PT - JOURNAL ARTICLE AU - Michael H Weisman AU - Patrick Durez AU - David Hallegua AU - Richard Aranda AU - Jean-Claude Becker AU - Isaac Nuamah AU - George Vratsanos AU - Ye Zhou AU - Larry W Moreland TI - Reduction of inflammatory biomarker response by abatacept in treatment of rheumatoid arthritis. DP - 2006 Nov 01 TA - The Journal of Rheumatology PG - 2162--2166 VI - 33 IP - 11 4099 - http://www.jrheum.org/content/33/11/2162.short 4100 - http://www.jrheum.org/content/33/11/2162.full SO - J Rheumatol2006 Nov 01; 33 AB - OBJECTIVE: Abatacept, a soluble selective costimulation modulator, selectively modulates T cell activation via the CD80/CD86:CD28 costimulation pathway. Data from a Phase II trial showed efficacy in patients with active rheumatoid arthritis (RA) and inadequate response to methotrexate when treated with abatacept (10 mg/kg or 2 mg/kg). To determine the mechanism of action of abatacept, we analyzed changes in the serum levels of inflammatory biomarkers in the patients enrolled in this trial. RESULTS: Following 12 months' treatment, serum levels of interleukin 6 (IL-6), soluble IL-2 receptor, C-reactive protein, soluble E-selectin, and soluble intercellular adhesion molecule-1 were significantly lower in patients receiving abatacept 10 mg/kg versus placebo. Smaller reductions in tumor necrosis factor-a and rheumatoid factor were also observed in the abatacept 10 mg/kg group compared with the placebo group. Although there was no evidence for efficacy of the 2 mg/kg dose, small reductions in inflammatory biomarkers at this dosage support the biologic effect of this therapy. CONCLUSION: These findings reveal the antiinflammatory and immunomodulatory effects of abatacept in patients with RA, and are consistent with the concept that modulating T cell activation improves clinical signs and symptoms and inhibits the progression of structural damage. These data suggest that selective modulation of the CD80/CD86:CD28 pathway with abatacept may affect several inflammatory cell types and cytokines that are involved in the proinflammatory cascade.