Fig. 4

Tofacitinib treatment of PBMC from DM, ASyS and OM significantly reduces B cell proliferation, but mainly affects their differentiation and antibody production in a 6-day culture. (A) Histograms show the percentage of proliferation based on CFSE staining from a representative ASyS patient within CD19⁺CD20⁺ B cells. Graphs include analysis from all samples. (B) Percentage of CD27⁺CD38⁺ plasmablasts (of CD19⁺CD20⁺ B cells) and of CD138⁺ PC (of CD3^- cells). (C) Representative dot plots and analysis of the percentage of naive and memory populations (within CD19⁺CD20⁺ B cells): switched memory (SWM) (CD27⁺IgD^-), non-switched memory (NSM) (CD27⁺IgD⁺), naive (CD27^-IgD⁺) and double negative (DN) (CD27^-IgD^-). (D) Analysis of the IgG, IgM and IgA levels in the culture supernatants. DM: dermatomyositis, ASyS: anti-synthetase syndrome, OM: overlap myositis. Tofa: tofacitinib (2.5 µM). Graphs show the mean, SD and individual values (**p < 0.01; ***p < 0.001, n = 4/IIM subgroup)