Diagnostic Accuracy of Peritoneal Fluid GeneXpert in the Diagnosis of Intestinal Tuberculosis, Keeping Histopathology as the Gold Standard

Abstract

Background The diagnosis of abdominal tuberculosis is a major health challenge. Limited data are available to support the use of GeneXpert MTB/RIF in the diagnosis of abdominal tuberculosis. The current study is an analysis of the sensitivity and specificity of GeneXpert MTB/RIF for the diagnosis of abdominal tuberculosis, keeping histopathology as the gold standard. Materials and methods A prospective study was conducted in Surgery Unit-I of Holy Family hospital in the year 2017. Data of 21 patients presenting with abdominal tuberculosis were collected. The samples collected were ascitic fluid for GeneXpert and acid-fast bacilli (AFB) and a tissue sample for histopathology, which included either the enlarged lymph nodes or the involved gut segment. Results Out of a total of 21 patients, 10 were male and 11 were female. The predominant age group was less than 30 years with 76.2% cases. Of the 21 samples analyzed, all were positive for tuberculosis (TB) by histopathology. GeneXpert was positive in six and negative in 15 patients. The sensitivity of GeneXpert was 28.57% and specificity was 0%. The positive predictive value was 100%. The diagnostic accuracy was found to be 28.57%. Conclusion In our study, GeneXpert has shown poor sensitivity and specificity for the detection of abdominal TB from ascitic fluid samples. On the basis of this data, we lay stress on finding new tests and biomarkers for the rapid diagnosis of abdominal TB.

Keywords: abdominal tuberculosis; genexpert.