B-lymphocyte activating factor in systemic lupus erythematosus and rheumatoid arthritis in relation to autoantibody levels, disease measures and time

• Published in: Lupus Vol. 15; no. 9; pp. 570 - 576
• Main Authors: Becker-Merok, A, Nikolaisen, C, Nossent, H C
• Format: Journal Article
• Language: English
• Published: Thousand Oaks, CA SAGE Publications 01.01.2006; Sage Publications Ltd
• Subjects: Adult; Age Factors; Antibodies; Antibodies, Anticardiolipin - blood; Antibodies, Antinuclear - blood; Antigens; Arthritis, Rheumatoid - blood; Arthritis, Rheumatoid - immunology; Arthritis, Rheumatoid - pathology; Autoantibodies - blood; B-Cell Activating Factor - blood; Biomarkers - blood; Blood Sedimentation; C-Reactive Protein - metabolism; Cross-Sectional Studies; Disease; Enzyme-Linked Immunosorbent Assay; Enzymes; Female; Follow-Up Studies; Humans; Immunoassay; Laboratories; Longitudinal Studies; Lupus; Lupus Erythematosus, Systemic - blood; Lupus Erythematosus, Systemic - immunology; Lupus Erythematosus, Systemic - pathology; Lymphocytes; Male; Middle Aged; Rheumatoid arthritis; Rheumatoid Factor - biosynthesis; Rheumatoid Factor - blood; Rheumatology; Severity of Illness Index; Time Factors; Transgenic animals; Tumor necrosis factor-TNF; United States > US; Norway; Germany; B-cell activating factor; systemic lupus erythematosus; autoantibodies; rheumatoid arthritis
• ISSN: 0961-2033; 1477-0962
• DOI: 10.1177/0961203306071871

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 ≤ 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.