Does Lymphatic Absorption Change with the Duration of Peritoneal Dialysis?

Abstract

BackgroundUltrafiltration failure is an important complication of long-term peritoneal dialysis (PD). A high effective lymphatic absorption rate (ELAR) can contribute to impaired ultrafiltration. It is unknown whether the ELAR increases with time on PD.ObjectiveThe relationship between the ELAR and duration of PD was analyzed, as well as the correlation between the ELAR and other transport parameters. We also studied the relation between the ELAR and cancer antigen 125 (CA125) a marker for mesothelial cell mass.SettingPeritoneal dialysis unit in the Academic Medical Center, Amsterdam.DesignCross-sectional and longitudinal studies of standard peritoneal permeability analyses (SPAs; 4-hour dwells, dextran 70 as a volume marker) with glucose 3.86% in 130 PD patients.MethodsSPAs were analyzed in 130 stable PD patients (77 males). Median duration of PD was 25 months (range 1 – 214) in a cross-sectional study. The last SPA from each patient was analyzed. The longitudinal analysis included 24 patients (12 males) from whom at least 3 SPAs were available with a minimum interval of 8 months. Dextran 70, 1 g/L, was administered intraperitoneally at the initiation of the test. Lymphatic absorption was calculated from the disappearance rate of dextran 70 during the 4-hour dwell. Therefore, the ELAR included both transmesothelial and subdiaphragmatic uptake of dextran 70.ResultsMedian ELAR was 1.43 mL/minute (range 0.17 – 6.59 mL/minute). No relationship was found between the ELAR and duration of PD in the cross-sectional analysis, nor was there a trend in time for 20 of the 24 patients studied longitudinally. In 4 patients, a negative trend was found. None of these had ultrafiltration failure and all 4 patients had a different cause for end-stage renal failure. The ELAR was correlated with parameters of peritoneal solute transport, but not with CA125 when investigated in a cross-sectional analysis. Only after 48 months of PD treatment was a significant relationship between the ELAR and CA125 seen ( r = 0.46, p < 0.05).ConclusionsNo time trend is present for the effective peritoneal lymphatic absorption rate, and it is not associated with patient or technique survival. Although increased lymphatic absorption is one of the causes of ultrafiltration failure, it is unlikely to contribute to the development of ultrafiltration failure in long-term PD patients with well-maintained transcapillary ultrafiltration.