Repeatability of QuantiFERON-TB gold plus testing utilizing microparticle chemiluminescence.

Autor: Cornaby C; Immunology, Histocompatibility and Immunogenetics Laboratories/McLendon Clinical Laboratories UNC Hospitals, Chapel Hill, NC, USA., Giardina CK; UNC School of Medicine, Chapel Hill, NC, USA., Schmitz JL; Immunology, Histocompatibility and Immunogenetics Laboratories/McLendon Clinical Laboratories UNC Hospitals, Chapel Hill, NC, USA; Department of Pathology & Laboratory Medicine, UNC School of Medicine, Chapel Hill, NC, USA. Electronic address: John.Schmitz@unchealth.unc.edu.
Jazyk: angličtina
Zdroj: Journal of immunological methods [J Immunol Methods] 2022 Oct; Vol. 509, pp. 113340. Date of Electronic Publication: 2022 Aug 27.
DOI: 10.1016/j.jim.2022.113340
Abstrakt: Background: Detection of latent Mycobacterium tuberculosis (LTBI) in patients is important to prevent active infection and the spread of disease, particularly in vulnerable patient populations. In 2020, a kit on the high throughput Liaison XL (DiaSorin) became commercially available for the analysis of QuantiFERON-TB Gold Plus assay (Qiagen). Pilot testing indicated suboptimal repeatability of some samples with this assay. This study provides an extensive assessment of repeatability with DiaSorin system.
Results: Repeat testing of 481 IGRA positive samples, demonstrated substantial variability upon repeat analysis. Repeat results for TB1 and TB2 tubes, showed 73.73% and 72.82% concordance with initial results, respectively. TB1 and TB2 tube values minus the nil (IU/mL) were significantly higher in samples that were repeat positive (p < 0.001). Repeat results had better concordance with initial results if both TB1 and TB2 tubes were positive. Samples with TB1 tube values minus the nil (IU/mL) ≥ 4.54 and TB2 tube values minus the nil (IU/mL) ≥ 4.78 were found to always repeat positive. Assigning a threshold of 1.55 IU/mL for the TB1 tube value minus the nil and 1.45 IU/mL for the TB2 tube value minus the nil yielded a positive predictive value ≥95%.
Conclusion: These results identified a potential role for retesting of select IGRA positive samples on the Diasorin Liaison XL platform due to the high proportion of samples that show a lack of repeatability. Additionally, we identified a threshold that would determine samples most likely to repeat test positive and which samples should be retested.
Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to disclose.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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