PT - JOURNAL ARTICLE AU - Smadar Gertel AU - Gidi Karmon AU - Eszter Szarka AU - Ora Shovman AU - Esther Houri-Levi AU - Edna Mozes AU - Yehuda Shoenfeld AU - Howard Amital TI - Anticitrullinated Protein Antibodies Induce Inflammatory Gene Expression Profile in Peripheral Blood Cells from CCP–positive Patients with RA AID - 10.3899/jrheum.170822 DP - 2018 Mar 01 TA - The Journal of Rheumatology PG - 310--319 VI - 45 IP - 3 4099 - http://www.jrheum.org/content/45/3/310.short 4100 - http://www.jrheum.org/content/45/3/310.full SO - J Rheumatol2018 Mar 01; 45 AB - Objective. Anticitrullinated protein antibodies (ACPA) have major diagnostic significance in rheumatoid arthritis (RA). ACPA are directed against different citrullinated antigens, including filaggrin, fibrinogen, vimentin, and collagen. The presence of ACPA is associated with joint damage and extraarticular manifestations, suggesting that ACPA may have a significant role in the pathogenesis of RA.Methods. To verify the effect of ACPA on RA-immune cells, peripheral blood mononuclear cells (PBMC) from cyclic citrullinated peptide (CCP)–positive patients with RA and healthy controls were cocultured in vitro with ACPA. ACPA-positive stained cells were analyzed by flow cytometry and the effect of ACPA on mRNA expression levels was evaluated by real-time PCR. We tested whether the stimulatory effects induced by ACPA could be inhibited by the addition of a new multiepitope citrullinated peptide (Cit-ME).Results. We found that ACPA bind specifically to PBMC from CCP-positive patients with RA through the Fab portion. ACPA induce upregulation of pathogenic cytokine expression (4- to 13-fold increase) in PBMC derived from CCP-positive patients with RA. Moreover, ACPA upregulated IL-1β and IL-6 mRNA expression levels by 10- and 6-fold, respectively, compared to control IgG. Cit-ME, a genuine ligand of ACPA, inhibited the ACPA-induced upregulation of IL-1β and IL-6 by 30%.Conclusion. ACPA bind to a limited percentage of PBMC and upregulate inflammatory cytokine expression, suggesting that ACPA is involved in RA pathogenesis. Targeting ACPA to decrease their pathogenic effects might provide a novel direction in developing therapeutic strategies for RA.