True about post streptococcal glomerulonephritis

Robbins 9/e Pg 911 Poststreptococcal Glomerulonephritis This is a prototypical glomerular disease of immune complex etiology, which is decreasing in frequency in the United States but continues to be a fairly common disorder worldwide. It usually appears 1 to 4 weeks after a strepto- coccal infection of the pharynx or skin (impetigo). Skin infections are commonly associated with overcrowding and poor hygiene. Poststreptococcal glomerulonephritis occurs most frequently in children 6 to 10 years of age, but children and adults of any age can also be affectedOGY The classic histologic picture is one of enlarged, hypercellular glomeruli (Fig. 20-9). The hypercellularity is caused by (1) infiltration by leukocytes, both neutrophils and monocytes; (2) proliferation of endothelial and mesangial cells; and (3) in severe cases by crescent formation. The proliferation and leu- kocyte infiltration are typically global and diffuse, that is, involv- ing all lobules of all glomeruli. There is also swelling of endothelial cells, and the combination of proliferation, swelling, and leuko- cyte infiltration obliterates the capillary lumens. r