Urinary CD80 and Serum Soluble Urokinase Plasminogen Activator Receptor (SuPAR) as Novel Diagnostic Biomarkers in Pediatric Patients with Nephrotic Syndrome

Background: This study aimed to evaluate urinary CD80 and serum SuPAR in patients with primary nephrotic syndrome as a non-invasive diagnostic biomarker to predict steroid responsiveness in those patients.

Methods: This prospective cohort study was carried out on total 60 children and adolescents with idiopathic nephrotic syndrome (INS) at initial presentation and 30 healthy matched controls. Urinary CD80 and serum SuPAR were measured for all subjects. Patients were divided on follow up into two groups: group A: patients proved to be steroid sensitive nephrotic syndrome (n=30), group B: patients proved to be steroid resistant nephrotic syndrome or proved by biopsy to be focal segmental glomerulosclerosis (n=30).

Results: Urinary CD80 levels were significantly higher in group A than group B and C (P <0.001). SuPAR was significantly higher in group B than group A and C (P <0.001). Both urinary CD80 and serum SuPAR were positively correlated to 24h urinary protein, protein/ creatinine ratio and serum cholesterol (P = 0.001, 0.003, <0.001, <0.001 and <0.001 respectively). Also both urinary CD80 and SuPAR were negatively correlated to albumin (P <0.001 and <0.001 respectively). By ROC curve, urinary CD80 can predict steroid sensitivity with 80% sensitivity, 96.67% specificity and accuracy 95% and serum SuPAR can predict steroid resistance with 76.67% sensitivity, 88.33% specificity and accuracy 86%.

Conclusions: Urinary CD80 and serum SuPAR can be useful in predicting renal pathology or steroid responsiveness in patients with idiopathic nephrotic syndrome especially if renal biopsy is contraindicated.