The Role of a Mycobacterium Growth Inhibition Assay to Quantify Host Immune Control of M. Tuberculosis (MGIA)

Linköping University (LiU)

Status: Enrolling

Conditions: Immunologic Activity Alteration; Tuberculosis

Treatments: Other: No intervention.

Study type: Observational

Funder types: Other

Identifiers

NCT06580639

2022-06858-02

Details and patient eligibility

About

The goal of this observational study is to learn about how the blood leucocytes from patients with and without exposure or disease from tuberculosis (TB) are able to kill live mycobacteria (M. tuberculosis). The main question it aims to answer is:

Is intracellular growth suppression of M. tuberculosis in peripheral blood mononuclear cells variable among healthy blood donors and higher than in patients with latent TB compared to active TB?

Full description

Background: The host immune response is crucial in determining the outcome after exposure to Mtb. A substantial proportion of exposed individuals (40-70%) never develop infection indicating an efficient cell mediated immune response against Mtb and early clearance by the host immune defense (Verall et al, Immunology 2014). Thus, the outcome of exposure is highly dependent on host immunity. In this study, our aim was to investigate whether the previously developed mycobacterium groth inhibition assay (MGIA) method (Andersson et al, Tuberculosis 2020) could be used to quantify the host immune response to Mtb.

Study design: In this study we will include healthy donors (n=80), patient with active TB (n=40), subjects recently exposed to active TB (n=80) and patients with latent TB (LTBI) (n=80). Exclusion criteria for all groups are known HIV infection or other immunosuppression from treatment or disease. Patients and healthy blood donors will be recruited at the departments of infectious diseases in Region Kalmar and Region Östergötland. From patients giving oral and written consent, 40 ml of blood will be collected for MGIA analysis.

Primary aim: To determine the difference in MGIA between healthy blood donors and patients with latent and active TB as well as the variation in host control of Mtb within each group.

Method: The Mycobacterial growth inhibition assay (MGIA) using human PBMCs isolated by density gradient by Lymhoprep (Axis-Shield) and SepMate tubes (StemCell Technologies) will be performed as described in study I with minor modifications. The PBMCs are infected with GFP expressing M. tuberculosis H37Rv and intracellular growth of Mtb and viability of PBMCs are assessed by live-cell imaging (Incucyte©) and measured as relative fluorescence units (RFU) during 5 days with and without stimulation with the purified protein derivate (PPD) is included. The cytokine response following exposure to gamma-irradiated H37Rv will be quantified by Olink proteomics.

Enrollment: 280 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria: Healthy blood donors or subjects who will get vaccinated.

Exclusion Criteria:Known HIV infection, not Swedish citizen, chronic liver och kidney disease,immunosuppression from treatment or disease.

Trial design

280 participants in 4 patient groups

Healthy Individuals

Description:

Patients with a negative IGRA (Quantiferon) who are apparently healthy.

Treatment:

Other: No intervention.

Close contacts to patients with active TB

Description:

Close contacts to patients with active, smear positive pulmonary TB.

Treatment:

Other: No intervention.

Patients with (latent) tuberculosis infection

Description:

Patients without active TB who have a positive IGRA (Quantiferon Plus) result.

Treatment:

Other: No intervention.

Patients with active TB

Description:

Culture or PCR-verified active TB who are initiated on treatment.

Treatment:

Other: No intervention.