Solute transport at the start of peritoneal dialysis and the risk of peritonitis.

Background: In peritoneal dialysis (PD) approximately 40% of ultrafiltration (UF) during hypertonic dwell (mini-PET test) occurs as free water transport (FWT) through water channels, mainly aquaporin-1. Experimental studies have shown that aquaporin-1 plays a role in cell migration and inflammatory response.
Objectives: The purpose of the study was to evaluate if FWT is associated with the incidence of PD-related peritonitis.
Material and Methods: Standard PET and mini-PET tests were performed on 27 patients at the onset of PD. Clinical data was reviewed and PET transport parameters calculated. The peritonitis rate was assessed and the group of patients was divided into the subgroups of peritonitis-free patients (n = 18) and patients with peritonitis episode (n = 9).
Results: Solute transport, measured as D/P creatinine during the PET test was significantly higher in the group of patients with peritonitis episode than in the group of peritonitis-free patients (0.77 ± 0.12 vs. 0.66 ± 0.11, p = 0.02). In the mini-PET test, there was a tendency to have higher solute transport in the group of patients with peritonitis episode compared to the group of peritonitis-free patients (0.61 ± 0.13 vs. 0.51 ± 0.1, p = 0.07). Ultrafiltration (mL) in the mini-PET test was slightly higher in the group of peritonitis-free patients (642 ± 178 vs. 488.9 ± 161.6, p = 0.06). FWT was not different between the two groups.
Conclusions: Higher solute transport at the start of PD may be associated with the risk of peritonitis.