Chronic lymphocytic thyroiditis, also known as Hashimoto's thyroiditis, is the most common cause of thyroid disease in children and adolescents. It results from an autoimmune response against thyroid cells. The thyroid gland becomes inflamed and damaged over time from lymphocyte and plasma cell infiltration. This can lead to hypothyroidism. The disease is usually diagnosed based on the presence of antithyroid antibodies and is often treated with levothyroxine hormone replacement if hypothyroidism develops.

1. Chronic Lymphocytic
Thyroiditis
(Hashimoto Thyroiditis,
Autoimmune Thyroiditis)
Prof. Dr. Saad S Al Ani
Senior Pediatric Consultant
Head of Pediatric Department
Khorfakkan Hospital ,Sharjah, UAE
anahbaghdad@gmail.com

2. Background
Chronic lymphocytic thyroiditis
The most common cause of thyroid disease in children
and adolescents
The most common cause of acquired hypothyroidism,
with or without goiter.
One to 2% of younger school-age children and 6-8%
of adolescents have positive antithyroid antibodies as
evidence of autoimmune thyroid disease.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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3. Etiology
 Inheritance of susceptible genes involved in
immunoregulation ??
AND
Environmental triggers ??
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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4. Sequence of thyroid gland involvement
 Lymphoid follicle formation with germinal centers is almost always present
 The degree of atrophy and fibrosis of the follicles varies from mild to moderate.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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Thyroid hyperplasia
Infiltration of
lymphocytes and
plasma cells
between the follicles
Atrophy of the
follicles

