Most common cause of glomerulonephritis?

Ans. (a) P.S.G.NRef: Harrison 19th ed. /1837* Acute glomerulonephritis (GN) comprises a specific set of renal diseases in which an immunologic mechanism triggers inflammation and proliferation of glomerular tissue that can result in damage to the basement membrane, mesangium, or capillary endothelium.* Acute post-streptococcal glomerulonephritis (PSGN) is the archetype of acute GN. Acute nephritic syndrome is the most serious and potentially devastating form of the various renal syndromes.* Most often, the patient is a boy, aged 2-14 years, who suddenly develops puffiness of the eyelids and facial edema in the setting of a post-streptococcal infection. The urine is dark and scanty, and the blood pressure may be elevate* Rapidly progressive glomerulonephritis (RPGN) is defined as any glomerular disease characterized by extensive crescents (usually >50%) as the principal histologic finding and by a rapid loss of renal function (usually a 50% decline in the glomerular filtration rate within 3 mo) as the clinical correlate.