Analysis of CD180 expression in diffuse cutaneous systemic sclerosis (dcSSc) B cells. (A) Representative flow cytometry plots of peripheral blood leukocytes (a), B and T cells (b), and CD19+ B cells stained with CD27 and IgD defining the following four subsets: CD27+IgD+ non-switched memory (NS) B cells, CD27+IgD− switched memory (S) B cells, CD27−IgD+ naive B cells, and CD27−IgD− double negative (DN) B cells (c). (B) Flow cytometric analysis of CD180 expression in peripheral blood B cells, T cells, and monocytes of early untreated dcSSc patients compared to healthy controls (HCs). (C) CD180 mRNA expression in B cells of early untreated dcSSc patients compared to HCs. Gene expression was normalized to HCs and the horizontal line (value 1) represents the expression of control samples. Changes in gene expression are shown as relative quantification (RQ) values. Data are shown as mean ± standard error of the mean (SEM), n = 4 HC and n = 4 dcSSc, * p < 0.05.