Association of plasma B lymphocyte stimulator levels and disease activity in systemic lupus erythematosus.
OBJECTIVE
To determine the association of plasma B lymphocyte stimulator (BLyS) levels, immunosuppressive therapy, and other clinical parameters with disease activity in systemic lupus erythematosus (SLE).


METHODS
Two hundred forty-five SLE patients were evaluated prospectively over a 2-year period at 4 centers. Assessments were performed every 3-6 months. Univariate analysis was used to determine the association among the Safety of Estrogens in Lupus Erythematosus: National Assessment (SELENA) version of the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score, serum anti-double-stranded DNA (anti-dsDNA), and plasma BLyS levels. A multivariate repeated-measures model incorporating immunosuppressive therapy was utilized.


RESULTS
Ninety-two percent of the patients were female. Sixty-seven percent were white, 31% African American, and 2% Asian (all of these groups may include Hispanic). Mean values at baseline were as follows: age 41.5 years, disease duration 8.1 years, SELENA-SLEDAI 3.3 (median 2, range 0-18), BLyS 5.57 ng/ml, IgG 1,439 mg/dl, C3 104.4 mg/dl, and C4 21.3 mg/dl; among those positive for anti-dsDNA, the median titer was 1:40 (range 1:10-1:1,280). Univariate analysis showed that plasma BLyS levels were associated with anti-dsDNA titers (P = 0.0465) and SELENA-SLEDAI scores (P = 0.0002). In multivariate analyses, a greater increase in the SELENA-SLEDAI score from the previous visit was associated with higher BLyS levels at the previous visit (P = 0.0042) and with a greater increase in the BLyS level from the previous visit (P = 0.0007).


CONCLUSIONS
The findings of association between a greater increase in the BLyS level from the previous visit and a greater increase in the SELENA-SLEDAI score at the subsequent visit, and between an elevated BLyS level at the previous visit and a greater SELENA-SLEDAI score at the subsequent visit, demonstrate a relationship between circulating BLyS levels and SLE disease activity. These results lend support to the notion that BLyS is a candidate for therapeutic targeting in SLE.
Petri
Michelle
M
Johns Hopkins University School of Medicine, Division of Rheumatology, Baltimore, MD 21205, USA. mpetri@jhmi.edu
Stohl
William
W
Chatham
Winn
W
McCune
W Joseph
WJ
Chevrier
Marc
M
Ryel
Jeff
J
Recta
Virginia
V
Zhong
John
J
Freimuth
William
W
D000328:Adult; D053264:B-Cell Activating Factor / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000097:blood; D008137:Longitudinal Studies; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012720:Severity of Illness Index
D053264:B-Cell Activating Factor; D015415:Biomarkers; D007136:Immunoglobulins