Kidney diseases in children – early diagnosis and prevention

Pediatric kidney diseases were in the focus of the World Kidney Day 2016. Macedonian pediatric nephrologists gave their contribution with public appearance in kindergartens, primary and secondary schools, with interactive lectures and discussion with the youngest about the kidney function, healthy life style and simple measures to prevent kidney and urinary tract diseases. Besides promotive appearance in the media, series of lectures were presented in front of the health professionals. The aim was to attract the attention of the professionals for early diagnosis and prevention of kidney disease. The action starts in utero, followed by early postnatal imaging and assessment, conservative treatment and in selected cases surgical treatment. The emphasis is on the multidisciplinary and comprehensive approach to children and adolescents with kidney diseases.

Expression of Nephrin in Pediatric Kidney Diseases

Nephrin is a podocyte cell adhesion protein located at the slit diaphragm area of the kidney glomerulus. Mutations in the nephrin gene (NPHS1) lead to congenital nephrosis, suggesting that nephrin is essential for the glomerular filtration barrier. This prompted this study of the expression of nephrin in acquired pediatric kidney diseases usingin situhybridization and immunohistochemistry.In situhybridization for nephrin mRNA was performed in biopsy samples from patients with proteinuria caused by minimal change nephrosis, focal segmental glomerulosclerosis, and membranous nephropathy. The expression of nephrin mRNA was evaluated by grading the signal intensity visually and by counting the number of grains in separate glomeruli. No significant difference was observed in these samples as compared with controls. Immunostaining for nephrin was performed using antibodies directed against extra- and intracellular parts of the molecule. Nephrin staining gave a linear pattern along the glomerular capillary loops. In minimal change nephrosis, focal segmental glomerulosclerosis, and membranous nephropathy, the distribution of nephrin was similar to that in controls. In proliferative forms of glomerulonephritides (Henoch-Schönlein nephritis, IgA nephropathy, postinfectious and membranoproliferative glomerulonephritis), crescents and sclerotic lesions were negative for nephrin, and mesangial proliferation led to a scattered and sparse staining pattern. The staining pattern of nephrin was compared to that of ZO-1, a component of the cytoplasmic face of the slit diaphragm. The distributions of these two proteins in capillary tufts were similar in all disease entities studied. In conclusion, immunohistochemistry andin situhybridization did not reveal major alterations in the expression of nephrin in proteinuric kidney diseases in children. Further studies are needed for more precise evaluation of the role of nephrin in these diseases.