Quantification of β2-microglobulin and albumin in plasma and peritoneal dialysis fluid by a noncompetitive immunoenzymometric assay

Abstract

An enzyme-linked immunosorbent assay (ELISA) was developed for measuring β2-microglobulin (β2m) and albumin in continuous ambulatory peritoneal dialysis (CARD) fluid. Plasma concentrations of β2m were twofold greater in hemodialysis patients (41.3 ± 13.3 mg/L) than in CARD patients (23.6 ± 5.5 mg/L) matched for duration of treatment. Measurement of β2m in CARD fluid showed a substantial loss of this protein, ∼31 % of total body β2m, compared with a 5% loss of a protein of middle molecular mass (albumin). Because of the molecular sieving effects of the peritoneal membrane, peritoneal clearance of β2m was sixfold greater than that of albumin. Whether β2m losses prevent or delay the incidence of dialysis-induced amyloidosis in these patients remains to be established.