The data derived from the present study indicate that CD19+CD24−CD38hi plasmablasts/plasma cells are significantly elevated in the peripheral blood of patients with IgG4-RD, and this B-cell population notably correlates with the number of organs involved, serum IgG4, IgG4-RD RI, and the ratio of IgG4/IgG. Here, CD19 is linked to immunoglobulin G4-related sclerosing disease.