[Idiopathic rapidly progressive glomerulonephritis and small vessel vasculitis]

We analyzed the clinical and pathological characteristics of patients with idiopathic rapidly progressive glomerulonephritis (idiopathic RPGN), who had been hospitalized in recent three years. Five out of 8 patients with idiopathic RPGN were positive for anti-neutrophil cytoplasmic autoantibodies (ANCA), most of them showed pANCA by indirect immunofluorescence technique. Compared with those who were ANCA negative, ANCA positive patients had an elder onset age; most of them had fever, arthragia, myalgia, skin rash, and some patients also had deafness, eye and nasal disorders. ANCA positive patients had a positive CRP, elevated gammaglobulins and accelerated ESR (> 100 mm/1 h). Typical pathological findings for ANCA positive patients were focal segmental fibroid necrosis of the glomerular capillary tufts and diffuse crescents formation. After an intensive therapy, the renal functions of most ANCA positive patients were obviously improved and most of them became hemodialysis independent. The results suggested that idiopathic RPGN might be a renal limited form of small vessel vasculitis and the patients with idiopathic RPGN had a better prognosis. Early diagnosis and appropriate intensive therapy are critical for patients with idiopathic RPGN.