Septic patients and healthy controls
55 septic patients who met the clinical criteria for sepsis-3 [1] were recruited on admission to the Intensive Care Unit (ICU) of The Second Affiliated Hospital of Chongqing Medical University between October 2017 and March 2019. Clinical and demographic characteristics of patients were collected, including age, gender, co-morbidities, white blood cells (WBC), procalcitonin (PCT) and c-reaction protein (CRP), Acute Physiology and Chronic Health Evaluation (APCHE) II score and Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score at 24 h on admission. During the follow-up, other parameters were also recorded, such as microbiological findings, ventilation, use of vasopressors, use of hydrocortisone, renal replacement therapy, length of ICU stay, and mortality during the 28-day study period. Patients with pregnancy or breast-feeding, malignancy, organ transplantation, human immunodeficiency virus infection (HIV) infection, viral hepatitis, autoimmune diseases, and the use of immunosuppressive agents in the past 8 weeks were excluded. Peripheral blood was collected at the time of patient admission, and serum was then isolated and stored at −80 ℃. 30 age- and sex- matched healthy control blood samples were taken from healthy donors with no medical problems in the medical examination center. Human studies were reviewed and approved by the Clinical Research Ethics Committee of Chongqing Medical University (Registration number: LLZM-2012-0016), and informed consent was obtained from all participants according to the Declaration of Helsinki.