TB QuantiFERON®
Private TB QuantiFERON testing in London for £149, measuring one tuberculosis immune-response marker with results expected in around 4–5 days.
Turnaround time
4-5 business days
Biomarkers count
1
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Overview of the TB QuantiFERON Test
The TB QuantiFERON blood test measures the immune response to Mycobacterium tuberculosis-specific antigens, helping identify tuberculosis infection without requiring a traditional skin test.
The test assesses 1 specialist infectious-disease marker: TB Quantiferon®-TB Gold* 4 tubes.
QuantiFERON is an interferon-gamma release assay, commonly abbreviated to IGRA.
During testing, a person's white blood cells are exposed to specific tuberculosis antigens in dedicated collection tubes.
If immune cells have previously been sensitised to Mycobacterium tuberculosis, they can release interferon-gamma in response.
The laboratory measures this response to determine whether the test is positive, negative or indeterminate.
An important advantage of QuantiFERON testing is that it is not affected by previous BCG vaccination in the same way as a tuberculin skin test can be.
This makes it particularly useful for people who received BCG vaccination and require TB screening.
A positive result indicates evidence of immune sensitisation to tuberculosis bacteria.
However, the test cannot determine by itself whether infection is latent or active.
Latent tuberculosis infection means the bacteria are present in the body without causing active disease or symptoms.
Active tuberculosis involves ongoing disease and can require imaging, sputum testing and specialist clinical assessment.
A negative result makes TB infection less likely but does not completely exclude very recent exposure or infection in people whose immune response is significantly impaired.
Indeterminate results can occur when the immune response is insufficient or when specimen-related factors prevent a reliable interpretation.
QuantiFERON testing is commonly used for occupational screening, healthcare employment, immigration requirements, pre-immunosuppression assessment and investigation after recognised TB exposure.
What Does the TB QuantiFERON Test Check?
The test measures interferon-gamma release after blood cells are exposed to tuberculosis-specific antigens. This test measures 1 specialist biomarker.
TB Quantiferon®-TB Gold* 4 tubes
Measures the interferon-gamma immune response to Mycobacterium tuberculosis-specific antigens, supporting detection of latent or active TB infection when interpreted alongside clinical findings.
Who May Benefit From the TB QuantiFERON Test?
QuantiFERON testing can be useful for occupational, exposure-related and clinical screening for tuberculosis infection.
People who have been in close contact with somebody diagnosed with TB - Testing can help establish whether infection has occurred.
Healthcare professionals requiring occupational TB screening - QuantiFERON is widely used during employment and occupational-health assessment.
People requiring TB clearance for work, education or immigration - Some organisations require laboratory evidence of TB screening.
People who previously received BCG vaccination - QuantiFERON is not made positive simply by prior BCG vaccination.
People preparing to start immunosuppressive treatment - Latent TB may need to be identified before biologics or other significant immune suppression begins.
People with a previous positive or uncertain skin test - IGRA testing can provide additional information.
People with unexplained symptoms and possible TB exposure - QuantiFERON may contribute to the wider assessment but does not diagnose active disease by itself.
People with previous residence or prolonged travel in areas with higher TB prevalence - Screening may be appropriate depending on the exposure history.
How to Prepare
QuantiFERON requires dedicated blood-collection tubes and appropriate specimen handling.
Where possible, testing should be arranged through a collection service familiar with the laboratory requirements for this assay.
Symptoms and Reasons to Consider the TB QuantiFERON Test
Latent TB commonly causes no symptoms. Symptoms become more relevant when active tuberculosis disease is being considered.
Persistent cough lasting several weeks - Pulmonary tuberculosis can cause a prolonged cough.
Unexplained weight loss - Active TB can produce systemic illness and loss of weight.
Night sweats - Persistent drenching night sweats can occur with active tuberculosis.
Unexplained fever - TB can cause prolonged low-grade or recurrent fever.
Coughing up blood - Haemoptysis can occur with pulmonary TB and requires prompt assessment.
Close contact with a confirmed TB case - Infection can occur even before symptoms develop.
A requirement for occupational TB clearance - Healthcare and other settings may request an IGRA result.
Planned significant immunosuppression - Latent infection can reactivate when immune function is suppressed.
A positive QuantiFERON result does not distinguish latent tuberculosis from active TB disease.
Persistent cough, coughing blood, significant weight loss, fever or night sweats with possible TB exposure requires appropriate clinical assessment and may require chest imaging and microbiological testing.
A private blood test should not replace urgent assessment where active tuberculosis is suspected.
How to Book Your TB QuantiFERON Test
The TB QuantiFERON test can be booked privately for laboratory assessment of tuberculosis infection.
Choose the TB QuantiFERON
Select the individual TB QuantiFERON blood test online.
Select your sample collection option
Choose an in-clinic blood draw or professional home or hotel phlebotomy where the specialist collection requirements can be met.
Attend your appointment
A trained healthcare professional collects the required blood into the dedicated QuantiFERON tubes.
Laboratory analysis
Your sample undergoes interferon-gamma release analysis using TB Quantiferon®-TB Gold* 4 tubes.
Receive your results securely
Your authorised result is delivered securely and can be interpreted alongside exposure history, symptoms and imaging where appropriate.
When Will I Receive My Results?
The current live London Blood Tests page lists a turnaround of approximately 4–5 days after laboratory receipt for TB QuantiFERON.
This is a specialist interferon-gamma release assay requiring dedicated blood tubes and controlled laboratory processing.
The specimen undergoes incubation, immune-response measurement, quality-control procedures and result authorisation.
Turnaround begins when a suitable specimen reaches the laboratory rather than necessarily from the exact time of blood collection.
Understanding Your Results
A negative result means the laboratory did not detect a significant interferon-gamma response to the TB-specific antigens.
This makes tuberculosis infection less likely.
It does not completely exclude very recent infection or infection in somebody with substantially impaired immune function.
A positive result indicates immune sensitisation to Mycobacterium tuberculosis.
The test cannot determine whether the infection is latent or active.
A positive result therefore usually requires further clinical assessment.
This may include symptom review, chest imaging and microbiological testing where active disease is possible.
An indeterminate result means the test could not provide a reliable positive or negative classification.
This can occur because of reduced immune responsiveness or technical and specimen factors.
Repeat testing or an alternative TB investigation may be required.
BCG vaccination does not usually explain a positive QuantiFERON result because the assay uses tuberculosis-specific antigens not contained in the BCG vaccine.
Why Book With London Blood Tests?
London Blood Tests provides private QuantiFERON testing for occupational, exposure-related and clinical TB screening.
Uses an interferon-gamma release assay - The test measures immune response to specific tuberculosis antigens.
Not affected by previous BCG vaccination - This reduces one important limitation of traditional tuberculin skin testing.
Requires only one testing appointment - There is no need to return several days later to have a skin reaction measured.
Useful for latent TB screening - Infection can be detected even when no symptoms are present.
Relevant before immunosuppressive treatment - Latent tuberculosis may need to be identified before significant immune suppression begins.
Suitable for occupational screening - QuantiFERON is widely used in healthcare and employment assessment.
Professional specialist collection - Dedicated QuantiFERON tubes and appropriate laboratory handling are used.
Clear pricing - The TB QuantiFERON test costs £149.
Private TB QuantiFERON Blood Test in London
London Blood Tests provides private TB QuantiFERON testing for people requiring assessment of tuberculosis infection.
The test costs £149 and assesses 1 specialist biomarker.
Results are expected approximately 4–5 days after laboratory receipt.
A positive result demonstrates TB immune sensitisation but does not distinguish latent infection from active tuberculosis disease.