Hashimoto's Thyroiditis

Aslam MataniaGroup-3TSMU

Hashimoto's Thyroiditis

what is it …. Hashimoto's thyroiditis is an

autoimmune disease in which the thyroid gland is attacked by a variety of cell- and antibody-mediated immune processes, causing primary hypothyroidism

This form of thyroid disease may also be referred to as chronic lymphocytic thyroiditis.

The name Hashimoto thyroiditis is derived from the 1912 report by Hashimoto describing patients with goiter and intense lymphocytic infiltration of the thyroid (struma lymphomatosa)

Epidemiology This disorder is believed to be the most

common cause of primary hypothyroidism in North America; as a cause of non-endemic goiter

An average of 1 to 1.5 in 1000 people have this disease.in india secreened 6283 people and they found 58 having this

It occurs between eight and fifteen times more often in women than in men

observed in women between 30 and 60 years of age

Risk factors These factors may contribute to your risk of

developing Hashimoto's disease: Sex. Women are much more likely to get Hashimoto's

disease. Age. Hashimoto's disease can occur at any age but

more commonly occurs during middle age. Heredity. You're at higher risk for Hashimoto's

disease if others in your family have thyroid or other autoimmune diseases.

Other autoimmune disease. Having another autoimmune disease — such as rheumatoid arthritis, type 1 diabetes or lupus — increases your risk of developing Hashimoto's disease.

causes The exact cause of Hashimoto is not

know but many factors are believed to play role .

THEY INCLUDE – HORMONES EXCESSIVE IODINE RADIATION EXPOSURE

Pathogenesis Hashimoto thyroiditis is an autoimmune

disease in which the immune system reacts against a variety of thyroid antigens.

There is progressive depletion of thyroid epithelial cells (thyrocytes), which are gradually replaced by mononuclear cell infiltration and fibrosis.

Sensitization of autoreactive CD4+ T-helper cells to thyroid antigens appears to be the initiating event.

The effector mechanisms for thyrocyte death include the following: CD8+ cytotoxic T cell-mediated cell death: CD8+

cytotoxic T cells may cause thyrocyte destruction by one of two pathways: exocytosis of perforin/granzyme granules or engagement of death receptors, specifically CD95 (also known as Fas) on the target cell   

Cytokine-mediated cell death: CD4+ T cells produce inflammatory cytokines such as IFN-γ in the immediate thyrocyte milieu, with resultant recruitment and activation of macrophages and damage to follicles.

Binding of antithyroid antibodies (anti-TSH receptor antibodies, antithyroglobulin, and antithyroid peroxidase antibodies) followed by antibody-dependent cell-mediated cytotoxicity (ADCC)

The effector mechanisms for thyrocyte death:

Morphology

Morphology The thyroid is often diffusely enlarged.

The capsule is intact.

the gland is well demarcated from adjacent structures.

The cut surface is pale, yellow-tan, firm, and somewhat nodular.

Morphology

Symmetric enlargement with tan yellow cut surface.

Intact capsule.

Note the coarse facial features which include periorbital edema (puffy eyes), and thickened skin

Microscopic examination

• Electron microscopy image of thyroid tissue from a patient with Hashimoto’s thyroiditis, showing electron dense deposits of IgG and TG along the basement membrane of follicular cells.

INSERT NORMAL PIC HERE

NORMAL THYROID

CHRONIC LYMPHOCYTIC THYROIDITIS

lymphoid aggregates with germinal center formation within the thyroid tissue itself.  left, you can see the clusters of lymphocytes as well as areas fibrosis giving a lobulated look to the thyroid in general.

In areas of attempted regeneration you will see enthusiastic and stimulated follicular cells we call Hurthle cells. These are large, brightly pink stained cells that may or may not be seen to in direct association with a follicle

The symptoms: many of the symptoms associated with thyroid

hormone deficiency. Fatigue Drowsiness Difficulty with learning Dry, brittle hair and nails Dry, itchy skin Puffy face Constipation. Weight gain Heavy menstrual flow Increased frequency of miscarriages Increased sensitivity to many medications.

Complication GOITER HEART PROBLEM MENTAL HEALTH ISSUES MYXEDEMA BIRTH DEFECTS

Diagnosis TSH TEST-ultrasensitive test is usually

the first test performed .it detects even tiny TSH in blood TSH reading above normal mean person has hypothyroidism

T4 TEST –measure actual amount of thyroid hormone circulating in blood level of T4 in blood is lowered than normal

ANTITHYROID ANTIBODY-it looks for the presence of thyroid autoantibody

OTHER TEST –ultrasound CT scan

TREATMENT SYNTHETIC HORMONES -levothyroxine MONITORING DOSAGE -a tablet taken

keeps hormone level normal LOW LEVEL LASER THERPY - low level

infrared therpy proven effective GLUTEN FREE DIET -may reduce

autoimmune response for thyroid degeneration