**2.2.4 Concentrations of chemokines**

Patients on high-flux hemodialysis/hemodiafiltration had significantly higher concentrations of MCP-1, MIP-1α, IL-6, IL-8, TNF-α and high-sensitivity CRP (hsCRP) in the peripheral circulation, prior to dialysis treatment, compared with healthy subjects (Olsson et al. 2009). MMP-9/NGAL serum concentration was similar in patients on high-flux hemodialysis/hemodiafiltration and healthy subjects (Olsson et al. 2009). Significantly higher serum levels of β2-microglobulin and serum amyloid A (SAA) were observed in patients on high-flux hemodialysis/hemodiafiltration, compared with healthy subjects. The serum concentrations of chemokines, hsCRP, SAA and oxidized LDL were not influenced by the high-flux hemodialysis/hemodiafiltration session, while the concentration of β2 microglobulin was significantly reduced (unpublished data).

The concentrations of MIP-1α, MMP-9/NGAL and IL-8 at the sites of intermediate and intense inflammation were similar in patients and healthy subjects, and the concentration of MCP-1 at the sites of intermediate and intense inflammation was significantly higher in patients on highflux hemodialysis/hemodiafiltration, compared with healthy subjects (Olsson et al. 2009). At the site of intermediate inflammation, the concentration of IL-6 and TNF-α was significantly higher in patients compared with healthy subjects, reflecting a high inflammatory activity (unpublished data). There were no significant correlations between the concentrations of chemokines or the gradient between the concentration in the peripheral circulation and the interstitium, and the recruitment of neutrophils and monocytes and their expression of CD11b at the site of interstitial inflammation (unpublished data).
