Changes in circulating cytokine levels and lymphocyte subsets in healthy liver donors after partial hepatectomy

Aim: Studies of animal models have determined that liver regeneration after partial hepatectomy is mediated by a various cytokines. The aim of the present study was to evaluate the levels of these cytokines and subsets of circulating lymphocytes in healthy humans after partial hepatectomy. Methods: Four individuals underwent partial hepatectomy for living-related donor liver transplantation. We also evaluated for comparison, three patients with myoma uteri who underwent hysterectomy. Blood samples were obtained before surgery and on postoperative days (PD) 1, 3, and 7. Serum levels of hepatocyte growth factor, interleukin (IL)-6, -10, and plasma levels of transforming growth factor beta were measured. Results: Increased circulating levels of hepatocyte growth factor and transforming growth factor beta were observed after hepatectomy. The levels of IL-6 and IL-10 peaked on PD 1. Circulating white blood cell counts increased remarkably, whereas lymphocyte count decreased particularly on PD 1 and 3. CD4/CD8 and T-helper cell (Th)1/Th2 ratios were still decreased on PD 7. The percentage of natural killer cells was increased on PD 1. Partial hepatectomy in healthy humans leads not only to decreased lymphocyte counts, but also to remarkable changes in lymphocyte subsets. Conclusion: These findings suggest that immune suppression after partial hepatectomy involves decreases in CD4 + helper T cells, particularly Th1 cells.