CD27+memory B cells were greater producers of tumor necrosis factor α than naïve B cells and inversely correlated with interferon γ–producing CD4+cells in tumor necrosis factor–naïve patients. (A) Flow cytometry of tumor necrosis factor α (TNFα) production by CD27+ memory B cells and naïve CD27-IgD+ B cells in 14 rheumatoid arthritis (RA) patients at baseline (P < 0.001). Each data point represents one participant. Horizontal bars are medians, and whiskers are IQR (25th to 75 percentile). IgD, Immunoglobulin D; SSC-A, Side-scatter area (B) Correlation of proportion of CD27+ memory B cells and interferon γ (IFN-γ)–producing CD4+ cells in patients without therapy (TNFi-, n = 14) and with therapy (TNFi+, n = 8).