Effects of low dose of hydrocortisone on circulating thymus-dependent lymphocyte apoptosis in patients with septic shock

Abstract

Objective To investigate the effects of low-dose of hydrocortisone on circulating thymus-dependent lymphocyte (T lymphocyte) apoptosis in patients with septic shock. Method fifty-seven patients with septic shock admitted into ICU from January 2006 to January 2009 were prospectively randomized (random number) to treatment group and control group. Another 20 healthy volunteers and 18 patients with sepsis alone were included as external control groups.The patients of treatment group and control group were treated with low-dose of hydrocortisone and placebo,respectively. Samples of peripheral blood were taken from healthy volunteers and patients 0 hr,24 hrs,48 hrs,72 hrs and 168 hrs after onset of the disease to determine the circulating T lymphocyte apoptosis by using theassays of Annexin V and flow cytometry. Least significant difference t -test was used for multiple comparisons. Results The percentage of Annexin V-positive CD4+ T lymphocytes in the primary stage was (11.01 +4.52)% in septic shock patients, (4.41 + 1.45)% in healthy volunteers, and (7.87 + 3. 82)% in patients with sepsis alone. And in the initial setting, the percentage of Annexin V-positive CD4+ T lymphocytes in the septic shock patients was higher than that in healthy volunteers ( P 0.05 between three groups). The percentages of Annexin V-positive CD4+ T lymphocytes in control group after 24 his, 48 hrs and 72 hrs were(13.51+6.85)%, (19.39 + 6.63)% and (15.33+ 6.21)%, respectively. And the percentages of Annexin V-positive CD4+ T lymphocytes in treatment patients after 24 hrs, 48 hrs and 72 hrs were (17.4 + 7.21)%, (22.61 + 5.64)%, and (25.73 + 6.91)%, respectively. The percentage of Annexin V-positive CD4+ T lymphocytes in septic shock patients was higher than that in control groups ( P 0.05 between two groups). In the meantime, the percentages of Annexin V-positive CDS'1' T lymphocytes in control group and in treatment group were (12.72+ 19.69)% and (13.88 + 13.28)%, respectively (P >0.05). Conclusions Low-dose of hydrocortisone could induce CD4+ T lymphocyte apoptosis and has no effects on CD8+ T lymphocyte apoptosis when it is used to treat septic shock. Key words: Septic shock; Lymphocyte; Apoptosis; Hydrocortisone