Measurement of Anti-Human Cytomegalovirus T Cell Reactivity in Transplant Recipients and Its Potential Clinical Use: A Mini-Review

By allowing direct determination of the frequencies of antigen-specific memory T cells in peripheral blood, novel techniques based on flow cytometry provide new diagnostic opportunities in various clinical settings, including organ transplantation. While the importance of the T cell compartment for the anti-human cytomegalovirus (HCMV) immune response is undisputed, efficient monitoring of this response was previously impossible because the conventional methods for measuring CD4+ and CD8+ T cell responses are too time-consuming and cost-intensive. We analyzed how the rapid induction of anti-HCMV CD4+ and CD8+ memory T cells by HCMV viral lysate or HCMV-derived peptides, respectively, followed by a flow-cytometric detection step, may be used to monitor HCMV-specific CD4+ and CD8+ memory T cells in solid-organ recipients. We also discuss a number of preconditions for integrating such testing into the clinical routine.