BACKGROUND: Cytomegalovirus (CMV) specific T-cells are known to provide long-term control of CMV reactivation, which is a frequent complication of hematopoietic stem cell transplantation. We have studied 58 pediatric patients after hematopoietic stem cell transplantation who suffered from CMV reactivation to reveal which functional T cell subset is best correlating with successful reactivation resolution and which protects from reactivation episode. METHODS: Detection of 30 combinatorial subsets of four types of response to ex vivo CMV stimulation (IFNγ secretion, IL-2 secretion, CD40L upregulation and degranulation) that were detectable on either CD8+ or CD4+ T cells through flow cytometry intracellular cytokine staining was used. RESULTS: We found that the presence of CD8+ dual positive (IFNγ+ and IL-2+) cells is the most accurate functional parameter that can predict fast resolution of CMV reactivation. Next, we show that the presence of CD8+ dual positive (IFNγ+ and IL-2+) and CD8+ IFNγ+ cells provides a protective effect (a hazard risk of 0.28 (confidence interval 0.18 - 0.43) and 0.45 (CI 0.27 - 0.75), respectively) and the presence of corticotherapy increases the risk of reactivation (HR 2.47 (CI 1.82-3.36)). Thus, a patient without corticotherapy and with both of the critical T cell subsets present has a cumulative 19.6 times lower risk of developing CMV reactivation than a patient on corticotherapy and without CD8+ dual positive (IFNγ+ and IL-2+) or CD8+ IFNγ+ cells. CONCLUSIONS: We have established parameters of CMV specific functional response ex vivo that can be used in assisting clinical management of patients with CMV reactivation. © 2015 International Clinical Cytometry Society.

CLIP Childhood Leukemia Investigation Prague 2nd Faculty of Medicine Charles University Prague and University Hospital Motol 5 Uvalu 84 Prague 150 06 Czech Republic

Department of Pediatric Hematology and Oncology 2nd Faculty of Medicine Charles University Prague and University Hospital Motol 5 Uvalu 84 Prague 150 06 Czech Republic

References provided by Crossref.org

Immunogenicity of BNT162b2 mRNA COVID-19 vaccine and SARS-CoV-2 infection in lung transplant recipients

Novel SAMD9 Mutation in a Patient With Immunodeficiency, Neutropenia, Impaired Anti-CMV Response, and Severe Gastrointestinal Involvement

Common Variable Immunodeficiency patients with a phenotypic profile of immunosenescence present with thrombocytopenia