The Role of Genexpert in the Diagnosis of Tubercular Pleural Effusion in India

Abstract

Introduction: Tubercular pleural effusion is the second most common extrapulmonary form of tuberculosis in India. Developing nations like India face several health challenges and with limited resources, appropriate planning and channelization of the same is the need of the hour. Material and methods: The objective of the study was to determine the role of cartridge-based nucleic acid amplification test (CBNAAT) in the diagnosis of tubercular pleural effusion (TPE) and also to study if any association exists between CBNAAT and pleural fluid adenosine deaminase (ADA) and lymphocyte counts. Clinically suspected TPE, lymphocyte predominant (≥ 70%) exudates (according to the Lights criteria) with ADA ≥ 40 U/L and microbiologically confirmed pulmonary tuberculosis patients with a co-existent pleural effusion were included. Pleural fluid CBNAAT was performed on all the samples. Results: Out of a total of 75 patients, 57 were males and 18 were females. A lymphocyte predominance of ≥ 70% was seen in 73 subjects (97%). Mean ADA was 61.7 U/L ± 16.2 (SD). Pleural fluid CBNAAT was positive for Mycobacterium tuberculosis (MTB) in 24 patients (32%). Out of these patients, rifampicin resistance was detected in 2 individuals (8.3%). Sputum smear for acid fast bacilli (AFB) was positive in 3 (4%) patients, whereas in sputum CBNAAT MTB was detected in 8 (10.6%) persons. Association between pleural fluid ADA, lymphocyte count and CBNAAT positivity was evaluated by Student T-test. There was a significant association between higher ADA levels and CBNAAT (p value = 0.001). Conclusions: Pleural fluid CBNAAT, owing to its low sensitivity, should not be included in the diagnostic protocol of TPE in high prevalence areas. A high ADA ≥ 40 U/L in combination with Light's criteria to define exudates, with lymphocyte predominance is sufficient evidence to diagnose TPE and initiate anti-tubercular therapy, thereby deferring the need to perform an invasive pleural biopsy.

Role of ADA and CBNAAT(Cartridge Based Nucleic Acid Amplification Test) in diagnosis of Tuberculosis in straw coloured exudative pleural effusion in patients attending Government General Hospital, KAKINADA

“…In this study of 100 patients, 80 (80%) are males and 20(20%) females with sex ratio 4:1(M: F). The male predominance seen in our study (80%) is similar to studies done by Modi et al 1 (73.33%), Anushree Chakraborthy et al 8 (76%), Shubham Kumar Sharma et al 11 (78%) and Kate et al 9 (72%). Male predominance is nearer to the study done by Sharma et al The incidence of tuberculosis is more in males due to exposure to outdoor pollution, the presence of confounding factors like smoking, and migration to high prevalent areas.…”

“…7 2 mL of pleural fluid was collected in a sterile container and was either immediately analyzed or refrigerated at 4 • C and analyzed within two days. An ADA value >40IU/L was taken as a cut off value for diagnosing tubercular effusion 8,9 .…”

A Comparison Study of CBNAAT, Gene Xpert and Line Probe Assays in the Diagnosis of Tuberculosis in smear Negative Specimens

“…CBNAAT could identify 64 cases (31.2%) from smear negative samples was similar to Dash Manoranjan et al 20 The CBNAAT showed rifampicin sensitivity pattern in concurrent to Vishal Chopra et al 28 Sputum smear was AFB positive in 124 (48%) patients, and CBNAAT detected MTB in 113 (44%) subjects. Among them, 12 had rifampicin resistance similar to Anushree Chakrabortyet al 29 Out of 6.3% were resistant by about were rifamcin resistant LPA, whereas 9.85 were rifampicinresistant by CBNAAT. A total of 209/425 (49%) showed negative for MTB by LPA and 158/425 (37%) showed negative for MTB in CBNAAT which was not in concurrence with Tripathi et al 19 All AFB negative specimens were inoculated on LJ Media, 34 (17%) showed culture positive.…”

Better understanding extrapulmonary tuberculosis: A scoping review of public health impact in Pakistan, Afghanistan, India, and Bangladesh

“…A study by Chakraborty et al selected a total of 75 patients with tuberculous pleural effusion and found that 57 patients were males, showing male predominance. Associated symptoms include cough, chest pain, dyspnea, and fever, while none of them presented with hemoptysis 47 . In addition, the prevalence of MDR‐TB among EPTB is a significant health concern in India.…”