Sensitivity and Specificity of Cartridge Based Nucleic Acid Amplification Test in pleural biopsy obtained by thoracoscopy

Abstract

Cartridge based nucleic acid amplification test (CBNAAT) is used widely to detect Mycobacterium Tuberculosis infection. It detects DNA sequences specific for Mycobacterium Tuberculosis and rifampicin resistance by polymerase chain reaction. The reults are available in two hours, making it the fastest method to detect Tuberculosis and rifampicin resistance. It has shown to have high sensitivity and specificty in smear positive pulmonary tuberculosis (98%and98% respectively) and a resonable result in smear negative cases (67%and99% respectively). Tubercular pleural effusion is the second most common extrapulmonary tuberculosis. The diagnosis is mainly based on pleural fluid or pleural biopsy histopathology, pleural biopsy histopathology being considered as gold standard for diagnosis. At our center, utility of CBNAAT was evaluated on pleural biopsy samples obtained thoracoscopically. Thoracoscopy was performed in patient with indeterminate pleural effusions and multiloculated pleural effusions. The biposy sample obtained was subjected to Histopathology and CBNAAT. As our center is recognised by Government of India for programme “Universal Access for Tuberculosis Care”, the CBNAAT was done free of cost. Considering histopathology as gold standard, sensitivity and specificity of CBNAAT was calculated.