LAUSR

F ocal segmental glomerulosclerosis (FSGS) is a common pathologic diagnosis on kidney biopsy. It denotes focal and segmental intracapillary hyaline deposition and/or focal adhesions of capillaries to Bowman’s capsule. When it occurs without underlying alternate modes of kidney disease, together with the nephrotic syndrome and diffuse effacement of podocyte foot processes, it is likely to be deemed primary or idiopathic. This suggests that there is a circulating podocyte toxin, of unknown etiology, and that there is a poor prognosis when the disease goes untreated, with up to an 80% chance of kidney failure over 10 years. However, it also suggests the possibility of response to immunosuppressive drugs, especially early in the disease course. Over the past half century, the popularity of immunosuppressive therapy has waxed and waned, but overall review of data suggest that approximately one-half of patients with FSGS can respond to prolonged, high-dose oral steroids with