title: Associations of B cell-activating factor (BAFF) and anti-BAFF autoantibodies with disease activity in multi-ethnic Asian systemic lupus erythematosus patients in Singapore.
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.
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: H S
authors.identifier: 0000-0003-2656-136X
authors.initials: HS
authors.lastname: Howe
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: B Y H
authors.initials: BYH
authors.lastname: Thong
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: K O
authors.initials: KO
authors.lastname: Kong
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: H H
authors.initials: HH
authors.lastname: Chng
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: T Y
authors.initials: TY
authors.lastname: Lian
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: F L
authors.initials: FL
authors.lastname: Chia
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: K S S
authors.initials: KSS
authors.lastname: Tay
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.|Department of Medicine, National University Hospital System, Singapore.
authors.forename: T C
authors.initials: TC
authors.lastname: Lau
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: W G
authors.initials: WG
authors.lastname: Law
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.
authors.forename: E T
authors.initials: ET
authors.lastname: Koh
authors.affiliation: Department of Rheumatology, Allergy and Immunology, Tan Tock Seng Hospital, Singapore.|Department of Physiology, National University of Singapore, Singapore.|Health and Social Sciences, Singapore Institute of Technology, Singapore.
authors.forename: B P
authors.initials: BP
authors.lastname: Leung
mesh_terms: D000328:Adult; D044466:Asian People; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D053264:B-Cell Activating Factor / Q000097:blood* / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D057230:Limit of Detection; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000208:ethnology / Q000276:immunology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012846:Singapore / Q000453:epidemiology
chemical_list: D001323:Autoantibodies; D053264:B-Cell Activating Factor; D007074:Immunoglobulin G
keywords: BAFF; anti-BAFF; autoantibodies; systemic lupus erythematosus