Analysis Of Clinical,imaging And Serum Antibody Characteristics In Patients With Mild To Moderate COVID-19

Chapterl Clinical characteristics and risk factors of mild-to-moderate COVID-19 patients with false negative SARS-CoV-2 nucleic acidObjective:This study investigates the clinical and imaging characteristics of coronavirus Disease 2019(COVID-19)patients with false negative nucleic acids.Methods:Mild-to-moderate COVID-19 patients,including 19 cases of nucleic acid false negative patients and 31 cases of nucleic acid positive patients,were enrolled.Their epidemiological,clinical,and laboratory examination data,and imaging characteristics were analyzed.Risk factors for false negatives were discussed.Results:Compared with the nucleic acid positive group,the false negative group had less epidemiological exposure(52.6%vs 83.9%,P=0.025),less chest discomfort(5.3%vs 32.3%,P=0.035),and faster recovery(10(8,13)vs 15(11.18.5)days,P=0.005).The number of involved lung lobes was(2(1,2.5)vs 3(2,4),P=0.004),and the lung damage severity score was(3(2.5,4.5)vs 5(4,9),P=0.007),which was lighter in nucleic acid false negative group.Thus,absence of epidemiological exposure may be potential risk factors for false negative nucleic acids.Conclusions:The false negative cases of COVID-19 are worth noting because they have a risk of viral transmission without positive test results,lighter clinical manifestations,and less history of epidemiological exposure.Chapter2 Correlation of the rising rate of antibody levels(IgM/T and IgG/T)with disease severity and outcome in mild-to-moderate COVID-19 patientsObjective:Our study used the rising rate of antibody levels(the ratio of serum antibody concentration to days after symptom onset,IgM/T and IgG/T)to reflect the patient’s humoral immune status,and analyzed their correlation with COVID-19 disease severity and outcome.Methods:Clinical data of 50mild-to-moderate COVID-19 patients were retrospectively analyzed.Time-resolved fluorescence immunochromatography was used to quantitatively detect SARS-CoV-2 IgM and IgG.Correlation analysis was performed.Results:IgM antibody was positive on day 5 of symptom onset,increased within 2 weeks,and then gradually decreased.However,IgG antibody was positive on week 2 of symptom onset and continued to increase since.Additionally,IgM/T,but not IgG/T of recovery period(Spearman p=0.17;P=0.283),was negatively correlated with disease course in 2 weeks of symptom onset(Spearman p=-0.860;P=0.000).IgG/T of recovery period was positively correlated with clinical classification(Spearman p=0.432;P=0.004),number of involved lung lobes(Spearman p=0.343;P=0.026),and lung lesions(Spearman p=0.472;P=0.002).Conclusions:Within 2 weeks of symptom onset,higher IgM/T indicates faster recovery and shorter disease course.In recovery period,higher IgG/T suggests more serious disease.IgM/T or IgG/T may predict disease severity and outcome in mild-to-moderate COVID-19 patients.Chapter3 Clinical and CT features of mild-to-moderate COVID-19 after two sequential negative nucleic acid amplification testsObjective:To describe the clinical and pulmonary CT characteristics of mild-to-moderate COVID-19 patients whose nucleic acid turns negative for two consecutive times,and to explore the value of continued isolation and treatment after nucleic acid negative.Methods:Fifty one patients with Mild-to-moderate COVID-19 cases whose nucleic acid turns negative for two consecutive times were enrolled.Based on the disease severity,patients were divided into two groups,one is mild COVID-19(20 cases),another is moderate COVID-19(31 cases).Demographic,clinical,laboratory and radiological data were collected retrospectively.Results:After the SARS-CoV-2 nucleic acid turned negative,compared with first symptoms after diagnosis,the symptoms such as fever and cough were improved,and the laboratory results were generally normal.However,55.2%(16/29)of the 29 patients with moderate COVID-19 had two or more lobes involved.The most common CT imaging manifestations of lung were ground glass opacity and fibrous stripes((both 51.7%,15/29 cases).After 2 weeks of isolation treatment,the clinical and laboratory examination showed slight improvement,but lung CT improved significantly.Among them,68.2%(15/22)of lung lesions continued to absorb,63.6%(14/22)absorbed more than 50%,36.4%(8/22)absorbed more than 80%.Conclusions:After the nucleic acid turned negative for two consecutive times,the lung imaging improved significantly,which may mean that there is still a risk of virus transmission during this period.Further isolation and treatment are of great significance to the prevention and control of epidemic situation even after negative for respiratory nuclear acid test.