Immune response in liver transplantation: is there a preferential pattern in acute rejection?

To determine the immune factors involved in liver graft rejection, a study on 14 liver transplants was conducted. We have, in particular, studied CD4+CD7+ and CD8+CD38+ T cells in both liver tissue and blood of patients with and without acute rejection. Contemporarily, IL-2 and IL-4 secretion in both plasma and stimulated culture supernatants from hepatic T cells was evaluated. Early acute rejection was characterized by a higher expression of CD4+CD7+ and CD8+CD38+ T lymphocytes in the liver than in blood (p<0.001). Moreover, a preferential proinflammatory (Thl) cytokine profile was related to liver resident T cells in comparison with corresponding plasma (p<0.001). Conversely, in the patients without acute rejection CD4+CD7+ was higher in blood than in liver and the Th2-like cytokine profile characterized these subjects. Our data suggest that a preferential Th1 immune mechanism operates in a local fashion and may be involved in acute rejection.