Hashimoto thyroiditis is the most common type of hypothyroidism. It belongs to the group of autoimmune disorders.In this disease body attacks and damages the thyroid gland.
Hashimoto thyroiditis also known as autoimmune thyroiditis or chronic lymphocytic thyroiditis is a progressive autoimmune disease in which the body attacks and destroys the thyroid gland cells. It is characterized by inflammation of thyroid gland and high level of antibodies against thyroid enzymes. progressively it worsens to hypothyroidism in which thyroid gland produced the insufficient amount of thyroxine(T4) and tri iodo thyronineT3.
Hashimoto’s thyroiditis accounts for 6% of all thyroidectomies from 1942 to 2012
About 4%to 6% of general population ofUS is affected.It is 8 times more common in females than males, more common in whites,more common in people of 45 to 55 years of age. Hepatitis C is the risk factor of this disease. Women using interferon against hepatitis are at more risk.
Common symptoms are
* Cold intolerance
* Depressive mood
* Dry skin
* Weight gain
*’Slowed heart rate
* Puffy eyes
* Joint and muscle pain
Other autoimmune disorders along with Hashimoto disease are
* Rheumatoid arthritis
* Celiac disease
Celiac disease patients have twice the risk of cardiac disease.
Atrophic:In this body own antibodies attack thyroid gland cells damage them untill they are no longer working
Goitrous: In this thyroid gland becomes inflamed and swollen
1 higher level of TSH but lower level of thyroid hormones
TSH is secreted by the pituitary gland and is used commonly to test hypothyroidism.
The standard range is .27 to4.2 IU/ml
T3: 4.2 to 9.1
T4:10 to 27.2 pmol/L
Free T3: 2.5 to 4.3
Free T4: .9 to 1.7pg/ml
2 ) presence of thyroid antibodies
Four types of antibodies can be found
Thyroxin: least active hormone
Triiodothyronine:most active hormone
Thyroglobulin:a protein transporter for T4 and T 3
Thyroperoxidase: an enzyme that helps to produce T3 T4
Patient with autoimmune disorder shows an increase in at least one antibodies
ULTRASOUND AND NEEDLE BIOPSY
Thyroid ultrasound shows abnormal test of thyroid function.The doctor also obtain the sample by needle biopsy to check for cancer.
1 ) physical examination
Frontal side of throat is examined to check goiter or sweliing
2)URINE IODIDE CONCENTRATION/ EXCRETION
Autoimmune diseased patient affected by thyroiditis having age 6 to 12 have increased UIC/UIE
STAGES OF HASHIMOTO PROGRESSION
Stage 1) thyroid gland perform its function normally,no thyroid antibodies present,but people with genetic defect show immune defect
Stage 2)thyroid antibodies are present, Increase level of TSH are visible that lead to thyroid inflammation.
Stage 3)thyroid dysfunction is prominent antibody level progressively increase upto severe thyroiditis.
Stage 4) there is severe thyroiditis with visible hypothyroidism
Stage.5) hypothyroidism with other severe diseases (genetic,lifestyle) is common.
GENETIC FACTORS OF HASHIMOTO DISEASE
Abnormality of following genes causes thyroiditis
* ZFAT gene controll apoptosis.It produces protein necessary for cell development. Reduced production of ZFAT lead to death of connective tissues
* thyroglobulin gene Tg is involved in synthesis of T4 and T3
* PTPN 22 encodes a protein that prevents activation of T cells
* Vitamin D receptor gene is important for absorption.Its deficency is a risk factor of hypothyroidism
* HLA _B gene mutations are a risk factor for Hashimoto thyroiditis.
* postpartum hormonal fluctuations is a common risk factor.after birth there is increase in thyroid antibodies,which increase risk by 3_8% in women after birth
*High iodine levels have nevative affect on thyroid health. Increase innovation have a deterioting affect on thyroid hormones.
*Selenium deficency promotes inflammation and thyroiditis. Selenoproteins remove hydrogen peroxide that causes inflamation.
* Radiation exposure increases the production of thyroid antibodies and increases the incidence of Hashimoto diseases.
* Environmental pollutant like tobacco, smoke , toxic substances increses the risk of autoimmune disorders.
* Drugs misuse is a common risk factor. drugs use to treat viral infections or cancer eg interferon, methotrexate is associated with autoimmune disorders.
*Mercury toxicity associated with dental fillins like amalgam is a typical risk factor.
1) Hormone replacement:
Artifical thyroid hormone is injected to maintain normal thyroid hormones level.Most common is levothyroxine L_T4.It is mostly taken empty stomach at night, however in.some patient it is taken before breakfast.About 12% of the patient are non responsive of this hormone due to inability of its conversion into active form that lead to persistence of symptoms.Dessicated thyroid hormone is obtained from pigs is also effective against hypothyroidism.
2) vitamin D administration
Vit D deficiency is common factor risk factor in Hashimoto thyroiditis that also lead to hypothyroidism.A significant decrease in autoantibodies are observed soon after vit D administration.It is more effective in women with post partum thyroiditis than men.
3) Iron supplementation
Iron is important for the production of proteins that synthesize thyroid hormones,thus low iron level will lead to thyroid gland malfunctioning. Iron rich diet is an important preventive factor in Hashimoto disease especially in anemic women.
Selenium inoculation control the level of autoantibodies thus decreases the severity of hypothyroidism. Additionally, selenium-containing drugs like selenomethionine can decrease harmful thyroid antibodies.
5)correcting TH1,TH2 ,TH17 dominance
If irregularities inimmune cells and their associated proteins are corrected it will help to treat Hashimoto disease.
6) Vitamin B12
Vit B 12 deficency is common in hypothyroidism thus maintaining its level through diet decreases the symptoms of Hashimoto diseases like depression anf fatigue.
Melatonin hormone is synthesized by body pineal gland and performs the role of controlling the sleep-wake cycle.
Fatigue and sleep apnea related disorders due to thyroid malfunction are effectively treated by melatonin. Day exposure to sunlight produce natural melatonin that is also helpful in maintaining circadian rhythms
However, too much melatonin is a problem. Contrast to healthy individual people with autoimmune disorders produces excessive melatonin at night. The higher level of melatonin produces inflammatory response due to cytokines. It also damages the thyroid gland and its hormone secretion.
Low level of melatonin helps in effective sleep.
Stem cell therapy is commonly used in women to treat Hashimoto disease.It corrects imbalance of thyroid autoantibodies.Stem cells prevent activation of T cells that damage thyroid cells.
A diet with low carbohydrates and goitrogen and adequate iron, selenium.vit B12, is effective in preventing Hashimoto disease.