Features of indeterminate results of QuantiFERON-TB Gold In-Tube test in patients with haematological malignancies

Abstract

Background and aims: The application of QuantiFERON-TB Gold in-Tube (QFT-GIT) in patients with haematological malignancies (HMs) has not been well studied. Therefore, we aimed to investigate the features of patients with HMs whose QFT-GIT results were indeterminate. Methods: This study enrolled patients with HMs for the analysis of QFT-GIT tests and additional 2-year follow-up. The characteristics and predictors of QFT-GIT indeterminate results were identified. Mycobacterium tuberculosis (TB) incidence rate (IR) and incidence rate ratio (IRR) were also investigated. Results: Of 89 participants, 27 (30.3%) had QFT-GIT indeterminate results. The QFT-GIT indeterminate patients were characterized with the diagnosis of leukaemia (63.0% versus 32.3%, p = 0.044), abnormal white blood count (WBC) (88.9% versus 14.5%, p = 0.001), abnormal lymphocyte percentage (81.5% versus 14.5%, p = 0.001) and lower lymphocyte count (×109/l) (0.5 versus 2.2, p = 0.000) when compared with those with determinate results. Meanwhile, abnormal WBC [odds ratios (OR): 15.18, p = 0.003] and lymphocyte percentage (OR: 6.90, p = 0.033) were predictors of indeterminate results. One patient with the QFT-GIT indeterminate status and high interferon-γ level of negative control result developed active TB with a TB IR of 18.5 per 1000 person-years and an IRR of 0.1 (95% confidence interval, 0.01–0.71) when compared with positive QFT-GIT patients without prophylaxis treatment. Conclusion: Abnormal ranges of WBC and lymphocyte differential count percentage were independent predictors useful to determine the optimal timing of implementing QFT-GIT test in patients with HMs.

Acute Leukemia and Latent Tuberculosis Infection in Italy: Quantiferon-Tb Test Screening in a Low Tuberculosis Incidence Country

“…Abnormalities in the number and differentials of white blood cells have been found to be possible predictors of indeterminate results. 26 …”

Comparison of QuantiFERON-TB Gold In-Tube and QuantiFERON-TB Gold-Plus in the Diagnosis of Mycobacterium tuberculosis Infections in Immunocompromised Patients: a Real-World Study

“…This might explain the relatively higher incidence of indeterminate results, 9.7%, compared with previous reports. A previous study focused on patients with hematological malignancies found that the rate of QFT-GIT indeterminate results could be as high as 30.3%, associated with an abnormal white blood count and a lower median lymphocyte count ( 32 ). In our study, similar to other related studies ( 32 to 34 ), the CD4 + T cell absolute counts and lymphocyte counts in the immunocompromised group were significantly lower than those in the immunocompetent group.…”

“…A previous study focused on patients with hematological malignancies found that the rate of QFT-GIT indeterminate results could be as high as 30.3%, associated with an abnormal white blood count and a lower median lymphocyte count ( 32 ). In our study, similar to other related studies ( 32 to 34 ), the CD4 + T cell absolute counts and lymphocyte counts in the immunocompromised group were significantly lower than those in the immunocompetent group. We also found that patients with indeterminate results had lower lymphocyte absolute counts, CD4 + and CD8 + T cell absolute counts, and CD4/CD8 ratios.…”

In-hospital blood collection increases the rate of indeterminate results in interferon-gamma release assays

“…Some medical conditions that impair immune functionality can potentially reduce IFN-γ responses in the IGRA. [6][7][8][9] In addition, technical procedures may influence IGRA variability. [8][9][10][11][12] The IGRA has been available in Japan since 2005.…”

“…[6][7][8][9] In addition, technical procedures may influence IGRA variability. [8][9][10][11][12] The IGRA has been available in Japan since 2005. Currently, the newest IGRA, the QuantiFERON-TB Gold Plus (QFT-plus; Qiagen, Hilden, Germany), has been launched.…”