Associations of B cell‐activating factor (BAFF) and anti‐BAFF autoantibodies with disease activity in multi‐ethnic Asian systemic lupus erythematosus patients in Singapore |
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| Authors: | H. S. Howe B. Y. H. Thong K. O. Kong H. H. Chng T. Y. Lian F. L. Chia K. S. S. Tay T. C. Lau W. G. Law E. T. Koh B. P. Leung |
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| Affiliation: | 1. Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore;2. Department of Medicine, National University Hospital System, Singapore;3. Department of Physiology, National University of Singapore, Singapore;4. Health and Social Sciences, Singapore Institute of Technology, Singapore |
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| Abstract: | ![]()
To measure the levels of B cell‐activating factor (BAFF) and endogenous anti‐BAFF autoantibodies in a cohort of multi‐ethnic Asian systemic lupus erythematosus (SLE) patients in Singapore, to determine their correlation with disease activity. Serum samples from 121 SLE patients and 24 age‐ and sex‐matched healthy controls were assayed for BAFF and anti‐BAFF immunoglobulin (Ig)G antibody levels by enzyme‐linked immunosorbent assay (ELISA). The lowest reliable detection limit for anti‐BAFF‐IgG antibody levels was defined as 2 standard deviations (s.d.) from blank. Correlation of serum BAFF and anti‐BAFF IgG levels with disease activity [scored by SLE Activity Measure revised (SLAM‐R)], and disease manifestations were determined in these 121 patients. SLE patients had elevated BAFF levels compared to controls; mean 820 ± 40 pg/ml and 152 pg ± 45/ml, respectively [mean ± standard error of the mean (s.e.m.), P < 0·01], which were correlated positively with anti‐dsDNA antibody levels (r = 0·253, P < 0·03), and SLAM‐R scores (r = 0·627, P < 0·01). In addition, SLE patients had significantly higher levels of anti‐BAFF IgG, which were correlated negatively with disease activity (r = –0·436, P < 0·01), levels of anti‐dsDNA antibody (r = –0·347, P < 0·02) and BAFF (r = –0·459, P < 0·01). The majority of patients in this multi‐ethnic Asian SLE cohort had elevated levels of BAFF and anti‐BAFF antibodies. Anti‐BAFF autoantibody levels correlated negatively with clinical disease activity, anti‐dsDNA and BAFF levels, suggesting that they may be disease‐modifying. Our results provide further information about the complexity of BAFF pathophysiology in different SLE disease populations and phenotypes, and suggest that studies of the influence of anti‐cytokine antibodies in different SLE populations will be required when selecting patients for trials using targeted anti‐cytokine therapies. |
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| Keywords: | anti‐BAFF autoantibodies BAFF systemic lupus erythematosus |
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