Sensitivity of Polymerase Chain Reaction for Pleural Tuberculosis according to the Amount of Pleural Effusion Specimens

SARS-CoV-2 (severe acute respiratory syndrome-coronavirus-2) is a novel coronavirus identified for the first time in Wuhan (China) in 2019, responsible of the current pandemic infection known as Coronavirus-19 disease (COVID-19). Wide range of clinical presentation of COVD -19 has been observed, from asymptomatic carriers to ARDS. The common signs and symptoms of SARS-CoV-2 infection include fever, fatigue, dry cough, and dyspnoea; the severity of the disease is due to the impairment of the respiratory function. The radiological findings include a large variety of lesions; bilateral interstitial pneumonia is the most concerning presentation of COVID-19. Pleural involvement has been described in a minority of cases: pleural thickening had been observed in 32% of cases whereas pleural effusion is uncommon being described in only 5%. Furthermore, pleural involvement has been significantly associated with a worse prognosis. Coronavirus 2 (SARS-CoV-2), beyond the nasopharyngeal swab, has been detected in other samples; up to now, data about RT-PCR specific results in the pleural fluid of patients suffering from coronavirus disease 2019 5 (COVID-19) are very limited. The current gold standard for diagnosis is nucleic acid detection by real time Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) in nasopharyngeal swab. In this report, a case of a positive RT-PCR for Sars-Cov-2 in the pleura fluid and in the naso- pharyngeal swab of a patient affected by bilateral interstitial pneumonia and severe respiratory failure is described. As the presence of SARS-Cov-2 in the pleural fluid seems to be associated to a poor prognosis, physicians should carry out the specific RT-PCR assay both in the nasopharyngeal swab and in the pleural sample also when the fluid amount is very scarce and not recognizable in the chest X ray. Furthermore, the analysis of multiple samples allows to increase the test reliability.

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MOLECULAR DIAGNOSIS OF CLINICALLY SUSPECTED PLEURAL TUBERCULOSIS IN MOROCCO

Russian Journal of Infection and Immunity ◽

10.15789/2220-7619-mdo-1399 ◽

2019 ◽

Author(s):

I. CHAOUI ◽

S. Taoudi ◽

A. Oudghiri ◽

J. Benamor ◽

J. Bourkadi ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Prospective Study ◽

Pleural Fluid ◽

Sensitivity And Specificity ◽

Molecular Diagnosis ◽

Histopathologic Examination ◽

Chain Reaction ◽

Pleural Tuberculosis ◽

Polymerase Chain ◽

Pleural Tissue

Pleural tuberculosis (pTB) is a very common form of extrapulmonary tuberculosis (TB). Its diagnosis presents worldwidea major burning challenge due to the limitations of available conventional diagnosis tools. These latter include microscopic examination of the pleural fluid for acid-fast bacilli, mycobacterial culture of pleural fluid in solid or liquid media, sputum or pleural tissue, and histopathological examination of pleural tissue; these tests have recognized limitations for clinical use. Hence, to overcome these limitations, attention has been devoted to new nucleic acid amplification (NAA) diagnosistests such as the polymerase chain reaction (PCR) and real-time PCR (RT-PCR), owing to their accuracy, rapidity, high sensitivity and specificity. Within this context, this prospective study was conducted to evaluate the performance of molecular diagnosis methods for differentiation between tuberculosis and non-tuberculosis pleural effusions. Fifty patients with pleural effusion were enrolled in this prospective study in Rabat, Morocco. The efficacy of conventional polymerase chain reaction (PCR) in the diagnosis of tuberculous pleurisy by targeting IS6110 and mycobacterial internal transcribed spacer(MYITS) was evaluated against histopathologic examination and culture results.Our results showed that IS6110 PCR could “rule in” pTB, the sensitivity and specificity being 41.6 % and 85.7 % respectively.Therefore, the findings confirmed that molecular tests have a relatively high specificity in EPTB but lower sensitivity, thus a positive test is treated as a pTB case whereas negative one cannot exclude the disease. Although the study was limited by small sample size, it adds to the body of evidence of usefulness of molecular testing as adjunctsto histopathologic examination for accurate diagnosis of pTB, to treat timely and to avoid the emergence and spread of drug resistant pTB. However, further efforts should be made to increase the sensitivity of NAA methods and to identify the best molecular targets to be useful in clinical practice.

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