Possibility Related Posts:
The first attempt of classification of vasculitis returns to Zeek who in 1952 proposed to identify multiple entities according to their clinical and pathological (102): hypersensitivity vasculitis, allergic granulomatous vasculitis Churg-Strauss (SCS), the classic PAN and Horton’s disease. Since this classification has been refined by others but the main framework set forth therein remain valid. Fauci described then a “group of polyarteritis nodosa” including the PAN, the SCS and forms overlap (103). This classification had the advantage of being pragmatic and useful for the clinician but further work has to distinguish the microscopic polyangéite (MPA) as a distinct systemic vasculitis of PAN (299,95,104). This recognition has not been taken into account in the classification established in 1990 by the American College of Rheumatology (ACR) (105) (Table 1). Indeed, the PAN and MPA have long been not distinguished because of their resemblance clinical (general manifestations, neurological, gastro-intestinal .).
Nevertheless, these two diseases are distinct. According to the nomenclature proposed at Chapel Hill, PAN preferentially affects the vessels of medium caliber and MPA the small vessels, ie arterioles, capillaries and venules (104). Glomerulonephritis and pulmonary capillaritis observed in the MPA, while the PAN, renal disease is vascular and lung is spared. It is so easy to differentiate the NAP of the MPA in patients with vasculitis with severe renal impairment and / or lung. For cons, the majority of patients, particularly those with vasculitis respects the kidney and lung, the distinction is sometimes impossible even applying the Chapel Hill nomenclature or classification criteria of the ACR PAN (106). Furthermore, impairment of small vessels is possible during the NAP (107) and conversely a violation of vessels of medium size is possible during the MPA (105).
