Figure 1.

Frequency of CXCR5⁺CD4⁺ and forkhead box protein 3 (FoxP3)⁺CD4⁺ T cell subsets in peripheral blood mononuclear cells (PBMCs) from patients with Sjögren’s syndrome and healthy donors. (a) Gating strategy to identify Tfh (CXCR5⁺) CD4⁺ T cells (upper panel). (b) Gating strategy to identify CD25⁺FoxP3⁺CD4⁺ T cells (upper panel) regulatory CD4⁺ T cell subsets: Fraction I (CD45RA⁺FOXP3^low), Fraction II (CD45RA⁺CD25^high) and Fraction III (CD45RA^–Fox3^low) (lower panel), quantified in PBMC samples from patients with SS (n = 12) and healthy donors (HD) (n = 12) matched by age and sex. (b) Black dots indicate healthy donor (HD) samples and white dots indicate Sjögren’s syndrome (SS) samples; the line indicates the median. Gating strategy included lymphocyte gating (based on forward‐ and side‐scatter) followed by doublets, CD14⁺ and dead cell exclusion. CD4⁺ T cells were then selected. Mann–Whitney U‐test, P‐values less than 0·05 were considered statistically significant.