Reply to "cytomegalovirus-induced γδ T cells during rejection: An ambivalent T cell"

To the Editor:
We would like to thank Bachelet et al for their comments on our recent paper, in which we reported that primary cytomegalovirus (CMV) infection after liver transplantation (LT) is associated with donor-specific CD8+ T-cell hyporesponsiveness, and with a reduced acute rejection incidence late after transplantation. These observations surprised us, because they suggest that primary CMV infection may be associated with development of immunological tolerance to liver allografts, contrasting to findings from previous animal studies. In trying to obtain further evidence for this unexpected finding, we measured peripheral Vδ1/Vδ2 ϒδ T cells, because an increased peripheral Vδ1/Vδ2 ϒδ T cells ratio is the only biomarker that is consistently associated with operational tolerance after LT in independent studies (3–5). Indeed, we observed increased Vδ1/Vδ2 ratios in CMV IgG D+/R- compared to D-/R- and R+ LT patients, supporting our conclusion that primary CMV infection may be associated with development of immunological tolerance to liver allografts. [...]