Granulomatosis with polyangiitis (GPA), previously known as Wegener's granulomatosis

Wegener's granulomatosis, or Granulomatosis with polyangiitis (GPA), is an incurable form of vasculitis that affects the nose, lungs, kidneys and other organs.

The incidence of GPA is 10 cases per million per year where 90% of the patients are white. Due to its end-organ damage, it is life-threatening and requires long-term immunosuppression. Although GPA affects small and medium-sized vessels, it is formally classified as one of the small vessel vasculitides in the Chapel Hill system. Initial signs are extremely variable, and diagnosis can be severely delayed due to the nonspecific nature of the symptoms. Often the kidneys and lungs are affected and the renal and lung functions are impaired. A serious complication of GPA is rapidly progressive glomerulonephritis (RPGN). This is a syndrome of the kidney that is characterized by a rapid loss of renal function; usually a 50% decline in the glomerular filtration rate (GFR) within 3 months.

 

About Vasculitis

Vasculitis is a general term referring to a heterogeneous group of diseases that are characterised by inflammatory destruction of blood vessels. The condition occurs if the immune system attacks the blood vessels and this may happen as a result of an infection, a medicine or another disease.

Vasculitis can be acute or chronic and may affect any blood vessel in the body. The inflamed blood vessels cause changes in the vessel wall, including thickening, weakening, narrowing and scarring and this can lead to serious complications damaging the body’s organs. Specific signs and symptoms depend on which organ has been damaged and the extent of the damage. The cause of many forms of vasculitis is poorly understood. There is usually an immune component, but the trigger is often not identified. In these cases, the antibody found is sometimes used in classification, as in ANCA-associated vasculitides (Anti-neutrophil cytoplasmic antibodies).

Example of ANCA-associated vasculitides are granulomatosis with polyangiitis (GPA)  (previously named Wegener's granulomatosis), Churg-Strauss syndrome and microscopic polyangiitis (MPA).

Relevant Literature

  1. Arranz, O et al.Comparison of anti-PR3 capture and anti-PR3 direct ELISA for detection of ANCA in long-term clinical follow-up of PR3-ANCA-associated vasculitis patients. Clinical Nephrology 2001;  56: 295-301.
  2. Csernok E, Ahlquist D, Ullrich S, Gross W.L.  A critical evaluation of commercial immunoassays for antineutrophil cytoplasmic antibodies directed against proteinase 3 and myeloperoxidase in Wegener’s granulomatosis and microscopic polyangiitis. Rheumatology 2002;41:1313-1317.
  3. Csernok E, Holle J, Hellmich B et al. Evaluation of capture ELISA for detection of antineutrophil cytoplasmic antibodies directed against proteinase 3 in Wegener’s granulomatosis: first results from a multicenter study. Rheumatology 2004; 43: 174-180
  4. Gisslen, K et al.Relationship between ANCA determined with conventional binding and the capture assay and long-term clinical course in vasculitis.J. Intern Med  2002; 251: 0129-135.
  5. Sanders et al. Prediction of relapses in PR3-ANCA-associated vasculitis by assessing responses of ANCA titres to treatment. Rheumatology 2006; 45: 724-729.
  6. Savage COS et al. ABC of arterial and vascular disease - Vasculitis. Br Med J 2000; 320: 1326-1328
  7. Savige, J et al.ANCA and associated diseases: A review of the clinical and laboratory features. Kidney Int 2000; 57: 846-862.
  8. Segelmark M, et al. How and why should we detect ANCA? Clin Exp Rheumatol 2000, 18, 629-635.
  9. Westman, K et al.Relaps rate, renal survival and cancer morbidity in patients with Wegener’s granulomatosis or microscopic polyangiitis with renal involvement.J Am Soc Nephrol 1998; 9: 842-852.
  10. Won H, et al.Serial ANCA titers. Useful tool for the prevention of relapses in ANCA associated vasculitis. Kidney Int, 2003, 63, 1079-1085.