Membranous Nephropathy with Rapid Progression.

We report a 49-year-old man with microscopic hematuria, subnephrotic proteinuria, and rapidly progressive renal failure. His biopsy had features of PhosphoLipase A2 Receptor (PLA2R) positive membranous nephropathy with circumferential cellular crescents. Further work-up revealed IgG antiGlomerular Basement Membrane (anti-GBM) antibody titer of 188 U/mL (normal <7 U/mL). A final diagnosis of membranous nephropathy with anti-GBM disease was made. These two distinct pathological entities can occur together resulting in significant morbidity and mortality unless diagnosed early and treatment initiated promptly. Outcomes have been poor, given the nonspecific presentation and delay in diagnosis.