Inflammation of the glomeruli that is characterized by a rapid loss in renal function with glomerular crescent formation observed on biopsy; it is often seen in patients with concomitant autoimmune disease, like goodpasture's syndrome or systemic lupus erythematosus.

Rapidly progressive glomerulonephritis (RPGN) is a syndrome of the kidney that is characterized by a rapid loss of kidney function, (usually a 50% decline in the glomerular filtration rate (GFR) within 3 months) with glomerular crescent formation seen in at least 50% or 75% of glomeruli seen on kidney biopsies. If left untreated, it rapidly progresses into acute kidney failure and death within months...