title: Increase in antimicrosomal antibody-related IgG1 and IgG4, and titers of antithyroid peroxidase antibodies, but not antibody dependent cell-mediated cytotoxicity in post-partum thyroiditis with transient hyperthyroidism.
abstract: To evaluate possible immunological mechanisms involved in the development of postpartum thyroiditis with transient hyperthyroidism followed by transient hypothyroidism (PPT), antithyroid peroxidase antibodies (anti-TPO), antimicrosomal antibody (AMA) related immunoglobin G subclass and antibody-dependent cell-mediated cytotoxicity (ADCC) were studied in 43 post-partum (PP) women who were euthyroid at delivery and completed a subsequent 1 year follow up. Among the 25 mothers who developed PPT, 14 had positive AMA (PPT:AMA+) and 11 negative AMA (PPT:AMA-) at delivery. Among the 18 mothers who remained euthyroid (E) up to one year post-partum and were used as controls, 8 were AMA positive (E:AMA+) and 10 AMA negative (E:AMA-) at delivery. AMA measured by a hemagglutination method correlated well with anti-TPO antibodies measured by RIA in the PP mothers studied. When AMA-related IgG subclass activity was analysed comparing PPT women with appropriate euthyroid controls at the different time intervals studied, it was seen that PPT:AMA+ when compared to E:AMA+ women have significantly increased activity of AMA related IgG1 at all PP time intervals studied (p less than 0.001), but IgG4 was only increased at 5-7 months PP (p less than 0.05). PPT:AMA-when compared to E:AMA- have significantly increased IgG4 at 2-4 (p less than 0.001), 5-7 and 10-12 (p less than 0.05) months PP, but IgG1 is only increased at 5-7 months PP (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Mount Sinai Hospital, University of Toronto, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Briones-Urbina
authors.forename: A B
authors.initials: AB
authors.lastname: Parkes
authors.forename: U
authors.initials: U
authors.lastname: Bogner
authors.forename: S
authors.initials: S
authors.lastname: Mariotti
authors.forename: P G
authors.initials: PG
authors.lastname: Walfish
mesh_terms: D000328:Adult; D000920:Antibody-Dependent Cell Cytotoxicity; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000276:immunology*; D007074:Immunoglobulin G / Q000378:metabolism; D007453:Iodide Peroxidase / Q000276:immunology*; D049590:Postpartum Period; D011247:Pregnancy; D013966:Thyroiditis / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; C056626:thyroid microsomal antibodies; D007453:Iodide Peroxidase