Vascularites immunologiques des petits et moyens vaisseaux : physiopathologie et diagnostic biologique

Abstract

AbstractVasculitis is defined by inflammation of the vascular endothelium, it is rare and difficult to diagnose. This article will only discuss primary non-infectious vasculitis, as is done in the international nomenclature of Chapel Hill, the second version of which aimed to replace the eponymous names of diseases with expressions related to their pathophysiological mechanism or their histological characteristics. This nomenclature of vasculitis takes into account the size of the vessels and the pathophysiological mechanisms which, in the involvement of small and medium-sized vessels, are immunological mechanisms. These are first, vasculitis with immune complex deposition, including cryoglobulinemic vasculitis, vasculitis with IgA deposits, hypocomplementemic urticarial vasculitis (McDuffie’s disease) and vasculitis with anti-glomerular basement membrane Abs (Goodpasture’s disease), and second, vasculitis with anti-neutrophil cytoplasmic Abs (ANCA), including granulomatosis with polyangiitis (formerly Wegener’s syndrome), eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome) and microscopic polyangiitis. In this article, the pathophysiological mechanisms of these immunological vasculitides and the biological diagnostic tools will be developed, allowing biologists to participate in the diagnosis of these rare and frequently severe diseases.