Acute rejection after liver transplantation: Is there a specific immunological pattern?

The aim of the study was to assess various T-cell subsets and cytokine secretion patterns both in liver tissue and in the peripheral blood of 24 liver transplant patients to assess possible specific immunological involvement in early acute rejection episodes after liver transplantation. Particularly, we studied CD4(+)CD7(+), CD8(+)CD38(+), and CD4(+)CD25(+) T cells by flow cytometry, as well as contemporaneously, interleukin (IL)-2 and IL-10 secretion by ELISpot to determine possible Th1-like immune responses and the immunomodulation expressed by Treg cells in acute liver rejection, respectively. As a control group we included patients transplanted without acute rejection. Early acute rejection within the first 4 weeks was proven histologically in 42% of patients. It was associated with a greater expression of CD4(+)CD7(+) and CD8(+)CD38(+) T cells in the liver than in the blood (P < .001). A contemporaneous reduced expansion of liver Treg cells was evident in patients with acute rejection (P < .001). Our data suggested that a preferential Th1-like immune mechanism operated in local fashion as characterized by a decreased presence in the liver and blood of Treg cells.