Paraffin-embedded Sample Test Promotes the Diagnosis of Tuberculous Pleurisy

Tuberculous pleurisy (TP) is the most common manifestation of extrapulmonary tuberculosis and the most frequent cause of pleural effusion (PE). Clinicians make a definitive diagnosis of TP based on the isolation of the mycobacterium tuberculosis (MTB) from PE or a pleural biopsy. Since the currently available tests for TP all have limitations in making a definitive diagnosis, clinicians urgently need new diagnostic tests.

The study intended to compare the value in clinically diagnosing TP of the paraffin-embedded sample test (PEST), using pleural-effusion samples; an adenosine deaminase assay (ADA) using pleural fluid; and the T cell enzyme-linked immunospot test (T-SPOT), using peripheral-blood.

The research team performed a retrospective observational study.

The study took place at the Sir Run Run Hospital, Nanjing Medical University in Nanjing, Jiangsu, China.

Participants were 37 patients with suspected TP who had been admitted to the hospital between September 2018 and December 2022.

The research team assessed the diagnostic performance of PEST, ADA, and T-SPOT in the TP group, calculating the positive rate, sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of the tests.

Among the 37 participants, the testing confirmed that 24 had TP (64.86%), with 13 not having TP (35.14%). The PEST test produced a sensitivity of 83.3% for TP, with 20 out of 24 participants in the TP group testing positive (95% CI: 61.8 to 94.5), which was superior to the ADA, with only 9 out of the 24 participants (37.5%) in the TP group testing positive (95% CI: 19.6 to 59.2), with P < .001.

The PEST test possesses a high diagnostic value, and clinicians can use it as a time-saving, noninvasive, and highly sensitive method for TP diagnosis. It can be adjunct method to the currently used tests for diagnosing TP. A combination of several detection methods could promote effective treatment.