Clinical Epidemiology,Illness Profiles,and the Implication of COVID-19 Before and After the Nationwide Omicron Outbreak During the Winter of 2022

China.In this study,we aimed to investigate the clinical characteristics and outcomes of patients with coronavirus disease 2019(COVID-19)in the Beijing region.Methods:In this retrospective study,we enrolled inpatients admitted for COVID-19 in the Fifth Medical Center of Chinese PLA General Hospital in Beijing between November 10,2022,and January 30,2023.Demographic and clinical features and treatment outcomeswere comprehensively analyzed.We used logistic regression and linear regression analyses to explore the risk factors associated with disease severity and time of nucleic acid conversion,respectively.Results:A total of 1010 hospitalized patients with COVID-19 were enrolled.The median age was 43.0 years(interquartile range,28.0–63.0),and patients aged<60 years and≥60 years comprised 71.2%and 28.8%of total included patients,respectively.The clinical classification of mild(74.6%,753/1010),moderate(21.0%,212/1010),severe(2.7%,27/1010),and unidentified(1.8%,18/1010)was separately recorded;1005 patients were discharged,and 5 patients died in the hospital.The outbreak of the emerging epidemic witnessed an evident increase in the proportion of moderate(42.9%vs.16.4%)and severe(10.3%vs.1.1%)cases after December 7,2022.Patients with a moderate/severe classification had higher levels of procalcitonin,IL-6,serum ferritin,C-reactive protein,lactic dehydrogenase,serum urea nitrogen,and D-dimer and lower counts of CD4+T,CD8+T,and B cells(all P<0.001).Multivariable regression analysis revealed that increased odds of disease severity were associated with the following factors:age≥60 years,IL-6>7 pg/mL,lactic dehydrogenase level>245 U/L,cough,and fever at admission.Age≥80 years and chronic lung diseasewere independent risk factors in the nonmild group in elderly patients.In addition,the duration for nucleic acid to turn negativewas approximately 5.0 d(interquartile range,3.0–7.0).Prolonged time of nucleic acid conversion was associated with age≥60 years,serum urea nitrogen level>8.2 mmol/L,neutrophil count>7×10^(9)/L,and the presence of a chronic lung disease or carcinoma.Finally,unvaccinated patients accounted for 37.3%of enrolled patients;children and the elder people accounted for approximately half of that.The univariable analysis found that booster doses reduced disease severity and shortened the time of nucleic acid conversion in elderly patients.Conclusions:The outbreak ofOmicron rapidly increased the number of patientswith COVID-19 in Beijing.In elderly patients,booster doses may reduce disease severity and shorten the time of nucleic acid conversion.Healthcare systems should be optimized before an emerging epidemic outbreak.

High levels of circulating GM-CSF^(+) CD4^(+) T cells are predictive of poor outcomes in sepsis patients: a prospective cohort study

Granulocyte colony-stimulating factor(GM-CSF),produced by CD4^(+)T cells,has recently been implicated in the pathogenesis of inflammatory diseases,such as multiple sclerosis and juvenile arthritis.However,the role of GM-CSF-producing CD4^(+)T cells in sepsis remains unknown.This study reports peripheral changes in GM-CSF-producing CD4^(+)T cells in septic patients and the possible underlying mechanism by which GM-CSF influences the outcome of sepsis.Forty-three septic patients,20 SIRS patients,and 20 healthy controls were enrolled in this study and followed for 28 days to assess mortality.We measured the peripheral frequency of GM-CSF^(+)CD4^(+)T cells and recorded their associated relationship with disease progression.Our data demonstrated that peripheral GM-CSF-producing CD4^(+)T cells were significantly higher in septic patients than in both SIRS patients and healthy controls.These cells exhibit a memory phenotype and impaired IFN-γ-secreting capacity in sepsis patients.Using a receiver operating curve analysis with 8.01%as a cut-off point,the percentage of GM-CSF^(+)CD4^(+)T cells could predict the outcome of septic patients.Combined with the increase in GM-CSF-producing CD4^(+)T cells,inflammatory cytokines IL-1βand IL-6 were also upregulated.Using an in vitro neutrophil model,we found that GM-CSF inhibited C3aR expression,while inducing IL-8 production.Furthermore,this effect was transferrable in plasma from sepsis patients and was attenuated by inhibition of GM-CSF using an anti-GM-CSF antibody.These results indicate that GM-CSF-producing CD4^(+)T cells may serve as a marker of sepsis severity.Thus,targeting GM-CSF overproduction may benefit sepsis patients.