Role of polymerase chain reaction of ascitic fluid and its correlation with adenosine deaminase levels in the diagnosis of abdominal tuberculosis

Abstract

Background: It is still difficult to diagnose tuberculosis as a source of abdominal pain. Due to the lack of non-invasive diagnostic testing, the diagnosis remains a problem. Determining the role of polymerase chain reaction (PCR) in ascitic fluid in the diagnosis of abdominal tuberculosis, we can conclude whether it is sensitive/specific or not and further its use in the diagnosis of abdominal tuberculosis. Objective: The objective of the study was to determine the role of PCR in ascitic fluid in the diagnosis of abdominal tuberculosis and also to correlate the ADA levels of ascitic fluid with the PCR report. Materials and Methods: This prospective comparative study includes 41 clinically suspected abdominal tuberculosis patients (age range 15–65 years) over a period of 2 years. A detailed history, clinical evaluation, and relevant investigations, including radiology, were done in all patients. Bacteriological or histological approaches had to support the diagnosis of abdominal tuberculosis, and PCR was also tested for Mycobacterium tuberculosis in ascitic fluid. Results: The mean age of patients was 31.71±12.32 years with male:female ratio was 1.4:1. PCR was positive in 24 (58.8%) cases. A receiver operating characteristic curve showed that a cutoff value of 35.3 IU/L (AUC 0.998, P < 0.001) for the ADA level produced the best results as a diagnostic test for abdominal tuberculosis, yielding the following parameter values: Sensitivity 100%, specificity 94.1%, positive predictive value 96%, negative predictive value 100%, and diagnostic accuracy 97.56%. ADA values were significantly elevated during abdominal tuberculosis, indicating that ADA can still be a valuable diagnostic tool. Conclusion: Our findings indicate that ascitic fluid PCR is a safe tool for diagnosing it and should be tried at least before surgical intervention.