The role of chest X-ray in detecting latent tuberculosis among patients with low-risk inflammatory bowel disease before advanced therapy.

BACKGROUND: Patients treated with biologics or Janus kinase (JAK) inhibitors have an increased risk of reactivating latent tuberculosis infection (LTBI). ECCO guidance recommends screening for LTBI by using clinical data, epidemiological factors, chest X-ray (CXR), and either a tuberculin skin test or interferon-gamma release assay (IGRA). The evidence supporting CXR use is categorised at level 5. We aimed to determine the relation between CXR and IGRA test results in adults with inflammatory bowel disease (IBD) before starting immunosuppressive therapy in a low-risk population.

METHODS: This retrospective analysis identified adult patients with IBD on biologics or JAK inhibitors and their epidemiological data, CXR, and IGRA results were evaluated.

RESULTS: 356 patients diagnosed with IBD were included, 58.7% ( n  = 209) being male. Most patients had Crohn's disease (66.6%, n  = 237), 30.6% ( n  = 109) had ulcerative colitis, and the remaining 2.8% were classified as IBD-unclassified. The mean age of IBD diagnosis was 30.3 years (SD ± 15.7). None of the patients had any clinical suggestion or exposure to tuberculosis (TB); 93.8% ( n  = 334) of the IGRA results were negative and 4.2% ( n  = 15) were indeterminate. Among those with indeterminate results, 66.7% ( n  = 10) were undergoing corticosteroid treatment. The remaining 2.0% ( n  = 7) had a positive IGRA test result. None of the CXRs performed revealed any radiological signs of TB disease. None of these patients had TB reactivation after immunosuppresion.

CONCLUSION: Routinely performing a CXR in individuals with a negative IGRA offers limited benefits, and submits patients to unnecessary radiation.