Under or Over-function of Thyroid Gland » Inflammation of the thyroid (Hashimoto)
Thyroiditis (causes of the inflammation of the thyroid)
Chronic autoimmune thyroiditis (Hashimoto thyroiditis)
Subacute granulomatous thyroiditis (De Quervain thyroiditis)
Subacute lymphocytic thyroiditis (silent thyroiditis)
Post-partum thyroiditis (thyroiditis developed after childbirth)
Drug induced thyroiditis (IFN-a, IL-6, amiodarone)
Fibrous thyroiditis (Riedel thyroiditis)
Hashimoto thyroiditis (Chronic autoimmune thyroiditis) (Hashimoto)
It is a disease described by Hashimoto in 1912. Generally, iodine is found in sufficient regions and also the severity is increasing in the world. The most common cause of thyroid insufficiency (hypothyroidism) is Hashimoto's thyroiditis. It is seen in more than 10% of the population, more often in women, usually in the age group of 30-50 years. The disease risk in women of the same family is high due to genetic factors.
The mechanism of Hashimoto's disease
http://www.yesimerbil.com/eng/thyroid-antibodies Factors such as genetic factors, iodine, radiation, smoking and antibody positivity activate autoimmun mechanisms and cause the invasion of thyroid gland lymphocyte cells. As a result of lymphocyte invasion, antibodies are produced and the thyroid cell is broken down. Also, thyroid cell's self-killing (cell suicide = apoptosis) is another destructive event.
As a result of lymphocyte invasion in the thyroid cell, cells are broken down due to antibody production and cell death and thus, thyroid hormones are released into the bloodstream. Hyperthyroidism can be seen in the early stages of the disease. Usually this period is not noticed by the patient. Permanent hypothyroidism may develop according to the rate of the cell destruction. Permanent hypothyroidismdevelops in 20% of Hashimato patients.
Signs and laboratory findings of Hashimoto's disease
Most of the patients do not have a complaint. Hypothyroidism is detected in hormone tests performed for screening purposes and then it is investigated and diagnosed. Symptoms can be seen if the patients have developed hypothyroidism .
Malaise, fatigue, joint pain, gaining weight, skin dryness, hair loss, matted hair, feeling cold, constipation, irregular menstruations, infertility, depression, perceptual disorder and change in voice (coarse voice/hoarseness) are the signs of hypothyroidism. Dry skin, decreased pulse (bradycardia), coarse voice, slow reflexes, in some patients growth of the thyroid gland (goitre development) and edema are significant findings encountered during the examination.
The levels of t T3 and T4 hormones are found to be low, TSH level is found to be high. The levels of T3 and T4 hormones are found to be normal and TSH level is found to be high in subclinical hypothyroidism that does not cause clinical symptoms. Anti TPO is high in 85% of patients.
Hashimoto's disease may be accompanied by autoimmune diseases such as vitiligo, pernicious anemia, rheumatoid arthritis, type 1 diabetes. Thyroid gland shrinks as a result of the development of hypothyroidism. The shrunk thyroid gland is an indication that the hypothyroidism is permanent.
Risk factors in Hashimoto disease
It is seen in more than 10% of the population, more often in women, usually in the age group of 30-50 years. The incidence of the disease increases with increasing age. Although not yet certain, the risk factors can be listed as follows:
- Genetic predisposition
- Infections (Viral infection)
- Sex hormones
- Change in X chromosomes
- Iodine intake, smoking, radiation
The conditions to be suspicious of Hashimoto's disease
- Especially high levels of anti TPO with normal thyroid hormones or without goitre
- Patients with thyroid lymphoma
- Unexplained hypothyroidism
- Change in the thyroid tissue in thyroid ultrasonography (heterogeneous appearance)
Nodule development in Hashimoto disease
Thyroid tissue appears to be heterogeneous in theultrasonography , there is pseudo nodule in some patients. Hashimoto can be diagnosed by ultrasonography. Some patients have nodule development, these nodules are followed up according to ultrasonographic findings, needle biopsy is carried out where necessary. If a suspicious result shows up, thyroid surgery is performed.
Treatment of Hashimoto disease
Levothyroxine therapy is not necessary if the patient has normal levels of thyroid hormones. In young patients and patients with large goiters, treatment is initiated even if the levels of the hormones are normal. The thyroid volume is expected to decrease within 2-3 months. Sudden growth of thyroid gland in Hashimoto's disease suggests the possibility of "thyroid lymphoma" and a detailed examination is performed.
Thyroid hormone treatment (levothyroxine) is started according to the complaints of the patient and the hormone results. The target TSH in young people is 0.5 to 2.5 mIU/L. The target TSH is 1-4 mIU/L in patients with cardiac disease, atrial fibrillation (heart rhythm disorder), osteoporosis (bone loss) and in patients over 65 years of age. The target TSH in the first trimester of pregnancy is 0.1-2.5 mIU/L and the target TSH in the second and third trimesters is 0.2-3 mIU/L. The upper limit of TSH is accepted as 6 mIU/L in people between the age of 70-80 years, and the upper limit of TSH in people over 80 years is accepted as 7.5 mIU/L.
The ongoing high antibody levels in Hashimoto's disease is considered to be the finding of permanent hypothyroidism.
Selenium supplement is recommended for the patients with Hashimoto.
Subacute thyroiditis (Granulomatous thyroiditis, De Quervain thyroiditis)
It is rarely seen, the thyroid gland is usually painful and grows. Viral infection has been accused but it is not known which virus type it is. Half of the patients develop hyperthyroidism (thyrotoxicosis, toxic goiter). Swallowing and breathing difficulties, joint pain, palpitation, sweating, malaise and fever can be seen.
The levels of antibodies are high but sedimentation and CRP levels are found to be high unlike Hashimato. The diagnosis is based on the outcomes of physical examination of the patient, laboratory tests, ultrasonography and scintigraphy.
Since the cell destruction related hormones are released into the bloodstream during the first stage of the disease, anti-thyroid drugs are not effective for treatment. Anti-inflammatory drugs, sometimes cortisone and heart rate lowering drugs are used. The repetition of the disease increases the development risk of permanent hypothyroidism.
Post-partum thyroiditis = Thyroiditis developed after childbirth
It is a thyroiditis type seen in patients without pre-pregnancy thyroid disease within one year after pregnancy. The thyroid gland is painless, hard and small. The disease initially progresses with hyperthyroidism, in the following period it progresses with hypothyroidism. In some of the patients the hormones return to normal values, in other words, become euthyroid. When it is followed up for many years, permanent hypothyroidism is seen in 50% of the patients. The levels of antibodies are found to be high. Since hyperthyroidism is related to cell destruction, anti-thyroid drugs are not effective.