Background: The accurate diagnosis of latent tuberculosis infection (LTBI) in haemodialysis patients remains elusive. Impaired immune function associated with chronic kidney failure causes a high number of anergic tuberculin skin tests (TST). Interferon-gamma (INF-gamma) release assays (IGRAs) measuring the INF-gamma secretion of tuberculosis specific T-cells have several advantages over the TST but their significance in dialysis patients is currently uncertain.
Methods: This study examines the test-performances of the QuantiFERON Gold InTube (QFT-GIT) in a cohort of 39 haemodialysis (HD) patients and 52 healthy individuals.
Results: INF-gamma secretion in HD patients was significantly lower than in healthy controls, however, mitogen-anergic QFT-GIT results were only found in 2.5% of HD-patients. INF-gamma secretion was independent of duration of HD treatment, dialysis quality and nutritional status. The QFT-GIT showed a closer association with TB risk factors as a proxy for past exposure to TB than the TST.
Conclusions: We conclude that the QFT-GIT is a valid alternative to the TST. Together with the survey of TB risk factors, it may help to diagnose LTBI more accurately in HD-patients.