetil for remission maintenance in the treatment of Wegener's granulomatosis. Arthritis Rheum. Apr 15 2004;51(2):278-83. [Medline].

  10. Nowack R, Göbel U, Klooker P, Hergesell O, Andrassy K, van der Woude FJ. Mycophenolate mofetil for maintenance therapy of Wegener's granulomatosis and microscopic polyangiitis: a pilot study in 11 patients with renal involvement. J Am Soc Nephrol. Sep 1999;10(9):1965-71. [Medline].

  11. Iatrou C, Zerbala S, Revela I, Spanou E, Marinaki S, Nakopoulou L, et al. Mycophenolate mofetil as maintenance therapy in patients with vasculitis and renal involvement. Clin Nephrol. Jul 2009;72(1):31-7. [Medline].

  12. Terrier B, Saadoun D, Sène D, Ghillani P, Amoura Z, Deray G, et al. Antimyeloperoxidase antibodies are a useful marker of disease activity in antineutrophil cytoplasmic antibody-associated vasculitides. Ann Rheum Dis. Oct 2009;68(10):1564-71. [Medline].

  13. Guillevin L, Durand-Gasselin B, Cevallos R, et al. Microscopic polyangiitis: clinical and laboratory findings in eighty-five patients. Arthritis Rheum. Mar 1999;42(3):421-30. [Medline].

  14. Haubitz M, Koch KM, Brunkhorst R. Cyclosporin for the prevention of disease reactivation in relapsing ANCA-associated vasculitis. Nephrol Dial Transplant. Aug 1998;13(8):2074-6. [Medline].

  15. Jayne D. Review article: Progress of treatment in ANCA-associated vasculitis. Nephrology (Carlton). Feb 2009;14(1):42-8. [Medline].

  16. Jayne D, Rasmussen N, Andrassy K, et al. A randomized trial of maintenance therapy for vasculitis associated with antineutrophil cytoplasmic autoantibodies. N Engl J Med. Jul 3 2003;349(1):36-44. [Medline].

  17. Jayne DR, Gaskin G, Pusey CD, Lockwood CM. ANCA and predicting relapse in systemic vasculitis. QJM. Feb 1995;88(2):127-33. [Medline].

  18. Jennette JC. Antineutrophil cytoplasmic autoantibody-associated diseases: a pathologist's perspective. Am J Kidney Dis. Aug 1991;18(2):164-70. [Medline].

  19. Jennette JC, Falk RJ. Small-vessel vasculitis. N Engl J Med. Nov 20 1997;337(21):1512-23. [Medline].

  20. Kamesh L, Harper L, Savage CO. ANCA-positive vasculitis. J Am Soc Nephrol. Jul 2002;13(7):1953-60. [Medline].

  21. Lane SE, Watts RA, Shepstone L, Scott DG. Primary systemic vasculitis: clinical features and mortality. QJM. Feb 2005;98(2):97-111. [Medline].

  22. Lhote F, Cohen P, Genereau T, et al. Microscopic polyangiitis: clinical aspects and treatment. Ann Med Interne (Paris). 1996;147(3):165-77. [Medline].

  23. Liu LJ, Chen M, Yu F, Zhao MH, Wang HY. Evaluation of a new algorithm in classification of systemic vasculitis. Rheumatology (Oxford). May 2008;47(5):708-12. [Medline].

  24. Matteson EL. Small-vessel vasculitis. N Engl J Med. Apr 2 1998;338(14):994-5. [Medline].

  25. Ronco P, Verroust P, Mignon F, Kourilsky O, Vanhille P, Meyrier A, et al. Immunopathological studies of polyarteritis nodosa and Wegener's granulomatosis: a report of 43 patients with 51 renal biopsies. Q J Med. Spring 1983;52(206):212-23. [Medline].

  26. Savage CO, Harper L, Adu D. Primary systemic vasculitis. Lancet. Feb 22 1997;349(9051):553-8. [Medline].

  27. Sneller MC, Fauci AS. Pathogenesis of vasculitis syndromes. Med Clin North Am. Jan 1997;81(1):221-42. [Medline].

  28. Watts R, Lane S, Hanslik T, Hauser T, Hellmich B, Koldingsnes W, et al. Development and validation of a consensus methodology for the classification of the ANCA-associated vasculitides and polyarteritis nodosa for epidemiological studies. Ann Rheum Dis. Feb 2007;66(2):222-7. [Medline].

  29. Watts RA, Jolliffe VA, Carruthers DM, et al. Effect of classification on the incidence of polyarteritis nodosa and microscopic polyangiitis. Arthritis Rheum. Jul 1996;39(7):1208-12. [Medline].

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Further Reading

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Keywords

microscopic polyangiitis, MPA, small vessel vasculitis, microscopic polyarteritis nodosa, microscopic PAN, small vessel vasculitides, systemic vasculitis, Wegener granulomatosis, Wegener's granulomatosis, Churg-Strauss syndrome, polyarteritis nodosa

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Contributor Information and Disclosures

Author

Mehran Farid-Moayer, MD, Adjunct Clinical Faculty, Department of Psychiatry, Sleep Disorders Clinic, Stanford Medical Center
Mehran Farid-Moayer, MD is a member of the following medical societies: American Academy of Sleep Medicine, American Medical Association, and American Thoracic Society
Disclosure: Nothing to disclose.

Coauthor(s)

Spencer T Lowe, MD, Rheumatologist, Private Practice, Peninsula Medical Group, Burlingame, CA
Spencer T Lowe, MD is a member of the following medical societies: American College of Rheumatology, California Medical Association, and International Society for Clinical Densitometry
Disclosure: Nothing to disclose.

Medical Editor

Bryan L Martin, DO, Chief, Allergy Immunology Department, Walter Reed Army Medical Center; Associate Professor of Medicine and Pediatrics, Uniformed Services University of the Health Sciences; United States Army Consultant in Allergy Immunology and Immunizations
Bryan L Martin, DO is a member of the following medical societies: American Academy of Allergy Asthma and Immunology, American College of Allergy, Asthma and Immunology, American College of Osteopathic Internists, American College of Physicians, American Medical Association, and American Osteopathic Association
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Elliot Goldberg, MD, Dean of the Western Pennsylvania Clinical Campus, Professor, Department of Medicine, Temple University School of Medicine
Elliot Goldberg, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, and American College of Rheumatology
Disclosure: Nothing to disclose.

CME Editor

Alex J Mechaber, MD, FACP, Associate Dean for Undergraduate Medical Education, Associate Professor of Medicine, University of Miami Miller School of Medicine
Alex J Mechaber, MD, FACP is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians-American Society of Internal Medicine, and Society of General Internal Medicine
Disclosure: Nothing to disclose.

Chief Editor

Vecihi Batuman, MD, FACP, FASN, Professor of Medicine, Section of Nephrology-Hypertension, Tulane University School of Medicine; Chief, Medicine Service, Southeast Louisiana Veterans Health Care System
Vecihi Batuman, MD, FACP, FASN is a member of the following medical societies: American College of Physicians, American Society of Hypertension, American Society of Nephrology, and International Society of Nephrology
Disclosure: Nothing to disclose.

 
 
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