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.

Remodeling the tumor microenvironment through reprogramming tumor-associated macrophages (TAMs) and increasing the immunogenicity of tumors via immunogenic cell death (ICD) have been emerging as promising anticancer immunotherapy strategies. However, the heterogeneous distribution of TAMs in tumor tissues and the heterogeneity of the tumor cells make the immune activation challenging. To overcome these dilemmas, a hybrid bacterium with tumor targeting and penetration, TAM polarization, and photothermal conversion capabilities is developed for improving antitumor immunotherapy in vivo. The hybrid bacteria (B.b@QDs) are prepared by loading Ag₂S quantum dots (QDs) on the Bifidobacterium bifidum (B.b) through electrostatic interactions. The hybrid bacteria with hypoxia targeting ability can effectively accumulate and penetrate the tumor tissues, enabling the B.b to fully contact with the TAMs and mediate their polarization toward M1 phenotype to reverse the immunosuppressive tumor microenvironment. It also enables to overcome the intratumoral heterogeneity and obtain abundant tumor-associated antigens by coupling tumor penetration of the B.b with photothermal effect of the QDs, resulting in an enhanced immune effect. This strategy that combines B.b-triggered TAM polarization and QD-induced ICD achieved a remarkable inhibition of tumor growth in orthotopic breast cancer.