title: The long-term outcome of anti-TNF alpha therapy in perianal Crohn's disease.
abstract: BACKGROUND
  The aim of the present study was to evaluate the long-term outcomes of anti-tumour necrosis factor alpha therapy in perianal Crohn's disease and identify factors predicting response to treatment.
  
  
  METHODS
  Data from hospital clinical records and coding databases were retrospectively reviewed from a tertiary care hospital in Christchurch, New Zealand. The study included 75 adult patients with perianal Crohn's disease commenced on anti-tumour necrosis factor alpha therapy from January 2000 to December 2012. Response to treatment was determined from records relating to clinical evaluation, magnetic resonance imaging follow-up and whether further surgical intervention was required.
  
  
  RESULTS
  73% (55) of all patients and 38 of the 57 (67%) patients with perianal fistulas responded to anti-tumour necrosis factor alpha therapy. Patients with complex fistulas were less likely to improve as compared to patients without fistulising disease. Five of the 57 (13%) patients with perianal fistulas demonstrated complete healing on clinical evaluation; however, magnetic resonance imaging confirmed complete healing in only two. Patients that had taken antibiotics and those that had previously required abscess drainage were less likely to respond to treatment [relative risk (RR) = 0.707 and 0.615, respectively; p = 0.03, p = 0.0001]. Responders were less likely to require follow-up surgery (RR = 0.658, p = 0.014) including ileostomy or proctectomy.
  
  
  CONCLUSIONS
  Although anti-tumour necrosis factor alpha tends to improve symptoms of perianal Crohn's disease, in the long term, it rarely achieves complete healing. Perianal fistulising disease, a history of perianal abscess and antibiotic treatment are predictors of poor response to therapy.
authors.affiliation: Department of Surgery, Middlemore Hospital, Auckland, New Zealand. jrayen6@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Rayen
authors.affiliation: Department of Surgery, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: T
authors.initials: T
authors.lastname: Currie
authors.affiliation: Department of Gastroenterology, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: R B
authors.initials: RB
authors.lastname: Gearry
authors.affiliation: Department of Surgery, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: F
authors.initials: F
authors.lastname: Frizelle
authors.affiliation: Department of Surgery, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: T
authors.initials: T
authors.lastname: Eglinton
mesh_terms: D000068879:Adalimumab / Q000008:administration & dosage; D000328:Adult; D003424:Crohn Disease / Q000150:complications / Q000188:drug therapy*; D005260:Female; D005765:Gastrointestinal Agents / Q000008:administration & dosage*; D006801:Humans; D000069285:Infliximab / Q000008:administration & dosage; D008297:Male; D009520:New Zealand; D012003:Rectal Fistula / Q000150:complications / Q000188:drug therapy*; D012189:Retrospective Studies; D013995:Time; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage*
chemical_list: D005765:Gastrointestinal Agents; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab; D000068879:Adalimumab
keywords: Colorectal; Crohn’s disease; Fistula; Inflammatory bowel disease; Perianal