RENAL EPITHELIAL INJURY: A RISK FACTOR IN UROLITHIASIS

In humans, crystalluria is a relatively common event, and is an indicator of a urine’s supersaturation with regard to a given salt1. As long as the movement of these crystals through the urinary system remains free, they do not develop into symptomatic urinary stones. Obviously additional factors, responsible for crystal retention within the renal tubules, are necessary for the initiation of stone formation. What are these factors that can trigger stone formation? Vermeulen et. al2 suggested that massive crystalluria as a result of high supersaturation could succeed in blocking the papillary ducts and thus initiate the process. Finlayson and Reid calculated3 that it was not possible for single crystals of calcium oxalate monohydrate to grow large enough to block the urinary tubules within the time it takes the urine to flow from the glomerulus to the pelvis. Thus crystals must be “fixed” at some point within the renal tubules so that they have enough time to grow and initiate stone formation.