Comparative diagnostic efficacy of Gene Xpert MTB/RIF, AFB Smear and Culture in the diagnosis of Tuberculous Pleural Effusion

Abstract

Background: Tuberculosis is a life-threatening disease worldwide whereas pleural effusion is second common presentation as regard to extrapulmonary TB. Present study was conducted to see the efficacy of Gene Xpert MTB/RIF, AFB smear by microscopy and culture to diagnose tuberculous pleurisy.Methodology: This cross-sectional study was conducted at institute of chest medicine/PHRC King Edward Medical University during the period January 2017 to January 2019. Inclusion criteria consist, no gender distinction, no age limit, patients who have never taken ATT and exudative, lymphocytic predominant with high adenosine deaminase (ADA) level >40 IU/L in pleural effusion. Informed consent was taken to get the sample of 120 cc pleural fluid from each patient. A 20cc fluid from each patient was analyzed for biochemistry, cytology and ADA level. The remaining (100cc) sample was processed by PHRC lab for Gene Xpert MTB/RIF, ZN staining and culture. The data was processed by SPSS.Results: A total number of 150 cases of exudative lymphocytic with high ADA level in pleural effusion were included, of which 104 were males, and 46 were females. Age range was between 18 - 79 years with mean age of 37.1 ± 16.5years for males and for females it was between 16 - 70 years with mean age of 32.3 ± 14.3 years. ZN staining was positive in 12 (8%) patients and culture was positive in 18 (12%) cases, MTB was detected by Gene Xpert in 28 (18%) and RIF resistance was positive in 4 (50% of each were male and female) patients.Conclusion: Diagnostic efficacy of both smear and culture is low as compared to Gene Xpert but these techniques are of great use in the confirmation of diagnosis of tuberculous pleurisy.