P0404 Ileal Thickening in a TB-endemic Country : Crohn’s or Tuberculosis? Serial Intestinal Ultrasound Holds the Answer

Abstract Background In countries like India, which are endemic for Tuberculosis (TB), every symptomatic ileal thickening may not implicate a straightforward diagnosis of Crohn’s disease. In fact, most of these symptomatic findings are attributable to TB, and anti-tuberculosis therapy (ATT) leads to symptomatic as well as endoscopic improvement. In patients with Crohn’s Disease (CD), on the other hand, ATT leads to a deceptive symptomatic improvement; however, multiple studies from India found that it is not accompanied by endoscopic improvement, and if this is not picked up, there are higher chances of the patient later developing structuring CD. A colonoscopy at the end of two months of empirical ATT is the current protocol in India, to differentiate between TB and CD. This is resource-intensive for the patients as well as healthcare facilities. We explored the role of Intestinal Ultrasound (IUS) in differentiating ileo-cecal TB and CD. Methods All adult patients presenting to our centre with a symptomatic ileal or ileo-cecal thickening were subjected to IUS in addition to the standard of care evaluation (Inflammatory markers such as CRP and ESR, CT or MR Enterography, Ileo-colonoscopy with biopsy). After the evaluation, these patients were administered empirical ATT for two months, followed by a repeat IUS. The baseline ileal wall thickness, vascularity were noted. The patients received their diagnosis (TB or CD) based on the presence of endoscopic response at the end of the two-month ATT course. Results The mean ileal wall thickness, as measured in the baseline IUS, before ATT, was 2.9 mm for patients with ileo-cecal TB compared to 4.2 mm for CD (p < 0.0001). At baseline, the mean Limberg Score in patients with TB was 1 compared to 2.7 in those with CD (p < 0.0001). At the end of two months after the ATT course, the average decline in the wall thickness was 0.6 mm for TB compared to 0.09 mm for CD (p < 0.0001). This also correlated with persistent endoscopic findings after ATT, signifying presence of CD. The average Limberg score calculated at the end of the ATT for two months was 0.38 for TB compared to 2.7 for CD (p < 0.0001). Conclusion The higher baseline wall thickness and prominent vascularity is a significant predictor of CD in patients with ileo-cecal thickening. A lack of decline in the wall thickness and vascularity with ATT correlates with the lack of endoscopic response, and thus is able to differentiate between TB and CD.