From the Guidelines
Graves' disease (GD) antibodies are autoantibodies that cross the placenta and can cause fetal thyrotoxicosis or neonatal immune-mediated hypothyroidism or hyperthyroidism.
Key Characteristics of Graves' Disease
- Responsible for 95 percent of hyperthyroidism cases in pregnancy 1
- Distinctive signs include ophthalmic and dermal manifestations, such as eyelid lag or retraction and localized myxedema
- Diagnosis is based on elevated free thyroxine (FT4) level or free thyroxine index (FTI) with suppression of thyroid-stimulating hormone (TSH) 1
Clinical Implications
- Untreated hyperthyroidism increases the risk of severe preeclampsia, preterm delivery, heart failure, and miscarriage in pregnant women 1
- Fetal thyrotoxicosis and neonatal immune-mediated hypothyroidism or hyperthyroidism are potential concerns due to the presence of GD antibodies that cross the placenta 1
- Thioamides used to treat Graves' disease can increase fetal and neonatal risks, highlighting the need for careful management and consultation 1
From the Research
Definition of Graves' Disease Antibodies
- Graves' disease (GD) is an autoimmune disorder caused by the presence of antibodies to the thyroid stimulating hormone (TSH) receptor (TRAbs) 2.
- TRAbs are characteristic indicators for GD, with stimulating TRAbs leading to hyperthyroidism by acting in an agonistic manner to TSH 3.
- Patients' sera may contain different types of TRAbs, including stimulating, blocking, and cleavage antibodies, which can lead to varying clinical symptoms 3.
Types of Antibodies
- Thyroid stimulating antibodies (TSAb) are determinant in the pathogenesis of GD and its extrathyroidal manifestations, such as Graves' ophthalmopathy (GO) and pretibial myxedema 4.
- TSHR autoantibodies underlie GD, GO, and pretibial myxoedema, and their pathophysiology involves the synergism of insulin-like growth factor 1 receptor (IGF1R) with TSHR autoantibodies 5.
- Thyroid peroxidase antibodies (TPOAbs) may be present in patients with GD, but their role in the disease outcomes is still unclear 2.
Clinical Significance
- TRAbs are essential clinical laboratory markers for the diagnosis of GD and its extra-thyroidal manifestations, such as GO 6.
- The measurement of TRAbs can help in the diagnosis and management of GD, and advancements in technology have made automated commercial kits available for TRAb detection 6.
- The presence of TPOAbs may not be a useful biomarker to predict remission or relapse of hyperthyroidism in GD patients 2.