MO168: Urinary Podocin Cell Count in Relation to Glomerular Damage Markers in Patients with Primary Nephrotic Syndrome

Abstract

Abstract BACKGROUND AND AIMS Progressive renal failure in patients with glomerular disease is driven by podocyte depletion. Several methods have been proposed to monitor urinary podocyte loss. Here, we investigated the process of podocyte depletion in patients with primary nephrotic syndrome (PNS) by flow cytometric detection of podocin-positive cells in urine. METHOD We included nine patients with PNS. Urinary cell pellets were spun down, washed and stained for podocin and subsequently counted using FACS. Urinary protein and creatinine levels were determined from the same portion of urine. Normal values of urinary podocin-positive cells were obtained in urine samples of four healthy controls. RESULTS Mean urinary podocyte count (podocin-positive cells) was on average 100.0 (3.1–228.1) times higher in patients compared to healthy controls. Podocyte excretion showed significant correlations with urinary protein/creatinine ratios (R2 = 0.86, P < .01). CONCLUSION Urinary excretion of podocin-positive podocytes was significantly increased in patients with PNS, and correlated significantly with protein/creatinine ratios in patients with PNS. We conclude that this method can be used to monitor the process of podocyte depletion, and impact of treatment. We are planning prospective studies to evaluate the prognostic value of urinary podocin+ podocyte excretion in patients with PNS.