Background: Patients with rheumatoid arthritis (RA) frequently display an atherogenic lipid profile which has been linked with inflammation. Tumor necrosis factor-alpha (TNF-alpha), a pivotal pro-inflammatory cytokine in RA may be involved in the development of the disturbed lipid metabolism. We investigated whether infliximab, an anti-TNF-alpha therapy, may modify the lipid profile. Methods: 56 consecutive RA patients were treated with infliximab (3 mg/kg at weeks 0, 2, 6, 14, 22, 30). Lipid profile and CRP were assayed at baseline and before inibsion at weeks 6 and 30. Baseline values were compared with those in 56 healthy volunteers. Results: At baseline, the concentrations of HDL-cholesterol were lower in RA patients than in the controls (1.3 +/- 0.4 vs. 1.5 +/- 0.2 mmol/L; p < 0.01). The triglyceride concentrations (1.6 +/- 0.8 vs. 1.3 0.4 mmol/L, p < 0.01), the ratio of total cholesterol/HDL-cholesterot (4.3 +/- 1.6 vs. 3.2 +/- 0.5, p < 0.001) and LDL-cholesterol/HDL-cholesterol (2.6 +/- 1.2 vs. 1.7 +/- 0.5, p < 0.001) were significantly higher in RA patients than in controls. After 6 weeks of infliximab therapy, the mean total cholesterol concentration increased by 25% (p < 0.001), LDL-cholesterol by 24% (p < 0.001) and HDL-cholesterol by 30% (p < 0.001). The decrease in CRP levels to 30 week inversely correlated with the increase in HDL-cholesterol (r = -0.47, p = 0.005). Conclusions: Infliximab administration is associated with important increases in cholesterol levels in all its forms but as no significant beneficial effect on the atherogenic ratio. (c) 2005 Elsevier B.V. All rights reserved.