title: Antibodies to mannose binding lectin in patients with systemic lupus erythematosus.
abstract: Deficiency of mannose binding lectin (MBL), a C-type lectin with structural similarities to C1q, has been shown to predispose to the development of systemic lupus erythematosus (SLE). Some patients have low serum MBL levels which cannot be explained by either structural gene mutations or promoter polymorphisms. The objective of this study was to detect the presence of autoantibodies against MBL and to evaluate their relationship to serum MBL levels. Anti-MBL antibodies of IgM and IgG classes from consecutive SLE patients (n = 135) and healthy subjects (n = 50) were measured by an in-house ELISA. Using the 90th percentile of controls as a cutoff, more SLE patients [23.7% (32/135)] were found to have IgG anti-MBL antibodies than normal controls [10.0% (5/50)] (P = 0.04). The same trend was observed when ethnicity was taken into account by analysing Caucasians alone (n = 90). IgM anti-MBL antibodies were only found in two SLE patients (2/22, 9.1%) who had no concomitant IgG anti-MBL antibodies. Serum levels of IgG anti-MBL antibodies were found to correlate with serum MBL levels (r = 0.55, P = 0.049). However, the levels of anti-MBL antibodies did not correlate with overall disease activity. Thus the production of anti-MBL antibodies is likely to be a specific antigen-driven process. Its role in lupus pathogenesis remains to be elucidated.
authors.affiliation: Department of Immunology and Molecular Pathology and Rheumatology, Royal Free and University College Medical School, London, UK. mymok@netvigator.com
authors.forename: M Y
authors.initials: MY
authors.lastname: Mok
authors.forename: D L
authors.initials: DL
authors.lastname: Jack
authors.forename: C S
authors.initials: CS
authors.lastname: Lau
authors.forename: D Y T
authors.initials: DY
authors.lastname: Fong
authors.forename: M W
authors.initials: MW
authors.lastname: Turner
authors.forename: D A
authors.initials: DA
authors.lastname: Isenberg
authors.forename: P M
authors.initials: PM
authors.lastname: Lydyard
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology*; D008297:Male; D037241:Mannose-Binding Lectins / Q000172:deficiency / Q000276:immunology*; D012016:Reference Values; D012044:Regression Analysis
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D037241:Mannose-Binding Lectins