HIGH PERITONEAL CLEARANCE OF SMALL MOLECULES DID NOT PROVIDE LOW SERUM β2-MICROGLOBULIN CONCENTRATIONS IN PERITONEAL DIALYSIS PATIENTS

♦ Objective: Although early reports demonstrated that serum β β β β 2 -microglobulin (s-β 2 m) concentrations in patients on peritoneal dialysis (PD) were lower than those in patients on hemodialysis (HD), more recent studies demonstrated lower s-β 2 m concentrations in HD patients treated mainly with high-flux synthetic membranes. We therefore compared s-β 2 m concentrations between patients on PD and on HD, and also analyzed the relationship between sβ 2 m concentrations and other parameters in patients on PD. ♦ Patients and Methods: We investigated 24 patients who had been undergoing PD [11 on continuous ambulatory peritoneal dialysis, 13 on continuous cycling peritoneal dialysis] for 4.3 ± 2.7 years, and 24 patients who had been undergoing HD with high-flux synthetic membranes for 6.1 ± 3.2 years. Concentrations of s-β 2 m in the PD patients were compared to concentrations in the HD patients. In patients on PD, we also analyzed the relationship between s-β 2 m concentration and other parameters, including residual renal function, total weekly Kt/V urea, total weekly creatinine clearance (CCr), and dialysis schedules. ♦ Results: We found no significant difference in s-β β β β β 2 m concentrations between the PD and HD patients (33.6 ± 10.4 mg/L vs 30.3 ± 10.5 mg/L respectively). Concentrations of s-β 2 m in PD patients rose with PD duration and were significantly inversely correlated with residual renal function (r = ‐0.71, p < 0.0001). Unexpectedly, concentrations of s-β 2 m in anuric PD patients rose as peritoneal CCr increased. And most of the patients with high s-β β β β β 2 m