Divergences in KIR2D+ natural killer and KIR2D+CD8+ T-cell reconstitution following liver transplantation

Abstract Natural killer (NK) and CD8 + T cells may be active elements in the allograft response, but little is known about their role in liver transplantation. Some of these cells express killer immunoglobulin-like receptors (KIRs), which after binding specific ligands may transmit inhibitory/activating signals. In this study, circulating NK and CD8 + T cells expressing CD158a/h (KIR2DL1/S1) or CD158b/j (KIR2DL2/3/S 2 ) receptors were analyzed in 142 liver recipients by flow cytometry. They were underrepresented in patients before transplantation, but following transplantation, whereas the KIR2D + NK subsets experienced a late recuperation (day 365) mainly in C2-homozygous patients developing early acute rejection, recovery of the 2 CD8 + KIR2D + T cells started earlier, showing significant differences on day 365 between patients without acute rejection and those suffering from it ( p = 0.004 and p + NK cells in C2/C2 patients appears to be linked to acute rejection, the increase in early CD8 + KIR2D + T cells in overall liver recipients correlates with a most successful early graft outcome. Therefore, monitoring of KIR2D + cells appears to be a useful tool for liver transplant follow-up.