Comparative analysis of Mycobacterium tuberculosis-specific antigens and T-cell mitogen-stimulated interferon gamma production in hemodialysis patients and healthy individuals

Abstract Background The incidence of Tuberculosis (TB) is higher in patients undergoing chronic hemodialysis than in the general population; further, both the incidence and development of active TB from latent TB infection (LTBI) are considerably higher in patients undergoing hemodialysis than in any other group. The QuantiFERON-TB Gold In-Tube (QFT-GIT) assay is one of the most commonly used interferon gamma (IFN-γ) release assays (IGRAs) currently. We aim to know T-cell function of hemodialysis patients and the possible QFT false negatives. Methods In order to analyze the MTB-specific antigen-stimulated IFN-γ release in patients on hemodialysis, the QFT-GIT test was used in this study. A total of 84 hemodialysis patients and 52 healthy subjects were enrolled from Kosin University Gospel Hospital and Catholic University of Pusan, Busan, Republic of Korea; their whole blood samples were collected and used for the present study. Results The positivity results of the IGRAs in hemodialysis patients and normal subjects were 34/84 (40.4%) and 4/52 (7.6%), respectively. The mean value of MTB-specific antigen-stimulated IFN-γ in hemodialysis patients with LTBI and non-LTBI status in hemodialysis patients, healthy individuals were 1.85 IU/mL (4.44ng/mL) and 0.028 IU/mL (0.067 ng/mL) and 0.255 IU/mL (0.612 ng/mL) respectively. In addition, Of the 34 LTBI status in hemodialysis patients, 14 (41.2%) had T-cell mitogen-stimulated IFN-γ levels of 10 or less, and 20 (58.8%) had 10 or more T-cell mitogen-stimulated IFN-γ. Moreover, Of the 49 non-LTBI status in hemodialysis patients, 19 (38.8%) had T-cell mitogen-stimulated IFN-γ levels of 10 or less, and 30 (61.2%) showed T-cell mitogen-stimulated IFN-γ levels of 10 or more. On the other hand, there was no low level of T-cell mitogen-stimulated IFN-γ in the healthy individuals. Conclusion This reveals that T-cell function in hemodialysis patients was reduced as compared to the healthy individuals. Therefore, the cut-off value should be adjusted for the active TB high-risk group when using IGRA tests. The clinical manifestations of TB in patients on hemodialysis are quite non-specific, making timely diagnosis difficult, and delaying the initiation of curative treatment, delay being a major determinant of outcome.