Fig. 3

N-glycan profiling of whole serum proteins revealed changes in glycosylation state during COVID-19 infection. Box plot display relative signal intensities of whole-serum derived N-glycans of moderate COVID-19 patients, severe-COVID-19 patients, and healthy controls (n = 10, each). Assigned N-glycans are depicted as pictograms with purple diamond: sialic acid; yellow circle: galactose; blue square: N-acetylglucosamine; green circle: mannose, red triangle: fucose; blue circle: glucose. Symbolic representation of pictograms follows the guidelines of Symbol Nomenclature for Glycans (SNFG) [29]. Student’s t-test two-sided: one star (*) indicate a p-value < 0.05, two stars (**) indicate a p-value < 0.01, and three stars (***) indicate a p-value < 0.001 based on less significant differences when comparing control and each COVID-19 group