Racial differences in the incidence and renal outcome of idiopathic focal segmental glomerulosclerosis in children

The North American Pediatric Registry reports that from 1987 to 1989 blacks and Hispanic children accounted for 23% of all renal transplants performed but 38% of those performed for focal segmental glomerulosclerosis (FSGS). From these data, we infer that blacks and Hispanics form a disproportionate number of FSGS patients who progress to end-stage renal disease (ESRD) compared with white children. To explore this hypothesis we assessed our single-center experience of FSGS comparing black and Hispanic with white children. Of 177 black and Hispanic children followed in our clinic for idiopathic nephrotic syndrome (NS) between 1974 and 1989, 57 were diagnosed as having FSGS (group I). The mean age at onset of NS of these group I patients was 7.3±4.6 years and the mean duration of follow-up was 8.25±4.3 years. During the same period, 13 of 65 white patients (group II) with idiopathic NS were found to have FSGS. Their mean age (7.8±4.8 years) and duration of follow-up (8.8±4.8 years) were similar. Therapeutic modalities in the two groups were also similar. Of group I patients, 78% (42/54) reached ESRD compared with 33% (4/12) of group II patients (P<0.01). Life table analysis showed that 50% of black and Hispanic children will reach ESRD within 3 years of FSGS. In a subset of patients, multiple regression analysis revealed that the higher the serum creatinine at the onset of NS (P<0.01,r=0.519), and the higher the serum cholesterol at the onset of NS (P<0.02,r=0.511), the more rapid the progression to ESRD. Based on our findings, a national survey to determine if FSGS is more virulent in black and Hispanic children is warranted.Presented in part at the 22nd Annual Meeting of the American Society of Nephrology, Washington, D. C., December 1989