title: Baseline Serum Osteopontin Levels Predict the Clinical Effectiveness of Tocilizumab but Not Infliximab in Biologic-Naïve Patients with Rheumatoid Arthritis: A Single-Center Prospective Study at 1 Year (the Keio First-Bio Cohort Study).
abstract: OBJECTIVE
  To explore the baseline predictors of clinical effectiveness after tocilizumab or infliximab treatment in biologic-naïve rheumatoid arthritis patients.
  
  
  METHODS
  Consecutive biologic-naïve patients with rheumatoid arthritis initiating infliximab (n = 57) or tocilizumab (n = 70) treatment were included in our prospective cohort study. Our cohort started in February 2010, and the patients observed for at least 1 year as of April 2013 were analysed. We assessed baseline variables including patients' characteristics (age, sex, disease duration, prednisolone dose, methotrexate dose, other disease-modifying antirheumatic drug use, Clinical Disease Activity Index [CDAI]) and serum biomarker levels (C-reactive protein, immunoglobulin M-rheumatoid factor, anti-cyclic citrullinated protein/peptide antibodies, interferon-γ, interleukin (IL)-1β, IL-2, IL-6, IL-8, IL-10, IL-17, tumor necrosis factor-α, soluble intercellular adhesion molecule-1, bone alkaline phosphatase, osteonectin, osteopontin) to extract factors associated with clinical remission (CDAI ≤ 2.8) at 1 year using univariate analyses, and the extracted factors were entered into a multivariate logistic regression model. Similar analyses were also performed for Simplified Disease Activity Index (SDAI) remission (≤ 3.3) and Disease Activity Score with 28 joint counts, erythrocyte sedimentation rate (DAS28-ESR) remission (< 2.6).
  
  
  RESULTS
  There were no significant differences in the baseline characteristics except for methotrexate use between the groups. In the multivariate analyses, the low baseline osteopontin levels (OR 0.9145, 95% CI 0.8399-0.9857) were identified as predictors of CDAI remission in the tocilizumab group, whereas no predictors of CDAI remission were found in the infliximab group. Similar results were obtained when using SDAI and DAS28-ESR remission criteria.
  
  
  CONCLUSIONS
  Baseline low serum osteopontin levels predict clinical remission 1 year after tocilizumab treatment and not infliximab treatment in biologic-naïve patients with rheumatoid arthritis. Our prediction model provided insights into how to optimize the choice of biologics and warrants external validation in other cohorts.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.|Department of Connective Tissue Diseases, National Tokyo Medical Center, Tokyo, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Izumi
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Product Research Department, Fuji-Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., Gotemba, Japan.
authors.forename: Misato
authors.initials: M
authors.lastname: Hashizume
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yoshimoto
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Takeuchi
mesh_terms: D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D015415:Biomarkers / Q000097:blood*; D016207:Cytokines / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000069285:Infliximab / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D053495:Osteopontin / Q000097:blood*; D011379:Prognosis; D011446:Prospective Studies; D012074:Remission Induction
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents; D015415:Biomarkers; D016207:Cytokines; D053495:Osteopontin; D000069285:Infliximab; C502936:tocilizumab