Rapidly Progressive Glomerulonephritides, Diagnostic and Therapeutic Urgency

Rapidly progressive glomerulonephritides are relatively rare but serious disorders of diverse etiology, which share some clinical features: rapid evolution, progressive to renal failure, often accompanied by oliguria or anuria. They are characterized histopathologically by an intense extracapillary proliferation, with the development of crescents (semilunar lesions) in over 50% of examined glomeruli. The following pathological entities are referred to as rapidly progressive glomerulonephritides: ANCA-positive pauci-immune vasculitides (microscopic polyangiitis, granulomatosis associated with microscopic polyangiitis, allergic granulomatosis associated with microscopic polyangiitis), extracapillary proliferative glomerulonephritides by immune complexes and glomerulonephritides by anti-glomerular basement membrane antibodies. Due to major histopathological and functional complications, their evolution to death or renal replacement therapy occurs within 6-2 months after the diagnosis, if they are not treated, but the evolution is favorably influenced by aggressive immunosuppression, whether or not associated with plasmapheresis.