Endoscopic and clinical responses to anti-tubercular therapy can differentiate intestinal tuberculosis from Crohn's disease

Background Differentiation between intestinal tuberculosis and Crohn's disease is difficult and may require therapeutic trial with anti-tubercular therapy in tuberculosis-endemic regions. Aim To evaluate the role of therapeutic trial with anti-tubercular therapy in patients with diagnostic confusion between intestinal tuberculosis and Crohn's disease. Methods We performed retrospective-comparative (n = 288: 131 patients who received anti-tubercular therapy before being diagnosed as Crohn's disease and 157 intestinal tuberculosis patients) and prospective-validation study (n = 55 patients with diagnostic confusion of intestinal tuberculosis/Crohn's disease). Outcomes assessed were global symptomatic response and endoscopic mucosal healing. Results In the derivation cohort, among those eventually diagnosed as Crohn's disease, global symptomatic response with anti-tubercular therapy was seen in 38% at 3 months and in 37% who completed 6 months of anti-tubercular therapy. Ninety-four per cent of intestinal tuberculosis patients showed global symptomatic response by 3 months. Endoscopic mucosal healing was seen in only 5% of patients with Crohn's disease compared with 100% of intestinal tuberculosis patients. In the validation cohort, all the patients with intestinal tuberculosis had symptomatic response and endoscopic mucosal healing after 6 months of antitubercular therapy. Among the patients with an eventual diagnosis of Crohn's disease, symptomatic response was seen in 64% at 2 months and in 31% who completed 6 months of anti-tubercular therapy, none had mucosal healing. Conclusions Disproportionately lower mucosal healing rate despite an overall symptom response with 6 months of anti-tubercular therapy in patients with Crohn's disease suggests a need for repeat colonoscopy for diagnosing Crohn's disease. Patients with intestinal tuberculosis showing significant symptomatic response after 2-3 months of anti-tubercular therapy, suggest that symptom persistence after a therapeutic trial of 3 months of anti-tubercular therapy may indicate the diagnosis of Crohn's disease.