Adults with Mycobacterium tuberculosis infection and pre-diabetes have increased levels of QuantiFERON interferon-gamma responses

Abstract

Background: Diabetes is associated with increased prevalence of TB infection in the US. We assessed associations between diabetes and interferon-gamma (IFN-γ) TB antigen response among adults with TB infection using US representative data.

Methods: National Health and Nutrition Examination (NHANES) participants >19 years from 2011 to 2012 with positive QuantiFERON®-TB Gold-In-Tube (QFT) results were eligible. Diabetes was defined by combination of self-report and glycated hemoglobin (HbA1c). Quantitative IFN-γ TB antigen was classified as high (≥10 IU/mL), intermediate (1.01-9.99 IU/mL), or low (0.35-1.00 IU/mL). Analyses accounted for NHANES weighted design.

Results: Among NHANES participants >19 years, n = 513 had positive QFT (5.9%). Among those with positive QFT, diabetes prevalence was 22.2% and pre-diabetes was 25.9%. Overall, 16.7% of positive QFT participants had high IFN-γ TB antigen levels including 21.7% among those with diabetes, 20.8% among those with pre-diabetes, and 12.6% among euglycemic participants. In adjusted analyses, high IFN-γ TB antigen response was more common among those with pre-diabetes (aOR 1.9, 95%CI 1.0, 3.6) compared to euglycemic participants.

Conclusion: Higher antigen responses may reflect immunopathy consistent with an exaggerated inflammatory but ineffectual response to TB or a reflection of more Mtb replication in participants with pre-diabetes or diabetes.

Keywords: Diabetes mellitus; Interferon-gamma; Tuberculosis infection.

Figure 1.

Flow diagram of eligible study participants from NHANES 2011–2012 Prevalence estimates cannot be obtained from the flow diagram because is does not account for weighted survey design