SDC1 and systemic lupus erythematosus: Similar decreases in the levels of B cell subsets (CD20+; naïve CD19+/CD20+/CD27−; activated CD19+/CD20+/CD69+; memory CD19+/CD20+/CD27+; plasmacytoid CD19+/CD20+/CD138+; plasma CD19+/CD20−/CD138+; SLE subset CD19+/CD38b+/CD27b+ lymph; transitional CD19+/CD24b+/CD38b+/CD27−) were observed in SRI responders and non-responders from baseline to week 52 (data not shown).