<prompt> Most common cause of glomerulonephritis?P.S.G.NDiabetes mellitusAutosomal dominant Polycystic kidney diseaseCrescentric Glomerulonephritis  <response>: 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. 