Predictive Values of Next Generation Interferon Gamma Release Assays for Latent Tuberculosis Infection

Study Overview
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Brief Summary
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This study will assess the next generation of blood tests for latent TB infection, which may be able to indicate how treatment is working as well as in diagnosis infection.

Detailed Description
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Currently available blood tests for latent tuberculosis infection (LTBI) identify people who have been previously infected with M. tuberculosis. Whilst they are sensitive and specific, they cannot be used to monitor the effectiveness of treatment for LTBI. New blood tests (fourth generation Quantiferon tests) give a more complete measurement of the workings of the immune system, which may be useful to show whether treatment is working. These new tests have not yet been evaluated in clinical practice, so their usefulness in identifying people at highest risk of TB disease and monitoring treatment is unknown. Mass gatherings, such as the annual Hajj pilgrimage, may encourage the spread of infectious diseases, including respiratory infections such as influenza, respiratory syncytial virus, and possibly also tuberculosis. However, the risk of TB infection during the Hajj has not been reliably measured. It is important to measure this risk so that pilgrims can be given suitable advice about preventing infection.

Official Title
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Predictive Values of Next Generation Interferon Gamma Release Assays for Latent Tuberculosis Infection

Conditions
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Tuberculosis

Intervention / Treatment
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* Procedure: blood test, not yet marketed, no trade name


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Contacts: Adult (aged 16 years or older) contacts of smearpositive pulmonary TB patients attending participating TB clinics or primary care centres for screening will be invited to take part. Contacts will include all individuals with a cumulative duration of exposure of greater than eight hours to the relevant index case in a confined space during the period of infectiousness (prior to initiation of treatment). Patients with active TB: Newly diagnosed, microbiologically confirmed tuberculosis disease (pulmonary or extrapulmonary) attending participating TB clinics or primary care centres. Hajj pilgrims: Individuals arranging travel to Saudi Arabia for the Hajj through participating tour operators. Exclusion Criteria: - Contacts: Active TB disease. Individuals who are unable to give informed consent. Children aged under 16 years. TB cases: Individuals who are unable to give informed consent. Children aged under 16 years. Hajj pilgrims: Active TB disease. Any health indication which would prevent travel to Saudi Arabia. Individuals who are unable to give informed consent. Children aged under 16 years.

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Contacts of TB cases<br>Blood test, not yet marketed, development phase | Procedure: blood test, not yet marketed, no trade name<br>* blood test using the new TB diagnostic test<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| assess prognostic ability of blood test by assessing development of active TB disease compared to the current gold standard | assess prognostic ability of blood test by assessing development of active TB disease. | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| assess the sensitivity of new blood tests for detecting TB infection in patients with active TB disease compared to teh current godl standard | estimate the sensitivity of new blood tests for detecting TB infection in patients with active TB disease | 1 year | 
| estimate the risk of infection with M. tuberculosis and other respiratory pathogens amongst UK pilgrims undertaking the Hajj. | estimate the risk of infection with M. tuberculosis and other respiratory pathogens amongst UK pilgrims undertaking the Hajj. | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tuberculosis, diagnostic test