Urinary Claudin-1 Level as a Marker of Podocyte Injury in Patients with Proteinuria

Abstract

Abstract Background The biology of claudins is a rapidly evolving field, and many intriguing questions remain unanswered. Although it had been assumed that the reason there are ≥24 isoforms of claudin is that each one has distinct permeability properties. The nephron displays a wide spectrum of claudins, whose distribution varies in each tubular segment. In diabetic nephropathy and glomerulonephritis the gene expression of claudin-1, is markedly upregulated in the podocyte, accompanied by a tighter filtration slit diaphragm (cell-cell junction made by the glomerular podocytes) and the appearance of TJ-like structures between the foot processes causing further podocytes injury and proteinuria. Aim of the work to assess urinary claudin -1 level as a marker of podocyte injury in patients with proteinuria. Patients and Methods it is a case control study which was conducted upon 90 subjects who were divided into three groups: group I included 30 patients with type II DM, group II included 30 patients with glomerulonephritis and group III had 30 healthy subjects as controls. Urinary claudin-1 level was measured by Enzyme linked Immunosorbent Assay (ELISA) Results In this study, we found that urinary claudin-1 level was significantly higher in diabetics group and GN group than in control group. In comparison between GN group and diabetic group, we found that urinary claudin-1 level was higher in GN group than in diabetics group but with no statistically significant difference between the two groups. Conclusion urinary claudin-1 level was significantly higher in diabetics and GN group and has positive correlation with uACR. So it can be used as marker of podocytes injury and proteinuria