CR2 and rheumatic disorder: In patients with primary Sjögren’s syndrome, an inflammatory rheumatic disease characterized by sicca symptoms and an increased risk of developing lymphoproliferative disease, the expanded CD21–/low MBCs have been described as CD27–CD38low, most were IgM+IgD+ and mutated, whereas only a small (approx. 20%) proportion expressed Tbet or CD11c [40, 72].