pleural tuberculosis

Pleural Tuberculosis: An Overview

Pleural tuberculosis (TB) is a type of extrapulmonary TB that affects the pleura, which is the thin layer of tissue surrounding the lungs. It is characterized by an intense chronic accumulation of fluid and inflammatory cells in the pleural space.

• Causes: Pleural TB occurs as a result of Mycobacterium tuberculosis infection of the pleura, often following a delayed hypersensitivity reaction or T-Helper type-1 response to acquired infection of the pleural space from the lung parenchyma [14].
• Symptoms: The symptoms of pleural TB can vary but often include fever, cough, and pleuritic chest pain. The pleural fluid is typically an exudate with predominantly lymphocytes [8].
• Diagnosis: Diagnosis of tuberculous pleurisy is usually made through a combination of clinical history, pleural fluid analysis (lymphocytic-predominant cell count, protein concentration >3.0 g/dL), and mycobacterial culture or PCR-based techniques [12].
• Treatment: Treatment regimens for pleural TB 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 [15].

Key Statistics

• Pleural TB is the second most common form of extrapulmonary tuberculosis (TB) after lymphatic

Common Signs and Symptoms of Pleural Tuberculosis

Pleural tuberculosis (TB) can manifest in various ways, depending on the severity and location of the infection. Here are some common signs and symptoms associated with pleural TB:

• Chest pain: A sharp or dull ache in the chest area, which worsens when breathing, coughing, or sneezing [10].
• Fever: Elevated body temperature, often accompanied by night sweats [3].
• Weight loss: Unintentional weight loss due to decreased appetite and energy levels [3].
• Loss of appetite: Reduced interest in food and drinks, leading to weight loss [3].
• Sense of illness or loss of energy: Feeling unwell or tired, even when resting [3].
• Breathing difficulty: Shortness of breath or feeling like you can't catch your breath [14].

In some cases, pleural TB can also cause:

• Pleuritic chest pain: Pain in the chest that worsens with breathing, coughing, or sneezing [15].
• Nonproductive cough: Coughing without producing mucus or phlegm [15].
• Coughing up blood: Spitting up blood or rust-colored sputum [9].

It's essential to note that these symptoms can be nonspecific and may resemble those of other conditions. A proper diagnosis by a healthcare professional is necessary for an accurate assessment and treatment plan.

References:

[3] Generalised constitutional symptoms and pulmonary symptoms or signs may be absent, but are more often reported in HIV-infected patients. [9] Pulmonary tuberculosis (TB) is a contagious, infectious disease that attacks your lungs. People with the germ have a 10 percent lifetime risk of getting sick with TB. [10] Signs and symptoms of pleurisy might include: Chest pain that worsens when you breathe, cough or sneeze. [14] Symptoms · Breathing difficulty · Chest pain · Cough (usually with mucus) · Coughing up blood · Excessive sweating, particularly at night · Fatigue ... [15] The most frequent symptoms of TPE are nonproductive cough and pleuritic chest pain; if both cough and chest pain are present, the pain usually precedes the ...

Diagnostic Tests for Pleural Tuberculosis

Pleural tuberculosis (TB) is a challenging condition to diagnose due to its paucibacillary nature. Various diagnostic tests have been developed to aid in the diagnosis, but their accuracy and reliability vary.

• Mycobacterial culture: This is considered the gold standard for diagnosing pleural TB. However, it can take several weeks to obtain results, and the sensitivity of this test is relatively low [4][9].
• Adenosine deaminase (ADA) assay: Elevated ADA levels in pleural fluid have been associated with tuberculous pleuritis. While this test has some utility, its specificity and sensitivity are limited [1][14].
• Interferon-γ (IFN-γ) release assays: These tests measure the immune response to Mycobacterium tuberculosis antigens. However, their accuracy in diagnosing pleural TB is still being evaluated [2][11].
• Pleural biopsy: This invasive procedure involves taking a sample of tissue from the pleura for examination under a microscope or culture. It is considered the most accurate diagnostic tool but also the most expensive and invasive [3][6].
• Ziehl-Neelsen staining: This test involves examining the pleural fluid or biopsy specimen for acid-fast bacilli, which are characteristic of M. tuberculosis. However, this test has limited sensitivity and specificity [4][9].
• 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scan: This imaging technique can help differentiate between malignant pleural effusion and tuberculous pleuritis. However, its role in diagnosing pleural TB is still being evaluated [8].

Limitations of classical diagnostic tests

The limitations of these classical diagnostic tests are well-documented. They often have low sensitivity and specificity, which can lead to false-negative or false-positive results [13]. In many cases, a definitive diagnosis of pleural TB can only be confirmed by the identification of M. tuberculosis through microscopy and/or culture from sputum, pleural fluid, or pleural biopsy specimens.

