Figure 2.

Clinical association of DP-Tfh cells in IgG4-RD lesions. (A) Scatter plots showing relationships between various clinical parameters associated with the IgG4-RD disease state and the ratios of DP-Tfh cells (CD3⁺CD4⁺CD8⁺CXCR5^hiPD-1^hi) to total GC-type Tfh cells (CD3⁺CD4⁺CXCR5^hiPD-1^hi) in SMG lesions of IgG4-RD (n = 22). (B) Flow cytometry profiles showing selected windows and gating strategies applied to identify B cells (CD3^-CD19⁺) and B-cell subsets (naïve B cells, CD3^-CD19⁺IgD⁺CD27^-; memory B cells, CD3^-CD19⁺IgD^-CD27⁺; GC B cells, CD3^-CD19⁺CD20⁺CD38⁺; regulatory B cells, CD3^-CD19⁺CD24^hiCD27⁺; plasmablasts, CD3^-CD19⁺CD24^-CD38⁺; plasma cells, CD3^-CD19⁺CD138⁺) in SMG lesions of IgG4-RD. (C) Scatter plots indicating the relationships between the ratios of various B-cell subsets and ratios of DP-Tfh cells to total GC-type Tfh cells in SMG lesions of IgG4-RD (n = 22) measured by flow cytometry. (D) Scatter plots indicating relationships between the ratios of various B-cell subsets and ratios of DP-Tfh cells to total GC-type Tfh cells in tonsils (n = 14) measured by flow cytometry. (E) Flow cytometry profiles showing selected windows and gating strategy for IgG4-expressing memory B cells of lymphocytes of tonsils and SMG lesions of IgG4-RD. (F) Naïve and memory B cells in SMG lesions of IgG4-RD (n = 14) and tonsils (n = 12) analyzed by flow cytometry. (G) High frequency of memory B cells expressing IgG4 (IgG4⁺ memory B cells) in SMG lesions of IgG4-RD analyzed by flow cytometry (IgG4-RD, n = 4; tonsil, n = 4). Data in (A, C, D) were analyzed by the Spearman’s rank correlation test, and data in (F, G) were studied by the Mann–Whitney U test.