Abstract
With the increase in the number of long-term hemodialysis patients, dialysis amyloid osteoarthropathy has attracted attention as a serious complication. We evaluated the presence of amyloid in the synovial fluid of 8 patients on maintenance hemodialysis showing retention of synovial fluid due to gonarthritis (2 males and 6 females; mean age, 65.9 years; mean duration of hemodialysis, 106 months). In addition, the β2-microglobulin concentrations in the synovial fluid and serum were measured. Similar examinations were performed on the synovial fluid in controls with normal renal function. Staining for amyloid showed the absence of amyloid in the control group while it was present in 6 of the 8 patients on maintenance hemodialysis. The mean duration of hemodialysis in the 6 patients was 132.0 months. Carpal tunnel syndrome as a complication was observed in 4 of the 6 patients, suggesting typical synovial amyloidosis. However, amyloid was also detected in a patient with a short duration of dialysis (61 months). This finding suggests that amyloid deposition in the articular synovium occurs in a relatively early stage after introduction of hemodialysis. In this patient, no clinical symptoms except gonarthritis are observable at present, but other symptoms are expected to develop with prolongation of the duration of hemodialysis. In the maintenance hemodialysis patients, the β2-microglobulin concentration in the synovial fluid (18.3±4.9mg/l) was significantly lower than the serum β2-microglobulin concentration (31.5±7.6mg/l). In the control group, no significant difference was observed between the synovial and serum concentrations. These findings suggest the presence of proteinase in the synovial fluid in maintenance hemodialysis patients showing arthritis. However, in patients showing deposition of a large amount of amyloid in the articular synovium, dilution due to impaired transfer by tissue fluid caused by circulation failure in the blood and lymphatic vessels is also possible. A significant positive correlation was observed between the serum and synovial β2-microglobulin concentration in both control and dialysis patient groups.
