AN INQUIRY INTO THE VALUE OF PCT, IL-10, AND CD8+ T CELLS IN JUDGING THE BAD PROGNOSIS AND DEATH RISK OF CRITICALLY ILL PATIENTS IN THE ICU

Lina Gao, Yubin Wang, Qiong Wu, Yunyan Pan^*

Department of Clinical Laboratory Medicine Center, Lanzhou University Second Hospital, Lanzhou 730030, PR China

Objective: This article explores the value of PCT, IL-10, and CD8⁺ T cells in judging the poor prognosis and death risk of critically ill patients in the ICU.

Methods: From October 2016 to February 2018, 128 critically ill patients admitted to our hospital’s ICU were divided into a survival group (83 cases) and a death group (45 cases), according to the 28-day mortality rate. Both groups of patients had fasting peripheral venous blood drawn on the 2nd, 5th, and 8th days of admission. A quantitative luminescence immunoassay was detected by the concentration of procalcitonin (PCT). The levels of interleukin 6, 8, 10 (IL-6, IL-8, IL-10), and the tumor necrosis factor-alpha (TNF-α) were detected by an enzyme-linked immunosorbent assay (ELISA). The levels of CD4⁺ and CD8⁺ T cells were detected by flow cytometry, and the ratio of CD4⁺ T/CD8⁺ T was detected. The receiver operating characteristic curve (ROC) was evaluated using the predictive ability of the relevant indicators for the critically ill patients’ prognoses.

Results: On the 8th day of admission, the PCT level of the patients in the survival group was significantly lower than that of the patients in the death group (P<0.05). The PCT indicators measured at other time points were not statistically different between the 2 groups (P>0.05). The levels of IL-6 and IL-8 in the survival group were significantly higher than that of the death group on the 8th day of admission, and the levels of IL-10 were significantly lower than that of the death group on the 5th day of admission. The difference was statistically significant (P<0.05). The levels of IL-6, IL-8, IL-10, and TNF-α were not statistically different (P>0.05). The level of CD8⁺ T cells in the survival group was lower than that of the death group on the 2nd day of admission (P<0.05). The CD4⁺ T level and CD4+ T/CD8+ T ratio of the survival group were higher than that of the death group on the 8th day of admission, and the difference was statistically significant (P<0.05). At other time points, there was no statistical difference between the levels of CD4⁺ and CD8⁺ T and the ratio of CD4⁺ T/CD8⁺ T between the 2 groups (P>0.05). PCT, IL-10, and CD8⁺ T cells predicted for the area under the curve (AUC) of patients admitted to the hospital at 28 days were 0.92, 0.78, and 0.80, respectively, which can be used as indicators to evaluate the prognoses of critically ill patients.

Conclusion: The prognoses of critically ill patients in the ICU will become worse with the suppression of their immune function. PCT, IL-10, and CD8⁺ T can be used to judge the prognosis and death risk of patients. The dynamic monitoring of changes in immune-related indicators can help predict the progress of the disease.