Kinetic and Clinical Studies of 2Microglobulin in Continuous Ambulatory Peritoneal Dialysis: Influence of Renal and Enhanced Peritoneal Clearances Using Glucose Polymer

Abstract

A risk of beta 2-microglobulin (beta 2-M)-associated amyloidosis in long-term CAPD patients has been recognised. We examined the kinetics of beta 2-M and potential clinical manifestations of amyloidosis in patients well-established on CAPD for 1-76 months (mean +/- SEM; 16.4 +/- 14 months). In 57 patients, serum beta 2-M concentration was elevated to 30 +/- 1.8 (mean +/- SEM, mg/l) and correlated positively with the duration on CAPD. In 18 patients studied with variable degrees of residual renal function, serum beta 2-M concentration increased with declining renal function; this was most marked when the creatinine clearance was less than 1 ml/min. Using an isosmolar solution (302 +/- 1.3 mOsm/kg) containing 5% glucose polymer (9.4 mmol/l; MW 16,800), the transperitoneal elimination of beta 2-M was significantly enhanced (1.6 times) compared to conventional 1.36% glucose solution, but without a detectable change in serum concentrations during a 6-h study. No significant difference was found between the estimated minimum volume of distribution of beta 2-M in CAPD and haemodialysis patients. Symptomatic amyloid-associated disease was absent in patients in this study, and may be attributed to the short duration of dialysis.