ABSTRACT
SETTING AND OBJECTIVES: the sensitivity of the interferon-gamma release assays (IGRAs) in the detection of Mycobacterium tuberculosis infection or disease may be affected by immune dysregulation in diabetes. As millions of type 2 diabetes patients are at risk for tuberculosis (TB) worldwide, it is important to determine if the sensitivity of IGRAs is compromised in this vulnerable population. DESIGN: the sensitivity of the IGRAs QuantiFERON®-TB Gold (QFT-G) and T-SPOT®.TB was evaluated among specimens from newly diagnosed adults with microbiologically confirmed TB with and without diabetes. We also evaluated the association between QFT-G results and diabetes-associated conditions (dyslipidemia, obesity). RESULTS: QFT-G sensitivity was 70% among TB patients. Patients with diabetes, chronic hyperglycemia or overweight/obesity were more than twice as likely to have positive test results in multivariate models (P < 0.05). Low high-density lipoprotein cholesterol or high triglycerides were not associated with assay results. In a separate group of TB patients (n = 43), T-SPOT.TB was 93% sensitive, with similar performance in patients with and without diabetes. CONCLUSION: IGRA sensitivity is not compromised by diabetes in TB patients. Accordingly, IGRAs may also be suitable for diagnosing TB infection in diabetes patients, which is required to assess TB risk.
