Injury to E‐ and <scp>VE</scp> ‐Cadherin in Paediatric Idiopathic Steroid‐Sensitive Nephrotic Syndrome: Potential Markers of the Disease Status

AIM: The pathophysiology of idiopathic steroid-sensitive nephrotic syndrome (ISSNS) remains unclear. This study aimed to explore the pathophysiology by examining E-cadherin injury, observed in atopic dermatitis, and VE-cadherin injury, associated with systemic edema formation. METHODS: Twenty-one paediatric patients with ISSNS were enrolled. Serum E- and VE-cadherin levels were measured using ELISA and compared between the nephrotic and remission phases. Correlations between each serum E- and VE-cadherin level and urinary protein/creatinine (UP/UCr) ratios and serum albumin (Alb) levels were analysed. Additionally, a correlation between changes in serum VE-cadherin levels and in body weight between phases was analysed. RESULTS: Both serum E- and VE-cadherin levels were elevated in the nephrotic phase compared to the remission phase (p < 0.01 for both). Remission-phase E-cadherin levels remained higher than those in healthy children, while remission-phase VE-cadherin levels were similar to those in healthy children. Serum E-cadherin levels showed a significant correlation with UP/UCr ratios (p = 0.04), but not with serum Alb levels. Serum VE-cadherin levels did not correlate with either UP/UCr ratios or serum Alb levels. However, changes in VE-cadherin levels between the phases were significantly correlated with changes in body weight (p = 0.04). CONCLUSION: Elevated E- and VE-cadherin levels during the nephrotic phase suggest that injury to these adhesion molecules may be correlated with the disease status and could serve as biomarkers for paediatric ISSNS. Injury to E-cadherin may contribute to proteinuria while injury to VE-cadherin may lead to systemic edema. These findings provide new insights into paediatric ISSNS pathophysiology.