HDCN Article Review/Hyperlink

Korbet SM, Rosangela MG, Borok RZ, Schwartz MM

The racial prevalence of glomerular lesions in nephrotic adults

Am J Kidney Dis (May) 27:647-651 1996

A retrospective review of the renal biopsies of adult patients with nephrotic range proteinuria from 1975 to 1994 at Rush-Presbyterian-St. Luke's Medical Center was performed. Of the 1369 biopsies performed during this time, there were 340 biopsies in which there was > 3.0 gm of proteinuria per 24 hours with no evidence of a secondary cause of nephrotic syndrome. The racial distribution of this group of patients was 50% white, 36% black, 7% other and 7% unknown. Membranous glomerulonephritis was present in 33% of biopsies, significantly more in white patients than blacks. Focal segmental glomerular sclerosis was present in 34% of biopsies and was four times as likely to occur in blacks than in whites. Though FSGS was a major cause of nephrotic syndrome in black patients > 45 years, its prevalence was significantly less than in the younger patients. Overall minimal change disease accounted for 16% of the total biopsies; however, the incidence decreased from 25% to 11% when comparing the first nine and the last nine years of this study. During this period of time the incidence of FSGS increased from 29% to 38%. After 1985 this was accounted for primarily by black patients. The incidence of other glomerular lesions in the study was: membranoproliferative glomerulonephritis - 6%, IgA nephropathy - 7% and immunotactoid glomerulopathy - 4% of biopsies.

Comment: The authors pointed out that their study supports previous data demonstrating that FSGS is the most common cause of nephrotic syndrome in black patients. Speculation as to the cause of this increased incidence of FSGS included a genetic predisposition, the possibility of reduced nephron mass in comparison to white patients with a higher prevalence of hypertension, or an increase in the collapsing variant of FSGS. Treatment of FSGS frequently requires long courses of steroid therapy in contrast to patients with membranous glomerulonephritis which often undergoes spontaneous remission. This underscores the importance of renal biopsy in prognosis and treatment of all patients with idiopathic nephrotic syndrome. This article up-dates information regarding the incidence of types of primary glomerular lesions in idiopathic nephrotic syndrome in adults and points out important changes in the patterns of incidences among races. (N. Kevin Krane, M.D., Tulane University)