CD40LG and systemic lupus erythematosus: We further evaluated the Bnd compartment and found that Bnd2 cells (CD27-IgM-IgD+CD21loCXCR5-), which express increased markers of activation and are thought to be extrafollicular in derivation (52), are increased in cSLE vs. HC (p = 0.0058, median SLE = 1.48% vs. HC = 0.913%; Figure 5A).