Double-Positive Anti-GBM and ANCA-MPO Vasculitis Presenting With Crescentic Glomerulonephritis

We report the case of a 61-year-old man with rapidly progressing glomerulonephritis (RPGN) due to double-positive anti-neutrophil cytoplasmic antibodies (ANCA) and anti-glomerular basement membrane antibodies (GBM) vasculitis. The past medical history included stable untreated psoriatic arthritis and arterial hypertension. He presented with asthenia, anorexia, and rapidly deteriorating renal function with metabolic acidosis and hyperkalemia...