['Vascular access (VA) dysfunction is a major clinical complication in the hemodialysis population and has a direct effect on dialysis outcome. This study was conducted to explore the role of microinflammation in the VA dysfunction in maintenance hemodialysis patients.', 'Forty-seven patients (male 35 and female 12) receiving maintenance hemodialysis were included for this study. They were divided into three groups: group 1 (n = 15), patients with initial hemodialysis and new arteriovenous fistula (AVF); group 2 (n = 18), patients treated with hemodialysis for long term with well-functional VA; group 3 (n = 14), maintenance hemodialysis patients with VA dysfunction. Biochemical parameters and serum tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) were determined. High-sensitivity C-reactive protein (hs-CRP) was determined by latex-enhanced immuno-nephelometric method. Tissues of radial artery were taken from group 1 and group 3 for the histological study. Expression of CD68 and MCP-1 in the radial artery was determined by immunohistochemistry.', 'Serum hs-CRP in group 3 was significantly higher than those in group 1 and group 2 ((7.40 +/- 2.42) mg/L vs (4.21 +/- 1.62) mg/L and (5.04 +/- 3.65) mg/L, P < 0.01 and P < 0.05, respectively). Serum TNF-alpha in group 3 was significantly higher than those in group 1 and group 2 ((64.03 +/- 9.29) pg/ml vs (54.69 +/- 12.39) pg/ml and (54.05 +/- 7.68) pg/ml, P < 0.05 and P < 0.01, respectively). Serum IL-6 in group 3 was also significantly higher than those in group 1 and group 2 ((70.09 +/- 14.53) pg/ml vs (56.43 +/- 10.11) pg/ml and (60.77 +/- 9.70) pg/ml, P < 0.01 and P < 0.05, respectively). Patients in group 3 had a thicker internal layer of vessels than in group 1 ((0.356 +/- 0.056) mm vs (0.111 +/- 0.021) mm, P < 0.01). Expression of CD68 and MCP-1 in the fistula vessel walls in group 3 were much higher than those in group 1 (P < 0.01). Moreover, serum hs-CRP level was positively correlated with the neointimal hyperplasia, the expression of CD68 and MCP-1 in fistula vessel (P < 0.01, respectively).'] Is microinflammation involved in the dysfunction of arteriovenous fistula in patients with maintenance hemodialysis?