title: B cell activation in clinically quiescent systemic lupus erythematosus (SLE) is related to immunoglobulin levels, but not to levels of anti-dsDNA, nor to concurrent T cell activation.
abstract: In clinically quiescent SLE hypergammaglobulinaemia, presence of autoantibodies, and increased soluble IL-2 receptors (sIL-2R) have been reported, suggesting persistent B as well as T cell activation. In contrast, the primary immune response to test antigens is markedly decreased. To analyse these phenomena at a cellular level, we undertook a cross-sectional study on 13 non-active SLE patients and 15 controls. We determined the composition of lymphocyte subsets with special attention to activation markers (CD25, HLA-DR, CD38) and the presence of naive T cells (CD45RO-), and related those findings to serological parameters. In non-active SLE patients the expression of activation markers on B cells and T cells was higher than in normal controls (P < or = 0.02), but was not interrelated. Percentages of activated B cells in SLE were related to levels of total IgG (P < 0.02) and IgM (P < 0.02) but not to anti-dsDNA, suggesting a disordered immune system also in clinically quiescent SLE. Numbers of CD4+ cells (P < 0.001) and CD4+CD45RO- cells (P < 0.05) were decreased. The latter finding might explain the anergy to primary test antigens in clinically quiescent SLE.
authors.affiliation: Department of Internal Medicine, University Hospital Groningen, The Netherlands.
authors.forename: P E
authors.initials: PE
authors.lastname: Spronk
authors.forename: B T
authors.initials: BT
authors.lastname: vd Gun
authors.forename: P C
authors.initials: PC
authors.lastname: Limburg
authors.forename: C G
authors.initials: CG
authors.lastname: Kallenberg
mesh_terms: D000328:Adult; D000974:Antibodies, Antinuclear / Q000032:analysis*; D015703:Antigens, CD / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D003430:Cross-Sectional Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006942:Hypergammaglobulinemia / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D007136:Immunoglobulins / Q000032:analysis*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000974:Antibodies, Antinuclear; D015703:Antigens, CD; D001323:Autoantibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins