Objective: HDL anti-atherogenic functions seem to be diminished during inflammatory conditions such as rheumatoid arthritis (RA). The aim of this study was to investigate the effects of TNF inhibition on the anti-oxidative capacity of HDL in RA.
Methods: Plasma lipids and paraoxonase (PON)-1 activity were investigated in 45 RA patients, before and during 6 months of anti-TNF therapy. In addition, HDL was isolated and tested for its ability to inhibit copper induced oxidation of LDL in vitro.
Results Plasma HDL concentrations did not considerably change after 6 months of therapy. However, stable increases of PON-1 activities were observed throughout the same period (p<0.03). The increases were more obvious when related to HDL or apolipoprotein A-I concentrations. HDL total anti-oxidative capacity significantly improved 6 months after initiation of anti-TNF therapy (p = 0.015). The initial improvement of PON-1 activity paralleled a decrease of the inflammatory status, whereas specific TNF blockade was likely to be responsible for the long-term effects.
Conclusions: Anti-TNF therapy with infliximab has beneficial effects on lipids through changes in HDL anti-oxidative capacity, which might be clinical relevant and contribute to the reported protective effect of anti-TNF on cardiovascular morbidity in RA. This emphasizes the importance of HDL anti-atherogenic capacity for the cardiovascular risk in chronic inflammatory conditions.