Depressed serum IgM levels in SLE are restricted to defined subgroups

作者：Gronwall Caroline^*; Hardt Uta; Gustafsson Johanna T; Elvin Kerstin; Jensen Urstad Kerstin; Kvarnstrom Marika; Grosso Giorgia; Ronnelid Johan; Padykov Leonid; Gunnarsson Iva; Silverman Gregg J; Svenungsson Elisabet

来源：Clinical Immunology, 2017, 183: 304-315.

DOI：10.1016/j.clim.2017.09.013

• SLE
• Natural IgM
• Sjogren's syndrome
• Antiphospholipid syndrome
• IgM anti-PC
• IgM anti-MDA
• IgM anti-CWPS
• SS
• APS
• Autoantibodies

Natural IgM autoantibodies have been proposed to convey protection from autoimmune pathogenesis. Herein, we investigated the IgM responses in 396 systemic lupus erythematosus (SLE) patients, divided into subgroups based on distinct autoantibody profiles. Depressed IgM levels were more common in SLE than in matched population controls. Strikingly, an autoreactivity profile defined by IgG anti-Ro/La was associated with reduced levels of specific natural IgM targeting phosphoiylcholine (PC) antigens and malondialdehyde (MDA) modified-protein, as well as total IgM, while no differences were detected in SLE patients with an autoreactivity profile defined by anti-cardiolipin/beta(2)glycoprotein-I. We also observed an association of reduced IgM levels with the HEA-DRB1*03 allelic variant among SLE patients and controls. Associations of low IgM anti-PC with cardiovascular disease were primarily found in patients without antiphospholipid antibodies. These studies further highlight the clinical relevance of depressed IgM. Our results suggest that low IgM levels in SLE patients reflect immunological and genetic differences between SLE subgroups.

• 出版日期2017-10