Furancarboxylic acid in patients with terminal renal insufficiency: description of the detection method and own experience

Uremic syndrome is followed by the increase in the concentrations of many substances in blood, which induce different pathological changes and designated as uremia. 3-Caboxy-4-methyl-5-propyl-2-furanpropionic acid (furancarboxylic acid, CMPF) is an endogenic metabolite of the fatty acids in the organism, which is a component of dietary phospholipids and was detected in the urine in year 1979. This substance was showed to be accumulated in the blood during the uremia and have a high affinity to albumin preventing its linkage to other substances. This is considered to be the main factor for the reduced binding of medicaments in uremic plasma. Accumulation of the CMPF is considered to induce some pathological changes including anemia, disturbances in the function of thyroid gland and central nervous system due to the blockade of the organic ion transport through hemato-encephalic barrier. Recent data shows the deterioration of active tubular secretion by CMPF. Thus, CMPF could be related to the classic uremic toxins. The aim of the study was to develop a method for detection of CMPF. After the standard probe processing ultraeffective liquid chromatography was carried out in the lane C18 with positive electrospraying and tandem mass-spectrometry. The limit of the quantitative detection was 0.2 mkg/ml, limit of detection - 0.05 mkg/ml. This method was tested in 23 serum samples from patients with terminal kidney disease and without it. The collected data correspond to other published studies and showed high concentration of CMPF in patients with terminal kidney disease.