Increased urinary lipoperoxide levels in renal transplant patients

Using high performance liquid chromatographic methods, both plasma and urine lipoperoxide concentrations were measured, as malondialdehyde (MDA), in 30 stable renal transplant patients receiving daily cyclosporine and/or azathioprine therapy. Their MDA concentrations were compared with previously reported reliable reference values using the same liquid chromatographic methods. Although their plasma concentrations were within the reference range, their mean urine MDA values averaged 3.7 to 5.0 times the normal reference values (p less than 0.001). The primary cause of the increased urine MDA concentrations following renal transplantation in these patients is unknown; it could be due to (a) renal lipid peroxidation directly related to the cyclosporine/azathioprine therapy, (b) drug-induced or other nephrotoxicity by an alternative mechanism with secondary lipid peroxidation, (c) increased lipid peroxidation owing to an immunologic response to the kidney graft, or (d) a combination of these possibilities.