5. Infiltrating cells
Approximately 60% of infiltrating lymphoid cells
are T cells, and approximately 30% express B-cell
markers
 The T-cell population is represented by helper
(CD4 +) and cytotoxic (CD8 + ) cells.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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6. Infiltrating cells (Cont.)
 Human leukocyte antigen (HLA) haplotypes:
 HLA-DR4 & HLA-DR5 :
Are associated with an increased risk of
goiter and thyroiditis
 HLA-DR3:
Are associated with the atrophic variant of
thyroiditis.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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7. Thyroid antigen autoantibodies
A variety of different thyroid antigen autoantibodies are also
involved.
 Thyroid antiperoxidase antibodies (TPO-Abs)
 Antithyroglobulin antibodies (anti-Tg Abs)
Are demonstrable in the sera of 90% of children with
chronic lymphocytic thyroiditis
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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8. Thyroid antigen autoantibodies (Cont.)
TPO-Abs are involved in:
o Activation of the complement cascade
o Antibody-dependent, cell-mediated cytotoxicity.
Anti-Tg Abs do not appear to play a role in the autoimmune
destruction of the gland.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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9. Cont.
 Thyroid-stimulating hormone (TSH) receptor–
blocking antibodies
o Are related to the development of hypothyroidism
and thyroid atrophy
o they have been demonstrated in 18% of patients
with severe hypothyroidism (TSH >20 mU/L)
caused by autoimmune thyroiditis.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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10. Cont.
 Antibodies to pendrin,
oan apical protein on thyroid follicular cells
o have been demonstrated in 80% of children with
autoimmune thyroiditis.
 Antibodies against the sodium–iodide symporter
their pathogenic role is unclear.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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11. Clinical Manifestations
The disorder is 4-6 times more common in girls than
in boys.
 It can occur during the 1st 3 yr. of life
Becomes sharply more common after 6 yr. of age
and reaches a peak incidence during adolescence.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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12. Clinical Manifestations (Cont. )
The most common clinical manifestations are goiter
and growth retardation.
 The goiter can appear insidiously and may be small
or large.
 In most patients, the thyroid is diffusely enlarged,
firm, and nontender.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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13. Clinical Manifestations (Cont. )
In approximately 30% of patients, the gland is
asymmetric and can seem to be nodular.
Most of the affected children are clinically euthyroid
and asymptomatic; some may have symptoms of
pressure in the neck, including difficulty swallowing
and shortness of breath.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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14. Clinical Manifestations (Cont. )
Some children have clinical signs of hypothyroidism,
but others who appear clinically euthyroid have
laboratory evidence of hypothyroidism.
A few children have manifestations suggesting
hyperthyroidism, such as nervousness, irritability,
increased sweating, and hyperactivity, but results of
laboratory studies are not necessarily those of
hyperthyroidism
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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15. Clinical course
The clinical course is variable.
The goiter might:
 Become smaller
 Disappear spontaneously
 Persist unchanged for years while the patient remains
euthyroid.
Most children who are euthyroid at presentation remain
euthyroid, although a percentage of patients acquire
hypothyroidism gradually within months or years.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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16. Clinical course (Cont.)
In children who initially have mild or subclinical
hypothyroidism (elevated serum TSH, normal free
thyroxine[T4]level), over several years approximately:
 40% revert to euthyroidism
 50% continue to have subclinical hypothyroidism,
 10% develop overt hypothyroidism (elevated serum
TSH, subnormal free T 4 level).
Chronic lymphocytic thyroiditis is the cause of most
cases of nongoitrous (atrophic) hypothyroidism
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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17. Other associated autoimmune disorders
 The disorder is associated with many other autoimmune
disorders.
 Autoimmune thyroiditis occurs in:
 10% of patients with type I autoimmune polyglandular
syndrome (APS-1)
 70% of patients with APS-2
 Immunodysregulation polyendocrinopathy enteropathy X-linked
(IPEX) syndrome
 Associated with pernicious anemia, vitiligo, or alopecia
 Children with congenital rubella.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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18. Associated with chromosomal disorders
 Chronic lymphocytic thyroiditis also is associated with certain
chromosomal disorders, particularly Turner syndrome and
Down syndrome.
 In children with Down syndrome:
28% had antithyroid antibodies (predominantly anti-TPOs)
7% had subclinical hypothyroidism
7% had overt hypothyroidism,
5% had hyperthyroidism
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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19. Associated with chromosomal disorders (Cont.)
 In a study of girls with Turner syndrome
41% had antithyroid antibodies (again, predominantly
anti-TPOs),
18% had goiter
 8% had subclinical or overt hypothyroidism.
 Autoimmune thyroid disease increased from the 1st
(15%) to the 3rd (30%) decade of life.
 Boys with Klinefelter syndrome appear to be at risk for
autoimmune thyroid disease
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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20. Laboratory Findings
 Thyroid function tests (free T 4 and TSH) are often normal
 In some patients, the level of TSH may be slightly or even
moderately elevated which is termed subclinical
hypothyroidism.
 Many children do not have elevated levels of TSH (indicates
that the goiter is caused by:
 Lymphocytic infiltrations
or
 Thyroid growth-stimulating immunoglobulins.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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21. Laboratory Findings (Cont.)
In young children with chronic lymphocytic thyroiditis
have serum TPO-Abs and the anti-Tg Abs are
positive in <50%.
In adolescents with chronic lymphocytic thyroiditis,
TPO-Abs and anti-Tg Abs are found equally.
When both tests are used, approximately 95% of
patients with thyroid autoimmunity are detected.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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22. Laboratory Findings (Cont.)
 Levels in children and adolescents are lower than
those in adults with Hashimoto thyroiditis,
In adolescent females with overt hypothyroidism,
measurement of TSH receptor–blocking antibodies
may identify patients at future risk of having babies
with transient congenital hypothyroidism.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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23. Laboratory Findings (Cont.)
Thyroid scans and ultrasonography usually are not
needed.
The definitive diagnosis can be established by
biopsy of the thyroid; this procedure is rarely
clinically indicated.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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24. Histopathology
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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25. Treatment
If there is evidence of overt hypothyroidism (elevated
TSH, low T 4 or free T 4) , replacement treatment with
levothyroxine (at doses specific for size and age) is
indicated.
The goiter usually shows some decrease in size but
can persist for years.
 In a euthyroid patient, treatment with suppressive
doses of levothyroxine is unlikely to lead to a
significant decrease in size of the goiter.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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26. Treatment (Cont.)
Antibody levels fluctuate in both treated and untreated
patients and persist for years.
The disease is self-limited in some instances, so the
need for continued therapy requires periodic
reevaluation.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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27. Treatment (Cont.)
Untreated patients should also be checked periodically.
Concerning subclinical hypothyroidism (elevated TSH,
normal T 4 or free T 4 ), It is preferable to treat such
children until growth and puberty are complete, and
then reevaluate their thyroid function.
8/29/2017Chronic lymphocytic thyroiditis Prof. Dr. Saad S Al Ani
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28. References
 Brown RS: Autoimmune thyroiditis in childhood. J Clin Res Pediatr Endocrinol 2013; 5: pp. 45-49.
 de Vries L, Bulvik S, Phillip M: Chronic autoimmune thyroiditis in children and adolescents: at presentation and during long-term follow-up. Arch Dis
Child 2009; 94: pp. 33-37.
 Fava A, Oliverio R, Giuliano S, et. al.: Clinical evolution of autoimmune thyroiditis in children and adolescents. Thyroid 2009; 19: pp. 361-367.
 Zimmermann MB, Hess SY, Molinari L, et al., New reference values for thyroid volume by ultrasound in iodine-sufficient schoolchildren: a World
Health Organization/Nutrition for Health and Development Iodine Deficiency Study Group Report. Am J Clin Nutr 79 (2004) 231-237
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