B-lymphocyte activating factor in systemic lupus erythematosus and rheumatoid arthritis in relation to autoantibody levels, disease measures and time.
Overexpression of B-lymphocyte activating factor (BAFF) results in arthritis, glomerulonephritis and autoantibody formation in mice, but its role in human autoimmune disease is less obvious. Serum BAFF levels in patients with systemic lupus erythematosus (SLE) (n=42) and rheumatoid arthritis (RA) (n=60) were related to levels of disease activity, anti-dsDNA Ab, anti-ENA Ab, rheumatoid factor (RF) and anti-CCP Ab. BAFF levels were also followed over time in 19 SLE patients. BAFF levels correlated inversely with age, were higher in SLE than RA (median 2.7 versus 1.4 ng/mL, P < 0.01) and more SLE than RA patients had increased BAFF levels (57% versus 10%, P < or = 0.01). In SLE, BAFF levels correlated with SLEDAI scores but not with anti-dsDNA Ab levels. SLE patients with increased BAFF levels had higher SLEDAI and CRP levels. In RA, BAFF levels correlated weakly with anti-CCP levels (Rs 0.27, P = 0.07), but not with joint counts, ESR, CRP or RF levels. Longitudinal BAFF levels remained unaltered in two thirds of SLE patients and changes in BAFF levels were unrelated to disease flares. These findings suggest that BAFF stimulation of B-cells may contribute to SLE by other mechanisms than autoantibody production.
Becker-Merok
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A
Department of Rheumatology, Institute of Clinical Medicine, University of Tromsø, Norway.
Nikolaisen
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C
Nossent
H C
HC
D000328:Adult; D000367:Age Factors; D017153:Antibodies, Anticardiolipin / Q000097:blood; D000974:Antibodies, Antinuclear / Q000097:blood; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000276:immunology / Q000473:pathology; D001323:Autoantibodies / Q000097:blood*; D053264:B-Cell Activating Factor / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012217:Rheumatoid Factor / Q000096:biosynthesis / Q000097:blood; D012720:Severity of Illness Index; D013997:Time Factors
D017153:Antibodies, Anticardiolipin; D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D053264:B-Cell Activating Factor; D015415:Biomarkers; D002097:C-Reactive Protein; D012217:Rheumatoid Factor