Associations of T helper 1, 2, 17 and regulatory T lymphocytes with mortality in severe sepsis

T helper 17 (Th17) and regulatory T (T-reg) lymphocytes might play important roles in patients with severe sepsis. The association of Th17 or T-reg lymphocytes with survival is also unclear. Eighty-seven patients with severe sepsis were enrolled from our intensive care units between August 2008 and July 2010. Leukocyte antigens and clinical data were determined on day 1 in all patients and on day 7 in first-year patients. The percentages in peripheral blood mononuclear cells (PBMCs) and circulatory counts of CD4(+) and CD8(+) lymphocytes in survivors were higher than those in non-survivors. Th1/CD4(+) ratios and circulatory Th1 lymphocyte counts in survivors were higher than in non-survivors. Absolute counts of Th17 and T-reg lymphocytes in survivors were higher than in non-survivors. The percentages of CD4(+) and CD8(+) in survivors' PBMCs were increased after 6 days. Th17/CD4(+) ratios and circulatory Th17 lymphocyte counts in survivors were increased after 6 days. Higher Th1 differentiation and total CD4(+) T lymphocyte counts were associated with higher survival. The association of circulatory Th17 and T-reg lymphocytes with mortality in severe sepsis may be due to the change in total CD4(+) T lymphocytes. In survivors, Th17 differentiation and counts were restored.