CD2AP, alpha-actinin-4 and
podocalyxin are thought to play an important role in the structure and function of glomerular podocytes, therefore we intended to evaluate quantitatively, using computer image analysis system, the immunoexpression of these
proteins in renal biopsy specimens in glomerulopathies presented with
nephrotic syndrome: minimal change disease (MCD),
focal segmental glomerulosclerosis (FSGS) and
nephropathy IgA (IgAN). As a control 10 biopsy specimens of the kidneys removed because of
trauma were used. In normal kidneys CD2AP, alpha-actinin-4, and
podocalyxin showed intense staining in podocytes along the capillary walls of the glomeruli. The intensity of immunoexpression of CD2AP and alpha-actinin-4 in renal tissue in patients with MCD, FSGS, and IgAN was similar to normal controls, but the distribution of these
proteins was more granular in glomeruli of diseased kidney. The immunostaining of
podocalyxin was weaker in podocytes in patients with FSGS as compared with normal glomeruli. The immunostaining of
podocalyxin was not significantly altered in MCD and IgAN. The immunostaining of CD2AP and alpha-actinin-4 did not correlate with the intensity of
proteinuria in patients with MCD, FSGS and IgAN, whilst in FSGS patients the significant correlation was found between the glomerular immunostaining of
podocalyxin and
proteinuria. In conclusion, revealed in our study diminished immunoexpression of
podocalyxin and significant correlation with the level of
proteinuria in FSGS patients suggests a possible role of this
sialoprotein in the alteration of the glomerular filtration barrier in this disease.