Fig. 4: ACPA IgG1 harbor high levels and variable numbers of Fab glycans, with an expansion of molecules harboring two or more Fab glycans.

a Exemplary ACPA IgG1 Fab profile, indicating the distribution of ACPA IgG1 Fab molecules across mass ranges of non-modified and mass ranges of glycosylated Fab molecules. Glycovariants detected for an exemplary high abundant ACPA IgG1 Fab molecule are indicated in the zoom. Differences of individual N-acetylglucosamines, galactoses or sialic acids are indicated as horizontal blue, yellow and purple lines, respectively. Glycovariants belonging to the ten most abundant Fab molecules are indicated by an asterisk. b,c Relative abundance of (b) glycosylated Fab molecules and (c) Fab molecules harboring zero, one, or two or more glycans among total plasma and ACPA IgG1 repertoires. Each dot represents an individual RA patient. The median and range of all RA patients studied (n = 8) is indicated. P values calculated by two-tailed Wilcoxon matched-pairs rank test (c) and two-tailed Wilcoxon matched-pairs rank test corrected for multiple testing using the Bonferroni-Dunn method (d) are displayed. d Relative abundance of total plasma and ACPA IgG1 Fab molecules with zero, one, or two or more glycans. Relative abundances were determined based on the summed concentrations of all Fab molecules detected within the respective mass range and are indicated per RA patient. Mass ranges and relative abundances of Fab molecules with zero, one, or two or more glycans are highlighted by white, blue and green backgrounds, respectively.