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