When is repeat TB testing indicated for patients on anti-TNF therapy?

Mar 7, 2017 - E-Mentoring in IBD | Volume 10 • 2017

Issue 05

Clinical Question

In spite of negative tuberculosis (TB) screening results, some patients with IBD are subsequently diagnosed with TB after initiating anti-TNF therapy. What unique characteristics place these patients at risk for TB?

Editor’s Bottom Line

Patients with IBD being treated with an anti-TNF agent, and at risk for developing tuberculosis following a negative screening test, are those who:

  1. Have an occupational risk exposure (e.g., health care), or
  2. Travel to endemic regions.

These individuals should be re-tested at intervals or be aware that they are at risk for TB development following anti-TNF initiation.

Reference

Abitbol Y, Laharie D, Cosnes J, et al; GETAID. Negative screening does not rule out the risk of tuberculosis in patients with inflammatory bowel disease undergoing anti-TNF treatment: a descriptive study on the GETAID cohort. J Crohns Colitis. 2016 Oct;10(10):1179–85. https://www.ncbi.nlm.nih.gov/pubmed/27402916

Synopsis

This retrospective study recruited patients from 20 hospital centres belonging to the GETAID study group. Eligible adult patients were negative for TB testing and then went on to develop TB between 2001 and 2015. Patient data was collected via a questionnaire concerning possible exposure routes to Mycobacterium tuberculosis, TB screening method, IBD features, as well as infection characteristics.

A total of 44 patients who developed TB were identified (M:F was 1:1; age range: 18–66 years; CD=82%; UC=18%). Twenty-five patients were screened with the skin test, 12 completed interferon-gamma release assays, and 7 had both tests performed. A median time of 14.5 months (interquartile range [IQR] 25–75: 4.9–43.3) lapsed between the initiation of anti-TNF therapy and diagnosis of TB. The majority of patients (91%) had extrapulmonary TB involvement while 57% had pulmonary involvement. In 32%, exposure to the infectious organism was identified via occupation activities (n=7) while the remaining patients had travelled to endemic regions. After a median of 11.2 months (IQR 25–75: 4.4–15.2), anti-TNF therapy was re-initiated in 27 patients without infection recurrence.

Details

Study Design: Retrospective, observational study
Funding: None
Allocation: n/a
Setting: France & Switzerland
Level of Evidence: 2b (Oxford Levels of Evidence)

The summary and conclusion in this issue of E-mentoring in IBD pertains to the manuscript(s) being reviewed, and should be considered in the context of what is already known surrounding the topic and incorporated into practice as deemed appropriate by the individual learner.