DETECTION OF NOVEL BETA-2-MICROGLOBULIN IN THE SERUM OF HEMODIALYSIS-PATIENTS AND ITS AMYLOIDOGENIC PREDISPOSITION

Abstract

Serum from 8 undialyzed patients and 30 dialyzed patients was examined by immunoblotting using anti .beta.2-microglobulin (.beta.2M) serum after two-dimensional gel electrophoresis (2 .cntdot. DE). One major spot and three minor spots were detected in the ultrafiltrate as well as the serum. One major spot was determined to be native .beta.2M and three minor spots were found to be novel .beta.2M. Novel .beta.2M had a lower molecular weight (MW) and a higher acidic isoelectric point (pI). Novel .beta.2M was recognized in the sera of 5 out of 20 hemodialysis (HD) patients without carpal tunnel syndrome (CTS), 2 of whom had been on HD from 5 to 10 years and 3 for more than 10 years, as well as in the sera of all 10 patients with CTS. By chromatofocusing, pI of novel .beta.2M was 5.2, while pI of native .beta.2M was 5.7. When the tissue specimen of transverse carpal ligament of 2 HD patients with CTS was examined by immunoblotting after 2 .cntdot. DE, the spot of novel .beta.2M was larger than that of native .beta.2M. It is possible that some metabolic abnormality of .beta.2M occurs through long-term hemodialysis, and it is possible that novel .beta.2M might relate to amyloidogenic predisposition.