CD19 and immunoglobulin G4-related sclerosing disease: Our previous studies revealed that CD19+CD24−CD38hi plasmablasts/plasma cells were significantly increased in the peripheral blood of patients with IgG4-RD (6.99 ± 6.24%), higher than that in patients with Sjögren’s syndrome (2.39 ± 2.64%, P < 0.001) and healthy control subjects (2.16 ± 1.65%, P < 0.001) [17].