title: Polyarthritis flare complicating rheumatoid arthritis infliximab therapy: a paradoxic adverse reaction.
abstract: BACKGROUND
  The treatment of rheumatoid arthritis (RA) has changed dramatically over the past decade with the introduction of antitumor necrosis factor (anti-TNF) agents. Although subsets of patients may have only partial or no response, there is no report yet on possible worsening of RA with this therapy.
  
  
  OBJECTIVE
  The objective of this study was to determine whether infliximab may paradoxically exacerbate RA.
  
  
  METHODS
  One hundred seven patients with RA refractory to 3 disease-modifying antirheumatic drugs were treated with 3 mg/kg infliximab and methotrexate for at least 6 months.
  
  
  RESULTS
  In 3 patients, there was an exacerbation of RA associated with the use of infliximab. The flare occurred during the first 6 to 12 months of treatment with polyarthritis, fever, and elevated acute phase reactants. Increase of infliximab dose resulted in further deterioration.
  
  
  CONCLUSIONS
  We describe a paradoxic reaction, an exacerbation of RA, with infliximab. The mechanism of this side effect is unclear but may be related to altered immunity induced by the inhibition of TNF activity in predisposed patients.
authors.affiliation: Department of Rheumatology, Bnai Zion Medical Center, Haifa, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Rozenbaum
authors.forename: Nina
authors.initials: N
authors.lastname: Boulman
authors.forename: Gleb
authors.initials: G
authors.lastname: Slobodin
authors.forename: Elena
authors.initials: E
authors.lastname: Ayubkhanov
authors.forename: Itzhak
authors.initials: I
authors.lastname: Rosner
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal / Q000009:adverse effects* / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000145:classification / Q000188:drug therapy* / Q000473:pathology*; D005260:Female; D006801:Humans; D000069285:Infliximab; D008297:Male; D008875:Middle Aged
chemical_list: D000911:Antibodies, Monoclonal; D000069285:Infliximab