It is well known that glomerular podocyte injury and loss are present in numerous nephropathies and that the pathophysiologic consecution of disease hinges upon the fate of the podocyte. While multiple factors play a hand in glomerulopathy progression, basic logic lends that if one monitors the podocyte’s status, that may reflect the status of disease. Recent investigations have focused on what one can elucidate from the noninvasive collection of urine, and have proven that certain, specific biomarkers of podocytes can be readily identified via varying techniques. This paper has brought together all described urinary biomarkers of podocyte injury and is made to provide a concise summary of their utility and testing in laboratory and clinical theatres. While promising in the potential that they hold as tools for clinicians and investigators, the described biomarkers require further comprehensive vetting in the form of larger clinical trials and studies that would give their value true weight. These urinary biomarkers are put forth as novel indicators of glomerular disease presence, disease progression, and therapeutic efficacy that in some cases may be more advantageous than the established parameters/measures currently used in practice. 1. Introduction The glomerulus is the functional unit of the kidney that creates from the afferent blood flow an ultrafiltrate, which passes through the remainder of the nephron for further modification. The glomerulus can be compared to a selective filter in that it discerns based on size and charge what passes on through to become the formed ultrafiltrate. This selectivity is intrinsic to the glomerular filtration apparatus and is dictated by the structural integrity of the three main components of which it is made: the capillary endothelium, the glomerular basement membrane (GBM), and the visceral epithelium overlying the GBM. Material that navigates through the glomerular filter must pass through these three components in that order to attain passage from the vascular capillary side into Bowman’s space. The visceral epithelial layer of the glomerulus is made up of podocytes: terminally differentiated cells that have formed foot processes that encircle the GBM. The foot processes interdigitate between one another, with the space between each laying the slit diaphragm: described as a zipper-like interaction of membrane proteins between adjacent podocyte foot processes [1]. The slit diaphragm is considered to be the size limiting component of the glomerular filtration apparatus: permitting material approximately under
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