Evaluation of peritoneal transport and membrane status in peritoneal dialysis: focus on incident fast transporters

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.

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.

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).

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.