The value of empiric anti-tuberculosis therapy in the differential diagnosis between intestinal tuberculosis and Crohn's disease in China

Objective: To find out the criteria, the suitable duration and the efficacy of using empiric anti-tuberculosis to differentiate intestinal tuberculosis (ITB) from Crohn's disease (CD). Methods: Forty-eight patients receiving empiric anti-tuberculosis therapy were retrospectively analyzed and underwent 4-10 years follow-up. Among them, 28 were confirmed as ITB and 20 as CD at final evaluation. Clinical manifestations, endoscopic changes and the response to anti-tuberculosis therapy were compared between ITB and CD groups. Results: 1) The baseline clinical characteristics anal fistula/perianal abscess and aphthous ulcers were significantly different between 2 groups. Strong positive skin test (PPD test) result was also not comparable between 2 groups; 2) Clinical symptoms improved in both groups after 3 mo empiric anti-tuberculosis therapy. The non-improvement rate in ITB group was 0%, whereas that of CD group was 15.0% (P= 0.007); 3) Endoscopic appearance improved significantly in ITB group but not CD group after 3 mo or 6 mo empiric anti-tuberculosis therapy, Ulcer disappearance rate in ITB group was 90.9% (20/22) in 3 mo and 100% (28/28) in 6 mo. Nodular transformation disappearance rate of in ITB group was 58.8% (10/17) in 3 mo and 76.5% (13/17) in 6 mo. There was no obvious improvement of active ulcer or nodular transformation in CD group at any time point (P < 0.001 compared with ITB). Conclusions: Three months of empiric anti-tuberculosis therapy was a proper duration for the purpose of differentiating ITB from CD. Disappearance of active ulcer and nodular transformation endoscopically, together with clinical cure or obviously improvement are engraved as effective.