Evaluation of Peritoneal Transport and Membrane Status in Peritoneal Dialysis: Focus on Incident Fast Transporters

Abstract

Background/Aim: The determinants of baseline fast solute transport are still unclear. We prospectively investigated the relationship of peritoneal solute transport with markers of inflammation, angiogenesis, and membrane status, with a focus on fast transporters. Methods: Seventy-one incident peritoneal dialysis patients were assessed with baseline and annual peritoneal equilibration tests, using a 3.86% glucose dialysis solution. Residual renal function and markers of inflammation, including systemic and intraperitoneal interleukin-6 (IL-6), effluent cancer antigen 125 (CA-125), and vascular endothelial growth factor (VEGF) appearance rates (ARs), were investigated. The time course of the dialysate-to-plasma ratio of creatinine (D/P creatinine ratio) and its relationship with the biomarkers were investigated by a mixed linear model. Results: Incident fast/fast average transporters had a similar age, diabetes prevalence, and serum and effluent IL-6 levels, but significantly higher levels of CA-125 and VEGF ARs than the slow/slow average group; the D/P creatinine ratio was not correlated with systemic IL-6, but was correlated with effluent CA-125 AR (r = 0.45, p < 0.0001) and VEGF AR (r = 0.52, p < 0.0001). The D/P creatinine ratio decreased with a U-shaped profile (p = 0.02). Intraperitoneal IL-6 was the significant and positive determinant of the time course of the D/P creatinine ratio (p < 0.0001). Effluent CA-125 decreased with time on peritoneal dialysis (p = 0.013). Conclusions: Baseline peritoneal fast transport was not associated with systemic inflammation, but was related to peritoneal locally produced substances able to mediate transitory hyperpermeability. The D/P creatinine ratio changed during the follow-up period with a U-shaped profile. This was associated with effluent IL-6 and partly with VEGF. CA-125 decreased throughout the follow-up period.

Dialysate CA125 levels after 5 years on continuous peritoneal dialysis

“…This result in accordance with those from published longitudinal studies [15][16][17]. This downward trend with time suggests a decrease in mesothelial cell mass.…”

“…Dialysate CA125 levels have been shown in some studies to decrease in long-term PD treatment [13][14][15][16], but there are currently limited longitudinal data on children undergoing long-term PD [17]. The aim of the study reported here was to evaluate changes in dCA125 levels in peritoneal effluent over time and to analyze relationships between dCA125 and PGE in children treated with long-term PD.…”

Peritoneal Membrane Evaluation in Routine Clinical Practice

“…Although this has been recently questioned [31] , the finding of low levels of effluent CA125 in long-term PD, notably with UFF make it worthwhile to be routinely measured, in order to clarify its predictive value. It was not the purpose of this study to investigate the relationship between mesothelial cell mass and peritoneal transport: an indirect role has recently been suggested but this seems to vary in short-and long-term PD, possibly mediated earlier by production of vasoactive factors [32][33][34] or later trough epithelial-mesenchymal transition [35] . This should be preferably investigated in longitudinal studies.…”

Is the Systemic Microvascular Endothelial Glycocalyx in Peritoneal Dialysis Patients Related to Peritoneal Transport?

“…It goes along with high effluent concentrations of CA125 [19] and the production of biomarkers that are partly vasoactive [20]. Inflammation may [21] or may not be present [22]. Therefore, the regulation of the peritoneal circulation in fast transporters is different from that of the systemic circulation.…”