The investigation of leukocyte subpopulation and serum cytokine concentration in the blood of patient with sepsis by Gram-positive and Gram-negative bacteria

• Main Authors: Yuan-Peir Wu, 吳元培
• Other Authors: Keh-Liang Lin Ph.D.
• Format: Others
• Language: en_US
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/24877171582912689077

碩士 === 中山醫學院 === 生物化學研究所 === 87 === Abstract Sepsis is caused by serious bacterial infections that induced severe systemic immune response and high mortality rate. The central theme of this thesis is to investigate the expression of lymphocyte surface marker and concentration of serum cytokines in four groups of patients with sepsis : Group 1, patients with Gram positive bacterial infection; Group 2, patients with Gram negative bacterial infection; Group 3, patients with negative cultures but strong evidence of infection; Group 4, patients without clinical and microbiologic evidence of infection as control group. The result of first part of this thesis demonstrated that patients with sepsis by positive blood culture had lower levels of T and B lymphocytes than control group (p <0.05). The reason for the reduction of T and B lymphocytes may be that the LPS of Gram negative bacterial cell wall in combined with CD14 and mediated apoptosis by CD95 (Fas) pathway. Apoptosis may be an important cause of immunologic suppression in sepsis by inducing widespread lymphocyte depletion. Second part of this project analyzed the production of cytokine by TH 1 and TH 2 in different group of sepsis as the above. Group 2 patients with sepsis by Gram negative bacteria had increased levels of TNF-α (p <0.05). Patients suspected of sepsis but a negative blood culture ( Group 3) had similar but milder increasing. Moreover, the increase in the concentration of IL-10 and TNF-α was associated with high mortality rate. Otherwise, increasing IL-4 production has been as a means of reducing mortality in sepsis. The differences in the serum concentration of cytokines produced by TH 1 or TH 2 can be helpful in predicting prognosis of sepsis. In conclusion, the result of this study indicates that activation of TH 2 may be beneficial to host survival by down-regulating the inflammatory response which accompanies sepsis.