Disease progression patterns and risk factors associated with mortality in deceased patients with COVID‐19 in Hubei Province, China

Background: Detailed descriptions of the patterns of disease progression of deceased coronavirus disease 2019 (COVID-19) patients have not been well explored. Objectives: This study sought to explore disease progression patterns and risk factors associated with mortality of deceased patients with COVID-19. Materials and Methods: Epidemiological, clinical, laboratory, and imaging data (from 15 January to 26 March 2020) of laboratory-confirmed COVID-19 patients were collected retrospectively from two hospitals, Hubei province, China. Disease progression patterns of patients were analyzed based on laboratory data, radiological findings, and Sequential Organ Failure Assessment (SOFA) score. Risk factors associated with death were analyzed. Results: A total of 792 patients were enrolled in this study, of whom 68 died and 724 survived. Complications during hospitalization, such as sepsis, severe acute respiratory distress syndrome, acute cardiac injury, and acute kidney injury, were markedly more frequent in deceased patients than in surviving patients. Deceased patients presented progressive deterioration pattern in laboratory variables, chest computed tomography evaluation, and SOFA score, while surviving patients presented initial deterioration to peak level involvement followed by improvement pattern over time. Days 10 to 14 after illness onset was a critical stage of disease course. Older age, number of preexisting comorbidities ≥2, and SOFA score were independently associated with death for COVID-19. Conclusions: Multiorgan dysfunction was common in deceased COVID-19 patients. Deceased patients presented progressive deterioration pattern, while surviving patients presented a relatively stable pattern during disease progression. Older age, number of preexisting comorbidities ≥2, and SOFA score were independent risk factors for death for COVID-19

Hypersensitive Detection and Quantitation of BoNT/A by IgY Antibody against Substrate Linear-Peptide

<div><p>Botulinum neurotoxin A (BoNT/A), the most acutely poisonous substance to humans known, cleave its SNAP-25 substrate with high specificity. Based on the endopeptidase activity, different methods have been developed to detect BoNT/A, but most lack ideal reproducibility or sensitivity, or suffer from long-term or unwanted interferences. In this study, we developed a simple method to detect and quantitate trace amounts of botulinum neurotoxin A using the IgY antibody against a linear-peptide substrate. The effects of reaction buffer, time, and temperature were analyzed and optimized. When the optimized assay was used to detect BoNT/A, the limit of detection of the assay was 0.01 mouse LD₅₀ (0.04 pg), and the limit of quantitation was 0.12 mouse LD₅₀/ml (0.48 pg). The findings also showed favorable specificity of detecting BoNT/A. When used to detect BoNT/A in milk or human serum, the proposed assay exhibited good quantitative accuracy (88% < recovery < 111%; inter- and intra-assay CVs < 18%). This method of detection took less than 3 h to complete, indicating that it can be a valuable method of detecting BoNT/A in food or clinical diagnosis.</p> </div

Effects of buffer in the ALc endopeptidase assay.

<p>A) The concentration–response relations between OD₄₅₀ and ALc with different buffer combinations. B buffer: 0.02 M Na₃PO₄, 0.5 M NaCl, 0.4 M imidazole, pH 7.4; PBS buffer: 0.008 M NaH₂PO₄, 0.002 M Na₂HPO₄, 0.145 M NaCl, pH 7.2; PB buffer: 0.008 M d NaH₂PO₄, 0.002 M Na₂HPO₄, pH 7.2. B) Sensitivity of endopeptidase assay in different buffer combinations.</p

Detection of BoNT/A with different concentration by anti-subA IgY.

<p>Detection of BoNT/A with different concentration by anti-subA IgY.</p

Effects of temperature and time in the ALc endopeptidase assay.

<p>A) Concentration–response relations between OD₄₅₀ and ALc with different reaction temperatures and time combinations. B) Sensitivity of the endopeptidase assay at different temperature and time combinations.</p

SDS-PAGE results of purified SNAP25 and ALc, as well as cleaved SNAP25 by BoNT/A and ALc.

<p>A) SDS-PAGE result of purified SNAP25. M: marker; 1: purified SNAP25. B) SDS-PAGE result of purified ALc. M: marker; 1: purified ALc. C) SDS-PAGE result of purified SNAP25 mixed with ALc. M: marker; 1: 10 µl of SNAP25; 2: 10 µl of SNAP25 + 5 µl of ALc; 3: 10 µl of SNAP25 + 10 µl of ALc; 4: 10 µl of SNAP25 + 15 µl of ALc; 5: 10 µl of SNAP25 + 20 µl of ALc.</p