Rapidly progressive glomerulonephritis

Rapidly progressive glomerulonephritis, also called crescentic glomerulonephritis, is a kidney syndrome marked by a rapid loss of kidney function, defined as a 50 percent decline in glomerular filtration rate within three months, together with characteristic crescent-shaped scars affecting at least half of the kidney's filtering units. In about half of cases it accompanies an underlying disease such as Goodpasture syndrome, systemic lupus erythematosus or granulomatosis with polyangiitis, while the remaining cases are idiopathic, with severe injury to the glomeruli arising through different immunological mechanisms depending on the underlying type. Patients typically show a severe and rapid loss of kidney function together with marked blood in the urine, red blood cell casts, and protein in the urine; some develop high blood pressure and swelling, and pronounced reduced urine output signals a poor prognosis. The syndrome is rare, with an incidence of roughly 3.9 cases per million people, but is considered a serious and often urgent kidney disease.