The impact of an oral glucose load on IFN-γ-release in persons infected with Mycobacterium tuberculosis

Hans Johan Niklas Lorentsson*, Christina Reinholdt Clausen, Daniel Faurholt-Jepsen, Katrine Bagge Hansen, Christian Ritz, Sidse Graff Jensen, Erik Michael Rasmussen, Anja Jørgensen, Troels Lillebaek, Filip Knop, Pernille Ravn

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Abstract

Background and objective
To diagnose tuberculosis infection (TBI), whole blood is incubated with M.tuberculosis (Mtb)-specific peptides and the release of interferon-γ (IFN-γ) is measured in IFN-γ-release assays (IGRAs). Hyperglycaemia and fluctuations in blood glucose may modulate IFN-γ-release. Here, we investigated if glucose intake affects IFN-γ-release or IGRA results in IGRAs taken during an oral glucose tolerance test (OGTT).

Methods
Persons with TB disease (TB) or TBI underwent a standard 75-g OGTT at the start and end of treatment for TB or TBI. Blood for the IGRA QuantiFERON-TB Gold Plus (QFT) containing Mtb-specific tubes (TB1 and TB2), a non-specific mitogen tube (MIT) and an empty control tube (NIL) was drawn at sample-timepoints -15 (baseline), 60, 90, 120 and 240 min during the OGTT. Blood glucose was measured in parallel at all timepoints. IFN-γ-release (after subtraction of NIL) at each timepoint was compared with baseline using linear-mixed-model analysis.

Results
Twenty-four OGTTs from 14 participants were included in the final analysis. Compared to baseline, IFN-γ-release was increased at sample-timepoint 240 min for TB1; geometric mean (95% confidence interval) 3.0 (1.5–6.2) vs 2.5 (1.4–4.4) IU/mL (p = 0.047), and MIT; 182.6 (103.3–322.9) vs 146.0 (84.0–254.1) IU/mL (p = 0.002). Plasma glucose levels were not associated with IFN-γ-release and the QFT test results were unaffected by the OGTT.

Conclusion
Ingestion of glucose after a 10-h fast was associated with increased IFN-γ-release after 240 min in the MIT tube. However, there was no association between plasma glucose levels at the QFT sampling timepoint and IFN-γ-release. Furthermore, the QFT test results were not affected by glucose intake. The overall effect of an OGTT and prevailing plasma glucose levels on IFN-γ-release in IGRAs seem limited.
OriginalsprogEngelsk
Artikelnummer1079
TidsskriftBMC Infectious Diseases
Vol/bind24
Udgave nummer1
Antal sider7
ISSN1471-2334
DOI
StatusUdgivet - 2024

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© 2024. The Author(s).

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