Fig. 7: ACPA⁺SE⁺ RA patient CD4⁺ T cells specific for citrullination-dependent epitopes tend to be activated effector memory cells.

a MHC class II tetramers containing three created fibrinogen peptides derived from NAPA (Fig. 5a) were used to stain PBMCs from ACPA⁺SE⁺ RA patients (n = 18), ACPA^–SE⁺RA patients (n = 10), and SE⁺ healthy controls (n = 10). The percentage of fibrinogen tetramer–positive (FibTet⁺) CD4⁺ T cells are shown for each patient group, and the dotted line denotes the positivity threshold of 0.5547%. Data are presented as mean ± SD, and P values were calculated by ordinary one-way ANOVA with Tukey’s multiple comparisons test. Only significant P values (≤0.05) are shown. b The percentage of individuals that bound any FibTet is shown for each group. Two-sided χ² tests were used to compare the frequency of T-cell responses between patient groups. Only significant P values (≤0.05) are shown. c, d Distribution of effector phenotypes (c) and regulatory T cells (d) for ACPA⁺SE⁺ RA patient and SE⁺ healthy control fibrinogen tetramer–positive T cells. Phenotypes denoted in key.