Role of CBNAAT and ADA in tubercular pleural effusion diagnosis at BMGMC hospital

In 2024, 10.8 million new tuberculosis cases were reported globally. Of these, 19% were extrapulmonary (EPTB), meaning the infection occurred outside the lungs. Tuberculous pleural effusion (TPE) is a difficult disease to diagnose because it is only paucibacillary, so consideration should be given to the rapid and easily available diagnostic tools in high tuberculosis prevalence environments. The study was an observational study aimed at assessing diagnostic value of adenosine deaminase (ADA) and Cartridge-Based Nucleic Acid Amplification Test (CBNAAT) in 200 patients with pleural effusion in a tertiary care center. This study established high sensitivity (92.5) but poor specificity (50) of ADA at 40 IU/L cut off; and low sensitivity (28.35) but high specificity (50) of CBNAAT at 40 IU/L cut off. Effusions of tuberculosis were 67 percent with males being the most at 68 percent in the age group of 41 to 50. There was a strong positive correlation between the lymphocyte predominance with the ADA levels (r=0.71, P=0.003) and the CBNAAT positivity (r=0.95, P=0.0015). Thus, we show that ADA is still a useful screening method in tuberculous pleural effusion, especially when it is used in conjunction with lymphocyte-predominant exudates and CBNAAT is a confirmatory study with the further benefit of identifying rifampicin resistance.