Dynamic changes of circulating T-helper cell subsets following severe thoracic trauma.

Major trauma induces profound immune dysfunction, which subsequently results in sepsis and multiple organ dysfunction syndromes (MODS). The functionally conducive immune cells are of paramount important in the early recovery and development of the post-traumatic organ failure. In this study, we investigated the immune deregulation after severe trauma by means of detecting the differentiation of CD4(+) T cells. Seven male patients with thoracic trauma (aged 29.8 ± 7.6 years) hospitalized in the Intensive Care Units (ICU) in our hospital were enrolled in the study. Peripheral blood was collected from all the patients on the 1st, 7th, 14th and 21st day of admission, respectively. Flow cytometry was carried out to determine the percentage of CD4(+) T cells differentiated into Th1, Th2, Th17 and Treg subsets, based on which the ratios of Th1/Th2 and Th17/Treg were also calculated. Twenty-five healthy male individuals (aged 34 ± 7 years) in the hospital in the same period of time served as controls. The frequencies of all the four subsets in the traumatic patients showed significant dynamic changes compared with those of the controls at the defined time points. The ratios of Th1/Th2 and Th17/Treg showed significant decrease at the study interval. Notably, the value of Th1/Th2 was significantly higher (P=0.004) in the trauma group than that of control group on the 1st day after admission, which was reversed on the 14th day (P=0.014). The imbalance of Th1/Th2 and Th17/Treg at the present study all reflected the immune dysfunction of CD4 T cells followed by the severe thoracic trauma.