Biological Effects of XyloCore, a Glucose Sparing PD Solution, on Mesothelial Cells: Focus on Mesothelial-Mesenchymal Transition, Inflammation and Angiogenesis

Glucose-based solutions remain the most used osmotic agents in peritoneal dialysis (PD), but unavoidably they contribute to the loss of peritoneal filtration capacity. Here, we evaluated at a molecular level the effects of XyloCore, a new PD solution with a low glucose content, in mesothelial and endothelial cells. Cell viability, integrity of mesothelial and endothelial cell membrane, activation of mesothelial and endothelial to mesenchymal transition programs, inflammation, and angiogenesis were evaluated by several techniques. Results showed that XyloCore preserves mesothelial and endothelial cell viability and membrane integrity. Moreover XyloCore, unlike glucose-based solutions, does not exert pro-fibrotic, -inflammatory, and -angiogenic effects. Overall, the in vitro evidence suggests that XyloCore could represent a potential biocompatible solution promising better outcomes in clinical practice.

Peritoneal equilibration test with conventional 'low pH/high glucose degradation product' or with biocompatible 'normal pH/low glucose degradation product' dialysates: does it matter?

BACKGROUND

The evaluation of the peritoneal transport characteristics is mandatory in peritoneal dialysis (PD) patients. This is usually performed in routine clinical practice with a peritoneal equilibration test (PET) using conventional dialysates, with low pH and high glucose degradation product (GDP) concentrations. An increasing proportion of patients are now treated with biocompatible dialysates, i.e. with physiological pH and lower GDP concentrations. This questions the appropriateness to perform a PET with conventional solutions in those patients. The aim of our study is to compare the results of the PET using biocompatible and conventional dialysates, respectively.

METHODS

Nineteen stable PD patients (13 males, 6 females; mean age: 67.95±2.36 years, mean body surface area: 1.83±0.04 m2, dialysis vintage: 2.95±0.19 years) were included, among which 10 were usually treated with biocompatible and 9 with conventional solutions. Two PETs were performed, within a 2-week interval, in each patient. PET sequence (conventional solution first or biocompatible solution first) was randomized in order to avoid 'time bias'. Small (urea, creatinine and glucose), middle (beta-2-microglobulin) and large molecules' (albumin and alpha-2-macroglobulin) dialysate/plasma (D/P) concentration ratios and clearances were measured during each PET. Ultrafiltration (UF) and sodium filtration were also recorded. Results of both tests were compared by the Wilcoxon paired test.

RESULTS

No statistical difference was found between both dialysates for small molecule transport rates or for sodium filtration and UF. However, a few patients were not similarly classified for small-solute transport characteristics within the PET categories. Beta-2-microglobulin and albumin D/P ratios at different time points of the PET were significantly higher with the biocompatible, when compared with the conventional, solutions: 0.10±0.03 versus 0.08±0.02 (P<0.01) and 0.008±0.003 versus 0.007±0.003 (P=0.01), respectively. A similar difference was also observed for beta-2-microglobulin that was higher with biocompatible dialysates (1.04±0.32 versus 0.93±0.32 mL/min, respectively).

CONCLUSION

Peritoneal transport of water and small solutes is independent of the type of dialysate which is used. This is not the case for the transport of beta-2-microglobulin and albumin that is higher under biocompatible dialysates. Vascular tonus modification could potentially explain such differences. The PET should therefore always be carried out with the same dialysate to make longitudinal comparisons possible.