Renal disease and vasculitis.

Vasculitis is rare in childhood, apart from Henoch-Schönlein purpura, and paediatric nephrologists see few cases of Wegener's granuloma or microscopic polyarteritis. In contrast, this pattern is reversed in adults. Recently much information about the presentation and longer-term course of both these conditions has been described in adults, and more aggressive treatment of severe cases with renal failure has improved the outlook from a 5-year survival of about 5%-80% or more. In parallel, it has become evident that the abundant immune complexes in the circulation of patients with vasculitis may play little or no role in the pathogenesis of the vasculitic lesions. Current interest centres both on the possible role of cell-mediated immunity and the recent finding of antibodies which react with antigens in the cytoplasm of leucocytes. These antibodies seem to be of clinical use in defining patients with vasculitis, especially when only the kidney is involved at a clinical level. The nature of this leucocyte antigen (or antigens) and the possible role of antibodies directed against them in the pathogenesis of the disease are subjects of current work in many laboratories.