RESUMEN
Background: Crohn's disease (CD) and intestinal tuberculosis (ITB) share similarities in disease manifestations, but their treatment methods are totally different. Thus, the differential diagnosis between CD and ITB is of great clinical importance. Aims: To investigate the significance of positive tuberculosis interferon-gamma release assay (TB-IGRA) in differential diagnosis and treatment of CD and ITB. Methods: Fifty-six consecutive patients with positive TB-IGRA and definite diagnosis of CD (n=23) or ITB (n=33) in the Tenth People's Hospital of Tongji University from Jan. 2015 to May 2018 were enrolled. All these patients have been proposed as CD at their first visit. The effects of TB-IGRA on diagnosis and treatment were analyzed. Results: ROC curve analysis demonstrated that the cut-off value, sensitivity and specificity of TB-IGRA for diagnosis of tuberculosis infection were 100 pg/mL, 88% and 74%, respectively. In patients with TB-IGRA≥100 pg/mL, 4 were CD and 29 were ITB, while in patients with TB-IGRA<100 pg/mL, 19 were CD and 4 were ITB (P<0.05); 75.0% (3/4) of the CD patients with TB-IGRA≥100 pg/mL and 5.3% (1/19) of the CD patients with TB-IGRA<100 pg/mL had a history of tuberculosis infection (P<0.05). Thirty-five patients received diagnostic anti-tuberculosis therapy, the efficacy of those with TB-IGRA≥100 pg/mL was significantly higher than those with TB-IGRA<100 pg/mL (96.2% vs. 22.2%, P<0.05). Conclusions: 100 pg/mL might be set as the cut-off value of TB-IGRA for differential diagnosis between CD and ITB. Diagnostic anti-tuberculosis therapy is preferred for patients with TB-IGRA≥100 pg/mL, while patients with TB-IGRA<100 pg/mL need comprehensive analysis. For patients with history of tuberculosis infection, false positive TB-IGRA is prone to occur.