T-cell-subpopulations in septic patients

Introduction

The dysfunction of the immune system is a main problem during the systemic inflammation. T-Lymphocytes are responsible for the different detection of antigens and the correct answer related to pathogens. Different T-cell function was described in the TH1/TH2 concept in these patients with changes in the cytokine pattern of the subpopulation of CD4+-T-cells during sepsis. These results have shown the important part of CD4+ cells during the development of immune dysfunction and paralysis. A second subpopulation of T-cells are the cytotoxic (CD8+) cells. To determine the changes in CD4+/CD8+ subpopulation, the present study investigated the relationship between these T-cells in septic patients.

Methods

Ten patients with sepsis of an Internal Intensive Care Unit, University hospital, were included and compared to 10 healthy controls. The severity of the disease was assessed at the APACHE II and SOFA-score. Also were measured the serum concentration of the C-reactive protein, procalcitonin, TNF-alpha and interleucin-6. Levels of CD4 and CD8-expression were analysed flow cytometrically ex vivo and after stimulation with PMA at day 1, day 7 and day 14 in culture (proliferation index).

Results

There was a significant difference in the CD4/CD8-ratio between septic patients and healthy controls (P < 0.05) ex vivo and at day 7. Also the severity of the disease showed a linear correlation to the changes in CD4/CD8-ratio after stimulation with PMA.

Conclusion

These results indicate that changes in CD4/CD8-ratio could be an important part of the immunologic response to pathogens in the septic process. Therefore T-cell-subpopulations are probably involved in the development of the dysfunction in the immune system.