β1-adrenergic and Muscarinic Acetylcholine Type 2 Receptor Antibodies Increased in Graves’ Hyperthyroidism

pattismith

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β1-adrenergic and Muscarinic Acetylcholine Type 2 Receptor Antibodies are Increased in Graves’ Hyperthyroidism and Decrease During Antithyroid Therapy
  • January 2021
DOI: 10.1055/a-1342-2853

Abstract


Objective

To determine the association between autoantibodies to G-protein-coupled receptors with effect on the cardiovascular system and the cardiac biomarker N-terminal pro-brain natriuretic peptide reflecting heart function in Gravesʼ disease.

Design and Methods

Sixty premenopausal women with Graves’ disease were analyzed for IgG autoantibodies against

β1-adrenergic,
muscarinic acetylcholine type 2 and
angiotensin II type 1 receptors


using enzyme-linked immunosorbent assays based on cell membranes overexpressing receptors in their native conformations.

N-terminal pro-brain natriuretic peptide and heart symptoms were analyzed in hyperthyroidism and after 7.5 months of antithyroid treatment.

Matched thyroid healthy controls were also assessed.

Results

Serum levels of antibodies against the β1-adrenergic and the muscarinic acetylcholine type 2 receptors were higher in hyperthyroid patients than in controls
(median β1-adrenergic receptor antibodies 1.9 [IQR 1.3–2.7] vs. 1.1 [0.8–1.7] μg/mL, P<0.0001; muscarinic acetylcholine type 2 receptor 20.5 [14.0–38.3] vs. 6.0 [3.2–9.9] U/mL, P<0.0001).

These antibodies decreased in euthyroidism (P<0.01), but were still higher than in controls (P<0.01).

Angiotensin II type 1 receptor levels did not differ.

N-terminal pro-brain natriuretic peptide was higher in hyperthyroidism (240 [134–372] vs. <35 [<35–67] ng/L, P<0.0001), normalized after treatment and did not correlate with autoantibodies.

Conclusion

Autoantibodies against the β1-adrenergic and the muscarinic acetylcholine type 2 receptors were increased in Graves’ patients, decreased with treatment, but did not correlate with cardiac function.


However, an autoimmune effect on the heart cannot be excluded in subpopulations, as the functional properties of the analyzed antibodies remain to be determined.
 

pattismith

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Interesting to compare with my own result in October 2019 when I had Grave's hyperthyroidism;

First observation: they didn't test for the full panel
Second: I really don't have the profile these patients have ;
my AT1R are very high, whereas it is normal in the study, and
my β1-adrenergic and muscarinic acetylcholine type 2 are normal...:lol:


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