title: Anti-C1q autoantibodies are linked to autoimmune thyroid disorders in pregnant women.
abstract: Anti-C1q antibodies (anti-C1q) have been implicated in the pathogenesis of autoimmune diseases, including autoimmune thyroid disorders (AITD). The aim of this study was to evaluate the association between anti-C1q and thyroid function in pregnancy-associated AITD. In 96 pregnant women screened positive for AITD (thyroid dysfunction and/or antibodies against thyroperoxidase - TPOAb), anti-C1q were measured during the 9-11th gestational week and after delivery (median 16 months after delivery), and compared to the corresponding serum levels of thyroid hormones. As controls, 80 healthy pregnant women, 72 non-pregnant AITD patients and 72 blood donors were included. In the non-pregnant AITD group, two serum samples ≥ 6 months apart were analysed. Compared to blood donors, anti-C1q levels were substantially higher in all pregnant women analysed. In pregnancy, anti-C1q levels were higher in the TPOAb-positive women than in controls (37 versus 17·5%, P < 0·0001). Anti-C1q-positive pregnant women screened positive for AITD had higher thyroid-stimulating hormone (TSH) levels than anti-C1q-negative women (2·41 versus 1·94 mU/l, P = 0·01), and TSH correlated positively with anti-C1q (r = 0·226, P = 0·045) in the TPOAb-positive women. After delivery, serum levels of anti-C1q decreased in the positively screened TPOAb-negative women (8·8 versus 5·9 U/l, P = 0·002), but not in the TPOAb-positive ones, and they no longer correlated with TSH. Anti-C1q antibody levels increase during pregnancy in general and even more in the context of AITD, where they correlate with thyroid stimulating hormone levels.
authors.affiliation: Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Czech Republic.
authors.forename: H
authors.initials: H
authors.lastname: Vitkova
authors.affiliation: Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Jiskra
authors.affiliation: Institute of Clinical Biochemistry and Laboratory Medicine, General University Hospital in Prague, Czech Republic.
authors.forename: D
authors.initials: D
authors.lastname: Springer
authors.affiliation: Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Czech Republic.
authors.forename: Z
authors.initials: Z
authors.lastname: Limanova
authors.affiliation: Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Czech Republic.
authors.forename: Z
authors.initials: Z
authors.lastname: Telicka
authors.affiliation: Institute of Biophysics and Informatics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Bartakova
authors.affiliation: Division of Internal Medicine and Laboratory of Clinical Immunology, University Hospital Basel.
authors.forename: M
authors.initials: M
authors.lastname: Trendelenburg
authors.affiliation: Division of Internal Medicine, University Hospital Basel.
authors.forename: E
authors.initials: E
authors.lastname: Potlukova
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D015415:Biomarkers; D015922:Complement C1q / Q000276:immunology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology*; D012189:Retrospective Studies; D013959:Thyroid Diseases / Q000276:immunology*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D015922:Complement C1q
keywords: anti-C1q antibodies; autoimmune thyroid disease; complement; postpartum thyroiditis; pregnancy