Atypical anti-glomerular basement membrane disease with anti-GBM antibody negativity and ANCA positivity: a case report.

This patient, whose serum was negative for the anti-GBM antibody but positive for p-ANCA and another atypical ANCA, had a rare case of anti-GBM disease. Insights from this unusual case might help physicians diagnose rare forms of glomerulonephritis and treat affected patients in a timely manner.