[Immunohistochemical analysis of podocytopathy with immature glomeruli and glomerulosclerosis in children with nephrotic syndrome].

Idiopathic nephrotic syndrome in children may be complicated by resistance to steroids with constant proteinuria in diffuse mesangial proliferation (DMP) and focal segmental glomerulosclerosis (FSGS). In our observation, sometimes in children with steroid-resistant nephrotic syndrome, the presence of immature renal glomeruli can be detected (hypercellularity and presence of a constant layer of cubical epithelial cells on the surface of glomerular tufts, without sclerosis, resembling M-stage of glomerulo-genesis). The aim of this study was immunohistochemical analysis of the podo-cyte-associated proteins, particularly ezrin, podocalyxin, synaptopodin and nephrin in glomeruli with and without signs of immaturity in children. In DMP with signs of immaturity podo-cytes situated in the central region of the glomerulus were immunohistochemically negative. The positive reaction was observed exclusively in the most superficial continuous 'layer' of podo-cytes. The unfavourable clinical course of nephrotic syndrome with signs of glomerular immaturity may be a consequence of decreased immunohistochemical expression of cytoskeleton-specific proteins.