Expansion kinetics of graft-versus-host T cell clones in patients with post-liver transplant graft-versus-host disease.

Graft-versus-host disease (GVHD) following liver transplantation is induced by the graft-versus-host (GVH) T cell that is transferred with the liver graft, but the dynamics remain poorly investigated in clinical liver transplantation GVHD. Here, we report that in two liver transplantation recipients who developed GVHD, both of whom showed donor T cell macrochimerism in the blood before clinical GVHD onset. Longitudinal tracking of GVH T cell clones in one of these recipients revealed that GVH T cell clonal expansion occurred before disease onset, and the dominant GVH T cells might also derive from non-hepatic tissue-resident memory T cells in the liver-graft. Additionally, a comparison of the inflammatory cytokine levels and TCR repertoire diversities in recipient pre-liver transplantation blood between 4 patients with GVHD and 12 non-GVHD patients showed that the levels of TNF-α and IL-8, and the overall TCR repertoire skewness in pre-transplant recipient blood samples may serve as potential independent risk factors for the disease.