Toward personalized hemodialysis by low molecular weight amino-containing compounds: future perspective of patient metabolic fingerprint

Background. L-carnitine deficiency is commonly observed in chronic hemodialysis patients, and this depletion may cause clinical symptoms like muscle weakness, anaemia, and hypotension. Materials and methods. We pursued a targeted metabonomics investigation in 28 hemodialysis patients (13 non diabetics and 15 diabetics) and in 10 age-matched healthy controls, on plasma levels of all carnitine esters and of several amino acids. Samples were taken before and after the first hemodialysis treatment of the week. Multiplexed data were collected in LCMRM (Multiple Reaction Monitoring) and analysed by unsupervised multivariate analysis. Results. In diabetic uremic patients, we observed lower values of propionylcarnitine than in other groups, while acylcarnitine concentration was higher in uremics compared to controls. The hemodialysis session induced a decline in free, short-chain, medium-chain and dicarboxylic acylcarnitines, whereas the long chain acylcarnitines remained unaffected. Plasma levels of amino acid proline, ornithine, citrulline and serine were significantly elevated in uremic patients before dialysis compared to controls. For most tested plasma amino acids, a significant reduction after hemodialysis session was found. Discussion. Our study is the first that investigated on possible modifications of the system of carnitine in diabetic patients in hemodialysis not only in relation to the condition of deficiency but also compared to lipid and glucose homeostasis alteration typical of diabetics. We proposed the application of targeted metabolic fingerprint in the management of the hemodialysis patients.