1390. A Novel Application of the Interferon-Gamma Release Assay (IGRA) Among End-Stage Heart Failure Patients Awaiting Heart Transplantation

Abstract

BackgroundThe optimal approach to assay the immune status in heart failure is challenging because of the inherent complexity of chronic inflammation. Interferon-gamma release assays (IGRAs) measure an aspect of cell-mediated immunity encompassing both the innate and adaptive immunity. In this study, we evaluated the utility of a commercial IGRA for predicting mortality and infectious complications among heart transplant candidates.MethodsThis prospective cohort study was conducted between August 1, 2014 and January 31, 2019 at a medical center in Taiwan. All heart transplant candidates received an IGRA (QuantiFERON®-TB Gold In-Tube, QFT-GIT) at baseline as part of the initiative to screen for latent tuberculosis. Impaired cell-mediated immunity was defined as the release of <1 IU/mL of interferon-γ (IFN-γ) in response to the common mitogen in the positive control tube.The patients were then followed until death or January 31, 2019.ResultsA total of 102 patients were enrolled; of whom, 23 (22.5%) had impaired cell-mediated immunity at baseline. During the study period with a median follow-up of 1.90 years (IQR 1.17–3.56), 23 (22.5%) patients died and 45 (44.1%) patients developed an infectious complication. Overall mortality was significantly greater among those with impaired cell-mediated immunity [39.1% (9/23) vs. 17.7% (14/79), P = 0.031]. A trend toward higher rates of infection was observed among impaired cell-mediated immunity group [60.9% (14/23) vs. 39.2% (31/79), P = 0.066]. The most common cause of death was infection (56.5%). No patient developed active tuberculosis during the study and the most common infection was bacteremia (35.6%). In the age-adjusted multivariate analysis, impaired cell-mediated immunity was an independent predictor of mortality (HR 2.87, CI 1.23–6.68, P = 0.014) and subsequent infectious event (HR 3.00, CI 1.56–5.76, P = 0.001).ConclusionAn interferon-γ release assay utilizing the positive control tube of the QuantiFERON®-TB Gold In-Tube kit was predictive of overall mortality and infections among patients with advanced heart failure awaiting heart transplantation. Disclosures All authors: No reported disclosures.