title: Yield and cost effectiveness of mycobacterial infection detection using a simple IGRA-based protocol in UK subjects with inflammatory bowel disease suitable for anti-TNFα therapy.
abstract: OBJECTIVE
  Testing for LTBI is recommended prior to anti-TNFα agents. This includes an assessment of TB risk factors, chest radiograph, and interferon-gamma release assay alone or with concurrent Tuberculin skin testing. Here we review our experience and cost-effectiveness of using T-SPOT.TB IGRA to detect mycobacterial infection in patients with IBD suitable for anti-TNFα therapy.
  
  
  METHODS
  This was a single-centre, retrospective review and economic evaluation (compared to British Thoracic Society guidance) of 125 adult IBD patients (90 anti-TNFα naïve, 35 established on anti-TNFα) tested for LTBI using T-SPOT.TB IGRA.
  
  
  RESULTS
  All subjects had normal chest radiographs and no clinical evidence for TB. 109 (87%) were BCG vaccinated. 27 (22%) of all patients tested were not using immunomodulation at the time of testing. 66 (53%) were taking thiopurines, 22 (18%)corticosteroids, and 35 (28%) anti-TNFα agents. One hundred twenty two (98%) had a negative IGRA result, two (2%) had positive results, and one (1%) had an indeterminate IGRA. A strategy using IGRA to guide TB preventative treatment produced cost savings of £10.79 per person compared to the BTS guidance. Eighty eight percent of the anti-TNFα naïve group have subsequently received treatment with either infliximab or adalimumab (median follow-up of 24 months, IQR 18-30) with no cases of TB disease occurring.
  
  
  CONCLUSIONS
  The use of a simple screening protocol for LTBI incorporating T-SPOT.TB IGRA in place of TST in a largely BCG vaccinated population, many using immunomodulatory agents, appears to work well and is a cost-effective strategy in our IBD service.
authors.affiliation: Centre for Gastroenterology, 8 South Offices, 8th Floor, Royal Free Hospital NHS Foundation Trust, Pond Street, London, NW3 2QG, United Kingdom. K.greveson@nhs.net
authors.forename: Kay
authors.initials: K
authors.lastname: Greveson
authors.forename: James
authors.initials: J
authors.lastname: Goodhand
authors.forename: Santino
authors.initials: S
authors.lastname: Capocci
authors.forename: Sue
authors.initials: S
authors.lastname: Woodward
authors.forename: Charles
authors.initials: C
authors.lastname: Murray
authors.forename: Ian
authors.initials: I
authors.lastname: Cropley
authors.forename: Mark
authors.initials: M
authors.lastname: Hamilton
authors.forename: Marc
authors.initials: M
authors.lastname: Lipman
mesh_terms: D000068879:Adalimumab; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D001379:Azathioprine / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000188:drug therapy*; D000069285:Infliximab; D059425:Interferon-gamma Release Tests / Q000191:economics; D055985:Latent Tuberculosis / Q000150:complications / Q000175:diagnosis*; D008297:Male; D015122:Mercaptopurine / Q000627:therapeutic use; D008875:Middle Aged; D012189:Retrospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*; D006113:United Kingdom
chemical_list: D000305:Adrenal Cortex Hormones; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D007166:Immunosuppressive Agents; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab; D015122:Mercaptopurine; D000068879:Adalimumab; D001379:Azathioprine