Increase in plasma concentration of ubiquitin in dialysis patients: possible involvement in beta 2-microglobulin amyloidosis.
beta 2-Microglobulin(beta 2-M) amyloidosis is a serious complication of dialysis therapy; however, its pathogenesis is still unclear. Recent studies have indicated that ubiquitin has amyloid enhancing factor activity, raising the possibility that ubiquitin plays a role in beta 2-M amyloidogenesis. In this study, synovial tissue from patients with long-term dialysis was examined immunohistochemically. The synovial tissue was labeled with anti-ubiquitin antibody, indicating co-deposition of ubiquitin with beta 2-M amyloid. To elucidate the involvement of plasma ubiquitin, we established a specific radioimmunoassay for ubiquitin. Using this method, we observed that the plasma concentration of ubiquitin-like immunoreactivity in dialysis patients was significantly higher than that in normal subjects. In chronic renal failure patients, the plasma concentration of ubiquitin-like immunoreactivity was also significantly higher than that in normal controls, which finding suggests that a reduction in renal clearance is, at least in part, responsible for the increased plasma concentration of ubiquitin. In dialysis patients, plasma concentrations of ubiquitin-like immunoreactivity in patients with carpal tunnel syndrome, one of the major symptoms of beta 2-M amyloidosis, were significantly higher than those in patients not exhibiting this syndrome. These results suggest a possible involvement of plasma ubiquitin in beta 2-M amyloidosis.
Okada
M
M
Department of Pharmacology, Shionogi & Co., Ltd., Osaka, Japan.
Miyazaki
S
S
Hirasawa
Y
Y
D000686:Amyloidosis / Q000097:blood / Q000209:etiology*; D002850:Chromatography, Gel; D006801:Humans; D007150:Immunohistochemistry; D007676:Kidney Failure, Chronic / Q000097:blood; D011863:Radioimmunoassay; D017582:Renal Replacement Therapy / Q000009:adverse effects*; D013583:Synovial Membrane / Q000378:metabolism; D014452:Ubiquitins / Q000097:blood* / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000378:metabolism*
D014452:Ubiquitins; D001613:beta 2-Microglobulin