101. High Titers of Thyrotropin Receptor Antibodies Are Associated With Orbitopathy in Patients With Graves Disease
- Author
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Tanja Diana, George J. Kahaly, Paul D. Olivo, and Christian Wüster
- Subjects
Adult ,Male ,medicine.medical_specialty ,Serial dilution ,Endocrinology, Diabetes and Metabolism ,Graves' disease ,Clinical Biochemistry ,030209 endocrinology & metabolism ,Context (language use) ,Biochemistry ,Thyrotropin receptor ,Diagnosis, Differential ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Endocrinology ,Antithyroid Agents ,Internal medicine ,Medicine ,Humans ,Euthyroid ,Aged ,Autoantibodies ,Methimazole ,biology ,business.industry ,Biochemistry (medical) ,Autoantibody ,Receptors, Thyrotropin ,Middle Aged ,medicine.disease ,Prognosis ,Graves Disease ,Graves Ophthalmopathy ,Titer ,030220 oncology & carcinogenesis ,biology.protein ,Female ,Antibody ,business ,Follow-Up Studies - Abstract
ContextSerum TSH receptor autoantibody (TSH-R-Ab) is a biomarker of Graves disease (GD). Studies have shown that the levels of this TSH-R-Ab have clinical significance.ObjectiveTo differentiate between thyroidal GD only and Graves orbitopathy (GD + GO).DesignControlled, follow-up study.SettingAcademic tertiary referral center for GD + GO.SubjectsSixty patients with GD, GD + GO, and controls.InterventionSerial serum dilution analyses with six automated, ELISA, and cell-based assays for TSH-R-Ab.Main Outcome MeasureDifferentiation among GD phenotypes.ResultsAll undiluted samples of hyperthyroid-untreated GD patients were positive with the six assays but became negative at dilution 1:9 in four of six assays. In contrast, all undiluted samples of hyperthyroid-untreated GD + GO patients remained positive up to dilution 1:81, P < 0.001. At high dilutions 1:243, 1:729, 1:2187, and 1:6561, the rate of stimulating TSH-R-Ab positivity in the bioassay for GD + GO patients was 75%, 35%, 5%, and 0%, respectively (all P < 0.001). The five ELISA and/or automated assays confirmed this marked difference of anti-TSH-R-Ab detection between GD-only and GD + GO. In comparison, the baseline-undiluted samples of GD vs GD + GO showed an overlap in the ranges of TSH-R-Ab levels. Subsequent to 12-month methimazole treatment, samples from euthyroid GD + GO patients were still TSH-R-Ab positive at the high dilution of 1:243. In contrast, all GD samples were negative already at dilution 1:3. A GD patient with TSH-R-Ab positivity at dilution 1:729 developed de novo GO.ConclusionsTSH-R-Ab titers, as determined by dilution analysis, significantly differentiate between GD and GD + GO.
- Published
- 2018