1.1.1 Specimens
120 experience group blood samples were from 48 COVID-19 patients (confirmed by positive nucleic acid test, including 2 dead patients, 17 asymptomatic infected patients) in Loudi Center for Disease Control and Prevention, time from onset to discharge of 3 of other 29 patients were unknown, of the other 26 patients were shown in Figure 1; 88 control group blood samples were from The First Hospital of Hunan University of Chinese medicine (53 patients with malignant tumor, blood system disease, rheumatic immune system disease and other diseases that increase the level of inflammatory factors, and 35 healthy people). 75 experience group blood samples were from males and 35 from females, the age distribution of COVID-19 patients we collected were shown in Figure 2. All the selected cases and their families had given their informed consent.
Instruments and reagents
IL-10, IL-1β, IL-6, MCP-1, TNF-α, IP-10 and IL-4 test kits and their standard were purchased from Human diagnostic products (Beijing) Co., Ltd., the minimal detectable concentrations for they were 0.0225, 0.0355, 0.0600, 0.0655, 0.0386, 0.0102 and 0.1800 pg/mL, count the result which lower than the minimal detectable concentrations as half of the minimal detectable concentrations; all reagents had both good repeatability (CV < 10%) and specificity. TECAN 200-8 were purchased from TECAN (Shanghai) trading company. SAS-CoV-2 antibody test kit (colloidal gold immunochromtographic assay, Guangzhou Wanfu Biotechnology Co., Ltd.) and SAS-CoV-2 IgM and IgG antibody test kit (chemiluminescent immunoassay, purchased from Shenzhen Yahuilong Biotechnology Co., Ltd.) were selected for serum antibody test.