CD19 and systemic lupus erythematosus: These results confirmed former studies indicating that compared to controls, CD19+ B cells and also CD4+ T cells of lupus patients display increased CXCR4 expression levels, notably in neuropsychiatric lupus, that were correlated with SLEDAI score (Wang et al., 2010; Launay et al., 2013; Barrera-Vargas et al., 2018).