Pleural tuberculosis: A concise clinical review

Abstract

Tuberculosis (TB) is the leading infectious cause of death worldwide, and the commonest cause of death in people living with HIV. Globally, pleural TB remains one of the most frequent causes of pleural exudates, particularly in TB-endemic areas and in the HIV positive population. Most TB pleural effusions are exudates with high adenosine deaminase (ADA), lymphocyte-rich, straw-coloured and free flowing, with a low yield on mycobacterial culture. TB pleurisy can also present as loculated neutrophil-predominant effusions which mimic parapneumonic effusions. Rarely, they can present as frank TB empyema, containing an abundance of mycobacteria. Up to 80% of patients have parenchymal involvement on chest imaging. The diagnosis is simple if M. tuberculosis is detected in sputum, pleural fluid or biopsy specimens, and the recent advent of liquid medium culture techniques has increased the microbiological yield dramatically. Where the prevalence of TB is high the presence of a lymphocyte-predominant exudate with a high ADA has a positive predictive value of 98%. In low prevalence areas, the absence of an elevated ADA and lymphocyte predominance makes TB very unlikely, and pleural biopsy should be performed to confirm the diagnosis. Pleural biopsy for liquid culture and susceptibility testing must also be considered where the prevalence of drug resistant TB is high. Treatment regimens are identical to those administered for pulmonary TB. Initial pleural drainage may have a role in symptom relief and in hastening the resolution of the effusion. Surgical intervention may be required in loculated effusions and empyemas.

Pleural fluid ADA activity in tuberculous pleurisy can be low in elderly, critically ill patients with multi-organ failure

“…Typical manifestations of TPE are well-recognised, including submassive, unilateral pleural effusion with lymphocyte predominance and high ADA [1,8]. However, atypical presentations of TPE have been reported; falsely normal ADA activity occurs in up to 7% of patients with TPE [4,8].…”

“…Tuberculous pleural effusion (TPE) is a main cause of pleural effusion [1]. The proportion of TPE among all pleural effusions varies widely in accordance with the burden of tuberculosis worldwide.…”

Advances and Controversies in Thoracentesis and Medical Thoracoscopy

“…Bronchoscopy may be performed. 27 The yield of pleural fluid microscopy for Mtb is less than 10%, although up to twice that in HIV patients and those with TB empyema. Pleural fluid culture depends on the specific media used.…”

“…With loculated effusions or a TB empyema, neutrophils may predominate. 27 Unstimulated gamma interferon (IFN-γ) may be superior to ADA for the detection of TB pleural effusion; however, costs and availability limit its use. The interferon gamma release assays (IGRAs) such as QuantiFERON-TB Gold (Qiagen) and T-SPOT.TB (Oxford Immunotec) are unsuitable for the detection of TB pleural disease as it is inferred that lymphocytes in TB effusions are maximally stimulated.…”

“…The interferon gamma release assays (IGRAs) such as QuantiFERON-TB Gold (Qiagen) and T-SPOT.TB (Oxford Immunotec) are unsuitable for the detection of TB pleural disease as it is inferred that lymphocytes in TB effusions are maximally stimulated. 27 Sputum samples have a modest yield in pleural TB. Induced sputum yields positive cultures in up to 55% of patients without evidence of parenchymal involvement on chest radiograph.…”