[Hypocomplementemic urticarial vasculitis with glomerulopathy and renal venulitis]

A 58 year-old woman had atypical chronic urticaria, arthralgias and abdominal pain. Attacks of angioneurotic edema occurred. Proteinuria was discovered. She had clinical and biological signs of inflammation, leukoneutropenia , antileukocyte antibodies and low CH 50, C1q and C4 levels without functional C1 esterase deficiency. C1q precipitins were not detectable. Skin biopsy disclosed angiitis and by immunofluorescence a lupus band test was positive. Serologic investigations in search of SLE were negative. Renal biopsy showed mesangial deposits, capillary loop thickening and mesangial fixation of anti-IgG, C3 C1q and C4 antisera. In the interstitium, voluminous perivenular inflammatory infiltrates were visible. With corticosteroid treatment clinical manifestations subsided and proteinuria disappeared. This observation of McDuffie 's angiitis with renal venulitis leads to a review of the literature with discussion of the mechanisms of hypocomplementemia.