Fig. 2.

MZB1 is overexpressed in B-cell subsets and MZB1 mRNA increased in peripheral blood B cells from SLE patients with active disease. a Immunofluorescence showed slight colocalization of MZB1 with B-cell marker CD20 and strong colocalization with plasma cell marker CD138 and MZ B-cell marker IRTA1 in lymph nodes from SLE patients. b MZB1 mRNA levels in peripheral blood B cells from SLE patients with active disease (SLE-High) increased by 2.1-fold compared with those in healthy controls (HC) (p < 0.05). No significant increase in MZB1 mRNA levels observed in peripheral blood B cells from SLE patients with inactive disease (SLE-Low). c Two SLE patients with active disease had follow-up samples collected at 2 months of treatment. Relative MZB1 mRNA expression levels decreased with treatment. d MZB1 immunohistochemistry in tissue from patients with various autoimmune diseases. e Increased proportion of MZB1⁺ cells observed in lymph nodes from SLE patients and synovial tissue from rheumatoid arthritis (RA) patients compared with control lymph nodes (LN) and tonsils (p < 0.05). RA, scale bar = 50 μm; lupus nephritis, scale bar = 20 μm. Hashimoto Hashimoto’s thyroiditis, HPF high-power field, IgG4-RD IgG4-related pancreatitis, myositis dermatomyositis, PN polyarteritis nodosa, Pt patient, Sjs Sjögren’s syndrome, SLE systemic lupus erythematosus