Morphological changes in membranoproliferative glomerulonephritis - a quantitative approach.

Our study aimed to investigate the quantitative profile of the renal corpuscle components in membranoproliferative glomerulinephritis (MPGN). We have analyzed digital color images corresponding to relevant microscopic fields from renal biopsies (10 cases type I MPGN and 10 cases type II MPGN). A computerized morphometric algorithm was designed and applied in both red-green-blue (RGB) and hue-lightness-saturation (HLS) color spaces, allowing the automated measurement of areas for the following morphological characteristics of the renal corpuscles (RCs): glomerulus, Bowman space, cells, mesangial matrix and glomerular basement membranes, and capillaries. Student's t-test comparatively applied between the numerical data obtained for the measured morphological characteristics, for each individual color space, showed significant differences between type I MPGN and type II MPGN for Bowman space area (p=0.006) and for mesangial matrix and glomerular basement membranes area - exclusively in RGB color space (p=0.013). We have also demonstrated larger RCs and glomerular size in type II MPGN, comparative to those in type I MPGN. Consequently, we assume that the morphometrical characterization of RCs histological components could be used as an additional criterion not only in the diagnosis of MPGNs, but also in the stratification of evolution and prognosis of patients diagnosed with type I and II MNGN, respectively.