Utility of tissue Xpert-Mtb/Rif for the diagnosis of intestinal tuberculosis in patients with ileocolonic ulcers

Abstract

Introduction: Data on the use of Xpert Mtb/Rif for the diagnosis of intestinal tuberculosis is sparse. We report on the utility of Xpert Mtb/Rif testing for diagnosis of intestinal tuberculosis (ITB) in patients with ileocecal ulcers Methodology: We performed a retrospective analysis of patients with ileocecal ulcers and suspected to have ITB and in whom testing of intestinal tissue for Xpert Mtb/Rif was performed. The patients were divided into two groups: those with a final diagnosis of intestinal tuberculosis and those with other diagnosis. These patients were compared for clinical features and presentation. The sensitivity, specificity, positive predictive value, and negative predictive value of Xpert Mtb/Rif for the diagnosis of ITB were calculated. Results: Of the 40 patients studied, 23 were women and the mean age was 32.92 ± 12.78 years. Abdominal pain was present in 33 (88.5%) patients and diarrhea in 12 (30%). A total of 25 patients had underlying ITB whereas 15 patients had other diagnoses (Crohn’s disease, amebiasis, nonspecific ileitis, etc.). The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of GeneXpert-Mtb/Rif was 32% (CI: 14.95–53.50%), 100% (78.2–100), 46.88% (40.27–53.59%), 100 & 57.50 (40.89–72.89%) respectively. Conclusion: A positive GeneXpert-Mtb/Rif helps in the diagnosis of ITB, but the sensitivity is low.