PLASMA ADVANCED GLYCOSYLATION END-PRODUCTS IN MAINTENANCE HEMODIALYSIS-PATIENTS

Background. Pentosidine is a useful marker of advanced glycation end-p roducts (AGE) which form cross-links between proteins and have been fo und elevated in plasma and tissues of uraemic and haemodialysed subjec ts. The origin and fate of these molecules are not clearly understood, but they might play a role in the cardiovascular complications of end stage renal failure. The aim of this study was to evaluate the effect of different types of substitutive therapy on the removal of pentosid ine. Methods. Pentosidine was measured by a two-step HPLC methodology. Its concentration was evaluated in plasma before and after dialysis s ession, in 24-h urine, and in dialysate of subjects treated with three types of chronic substitutive therapy: bicarbonate haemodialysis, ace tate-free biofiltration, and haemofiltration. Pentosidine levels were compared among the three therapy modalities and correlated with clinic al and biochemical parameters. Results. Plasma pentosidine level was e xtremely high (23.7+/-2.0 pmol/mg protein) in the patients treated wit h the different dialysis modalities. The dialysis session had no signi ficant effect on its plasma concentration, but haemofiltration seemed to be the most efficient method (300-2000 nmol of pentosidine removed per session versus 250-700 nmol per session with the two other approac hes). An interesting correlation was found between pentosidine and blo od urea nitrogen (r = 0.58, P < 0.01) and pentosidine with uric acid ( r = 0.48, P < 0.05). Conclusions. These results suggest that none of t he methodology showed a good removal of pentosidine, but among them ha emofiltration has the best efficiency. The statistical relationships b etween pentosidine and urea and uric acid respectively might provide i nsight into the origin of pentosidine. The accumulation of reactive AG E in uraemic patients may be implicated in the organ and tissue damage observed in uraemia.