Journal: Frontiers in Immunology
Article Title: Antibodies to a Citrullinated Porphyromonas gingivalis Epitope Are Increased in Early Rheumatoid Arthritis, and Can Be Produced by Gingival Tissue B Cells: Implications for a Bacterial Origin in RA Etiology
doi: 10.3389/fimmu.2022.804822
Figure Lengend Snippet: The anti-CPP3 antibody response in relation to the autoimmune ACPA response. (A) Anti-CPP3 (top panel) and anti-RPP3 (bottom panel) IgG levels in EIRA RA patients (n=2,859) and controls (n=372), measured by multiplex microarray; 98 th percentile cut-off (red line), and 80 th percentile cut-off (blue line) are shown; p-values indicate differences in CPP3/RPP3 IgG levels between groups. (B) Pie chart illustrating the frequency (%) of CPP3+ RA patients (98 th percentile cut-off) in relation to CCP2 status (n=2,859) (top panel), and co-occurrence of anti-CPP3 IgG (98 th percentile cut-off) in relation to eight autoimmune ACPA fine-specificities (measured by multiplex microarray) in EIRA RA patients (n=2,859) (bottom panel); correlation between antibody expression vectors (corrplot package v. 0.77) was used to illustrate co-occurrence, colours signify degree of correlation according to Pearson correlation coefficient (full scale shown on the right). (C) CPP3/RPP3 reactivity in a pool of affinity-purified anti-CCP2 IgG (top panel) and corresponding anti-CCP2 IgG-depleted IgG pool (bottom panel), at different IgG concentrations. AU, arbitrary units; CPP3, citrullinated P. PAD peptide; RPP3, arginine-containing version of CPP3; RA, rheumatoid arthritis; CCP2, cyclic citrullinated peptide(s); OD, optical density; cfc1-cyc, cyclic citrullinated filaggrin peptide 1; Cit-Vim, citrullinated vimentin; Cit-Fib, citrullinated fibrinogen; CEP-1, citrullinated α-enolase peptide 1; Cit-C1, citrullinated triple helical C1 epitope on collagen type II.
Article Snippet: Sera from 2,859 RA patients and 372 controls were screened on a custom-made multiplex microarray (ThermoFisher Scientific, ImmunoDiagnostics Division, Uppsala, Sweden) for IgG reactivity against citrullinated peptides derived from Pg PAD (CPP3) and human proteins , as previously described ( , ).
Techniques: Multiplex Assay, Microarray, Expressing, Affinity Purification