We examined fourteen patients with idiopathic mesangial proliferative glomerulonephritis (MPG) who received repeated renal biopsies and for whom both light and electron microscopy as well as immunofluorescence microscopy and full clinical data had been available. Morphometric investigations were performed by means of a computer image analysis system that evaluated the progression of the disease in re-biopsied patients, as well as demonstrated whether hypercellularity and mesangial increase could correlate with the degree of proteinuria. The morphometric study demonstrated that mean values of the total glomerular area, total amount of glomerular cells per total glomerular area and total amount of glomerular cells per unit of glomerular area were similar at the time of the initial biopsy and during re-biopsy. On the other hand mean values of mesangium (% of total glomerular area) were significantly decreased during re-biopsy, while mean values of relative interstitial volume were significantly increased at the time of the second biopsy. Correlations between mesangial hypercellularity as well as mesangial areas and proteinuria were during initial biopsy and at re-biopsy weak and insignificant. This data indicates that glomerular morphology does not correspond to the clinical outcome. Moreover, an increase of the relative interstitial volume demonstrates, that despite the clinical improvement at re-biopsy, MPG is a progressive glomerular disease which may lead towards renal failure.

Keywords: renal diseases, Glomerulonephritis, diagnesis, Biopsy, morphometry