Characterization of peritoneal dialysis effluent-derived cells: diagnosis of peritoneal integrity.

To assess the integrity of the peritoneal membrane, we characterized the functionality of the cellular components derived from peritoneal dialysis effluent (PDE). About 3 % of all cells collected from the PDE attached to the plastic dish, and 97.1 ± 3.1 % of the adherent cells expressed CK-18 (PDE-HPMC). A typical cobble-stone-like morphology under neutralized PD solution was obtained over 65 out of 74 primary cultures (88 %) while only 53 % under acidic PD solution in a previous report by Yanez-Mo et al. However, 26.6 ± 10.3 % of PDE-HPMC expressed the EMT marker α-SMA. Transepithelial resistance (TER) as a marker of cell polarity was 34 % lower than that of omentum-derived(OM)-HPMC. We found a significant decrease in the rate of PDE-HPMC proliferation compared to OM-HPMC, accompanied by a significant increase of cell area within the tertiary passage. Comparison of TER, α-SMA and SA-β-Gal between CAPD durations suggests that cell polarity weakens with increased duration of CAPD, reflecting the occurrence of EMT and cell senescence. We conclude that functional characterization of cellular components in PDE reflects how well the peritoneum is preserved.