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AIM: To compare high definition white light endoscopy and bright narrow band imaging for colon polyps' detection rates. METHODS: Patients were randomised to high definition white light endoscopy (HD-WLE) or the bright narrow band imaging (bNBI) during withdrawal of the colonoscope. Polyps identified in either mode were characterised using bNBI with dual focus (bNBI-DF) according to the Sano's classification. The primary outcome was to compare adenoma detection rates (ADRs) between the two arms. The secondary outcome was to assess the negative predictive value (NPV) in differentiating adenomas from hyperplastic polyps for diminutive rectosigmoid lesions. RESULTS: A total of 1006 patients were randomised to HD-WLE (n = 511) or bNBI (n = 495). The mean of adenoma per patient was 1.62 and 1.84, respectively. The ADRs in bNBI and HD-WLE group were 37.4% and 39.3%, respectively. When adjusted for withdrawal time (OR = 1.19, 95%CI: 1.15-1.24, P < 0.001), the use of bNBI was associated with a reduced ADR (OR = 0.69, 95%CI: 0.52-0.92). Nine hundred and thirty three polyps (86%) in both arms were predicted with high confidence. The sensitivity (Sn), specificity (Sp), positive predictive value and NPV in differentiating adenomatous from non-adenomatous polyps of all sizes were 95.9%, 87.2%, 94.0% and 91.1% respectively. The NPV in differentiating an adenoma from hyperplastic polyp using bNBI-DF for diminutive rectal polyps was 91.0%. CONCLUSION: ADRs did not differ between bNBI and HD-WLE, however HD-WLE had higher ADR after adjustment of withdrawal time. bNBI surpassed the PIVI threshold for diminutive polyps.
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BACKGROUND: Screening for latent tuberculosis (TB) is mandatory in inflammatory bowel disease (IBD) before starting anti-tumor necrosis factor therapy. Data on the utility of screening tests in populations with moderate background risk of TB are limited. This study aims to evaluate the performance of interferon-gamma release assay (IGRA) with QuantiFERON-TB Gold in IBD patients in a TB endemic region. METHODS: Two hundred sixty-eight consecutive adult IBD patients and 234 healthy controls were prospectively recruited. Detailed clinical history, chest x-ray findings, and IGRA results were documented for all individuals. The IGRA positive rates between IBD patients, with or without immunosuppressant, and healthy controls were compared. RESULTS: The IGRA result was positive in 21.9% of IBD patients and 19.2% of healthy controls (P = 0.535). IBD patients on immunosuppressive therapy had a significantly lower IGRA positive rate (13.0% versus 29.6%; P = 0.002) compared with immunosuppressant-naive IBD patients. This difference seemed to be most prominent for patients taking azathioprine (11.8% versus 27.3%, P = 0.006). CONCLUSIONS: IGRA results are negatively impacted by immunosuppressive therapy. Current guidelines suggesting TB screening before anti-tumor necrosis factor therapy may be inadequate in patients already on immunosuppressive drugs. Latent TB testing seems best performed before the initiation of immunosuppressive therapies in IBD patients.