ELSEVIER Toxicology Letters Toxicology Letters 77 (1995) 313-318 The assay of laminin fragments in serum and urine as an indicator of renal damage induced by toxins R.G. Price*a, S.A. Taylora, E. Crutchera, E. Bergamaschib, I. Franchinib, A.D.R. Mackie”” zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQ ‘Biochemistry Section, Division of Li$e Sciences, King’s College, Campden Hill Road, London W 8 7AH, UK bLaboratory of Industrial Toxicology, University of Parma Medical School, 43100 Parma, Italy ‘Kings College Hospital, Bessemer Road, London SE5 9PJ. UK Accepted 13 January 1995 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM Abstract An ELBA protzdure for the assay of laminin fragments in serum and urine is described. Samples from solvent- exposed workers and diabetic patients were studied. In cohorts exposed to perchloroethylene serum and urine laminin fragments were elevated but the urinary N-acetyl-&@ucosaminidase (NAG) was unaffected. The data indicate that the urinary assay may be more specific for renal damage than the serum method. Differences in the excretion of NAG and urinary laminin fragments were observed in the diabetic groups suggesting that the excretion of these two com- ponents reflects di.fferent stages of severity of the disease. Keywords: Renal damage; Enzyme immunoassay; Laminin fragments; N-Acetyl-@-D-glucosaminidase; Diabetics; Perchloroethylene 1. Introduction Laminin is a major glycoprotein which is a structurally and biologically active component of basement membranes [l]. The presence of break- down products of laminin in serum is indicative of the normal turnover of basement membranes. The most widely used marker for laminin metabolism in humans is the LPl fragment and its assay in * Corresponding author. ’ Present address: Department of Epidemiology, Box 49, Addenbrooke’s Hospital, Cambridge, UK serum has proved useful in the monitoring of pa- tients with malignancies and liver disease 121.In a recent study [3] on individuals exposed to per- chlorethylene, one of the renal changes observed was an elevation of serum laminin fragments. Ab- normal elevation was also observed for urinary fibronectin and glycosaminoglycans. Together these changes suggest diffuse structural and func- tional changes in the kidney possibly resulting from generalised membrane disturbances caused by the solvent itself or by reactive metabolites. Pre- vious attempts to measure LPl in urine proved un- successful and therefore we have developed an 0378- 4274/95609.50 0 1995 Elsevier Science Ireland Ltd. All rights reserved SSDI 0378-4274(95)03312-Z