Journal: Research Square

Article Title: Immune responses in COVID-19 respiratory tract and blood reveal mechanisms of disease severity

doi: 10.21203/rs.3.rs-802084/v1

Figure Lengend Snippet: Higher anti-RBD IgM seroconversion rate in respiratory samples compared to paired blood samples of COVID-19 patients. a ELISA titration curves against the SARS-CoV-2 receptor-binding domain (RBD) for IgM, IgG, and IgA in COVID-19 respiratory and paired blood samples and non-COVID-19 respiratory samples. Dotted lines within each graph indicates the cut-off used to determine end-point titres. b Endpoint titres of SARS-CoV-2 RBD antibodies between (i) respiratory samples of COVID-19 and non-COVID-19 patients, and (ii) plasma and respiratory samples of COVID-19 patients. (i) Bars indicate median with interquartile range. Dotted line indicates the detection level. (ii) Dotted lines connect the most closely matched plasma and respiratory samples from each patient. Statistical significance was determined with Mann-Whitney test. c ELISA titration curves against the SARS-CoV-2 RBD for 3 COVID-19 patients with serial respiratory samples. d Heatmap of percentage (%) inhibition tested by surrogate virus neutralization test (sVNT) and anti-RBD ELISA titres. e Correlation between anti-RBD antibody titres and (%) sVNT inhibition. Correlation was determined with Spearman’s correlation. f Number of (i) samples and (ii) patients with seroconverted anti-RBD IgM, IgG, IgA and positive % sVNT inhibition. Pink curved lines surrounding the donut graphs indicate the samples/patients with seroconverted IgM. Earliest samples were used for each patient when determining seroconversion which was defined as average titre +2xSD of non-COVID-19 samples. Positive % sVNT inhibition was defined as % sVNT inhibition ≥ 20%.

Article Snippet: Correlations were assessed using Spearman’s correlation coefficient ( r s) and visualized in R 3.6.2 as heatmaps using the corrplot package or using the online Morpheus heatmap software ( https://software.broadinstitute.org/morpheus ; the Broad Institute, MA, USA) and p-values of correlations were corrected for multiple comparisons by FDR in R 3.6.2.

Techniques: Enzyme-linked Immunosorbent Assay, Titration, Binding Assay, Clinical Proteomics, MANN-WHITNEY, Inhibition, Virus, Neutralization

Journal: Nature Communications

Article Title: SARS-CoV-2 infection results in immune responses in the respiratory tract and peripheral blood that suggest mechanisms of disease severity

doi: 10.1038/s41467-022-30088-y

Figure Lengend Snippet: a ELISA titration curves against the SARS-CoV-2 receptor-binding domain (RBD) for IgM, IgG, and IgA in COVID-19 respiratory and paired plasma samples and non-COVID-19 respiratory samples as negative controls. Dotted lines within each graph indicates the cut-off used to determine end-point titres. b End-point titres of SARS-CoV-2 RBD antibodies between top left panel: respiratory samples of COVID-19 and non-COVID-19 patients, top right panel: respiratory and paired plasma samples of COVID-19 patients, and bottom panel: endotracheal tube aspirate (ETA), sputum, or bronchoalveolar lavage (BAL) and paired plasma samples of COVID-19 patients. Top left panel: Bars indicate median with interquartile range. Dotted line indicates the detection level. n ETA = 15, n Sputum = 20, n BAL = 6, n Non-COVID-19 ETA = 5, n Non-COVID-19 sputum = 1. Top right panel: Dotted lines connect the most closely matched plasma and respiratory samples from each patient. Bottom panel: Bars indicate the median. Statistical significance was determined with a two-sided Mann-Whitney test. n ETA = 15, n ETA matched plasma = 14, n Sputum = 20, n Sputum matched plasma = 19, n BAL = 6, n BAL matched plasma = 3. c Heatmap of percentage (%) inhibition tested by surrogate virus neutralization test (sVNT), anti-RBD ELISA titres and days post disease onset. d Correlation between anti-RBD antibody titres and (%) sVNT inhibition. Correlation was determined with a two-tailed Spearman’s correlation. e Number of samples and patients with seroconverted anti-RBD IgM, IgG, IgA and positive % sVNT inhibition. Red curved lines surrounding the donut graphs indicate the samples/patients with seroconverted IgM and IgG. Earliest samples were used for each patient when determining seroconversion which was defined as average titre + 2×SD of non-COVID-19 respiratory samples. Positive % sVNT inhibition was defined as % sVNT inhibition ≥ 20%. f Correlation of anti-RBD ELISA titres and % sVNT inhibition between respiratory samples (ETA, sputum, and BAL) and paired plasma samples collected at the closest timepoint for each patient. Correlation was determined with a two-tailed Spearman’s correlation. n ETA = 15, n ETA matched plasma = 14, n Sputum = 20, n Sputum matched plasma = 19, n BAL = 6, n BAL matched plasma = 3. Source data are provided as a Source Data file.

Article Snippet: Correlations were assessed using two-tailed Spearman’s correlation coefficient ( r s ) and visualized in R v3.6.2 as heatmaps using the corrplot package or using the online Morpheus heatmap software ( https://software.broadinstitute.org/morpheus ; the Broad Institute, MA, USA) and p-values of correlations were corrected for multiple comparisons by FDR in R v3.6.2.

Techniques: Enzyme-linked Immunosorbent Assay, Titration, Binding Assay, Clinical Proteomics, MANN-WHITNEY, Inhibition, Virus, Neutralization, Two Tailed Test