title: How frequently do tuberculosis screening tests convert in inflammatory bowel disease patients on anti-tumour necrosis factor-alpha? A pilot study.
abstract: BACKGROUND
  Tuberculosis reactivation can lead to severe complications in patients treated with anti-tumour necrosis factor-alpha.
  
  
  OBJECTIVE
  To assess the usefulness of repeat tuberculosis screening tests in inflammatory bowel disease patients on stable anti-TNF therapy.
  
  
  METHODS
  Cross-sectional study, in patients on prolonged anti-TNF treatment (≥ 12 months) and basal negative screening for latent tuberculosis. Quantiferon(®)-TB Gold In-tube test was performed and then, tuberculin skin test was administered.
  
  
  RESULTS
  74 patients were included, median duration of anti-TNF treatment was 30 months (IQR 19-54); 47 patients on infliximab and 27 on adalimumab; no patient was on glucocorticoids. Previous BCG vaccination was present in 5 cases. After anti-TNF was started, 4 patients suffered from potential tuberculosis exposure and two cases travelled to endemic areas. The cumulative incidence of tuberculin skin test conversion was 2.7% (95% CI 0.3-9.4%, 2/74), and the incidence rate of tuberculin skin test conversion was 0.83% (95% CI 0.1-2.9%) per patient-year of treatment with anti-TNF drugs. All Quantiferon tests but one (a patient with an indeterminate result and a negative tuberculin skin test) were negative.
  
  
  CONCLUSIONS
  The incidence rate of conversion of tuberculosis screening tests among patients on anti-TNF treatment seems to be low and these conversions were diagnosed based on a positive tuberculin skin test and were discordant with Quantiferon testing.
authors.affiliation: Department of Gastroenterology, Hospital Universitario de Fuenlabrada, Madrid, Spain. Electronic address: fbermejos@medynet.com.
authors.forename: Fernando
authors.initials: F
authors.lastname: Bermejo
authors.forename: Alicia
authors.initials: A
authors.lastname: Algaba
authors.forename: María
authors.initials: M
authors.lastname: Chaparro
authors.forename: Carlos
authors.initials: C
authors.lastname: Taxonera
authors.forename: Elena
authors.initials: E
authors.lastname: Garrido
authors.forename: Isabel
authors.initials: I
authors.lastname: García-Arata
authors.forename: Iván
authors.initials: I
authors.lastname: Guerra
authors.forename: Javier P
authors.initials: JP
authors.lastname: Gisbert
authors.forename: David
authors.initials: D
authors.lastname: Olivares
authors.forename: Gema
authors.initials: G
authors.lastname: de-la-Poza
authors.forename: Antonio
authors.initials: A
authors.lastname: López-Sanromán
mesh_terms: D000068879:Adalimumab; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000188:drug therapy*; D000069285:Infliximab; D059425:Interferon-gamma Release Tests; D055985:Latent Tuberculosis / Q000150:complications / Q000175:diagnosis*; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D010865:Pilot Projects; D014374:Tuberculin Test; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D000893:Anti-Inflammatory Agents; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab; D000068879:Adalimumab
keywords: Anti-tumour necrosis factor; Inflammatory bowel disease; Quantiferon; Tuberculin skin test; Tuberculosis