Relationship between carpal tunnel syndrome and serum cytokines in chronic hemodialysis patients

Abstract

Carpal tunnel syndrome (CTS), which is diagnosed by burning sensations, numbness and stiffness of the hand, is common in patients undergoing long term hemodialysis. Some investigators have reported that CTS is due to the deposition of amyloid protein which consists of β₂-microglobulin (β₂-MG) in the carpal tunnel area. On the contrary, it was reported that macrophages migrated to the surrounding tissue of amyloid deposition and that connective tissue then proliferated in this area. However, the underlying mechanisms remain obscure. Seventy one patients undergoing long term hemodialysis entered this study. None of these patients had liver disease, rheumatoid arthritis, other inflammatory disease or cancer. Patients were divided into two groups; group 1 (n=40) served as the control without CTS while group 2 (n=31) had CTS. Serum β₂-MG, IL-6 and macrophage colony-stimulating factor (M-CSF) concentrations were measured. The difference in serum β₂-MG between the two groups was not significant. However, serum IL-6 in group 2 was significantly higher than that in group 1 (12.8±20.0pg/ml vs 6.2±2.5pg/ml). Furthermore, serum M-CSF in group 2 was also significantly higher than that in group 1 (4.43±0.73ng/ml vs 3.82±0.83ng/ml). Serum M-CSF correlated significantly with serum IL-6 (r=0.282, p<0.05). There may be a relationship between CTS and elevated IL-6 and M-CSF.