ABSTRACT
To identify the risk factors of mortality for the coronavirus disease 19 (COVID-19) patients admitted to intensive care units (ICUs) through a retrospective analysis. The demographic, clinical, laboratory, and chest imaging data of patients admitted to the ICU of Huoshenshan Hospital from February 10 to April 10, 2020 were retrospectively analyzed. Student's t-test and Chi-square test were used to compare the continuous and categorical variables, respectively. The logistic regression model was employed to ascertain the risk factors of mortality. This retrospective study involved 123 patients, including 64 dead and 59 survivors. Among them, 57 people were tested for interleukin-6 (IL-6) (20 died and 37 survived). In all included patients, the oxygenation index (PaO2/FiO2) was identified as an independent risk factor (odd ratio [OR] = 0.96, 95% confidence interval [CI]: 0.928-0.994, p = 0.021). The area under the curve (AUC) was 0.895 (95% CI: 0.826-0.943, p < 0.0001). Among the patients tested for IL-6, the PaO2/FiO2 (OR = 0.955, 95%CI: 0.915-0.996, p = 0.032) and IL-6 (OR = 1.013, 95%CI: 1.001-1.025, p = 0.028) were identified as independent risk factors. The AUC was 0.9 (95% CI: 0.791-0.964, p < 0.0001) for IL-6 and 0.865 (95% CI: 0.748-0.941, p < 0.0001) for PaO2/FiO2. PaO2/FiO2 and IL-6 could potentially serve as independent risk factors for predicting death in COVID-19 patients requiring intensive care.
Subject(s)
COVID-19/mortality , Interleukin-6/analysis , Aged , Area Under Curve , COVID-19/pathology , COVID-19/virology , Comorbidity , Female , Humans , Intensive Care Units , Logistic Models , Male , Middle Aged , Oxygen Consumption , ROC Curve , Retrospective Studies , Risk Factors , SARS-CoV-2/isolation & purificationABSTRACT
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in December 2019 in Wuhan, China, and then rapidly spread causing an unprecedented pandemic. A robust serological assay is needed to evaluate vaccine candidates and better understand the epidemiology of coronavirus disease (COVID-19). Methods: We used the full-length spike (S) protein of SARS-CoV-2 for the development of qualitative and quantitative IgG and IgA anti-S enzyme linked immunosorbent assays (ELISA). A total of 320 sera used for assay development were comprised of pandemic sera from SARS-CoV-2 infected adults (n=51) and pre-pandemic sera (n=269) including sera from endemic human coronavirus infected adults. Reverse cumulative curves and diagnostic test statistics were evaluated to define the optimal serum dilution and OD cutoff value for IgG anti-S and IgA anti-S ELISAs. The IgG and IgA anti-S, and three functional antibodies (ACE-2 receptor blocking antibody, lentipseudovirus-S neutralizing antibody, and SARS-CoV-2 neutralizing antibody) were measured using additional SARS-CoV-2 PCR positive sera (n=76) and surveillance sera (n=25). Lastly, the IgG and IgA anti-S levels were compared in different demographic groups. Results: The optimal serum dilution for the qualitative IgG anti-S ELISA was at 1:1024 yielding a 99.6% specificity, 92.2% sensitivity, 92.9% positive predictive value (PPV), and 99.6% negative predictive value (NPV) at a SARS-CoV-2 seroprevalence of 5%. The optimal serum dilution for the qualitative IgA anti-S ELISA was at 1:128 yielding a 98.9% specificity, 76.5% sensitivity, 78.3% PPV, and 98.8% NPV at the same seroprevalence. Significant correlations were demonstrated between the IgG and IgA (r=0.833 for concentrations, r=0.840 for titers) as well as between IgG and three functional antibodies (r=0.811-0.924 for concentrations, r=0.795-0.917 for titers). The IgG and IgA anti-S levels were significantly higher in males than females (p<0.05), and in adults with moderate/severe symptoms than in adults with mild/moderate symptoms (p<0.001). Conclusion: We developed a highly specific and sensitive IgG anti-S ELISA assay to SARS-CoV-2 using full length S protein. The IgG anti-S antibody level was strongly associated with IgA and functional antibody levels in adults with SARS-CoV-2 infection. Gender and disease severity, rather than age, play an important role in antibody levels.
Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Immunoglobulin A/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Adult , COVID-19/diagnosis , COVID-19 Serological Testing , Female , HEK293 Cells , HumansABSTRACT
BACKGROUND: Two months after the outbreak of coronavirus disease 2019 (COVID-19) in Wuhan, China, tens of thousands of hospitalized patients had recovered, and little is known about the follow-up of the recovered patients. METHODS: The clinical characteristics, reverse transcriptase-polymerase chain reaction (RT-PCR) results from throat swab specimens and the results of serological COVID-19 rapid diagnostic test (RDT) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were retrospectively reviewed for a total of 758 recovered patients who were previously hospitalized in 17 hospitals and quarantined at 32 rehabilitation stations in Wuhan, China. RESULTS: In total, 59 patients (7.78%) had recurrent positive findings for COVID-19 on RT-PCR from throat swabs. With regard to antibody detection, 50/59 (84.75%) and 4/59 (6.78%) patients had positive IgG or dual positive IgG/IgM RDT results, respectively. CONCLUSIONS: Some patients who had been quarantined and had subsequently recovered from COVID-19 had recurrent positive RT-PCR results for SARS-CoV-2, and the possibility of transmission of the virus by recovered patients needs further investigation. TRIAL REGISTRATION: Current Controlled Trials ChiCTR2000033580 , Jun 6th 2020. Retrospectively registered.