Cause:Altered regulation of production or structure of IgA
Pathophys:IgA immune complexes deposited in glomeruli, diffuse mesangial deposits; Henoch-Schönlein purpura similar morphologically, maybe etiologically
High prevalence in western Pacific Rim, low in US and Europe; M > F, esp under age 25 yr; most common form of GN worldwide, most common cause of asx hematuria
Sx:Goss hematuria, esp assoc w URI or gastroenteritis
Si:Hematuria (60%), asx (30%); AGN, or nephrotic syndrome (10%)
20-40% progress to chronic renal failure