Abstract
We previously reported that some systemic lupus erythematosus (SLE) patients have a population of circulating memory B cells with >2-fold higher levels of CD19. We show here that the presence of CD19(hi) B cells correlates with long-term adverse outcomes. These B cells do not appear anergic, as they exhibit high basal levels of phosphorylated Syk and ERK1/2, signal transduce in response to BCR crosslinking, and can become plasma cells (PCs) in vitro. Autoreactive anti-Smith (Sm) B cells are enriched in this population and the degree of enrichment correlates with the log of the serum anti-Sm titer, arguing that they undergo clonal expansion before PC differentiation. PC differentiation may occur at sites of inflammation, as CD19(hi) B cells have elevated CXCR3 levels and chemotax in response to its ligand CXCL9. Thus, CD19(hi) B cells are precursors to anti-self PCs, and identify an SLE patient subset likely to experience poor clinical outcomes.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Adult
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Antibodies, Monoclonal / therapeutic use
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Antibodies, Monoclonal, Murine-Derived
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Antigens, CD19 / blood*
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Antigens, CD19 / immunology
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Autoantigens / blood
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Autoantigens / immunology
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Autoimmunity
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B-Lymphocyte Subsets / immunology*
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Chemokine CXCL9 / blood
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Chemokine CXCL9 / immunology
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Female
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Humans
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Immunologic Factors / therapeutic use
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Immunologic Memory*
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Lupus Erythematosus, Systemic / complications
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Lupus Erythematosus, Systemic / drug therapy
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Lupus Erythematosus, Systemic / immunology*
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Lupus Erythematosus, Systemic / physiopathology
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Male
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Middle Aged
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Plasma Cells / immunology
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Plasma Cells / metabolism
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Receptors, CXCR3 / blood
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Receptors, CXCR3 / immunology
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Ribonucleoproteins, Small Nuclear / blood
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Ribonucleoproteins, Small Nuclear / immunology
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Rituximab
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snRNP Core Proteins
Substances
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Antibodies, Monoclonal
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Antibodies, Monoclonal, Murine-Derived
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Antigens, CD19
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Autoantigens
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CXCL9 protein, human
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CXCR3 protein, human
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Chemokine CXCL9
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Immunologic Factors
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Receptors, CXCR3
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Ribonucleoproteins, Small Nuclear
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snRNP Core Proteins
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Rituximab