Interferon-Gamma Release Assay in the Ascites: Early Hint for Diagnosis of Abdominal Tuberculosis

We report on a 20-year-old woman with abdominal tuberculosis. Standard microbiological examination of ascites showed no acid-fast bacilli (AFB), and analysis for the Mycobacterium tuberculosis (MTB)-complex DNA by PCR was negative. However, the interferon-γ release assay (IGRA) of the ascites was positive after specific stimulation with mycobacterial antigens (ESAT-6/CFP-10/TB7.7[p4]), indicating an infection with MTB. The diagnosis of tuberculosis was later confirmed by histology, MTB culture, and PCR analysis of MTB-complex DNA in tissue samples taken during laparoscopy. Thus, the IGRA of ascites may guide the decision to start active treatment for tuberculosis.