Work

Comparative analysis of adenosine deaminase (ADA) and polymerase chain reaction (PCR/GeneXpert) for diagnosing pleural and peritoneal tuberculosis

Year: 2026

Type: article

Abstract: Context: Tuberculosis (Tb) is one the most prevalent diseases, with a huge disease burden in various developing countries, such as India. Given the large burden of TB cases, the proportion of extrapulmonary tuberculosis (EPTB) cases has also risen in recent years. The diagnosis of EPTB poses a significant challenge, owing to its atypical characteristics. Adenosine deaminase (ADA) and GeneXpert/PCR (NAAT) are the primary tools for EPTB diagnosis currently in practice. The aim of the study was to contrast and highlight the efficacy of the two tests, investigating the utility of both, alone and in combination. Methods and Material: This study was a cross-sectional comparative study with a total of 77 samples included. Every diagnosis was documented to generate the values based on predictive power, which include sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results: In all the samples, ADA was first compared to GeneXpert in ascitic fluid (sensitivity 75%, specificity 6.9%, PPV 10% and NPV of 66.67%) and in pleural fluid (sensitivity 94.11%, specificity 3.70%, PPV 38.09% and NPV 50%). GeneXpert compared to ADA in ascitic fluid (sensitivity 10%, specificity 66.67%, and PPV 75%, and NPV 6.89%) and in pleural fluid (sensitivity 38.10%, specificity 50%, PPV 94.12% and NPV 3.70%). Conclusions: ADA can be used with relative confidence to test EPTB, due to its high sensitivity as well as reliable negative predictive value, in contrast GeneXpert/PCR is strongly recommended in the detection of pre-existing Tb cases, due to its high specificity. Further studies and investigations are required to help health care providers establish the collective use reducing both morbidity and mortality. This study reinforces the use of ADA in cases of EPTB.

Source: Journal of Family Medicine and Primary Care

DOI: 10.4103/jfmpc.jfmpc_1204_24