Diagnostic test for Thyriod disorders in children.pptx

1. azad82d@gmail.com
azad.haleem@uod.ac
Dr.Azad A Haleem AL.Mezori
MRCPCH,DCH, FIBMS
Assistant Professor
University Of Duhok
College of Medicine
Pediatrics Department
Diagnostic test for Thyriod
disorders in children
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2. Key points
• TSH Test
• Total T3
• Free T3
• Total T4
• Free T4
• TPO: Thyroid peroxidase

3. Introduction
• The thyroid gland makes hormones that control
metabolism, heart rate, body temperature, and
other body functions.
• Disorders of the thyroid gland are among the
most common endocrine disorders.
• Thyroid problems in children may include:
Goiter, Hyperthyroidism, Hypothyroidism,
Thyroid cancer, Thyroid nodules, Thyroiditis.

4. TSH
• Role
• Screening for primary hypothyroidism.
• For monitoring response to therapy in case of primary
thyrotoxicosis.
• Pre-analytical issues
• Timing
• Any time of day
• TSH should be assessed 6-8 weeks after dose initiation
• Container
• In plain-tube (serum).
• Transport
• Transport refrigerated.

5. TSH
• Reference range
• First 48 hour- 3.2–34 mIU/ml (3.2-34 IU/L)
• 3 – 7 days- 3–10 mIU/ml (3-10 IU/L)
• 1 – 4 weeks- 1.7–9.1 mIU/ml (1.7-9.1 IU/L)
• 1 – 12 months- 0.8–8.2 mIU/ml (0.8–8.2 IU/L)
• 1 – 19 years- 0.5–4.30 mIU/ml (0.5–4.30 IU/L)
• Interpretation
• Level should be interpreted in light of free T4 (FT4).
• Slightly elevated (up to 20 mIU/ml), normal or low level of TSH with
suggest central hypothyroidism.
• Slightly elevated (4.5–10 mIU/ml) with normal FT4 suggests
• Undetectable TSH with high free T4 and T3 suggests primary
• Detectable TSH with high free T4 and T3 suggest TSH secreting
hormone resistance.
• Low TSH with normal free T4 and T3 suggests subclinical

6. Total T3
• Role
• Diagnosis and follow-up of thyrotoxicosis (T3 toxicosis).
• Timing: Any time of day.
• Container: In plain-tube (serum).
• Transport: Refrigerated.
• Reference range
• 1 – 3 days- 89–405 ng/dL (1.3–6.22 nmol/L)
• 1 – 11 months- 91–300 ng/dL (1.4–4.6 nmol/L)
• 1 – 9 years- 85–250 ng/dL (1.3–3.8 nmol/L)
• 10 – 13 years- 127–221 ng/dL (1.9–3.4 nmol/L)
• 14 – 18 years- 97–186 ng/dL (1.5–2.9 nmol/L).
• Interpretation
• Increased T3 with normal T4 and low TSH level indicates T3
toxicosis.

7. Free T3
• Role
• Diagnosis and follow-up of thyrotoxicosis (T3 toxicosis).
• Timing: Any time of day.
• Container: In plain-tube (serum).
• Transport: Refrigerated.
• Reference range
• 1 – 3 days- 89–405 ng/dL (1.36–6.22 nmol/L)
• 1 – 11 months- 91–300 ng/dL (1.4–4.6 nmol/L)
• 1 – 9 years- 85–250 ng/dL (1.3–3.8 nmol/L)
• 10 – 13 years- 127–221 ng/dL (1.9–3.4 nmol/L)
• 14 – 18 years- 97–186 ng/dL (1.5–2.9 nmol/L).
• Interpretation
• Increased T3 with normal T4 and low TSH level indicates T3
toxicosis.

8. Total T4
• Role: Thyroid function assessment.
• Timing
• Any time of day in the absence of thyroid medications.
• T4 level should be done before the morning dose of
levothyroxine if on treatment.
• Container: Plain-tube (serum).
• Transport: Transport refrigerated.
• Reference range
• 0 to 5 days- 5-18.5 mcg/dL (64.4 – 238.1
nmol/L)
• 6 days to 2 months- 5.4-17 mcg/dL (69.5 – 218.7
nmol/L)
• 3-11 month- 5.7-16 mcg/dL (73.3 – 205.9
nmol/L)
• 1-5 years- 6-14.7 mcg/dL (77.2 – 189.2
nmol/L)
• 6-10 years- 6-13.8 mcg/dL (77.2 – 177.6
nmol/L)

9. Total T4
• Interpretation
• Total T4 level can be altered in conditions associated with
binding protein abnormality (nephrotic syndrome, liver
disease, TBG deficiency, estrogen or androgen use).
• High T4 indicates thyrotoxicosis while low level suggests
hypothyroidism.
• High TSH with low T4 suggests primary hypothyroidism.
• TSH level up to 20 with low T4 suggests central
hypothyroidism.
• TSH levels between 4.5 –10 with normal T4 suggest
subclinical hypothyroidism.
• Undetectable TSH with high T4 and T3 suggests
thyrotoxicosis.
• Low TSH with normal T4 and T3 suggest subclinical
thyrotoxicosis.
• High T4 and TSH during treatment of hypothyroidism suggest
poor compliance with a recent intake of thyroid medications.

10. Free T4
• Role
• Identification of hypothyroidism and thyrotoxicosis.
• For monitoring response to therapy in hypothyroidism and
thyrotoxicosis.
• Pre-analytical issues
• Timing
• Any time of day in a child not on thyroid medications
• In a child on levothyroxine therapy, the FT4 level should be done
before morning dose of levothyroxine.
• Container: Plain-tube (serum).
• Transport: Transport refrigerated.
• Reference range
• 1 to 3 days- 0.8-2.8 ng/dL (10.3-36 pmol/L)
• 4 to 30 days- 0.48-2.32 ng/dL (6.2-29.8 pmol/L)
• 1 to 11 months- 0.7-2 ng/dL (9-25.74 pmol/L)
• 1 to 5 years- 1.05-2.48 ng/dL (13.5-31.9 pmol/L)
• 6 to 10 years- 0.9-2.3 ng/dL (11.6-29.6 pmol/L)
• Above 10 years- 0.92-2.02 ng/dL (11.8-26 pmol/L)

11. Free T4
• Interpretation
• High FT4 indicates thyrotoxicosis, low level suggests
hypothyroidism and normal level indicates euthyroid state.
• The level should be interpreted in light of TSH.
• High TSH with low free T4 suggests primary hypothyroidism.
• Slightly elevated (up to 20 mU/L) or normal or low level of
TSH with low FT4 suggests central hypothyroidism.
• Slightly elevated (4.5-10 mU/L) with normal FT4 suggests
subclinical hypothyroidism.
• Undetectable TSH with high free T4 and T3 suggests
thyrotoxicosis.
• Low TSH with normal free T4 and T3 suggests subclinical
thyrotoxicosis.
• High FT4 and TSH levels in a treated child with
hypothyroidism suggest poor compliance and a recent intake
of thyroid medications.

12. TPO: Thyroid peroxidase
• Role
• To delineate the cause of acquired
hypothyroidism.
• To decide the need for treatment in subclinical
hypothyroidism
• Timing: At any time of the day.
• Container: In plain-tube (serum)
• Transport: Transport refrigerated.
• Reference range: Less than 35 IU/mL
• Interpretation:
• The level twice the upper limit of normal
suggests a positive test.

13. THANKS FOR YOUR
Attention