[The nephrotoxicity of ionic and nonionic contrast media in urography. An evaluation with immunoenzyme technics and...

The nephrotoxicity of ionic and nonionic contrast media (cm) was evaluated in 52 patients undergoing pyelography. The contrast media were i.v. injected in 30'. Urine samples were collected before, 2 and 48 hours after the injection. Urinary albumin (alb) and retinol binding protein (RBP) excretion was evaluated by immunoenzymatic methods; alb and RBP were considered as indicators of glomerular permeability and of tubular reabsorption, respectively. The urinary excretion of brush-border antigen of proximal tubule (BBA) was also measured, as an indicator of microtissue damage, by a sensitive double-antibody ELISA with monoclonal antibodies. The results demonstrate ionic cm to have greater functional effects than nonionic ones, as suggested by the increased urinary excretion of both alb and RBP. However, tubular damage seemed to be more severe with nonionic agents, as suggested by BBA excretion. Although toxic damage had little significance for the patients' health, long-term effects are not to be excluded.