Abstract
We report here 13 patients with idiopathic nephrotic syndrome examined by kidney biopsies at 5 months to 12 years intervals. All of the initial biopsy specimens showed 'minimal change'. At the second biopsy, however, 5 cases were diagnosed as focal glomerulosclerosis (FGS), because there observed sclerosing lesions with eosinophilic deposits, hyaline thrombi, foam cells and vacuoles in three or more glomeruli. Besides in these specimens interstitium was also more increased than in initial biopsy speci-mens. By retrospective detailed histological examination, 4 initial biopsy specimens from FGS patients showed segmental mesangial thickness and capsular adhesions to capillay loops in one or two glomeruli. Clinically, these 4 cases had been steroid-resistant from the early stage and more than 1g/day of urine protein remained throughout the follow up periods. One of the 4 FGS patients never showed throughout the follow up periods. One of the 4 FGS patients never showed any improvement in the nephrotic syndrome, and took a downhill course to uremia necessitating hemodialy sis 7 years after the onset of the disease. In another patient with FGS, steroid therapy was at first effective, but he died of renal failure 16 years after the onset. In the other 3 patients second biopsy specimens showed no abnormality but a few proliferative or hyalinized glomeruli. These cases were steroid-responsive and the renal function was not deterior ated throughout the follow up periods, although they often needed steroid therapy because of relapses of nephrosis. Four biopsy specimens from patients with FGS (3 at the second biopsy and 1 at the third biopsy) and 3 second biopsy specimens from patients with 'minimal change' were studied by immunofluorescent technique. Significant depositions of IgM and .β1c were demonstrated in all of FGS but no deposition in 'minimal change'. These findings lead us to assume that FGS is caused by different factors from that of 'minimal change' type nephrotic syndrome.
