[Rapidly progressing glomerulonephritis. Microangiitis associated with antibodies against the glomerula membrane].

A 53 year old man first presented with a mild anti-neutrophil cytoplasmic antibody (ANCA), type (MPO-ANCA) associated microscopic polyangiitis. Approximately one year later, he presented with fatigue, fever, cough, sore muscles and erythrocyturia. At admission he was uraemic. Kidney biopsy showed in LM extracapillary glomerulonephritis and in immunofluorescence microscopy linear deposition of IgG along the glomerular basement membrane (GBM). MPO-ANCA was still positive, but antibodies against GBM were now also present. Retrospective analysis revealed the presence of anti-GBM antibodies nine months before clinical illness. Pr3-ANCA (C-ANCA) was negative during the whole course. In spite of decreasing anti-GBM antibody levels during treatment, his condition aggravated, and he died from complications. Thus, coexisting anti-GBM antibodies may explain suddenly deteriorating renal function in patients with ANCA associated vasculitis.