title: Anti-TNF therapy is associated with an increased risk of serious infections in patients with rheumatoid arthritis especially in the first 6 months of treatment: updated results from the British Society for Rheumatology Biologics Register with special emphasis on risks in the elderly.
abstract: OBJECTIVE
  To evaluate the risk of serious infections (SIs) in patients with RA treated with anti-TNF therapy with emphasis on the risk across different ages.
  
  
  METHODS
  Using data from the British Society for Rheumatology Biologics Register, a prospective observational study, we compared the risk of SI between 11 798 anti-TNF-treated patients and 3598 non-biologic DMARD (nbDMARD)-treated patients.
  
  
  RESULTS
  A total of 1808 patients had at least one SI (anti-TNF: 1512; nbDMARD: 296). Incidence rates were: anti-TNF 42/1000 patient-years of follow-up (95% CI 40, 44) and nbDMARD 32/1000 patient-years of follow-up (95% CI 28, 36). The adjusted hazard ratio (adjHR) for SI in the anti-TNF cohort was 1.2 (95% CI 1.1, 1.5). The risk did not differ significantly between the three agents adalimumab, etanercept and infliximab. The risk was highest during the first 6 months of therapy [adjHR 1.8 (95% CI 1.3, 2.6)]. Although increasing age was an independent risk factor for SI in both cohorts, there was no difference in relative risk of infection in patients on anti-TNF therapy in the older population. There was no difference in hospital stay for SI between cohorts. Mortality within 30 days of SI was 50% lower in the anti-TNF cohort [odds ratio 0.5 (95% CI 0.3, 0.8)].
  
  
  CONCLUSIONS
  These data add to currently available evidence suggesting that anti-TNF therapy is associated with a small but significant overall risk of SI. This must be balanced against the risks associated with poor disease control or alternative treatments.
authors.affiliation: Arthritis Research UK Epidemiology Unit, The University of Manchester, Department of Infectious Diseases, North Manchester General Hospital, Stopford Building, Oxford Road, Manchester M13 9PT, UK.
authors.forename: James B
authors.initials: JB
authors.lastname: Galloway
authors.forename: Kimme L
authors.initials: KL
authors.lastname: Hyrich
authors.forename: Louise K
authors.initials: LK
authors.lastname: Mercer
authors.forename: William G
authors.initials: WG
authors.lastname: Dixon
authors.forename: Bo
authors.initials: B
authors.lastname: Fu
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Ustianowski
authors.forename: Kath D
authors.initials: KD
authors.lastname: Watson
authors.forename: Mark
authors.initials: M
authors.lastname: Lunt
authors.forename: Deborah P M
authors.initials: DP
authors.lastname: Symmons
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal / Q000009:adverse effects; D018501:Antirheumatic Agents / Q000009:adverse effects*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007239:Infections / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012042:Registries; D012044:Regression Analysis; D012307:Risk Factors; D000079424:Tumor Necrosis Factor Inhibitors; D048069:Tumor Necrosis Factors / Q000009:adverse effects; D006113:United Kingdom
chemical_list: D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D000079424:Tumor Necrosis Factor Inhibitors; D048069:Tumor Necrosis Factors