Wegener's granulomatosis
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In medicine (rheumatology), Wegener's granulomatosis is a form of vasculitis that affects the lungs, kidneys and other organs. Due to its end-organ damage, it can be a serious disease that requires long-term immune suppressionSeo P, Stone JH. The antineutrophil cytoplasmic antibody-associated vasculitides. Am J Med 2004;117:39-50. PMID 15210387..
It is part of a larger group of vasculitic syndromes that all feature the presence for an abnormal type of circulating antibody termed ANCAs (antineutrophil cytoplasmic antibodies) and affect small and medium-sized blood vessels. Apart from Wegener's, it includes Churg-Strauss syndrome and microscopic polyangiitis.
If the patient has renal failure or cutaneous vasculitis, these are the most logical organs to obtain a biopsy from. Rarely, thoracoscopic lung biopsy is required. On histopathological examination, a biopsy will show leukocytoclastic vasculitis with necrotic changes and granulomatous inflammation (clumps of typically arranged white blood cells) on microscopy. The latter is the main reason for the appellation of "Wegener's granulomatosis", although it is not an essential feature. Unfortunately, many biopsies can be aspecific and 50% provide too little information for the diagnosis of Wegener's.
Differential diagnosis (alternative possible diagnoses) can be extensive. ANCAs can be positive after the use of certain drugs, and other forms of vasculitis can present with very similar symptoms. The saddle nose deformity may also seen in cocaine abuse and in congenital syphilis.
It is now widely presumed that the anti-neutrophil cytoplasmic antibodies (ANCAs) are responsible for the inflammation in Wegener's. The typical ANCAs in Wegener's are those that react with proteinase 3, an enzyme prevalent in neutrophil granulocytesvan der Woude FJ, Rasmussen N, Lobatto S, Wiik A, Permin H, van Es LA, van der Giessen M, van der Hem GK, The TH. Autoantibodies against neutrophils and monocytes: tool for diagnosis and marker of disease activity in Wegener's granulomatosis. Lancet 1985;1(8426):425-9. PMID 2857806..
ANCAs activate neutrophils, increase their adherence to endothelium, and lead to their degranulation. This causes extensive damage to the vessel wall, particularly of arterioles.
The exact cause for the production of ANCAs is unknown, although some drugs have been implicated in secondary forms of Wegener's. As with many autoimmune disorders, the cause is probably genetic predisposition combined with molecular mimicry caused by a virus or bacterium.
Alternative treatments include:
Follow-up: general wellbeing and laboratory organ markers are checked on a regular basis to ascertain the patient has remained in remission.
Long-term complications are very common (86%): mainly chronic renal failure, hearing loss and deafness.
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.Signs and symptoms
Initial signs are protean, and diagnosis can be severely delayed due to the non-specific nature of the symptoms. The rhinitis is generally the first sign in most patients.
Diagnosis
Vasculitis such as Wegener's granulomatosis is usually only suspected when a patient has had unexplained symptoms for a longer period of time. Determination of ANCAs can aid in the diagnosis, but positivity is not conclusive, and neither are negative ANCAs enough to reject the diagnosis. Cytoplasmic staining ANCAs that react with the enzyme proteinase 3 (cANCA) in neutrophils (a type of white blood cell) are associated with Wegener's.Criteria
In 1990, the American College of Rheumatology accepted classification criteria for Wegener's. They were not intended for diagnosis, but for inclusion in randomised controlled trials. Two or more positive criteria have a sensitivity of 88.2% and a specificity of 92.0% of describing Wegener'sLeavitt RY, Fauci AS, Bloch DA, Michel BA, Hunder GG, Arend WP, et al. The American College of Rheumatology 1990 criteria for the classification of Wegener's granulomatosis. Arthritis Rheum 1990;33:1101-7. PMID 2202308..
According to the Chapel Hill Consensus Conference (CHCC) on the nomenclature of systemic vasculitis (1992), establishing the diagnosis of Wegener´s granulomatosis demandsJennette JC, Falk RJ, Andrassy K, Bacon PA, Churg J, Gross WL, Hagen EC, Hoffman GS, Hunder GG, Kallenberg CG, et al. Nomenclature of systemic vasculitides. Proposal of an international consensus conference. Arthritis Rheum 1994;37:187-92. PMID 8129773.:
Several investigators have compared the ACR and Chapel Hill criteriaBruce IN, Bell AL. A comparison of two nomenclature systems for primary systemic vasculitis. Br J Rheumatol 1997;36:453-8. PMID 9159539..Pathophysiology
Inflammation with granuloma formation against a nonspecific inflammatory background is the classical tissue abnormality in all organs affected by Wegener's granulomatosis.Treatment
Initial treatment is generally with corticosteroids and oral cyclophosphamide (CYC), 1 mg/kg/day and 2 mg/kg/day respectively. Occasionally CYC is given in monthly IV doses. Monitoring of the white blood count is essential during CYC therapy. Once remission is attained (normally 3 to 6 months), treatment is frequently changed to azathioprine or methotrexate, which are less toxic drugs. Total duration of therapy should be at least 1 year, or longer in high risk patients. Corticosteroids are tapered to a low maintenance dose, 5-10 mg/day. Plasmapheresis may be beneficial in severe disease or pulmonary hemorrhage. Experience with other treatment agents is very limited.
Non-immunosuppressive therapies are:
In some patients with severe subglottic stenosis, tracheotomy is required to maintain an airway.Epidemiology
The incidence is 8.5 cases per million per year. 90% of the patients are whites. While it mainly occurs in the middle-aged, it has been reported in much younger and older patients.Prognosis
25 to 40% of patients suffer from flare-ups, but a majority responds well to treatment. Anatomical problems (sinusitis, tracheal stenosis) may require surgery in a small proportion. Relapses can be long and troublesome.History
A certain Peter McBride (1854-1946) first described the condition in 1897 in a British medical journal, especially the characteristic nasal deformation. Heinz Karl Ernst Klinger (1907-) would add information on the anatomical pathology, but the full picture was presented by Friedrich Wegener (1907-1990), a German pathologist, in two reports in 1936 and 1939Who Named It [synd/2823].References
External links
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