Autoimmune​ thyroid disorder

SPECT scan
Uptake scan

I had a lot of different tests done. The first blood test showed that my thyroid is hyperactive. Further blood tests showed that I have thyroperoxidase (TPO) antibodies.

TPO is an enzyme involved in thyroid hormone synthesis, catalyzing the oxidation of iodide. Anti-TPO antibodies activate complement and are thought to be significantly involved in thyroid dysfunction and the pathogenesis of hypothyroidism.

They also did a Thyroid-Stimulating Immunoglobulin (TSI) test.

The TSI test measures the level of thyroid-stimulating immunoglobulin (TSI) in your blood. They measured high levels of TSI in the blood, which could indicate the presence of Graves’ disease, an autoimmune disorder that causes hyperthyroidism.

The final test was called Thyroid Scintigraphy & Uptake. I had to drink a solution with radioactive iodine (I-131), after two hours the uptake was measured. Twenty-four hours later the uptake was measured again, and a SPECT scan was made of my thyroid gland (see picture). The test showed a low uptake and an enlargement of the thyroid (right lobe more than left), and some possible nodules (places with no uptake) in the gland.

The endocrinologist told me that I am currently having thyroiditis (a painless inflammation of the gland, and that I have two autoimmune reactions, one that could cause hyperthyroidism and one that could cause hypothyroidism. The current blood values show hyperthyroidism, but according to her, a shift to hypothyroidism is to be expected.

The plan of action is to wait for 4-6 weeks, then have new blood tests done to show thyroid functioning (the antibodies remain, so no need to test them again). Also then an ultrasound will be made of my thyroid to check if the nodules resolved (they could be caused by the thyroiditis), or if they are caused by something else.

Based on these results a treatment plan will be made. In the meantime I have to wait. Luckily I am feeling slightly better.

Thyroid dysfunction is very common after treatment of MS patients with Lemtrada (a treatment for MS, and a form of chemotherapy). My treatment was not the same, but similar. Maybe it is related. The linked article reads: “Silent thyroiditis, the third classical AITD phenotype, is characterized by a self-limiting painless subacute lymphocytic thyroiditis, lasting for weeks to months. TPOAbs are often increased. In the first phase, increased thyroid hormone levels can be observed due to leakage caused by thyroid inflammation, whereas transient hypothyroidism can develop in the second phase. Eventually, thyroid function is restored.”

Let’s hope that that last statement is applicable.

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