title: Regulation of IFN response gene activity during infliximab treatment in rheumatoid arthritis is associated with clinical response to treatment.
abstract: BACKGROUND
  Cross-regulation between TNF and type I IFN has been postulated to play an important role in autoimmune diseases. Therefore, we determined the effect of TNF blockade in rheumatoid arthritis (RA) on the type I IFN response gene activity in relation to clinical response.
  
  
  METHODS
  Peripheral blood from 33 RA patients was collected in PAXgene tubes before and after the start of infliximab treatment. In a first group of 15 patients the baseline expression of type I IFN-regulated genes was determined using cDNA microarrays and compared to levels one month after treatment. The remaining 18 patients were studied as an independent group for validation using quantitative polymerase chain reaction (qPCR).
  
  
  RESULTS
  Gene expression analysis revealed that anti-TNF antibody treatment induced a significant increase in type I IFN response gene activity in a subset of RA patients, whereas expression levels remained similar or were slightly decreased in others. The findings appear clinically relevant since patients with an increased IFN response gene activity after anti-TNF therapy had a poor clinical outcome. This association was confirmed and extended for an IFN response gene set consisting of OAS1, LGALS3BP, Mx2, OAS2 and SERPING1 in five EULAR good and five EULAR poor responders, by qPCR.
  
  
  CONCLUSIONS
  Regulation of IFN response gene activity upon TNF blockade in RA is not as consistent as previously described, but varies between patients. The differential changes in IFN response gene activity appear relevant to the clinical outcome of TNF blockade in RA.
authors.affiliation: Department of Pathology, VU University Medical Center, De Boelelaan 1118, 1081 HZ, Amsterdam, The Netherlands. e.g.vanbaarsen@amc.uva.nl
authors.forename: Lisa Gm
authors.initials: LG
authors.lastname: van Baarsen
authors.forename: Carla A
authors.initials: CA
authors.lastname: Wijbrandts
authors.forename: François
authors.initials: F
authors.lastname: Rustenburg
authors.forename: Tineke
authors.initials: T
authors.lastname: Cantaert
authors.forename: Tineke Ctm
authors.initials: TC
authors.lastname: van der Pouw Kraan
authors.forename: Dominique L
authors.initials: DL
authors.lastname: Baeten
authors.forename: Ben Ac
authors.initials: BA
authors.lastname: Dijkmans
authors.forename: Paul P
authors.initials: PP
authors.lastname: Tak
authors.forename: Cornelis L
authors.initials: CL
authors.lastname: Verweij
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D000069285:Infliximab; D007370:Interferon Type I / Q000097:blood / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
chemical_list: D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D007370:Interferon Type I; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab