Diagnosing PTLD – for clinicians

A person with a medical history of post-TB lung disease may have a history of the following:

1. Previous tuberculosis (TB) infection: This is the most significant and essential factor in the development of post-TB lung disease. A person with a history of TB infection, either active or treated, is at risk of developing lung damage.
2. Respiratory symptoms: A person with PTLD may have had persistent respiratory symptoms such as a cough, shortness of breath, chest pain, or difficulty breathing. Some patients with PTLD have no symptoms at all.
3. Cardiac symptoms: either due to pulmonary hypertension or heart failure. A person with PTLD may experience chest pain, palpitations, syncope, dyspnoea or leg swelling.
4. Generalized non specific symptoms: A person with post-TB lung disease may have symptoms such as fatigue, weakness, weight loss, and anorexia.

It is important to establish other underlying medical conditions, such as HIV infection, diabetes, autoimmune conditions or other chronic lung disease.

It is also important to establish risk factors for worsening lung function, such as smoking cigarettes or smoking other drugs (for example Tik).

The symptoms of post-TB lung disease can vary depending on the extent of the lung damage, but some common symptoms include:

1. Shortness of breath: Difficulty breathing or feeling out of breath, especially with exertion.
2. Persistent cough: A persistent cough that produces phlegm or mucus can be a symptom of post-TB lung disease. Some patients may also experience haemoptysis which can be life-threatening.
3. Chest pain: especially if the lung tissue is scarred or inflamed.
4. Fatigue and lethargy
5. Loss of appetite: especially if the lung damage makes it difficult to breathe or the person is suffering from chronic fatigue.
6. Respiratory failure: In advanced stage of the disease, respiratory failure can occur, which is a medical emergency that requires immediate attention.
7. Heart failure: this may result due to Post-TB pulmonary hypertension or as a result of chronic lung disease.

It’s important to note that not all people with post-TB lung disease will have all of these symptoms, and the severity of the symptoms can vary depending on the individual and the extent of the lung damage.

In addition to symptoms, there are also physical examination signs that can indicate post-TB lung disease. Some common signs include:

1. Wheezing or crackling sounds: Wheezing or crackling sounds heard through a stethoscope when listening to the lungs can be a sign of post-TB lung disease, especially if the lung tissue is scarred or inflamed.
2. Clubbing: Clubbing of the fingers and toes, which is the enlargement and rounding of the fingertips, can be a sign of post-TB lung disease, especially if the lung damage is severe.
3. Cyanosis: Cyanosis is a bluish discoloration of the skin and mucous membranes caused by a lack of oxygen. This can be a sign of post-TB lung disease, especially if the lung damage makes it difficult to take in enough oxygen.
4. Barrel chest: Barrel chest is a condition where the chest becomes abnormally widened and rounded due to an increased amount of air in the lungs. This can be a sign of post-TB lung disease, especially if the lung damage leads to chronic hyperinflation.
5. Signs of pulmonary hypertension: left parasternal heave, loud palpable P2, raised JVP, +/- evidence of tricuspid regurgitation (pansystolic murmur loudest at the lower left sternal edge on inspiration) +/- signs of right heart failure (oedema, liver distension, ascites).
6. Other signs like lymphadenopathy, pleural effusion, and cachexia can also be observed in post-TB lung disease

It’s important to note that not all people with post-TB lung disease will have all of these signs, and the severity of the signs can vary depending on the individual and the extent of the lung damage.

Chest X-ray can be useful in detecting and assessing the extent of post-TB lung disease. The chest X-ray findings in post-TB lung disease can include:

1. Fibrosis: the formation of scar tissue in the lungs. Fibrosis can appear as hazy or cloudy areas in the lung tissue on a chest X-ray, or as a reticulonodular pattern.
2. Consolidation: regions of the lung that appear opaque and dense due to inflammation or infection. This can appear as a patchy or homogenous opacification in the lung fields.
3. Cavitation: fluid-filled spaces that can form in the lungs as a result of TB. These can appear as round or oval-shaped areas on the chest X-ray.
4. Bronchiectasis: the airways in the lungs become enlarged and distorted. This can appear as thickened or dilated airways on a chest X-ray.
5. Pleural thickening: thickening of the lining of the lung (pleura). This can be a sign of long-term inflammation or infection.
6. other findings like lymphadenopathy, pleural effusion, and loss of lung volume may also be seen on chest X-ray.

It’s important to note that not all of these findings may be present in every case of post-TB lung disease, and the specific chest X-ray findings can vary depending on the extent and duration of the disease. Some PTLD patients have a completely normal Chest X-ray.

Computed tomography (CT) scans can be useful in detecting and assessing the extent of post-TB lung disease. The CT findings in post-TB lung disease can include:

1. Fibrosis: the formation of scar tissue in the lungs. Fibrosis can appear as thickened or dense areas in the lung tissue on a CT scan.
2. Consolidation: regions of the lung that appear opaque and dense due to inflammation or infection.
3. Cavitation: fluid-filled spaces that can form in the lungs as a result of TB. These can appear as round or oval-shaped areas on the CT scan.
4. Bronchiectasis: the airways in the lungs become enlarged and distorted. This can appear as thickened or dilated airways on a CT scan (larger than the corresponding vessels).
5. Pleural thickening: thickening of the lining of the lung (pleura). This can be a sign of long-term inflammation or infection.
6. other findings like lymphadenopathy, pleural effusion, pulmonary emboli, pulmonary hypertension and loss of lung volume may also be seen on CT scan.

It’s important to note that not all of these findings may be present in every case of post-TB lung disease, and the specific CT findings can vary depending on the extent and duration of the disease.

Echocardiography (echo) is a non-invasive test that uses sound waves to create images of the heart, it’s not typically used to diagnose post-TB lung disease. However, in some cases, post-TB lung disease can affect the heart’s function, leading to changes that can be detected on an echocardiogram.

1. Pulmonary hypertension: Post-TB lung disease can lead to pulmonary hypertension, which is high blood pressure in the blood vessels of the lungs. This can be detected by echocardiography as an increase in the systolic pressure of the right ventricle. Most patients with suspected pulmonary hypertension should be referred for right heart catheterisation.
2. Right-sided heart failure: If pulmonary hypertension becomes severe, it can lead to right-sided heart failure, which can be detected by echocardiography as an enlarged right ventricle and a reduced ability to pump blood effectively.
3. Pericardial effusion: Post-TB lung disease can also cause a build-up of fluid around the heart (pericardial effusion), which can be detected by echocardiography as a thickened pericardium and/or a fluid-filled space around the heart.

It’s important to note that these changes are not specific for post-TB lung disease, and an echocardiogram may show normal findings in many cases of post-TB lung disease.

Lung function tests are commonly used to evaluate the extent of lung damage in post-TB lung disease and to monitor the response to treatment. Some common lung function tests include:

1. Spirometry: This test measures how much air a person can inhale and exhale and how fast they can inhale and exhale. It can be used to detect reduced lung function and to monitor changes over time.
2. Diffusing capacity of the lung for carbon monoxide (DLCO): This test measures how well the lungs are able to transfer oxygen from the air into the bloodstream. It can be used to detect reduced lung function and to monitor changes over time.
3. Lung volume measurement (plethysmography): This test measures the amount of air in the lungs and can be used to detect changes in lung volume, such as hyperinflation, which can occur in post-TB lung disease.
4. Other tests such as 6-minute walk test, and cardiopulmonary exercise test can also be used to evaluate lung function.

It’s important to note that the specific lung function tests used can vary depending on the individual and the extent of the lung damage. The results of these tests can help to guide treatment decisions and monitor the effectiveness of therapy.

There are several laboratory tests that can be used to help diagnose and monitor post-TB lung disease. These tests include:

1. Sputum culture: A sputum culture test is used to check for the presence of the organisms – for example fungal infections, recurrent TB infection or alternative bacterial infection.
2. Blood tests: Blood tests can be used to check for signs of inflammation or infection. These tests can include a complete blood count (FBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and monitoring of other organs (for example renal and liver function) that may affect treatment options.

This list is not exhaustive, however some other tests that may be useful in diagnosing PTLD may include:

1. Lung biopsy: In some cases, a lung biopsy may be necessary to confirm the diagnosis and determine the extent of the damage. A lung biopsy can be done using a needle or through a small incision in the chest.
2. Bronchoscopy: This is a procedure that involves inserting a flexible tube with a camera into the airways through the nose or mouth to examine the inside of the lungs. This can be used to detect signs of lung damage, inflammation, or infection and can also be used to obtain samples for culture or biopsy.