[Histopathologic study of primary glomerulopathies: retrospective analysis of 197 renal biopsies (1985-1987)].

The histopathological prevalence of primary glomerular diseases in patients aged 14 to 70 years (105 males, 92 females) was analysed: 140 (71%) were aged from 14 to 35 years and 57 (29%) were older than 35 years, the difference being significant (p less than 0.001). The following data were found at our Nephrological Unit: the prevalence of focal glomerular sclerosis was 37.1%; of the membranous glomerulonephritis 16.2%; of the IgA nephropathy 8.6%; of the membranoproliferative glomerulonephritis 6.1%; of the minimal change disease 5.1%. The acute diffuse glomerulonephritis, the rapidly progressive glomerulonephritis and the chronic glomerulonephritis showed the same prevalence of 4.6%, and the mesangial proliferative glomerulonephritis and the kidney in Alport's syndrome that of 3.6%. Diagnosis was not defined by renal biopsy in 6.1% of the patients. Failures to achieve diagnosis were due to biopsies with less than 5 glomeruli on optic microscopy or losses affecting the immunofluorescence procedures. It was concluded that the highest prevalence was that of the focal glomerular sclerosis, found in more than one third of the patients. It was followed by the prevalence of the membranous glomerulonephritis which occurred in about one sixth of our cases. The prevalence of IgA nephropathy, minimal change disease, membranoproliferative glomerulonephritis and of other primary glomerulopathies were low. The prevalence of focal glomerular sclerosis was significantly higher (p less than 0.001) in the younger group of patients (14-35 years) than in the older one; the same fact was seen in the prevalence of the proliferative histopathological forms of glomerulonephritis (p less than 0.025), grouping IgA nephropathy, membranoproliferative glomerulonephritis, rapidly progressive glomerulonephritis and mesangial proliferative glomerulonephritis.