title: Correlation of antinuclear antibody and anti-double-stranded DNA antibody with clinical response to infliximab in patients with rheumatoid arthritis: a retrospective clinical study.
abstract: BACKGROUND
  The induction of antinuclear antibodies (ANAs) or anti-double-stranded (ds) -DNA antibodies (Abs) after infliximab (IFX) therapy in rheumatoid arthritis (RA) is a well-known phenomenon, but the correlation of such Abs with the clinical response to IFX has not yet been determined. The aims of this retrospective observational study were to examine the prevalence of positive ANA and anti-ds-DNA Abs before and after IFX therapy in patients with RA and to investigate whether an increased titer of such Abs is associated with the clinical efficacy of IFX.
  
  
  METHODS
  One hundred eleven RA patients who had received IFX were studied. ANA (indirect immunofluorescence with HEp-2 cells) and anti-ds-DNA Abs (Farr assay) results were examined before and after IFX therapy.
  
  
  RESULTS
  The overall clinical response assessed by EULAR response criteria was as follows: good response in 55%, including remission in 38%; moderate response in 18%; and no response (NOR) in 27%. The positivity of ANA (≥ 1:160) and anti-ds-DNA Abs significantly increased from 25% to 40% (P = 0.03) and from 3% to 26% (P < 0.001) after IFX, respectively. EULAR response differed significantly according to the ANA titer before IFX (P = 0.001), and the efficacy of IFX became worse as the ANA titer before starting IFX increased. Furthermore, the differences in the clinical response of the ANA titer before IFX ≤ 1:80 and ≥ 1:160 were significant (good, moderate, and no response were 66%, 9%, and 25% in ≤ 1:80 group versus 26%, 33%, 41% in ≥ 1:160 group, respectively; P < 0.001). In 13 patients whose ANA had increased after IFX, 10 showed NOR, only one showed a good response, and none reached remission. These clinical responses were significantly different from ANA no-change patients. In 21 patients with positive anti-ds-DNA Abs after IFX, 16 showed NOR, only two showed a good response, and none reached remission.
  
  
  CONCLUSIONS
  The present study suggests that the ANA titer before starting IFX predicts the clinical response to IFX. The increased titers of ANA or anti-ds-DNA Abs after IFX may be useful markers of NOR.
authors.affiliation: Department of Rheumatology and Clinical Immunology, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan. naoichiy@kuhp.kyoto-u.ac.jp
authors.forename: Naoichiro
authors.initials: N
authors.lastname: Yukawa
authors.forename: Takao
authors.initials: T
authors.lastname: Fujii
authors.forename: Seiko
authors.initials: S
authors.lastname: Kondo-Ishikawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Yoshifuji
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kawabata
authors.forename: Takaki
authors.initials: T
authors.lastname: Nojima
authors.forename: Koichiro
authors.initials: K
authors.lastname: Ohmura
authors.forename: Takashi
authors.initials: T
authors.lastname: Usui
authors.forename: Tsuneyo
authors.initials: T
authors.lastname: Mimori
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000974:Antibodies, Antinuclear / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000276:immunology*; D045744:Cell Line, Tumor; D004334:Drug Administration Schedule; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D000069285:Infliximab; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D000069285:Infliximab