1. A Simple-to-Perform ifn-γ mRNA Gene Expression Assay on Whole Blood Accurately Appraises Varicella Zoster Virus-Specific Cell-Mediated Immunity After Allogeneic Hematopoietic Stem Cell Transplantation.
- Author
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Boccard M, Conrad A, Mouton W, Valour F, Roure-Sobas C, Frobert E, Rohmer B, Alcazer V, Labussière-Wallet H, Ghesquières H, Venet F, Brengel-Pesce K, Trouillet-Assant S, and Ader F
- Subjects
- Gene Expression, Humans, Immunity, Cellular, Interferon-gamma metabolism, Leukocytes, Mononuclear, RNA, Messenger genetics, Hematopoietic Stem Cell Transplantation, Herpesvirus 3, Human
- Abstract
Herpes zoster, which is due to the reactivation of Varicella zoster virus (VZV), is a leading cause of morbidity after allogeneic hematopoietic stem cell transplantation (allo-HSCT). While cell-mediated immunity (CMI) is critical to inhibiting VZV reactivation, CMI is not routinely assessed due to a lack of reliable tests. In this study, we aimed to evaluate VZV-specific CMI among allo-HSCT recipients (n = 60) and healthy individuals (HI, n = 17) through a panel of three immune functional assays after ex vivo stimulation by VZV antigen: quantification of (i) IFN-γ release in the supernatants, (ii) T-cell proliferation after a 7-day stimulation of peripheral blood mononuclear cells (PBMC), and (iii) measurement of the ifn - γ mRNA gene expression level after 24 h of stimulation of a whole-blood sample. VZV responsiveness was defined according to IFN-γ release from VZV-stimulated PBMC. Upon VZV stimulation, we found that allo-HSCT recipients at a median time of 6 [5-8] months post-transplant had lower IFN-γ release (median [IQR], 0.34 [0.12-8.56] vs. 409.5 [143.9-910.2] pg/ml, P <.0001) and fewer proliferating T cells (0.05 [0.01-0.57] % vs. 8.74 [3.12-15.05] %, P <.0001) than HI. A subset of allo-HSCT recipients (VZV-responders, n = 15/57, 26%) distinguished themselves from VZV-non-responders (n = 42/57, 74%; missing data, n = 3) by higher IFN-γ release (80.45 [54.3-312.8] vs. 0.22 [0.12-0.42] pg/ml, P <.0001) and T-cell proliferation (2.22 [1.18-7.56] % vs. 0.002 [0.001-0.11] %, P <.0001), suggesting recovery of VZV-specific CMI. Interestingly, VZV responders had a significant fold increase in ifn-γ gene expression, whereas ifn-γ mRNA was not detected in whole blood of VZV-non-responders ( P <.0001). This study is the first to suggest that measurement of ifn-γ gene expression in 24-h-stimulated whole blood could be an accurate test of VZV-specific CMI. The routine use of this immune functional assay to guide antiviral prophylaxis at an individual level remains to be evaluated., Competing Interests: WM has a PhD grant CIFRE 2019 (conventions industrielles de formation par la recherche, Ministère de l’Enseignement supérieur, de la Recherche et de l’Innovation, Paris, France) half-funded by Lyon University and half-funded by bioMerieux SA. KB-P is an employee of bioMérieux SA, an in vitro diagnostic company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be constructed as a potential conflict of interest., (Copyright © 2022 Boccard, Conrad, Mouton, Valour, Roure-Sobas, Frobert, Rohmer, Alcazer, Labussière-Wallet, Ghesquières, Venet, Brengel-Pesce, Trouillet-Assant and Ader.)
- Published
- 2022
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