title: Effects of DMARDs on citrullinated peptide autoantibody levels in RA patients-A longitudinal analysis.
abstract: To study whether stable treatment with DMARDs affects anti-CCP2 antibody levels in patients with rheumatoid arthritis.
  
  
  
  In this longitudinal observational study 100 RA patients were followed for anti-CCP2 IgG antibody (U/L) and total IgG level (mg/dL) every 6 months for a total period of 2.5 years. All patients received stable DMARD treatment during this period. Five groups comprising each 20 patients were analyzed as follows: (1) methotrexate (MTX) alone, (2) tumor necrosis factor inhibitors (TNFi), (3) tocilizumab (TCZ), (4) rituximab (RTX), and (5) abatacept (ABA).
  
  
  
  Baseline demographic and disease-specific characteristics were comparable between the 5 groups. Anti-CCP2 antibody levels did not show significant changes in patients treated with MTX (mean ± SEM: -24.1 ± 8.1%), TNFi (-14.0 ± 11.1%) or TCZ (-24.3 ± 11.3%) between baseline and the 2.5 years follow-up. In contrast, anti-CCP2 antibody levels significantly decreased during treatment with RTX (-75.6 ± 4.4%) and ABA (-82.5 ± 3.7%). With respect to total IgG levels, no significant changes were observed with MTX (-1.6 ± 3.5%), TNFi (2.5 ± 3.4%), TCZ (-4.4 ± 3.1%), or ABA (-2.4 ± 3.8%) over 2.5 years. In contrast, total IgG levels significantly decreased during treatment with RTX (-22.0 ± 3.7%).
  
  
  
  DMARDs targeting the adaptive immune response such as ABA and RTX significantly lowered anti-CCP2 IgG levels, while cytokine inhibitors and methotrexate had no significant effects on anti-CCP2 IgG levels. RTX is the only DMARD, which also lowers total IgG level.
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology, University of Erlangen-Nuremberg, Ulmenweg 18, 91054, Erlangen, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Wunderlich
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology, University of Erlangen-Nuremberg, Ulmenweg 18, 91054, Erlangen, Germany.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Oliviera
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology, University of Erlangen-Nuremberg, Ulmenweg 18, 91054, Erlangen, Germany; Division of Rheumatology, Universidade des Sao Paulo, Sao Paulo, Brazil.
authors.forename: Camille P
authors.initials: CP
authors.lastname: Figueiredo
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology, University of Erlangen-Nuremberg, Ulmenweg 18, 91054, Erlangen, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Rech
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology, University of Erlangen-Nuremberg, Ulmenweg 18, 91054, Erlangen, Germany. Electronic address: georg.schett@uk-erlangen.de.
authors.forename: Georg
authors.initials: G
authors.lastname: Schett
mesh_terms: D000069594:Abatacept / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000075422:Anti-Citrullinated Protein Antibodies / Q000097:blood*; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D000069283:Rituximab / Q000627:therapeutic use; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
chemical_list: D000075422:Anti-Citrullinated Protein Antibodies; D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents; D014409:Tumor Necrosis Factor-alpha; D000069283:Rituximab; D000069594:Abatacept; C502936:tocilizumab; D008727:Methotrexate
keywords: Anti-CCP2 antibodies; DMARDs; Immunglobulins; Rheumatoid arthritis