Conclusion

In conclusion, diagnosing pleural tuberculosis requires a combination of clinical evaluation, imaging studies, and laboratory tests. While various diagnostic tests have been developed to aid in diagnosis, their accuracy and reliability vary. A definitive diagnosis can only be confirmed by the identification of M. tuberculosis through microscopy and/or culture from sputum, pleural fluid, or pleural biopsy specimens.

Treatment Options for Pleural Tuberculosis

Pleural tuberculosis (TB) requires effective treatment to prevent complications and ensure patient recovery. The standard treatment regimen for pleural TB is similar to that of pulmonary TB, but with some variations.

• Initial Empiric Treatment: For initial empiric treatment of TB, a 4-drug regimen consisting of isoniazid, rifampin, pyrazinamide, and ethambutol is recommended [4].
• Pharmacological Treatment: Pharmacological treatment of pleural TB is similar to that of pulmonary TB, but penetration of the pleural space may be suboptimal in complicated effusions [7]. Therefore, a longer duration of treatment or additional medications may be necessary.
• Recommended Regimens: The American Thoracic Society recommends a 6-month regimen for treatment of pleural TB consisting of a 2-month period of INH, RIF, PZA and EMB followed by INH and RIF for four months [8]. Another recommended regimen is a 4-drug regimen with isoniazid, rifampin, pyrazinamide, and ethambutol for two months followed by four months of two drugs, isoniazid and rifampin [9].

Key Considerations

• Duration of Treatment: The duration of treatment may vary depending on the severity of the disease and patient response.
• Medication Regimens: Different medication regimens may be necessary to ensure effective treatment and prevent complications.

References

[4] Oct 31, 2024 - Initial empiric treatment of TB [7] by E McNally · 2023 - Pharmacological treatment of pleural TB [8] by LA Sharan · 2016 - Recommended regimen for treatment of pleural TB [9] by K Zhai · 2016 - Recommended treatment for TPE

Differential Diagnosis of Pleural Tuberculosis

Pleural tuberculosis (TB) can be challenging to diagnose due to its nonspecific characteristics and paucibacillary nature [3]. The differential diagnosis for pleural TB includes various conditions that present with similar symptoms and radiological findings. Here are some key points to consider:

• Infections: Other potential differentials include infections such as TB, the sequelae of an empyema due to other pathogens or a non-malignant pleural fibroma [6].
• Malignancies: The imaging features of pleural TB can be similar to those of malignant pleural dissemination (MPD) with several case reports of CT findings in atypical presentations of PTB [15].
• Empyema: Empyema, a collection of pus in the pleural space, can also present with similar symptoms and radiological findings as pleural TB.
• Pleural fibroma: A non-malignant tumor that grows on the pleura, which can cause similar symptoms to pleural TB.

Diagnostic Approaches

The diagnosis of pleural TB is primarily based on the detection of Mycobacterium tuberculosis in pleural fluid or biopsy specimens [11]. However, this can be challenging due to the paucibacillary nature of the condition. Advances in mycobacterial culture media and PCR-based techniques have increased the yield from mycobacteriologic tests.

Surrogate Biomarkers

Surrogate biomarkers such as adenosine deaminase and interferon-γ in pleural fluid can perform well in diagnostic accuracy studies but must be interpreted with caution [11].

Clinical and Pleural Fluid Data

The combination of clinical and pleural fluid data can be used to calculate a score which helps facilitate differential diagnosis between tuberculous pleuritis and other conditions [8].

Risk Factors

Mycobacterium tuberculosis (MTB) in the UK is normally considered as a differential diagnosis for patients with particular risk factors, including originating from or travel to a high prevalence setting, known TB exposure, homelessness, and immunodeficiency [10].

In conclusion, the differential diagnosis of pleural TB is complex and requires careful consideration of various conditions that present with similar symptoms and radiological findings. A combination of clinical, radiological, and microbiological approaches can help facilitate accurate diagnosis.

References:

[3] Lipman K (2024) Pleural TB is challenging to diagnose due to nonspecific characteristics of the pleural fluid and a paucity of bacilli. [6] Philip KEJ (2018) Other potential differentials included infections such as TB, the sequelae of an empyema due to other pathogens or a non-malignant pleural fibroma. [8] Petborom P (2020) The combination of clinical and pleural fluid data can be used to calculate a score which helps facilitate differential diagnosis between tuberculous pleuritis and other conditions. [10] Mycobacterium tuberculosis (MTB) in the UK is normally considered as a differential diagnosis for patients with particular risk factors, including originating from or travel to a high prevalence setting, known TB exposure, homelessness, and immunodeficiency. [11] The diagnosis of pleural TB is primarily based on the detection of Mycobacterium tuberculosis in pleural fluid or biopsy specimens. [15] The imaging features of pleural TB can be similar to those of malignant pleural dissemination (MPD) with several case reports of CT findings in atypical presentations of PTB.