Objective To analyze the predictive value of serum levels of procalcitonin(PCT)and cytokines on the prognosis of patients with COVID-19 at admission.Methods From November 2022 to February 2023,patients diagnosed with COVID-19 who were admitted to Beijing Chest Hospital were enrolled.Chemiluminescence was used to detect serum PCT levels,and flow microsphere array was used to detect serum cytokines IL-1β,IL-2,IL-4,IL-5,IL-6,IL-8,IL-10,IL-12p70,IL-17A,IL-17F,IL-22,TNF-α,TNF-β,IFN-γ level.ICU admission,mechanical ventilation and in-hospital death were defined as poor prognosis.After excluding patients with bacterial infection,the relationship between serum PCT and cytokine levels at admission and the prognosis of COVID-19 patients was analyzed.After excluding patients with bacterial infection,the relationship between serum PCT and cytokine levels at admission and the prognosis of COVID-19 patients was analyzed.Results A total of 176 patients with complete data were included,including 134 in the PCT-normal group and 42 in the PCT-elevated group,with a median age of 71.50 years and 71.59%males.Patients in the PCT elevated-group had significantly higher rates of ICU admission(38.41%vs.13.11%,P<0.05),mechanical ventilation(76.92%vs.24.59%,P<0.001)and in-hospital mortality(38.46%vs.6.56%,P<0.001)were significantly higher than those in the PCT-normal group.Serum levels of cytokines IL-6(7.40 pg/mL vs.4.78 pg/mL,P = 0.033 4)and IL-8(10.97 pg/mL vs.5.92 pg/mL,P<0.001)were significantly higher in patients with poor prognosis than in those with good prognosis.The area under the curve for PCT,IL-6,and IL-8 to predict poor prognosis in COVID-19 patients was 0.687,0.660,and 0.746,respectively;sensitivity was 52.78%,55.17%,and 72.41%,respectively;and specificity was 81.58%,74.19%,and 74.19%,respectively,as calculated from the ROC curve.When PCT,IL-6 and IL-8 jointly predict the prognosis of COVID-19 patients,the area under the curve is 0.764,the sensitivity is 70.00%,and the specificity is 80.00%.Conclusion Serum PCT and cytokines IL-6 and IL-8 could be used as predictive markers for poor prognosis in patients with COVID-19.

Background Nitrogen dioxide (NO₂) is one of the main air pollutants, and though China's NO₂ pollution has been improving year by year, it maintains at a high level, threatening the health of the population. Objective To investigate the effect of short-term exposure to atmospheric NO₂ on the coagulation indexes in obese and normal-weight young individuals and potential modification effect of temperature. Methods Based on a parallel control panel study design, this study recruited 53 normal-weight and 44 obese young individuals. Three prospective follow-ups were conducted. Air pollution data were obtained from the fixed monitoring station closest to the participant's residences, and personal air pollution exposure was simulated based on time-activity log and infiltration factor for the week before every follow-up. Temperature was collected from China Meteorological Data Service Center. Venous blood samples were taken to measure platelet (PLT) count, mean platelet volume (MPV), soluble CD40 ligand (sCD40L), soluble P-selectin (sP-selectin), platelet aggregation rate (PAgT), and plasminogen activator inhibitor type-1 (PAI-1) during every follow-up. A linear mixed-effect model was used to assess the association between short-term atmospheric NO₂ exposure and the coagulation indexes of weight grouped young individuals, and a stratified analysis was used to explore potential modification effect of temperature. Results The median [interquartile range (IQR)] of personal atmospheric NO₂ exposure concentrations was 21.47 (8.01) µg·m⁻³. Short-term exposure to atmospheric NO₂ was significantly associated the increase of sCD40L and PAgT in the obese individuals, while the most significant association appeared at 5 d lag, and for each IQR increase in the average sliding exposure concentration of atmospheric NO₂ with a 5 d lag, sCD40L increased by 27.4% (95%CI: 4.2%, 56.6%) and PAgT increased by 37.5% (95%CI: 12.2%, 68.6%); short-term exposure to atmospheric NO₂ was significantly associated with the decrease of PLT and PAgT in the normal-weight individuals, while the most significant association appeared at 5 d lag or 7 d lag, and for each IQR increase in the average sliding exposure concentration of atmospheric NO₂ with a 5 d lag, PLT decreased by 11.8% (95%CI: −17.8%, −5.3%), and for each IQR increase in the average sliding exposure concentration of atmospheric NO₂ with a 7 d lag, PAgT decreased by 16.8% (95%CI: −30.6%, −0.4%). We didn't find statistically significant association of short-term exposure to atmospheric NO₂ with PLT in the obese individuals or sCD40L in the normal-weight individuals, nor statistically significant association between short-term exposure to atmospheric NO₂ and PAI-1, MPV, and sP-selectin in different weight grouped individuals. The stratified analysis found that short-term exposure to atmospheric NO₂ was significantly associated with PAgT in the normal-weight individuals, or with PLT, sCD40L, and sP-selectin in the obese individuals only at high temperature. Conclusions Short-term exposure to atmospheric NO₂ has adverse effects on the coagulation indexes of different weight grouped young individuals, and the obese individuals are more sensitive to it than the normal-weight individuals. High temperature can enhance the adverse health effect of short-term exposure to atmospheric NO₂.