pem lab h tiroid
TRANSCRIPT
-
7/24/2019 Pem Lab h Tiroid
1/40
Maimun ZA
Clinical Pathology Dept Medical
Faculty Brawijaya Univ
-
7/24/2019 Pem Lab h Tiroid
2/40
-
7/24/2019 Pem Lab h Tiroid
3/40
Structure of thyroid follicle -Euthyroid follicle
Thyroid C-cell
Basal membrane of epithelialcellsApical membrane of epithelialcells
Cuboidal epithelialcells
Basementmembrane
Colloid(glycoprotei
n)
Capillary(Rich blood
supply)
-
7/24/2019 Pem Lab h Tiroid
4/40
Physiology
The thyroid follicles secretes tri-iodothyronine(T)andthyro!in(T")synthesis in#ol#es combination ofiodine $ith tyrosine group to form mono and di-iodotyrosine $hich are coupled to form T andT"%
The hormones are stored in follicles bound tothyrogobulin %
&hen hormones released in the blood they arebound to plasma proteins and small amountremain free in the plasma %
The metabolic e'ect of thyroid hormones are due tofree (unbound)T and T"%
*of secreted hormones is T" but Tis the acti#ehormone so+ T"is con#erted to T peripherally%
-
7/24/2019 Pem Lab h Tiroid
5/40
Synthesis and libration of T and T" iscontrolled by thyroid stimulatinghormone(TS,)secreted by anterior pituitary
gland%TS, release is in turn controlled by thyrotropin
releasing hormone (TR,)from hypothalamus %Circulating Tand T" e!ert #e feedbac.
mechanism on hypothalamus and anterior
pituitary gland %So+ in hyperthyroidism $here hormone le#el in
blood is high +TS, production is suppressedand #ice #ersa
-
7/24/2019 Pem Lab h Tiroid
6/40
-
7/24/2019 Pem Lab h Tiroid
7/40
-
7/24/2019 Pem Lab h Tiroid
8/40
Hormone properties T4
T3
Total serum concentrations / 0g1dl %2"0g1dl
3raction of total hormone in
free form (serum)
%4 * % *
3ree (unbound hormone) inserum
42 5 2-24
67 5 2-24
6
Serum half life 8 d %89 d
3raction directly from thethyroid
2 * 4 *
Production rate+ includingperipheral con#ersion
0g1d 4 0g1d
:ntracellular hormone fraction ; 4 * ; 8 *
Characteristics of Circulating T"
and T
-
7/24/2019 Pem Lab h Tiroid
9/40
3unctions
ofthyroid hormones
-
7/24/2019 Pem Lab h Tiroid
10/40
3unctions of thyroid hormones
Generally, THs:
2% :ncreases metabolic rate% Stimulates increased
consumption of glucose+ fattyacids and other molecules%
4% :ncreases metabolic heat+ by mitochondrial no < acti#ity ATP+
% Stimulates rate of cellularrespiration by=
Production of uncouplingproteins%
:ncrease acti#e transport by>a? @? um s%
-
7/24/2019 Pem Lab h Tiroid
11/40
"% >ecessary for normal gro$th recycle synthesis of !IT< ITaccumulate%
!IT< IT$ill not be used for ne$T,s formation
THs%
-
7/24/2019 Pem Lab h Tiroid
20/40
::= ,ypothyroidism (my!edema) cont%
Symptoms o Hypothyroidism:- Jecreased metabolic rate%
- Slo$ heart rate < pulse% - Slo$ muscle contractions
- appetite+ $eight gain+ eed to loo. for other pituitarydeMciencies%
:f TS, is h < 3T" < 3T are normal $e call this condition
s$'clinical hypothyroidism
-
7/24/2019 Pem Lab h Tiroid
22/40
::= ,ypothyroidismChildren (Cretinism)
,ypothyroidism in childrenT,s%
,ypothyroid from end of 2st
trimester to 7 monthspostnatally+ or in the 2stfe$
years of life%
T3< T4ree! TSH% %dditional Si"ns * Symptoms:
+ Se#ere mental retardation% + Short stature (due to gro$th of
bones+ muscle+ < brain)%
-
7/24/2019 Pem Lab h Tiroid
23/40
Thyroid >odule
ery common
7 years old Q "%4* ( Palpation)
2 78* by ultrasound
Autopsy Q 9*
Thyroid Cancer is rare Q " 1 2+
cult thyroid cancer in 7 4" *autopsy
-
7/24/2019 Pem Lab h Tiroid
24/40
Thyroid >odule 4
Thyroid nodule #ery common
Thyroid cancer #ery rare butcurable
AIM IS NOT MISS THYROID CANCER
-
7/24/2019 Pem Lab h Tiroid
25/40
Thyroid nodule Risk factors
E!posure to radiation as child
3amily history
Lnder 4 years
#er 7 years
O male se!
,ourseness
3i!ed hard nodule Similar ris. for multinodular and
single nodule
-
7/24/2019 Pem Lab h Tiroid
26/40
Thyoid >oduleInvesigations
T3Ts
Lltra sound scan
Thyroglobulin and Calcitonin notrecommended ( LS uidelines)
3ine needle Aspration(3>A)
-
7/24/2019 Pem Lab h Tiroid
27/40
,ashimotoDs Thyroiditis
Symptoms * Si"ns:
Lsually presents $ith goitre in a patient $ho iseuthyroid or has mild hypothyroidism
Se! distribution= four females to one maleThe process is painless
lder patients may present $ith se#erehypothyroidism $ith only a small+ Mrm atrophicthyroid gland
Transient symptoms of thyroto!icosis can occurduring periods of hashito!icosis (spontaneously
resol#ing hyperthyroidism)
-
7/24/2019 Pem Lab h Tiroid
28/40
,ashimotos Thyroiditis
a': >ormal or lo$ thyroid hormone
le#els+ and if lo$+ TS, is ele#ated
,igh Tg Ab and1or TP Ab titres 3>A b! re#eals a large inMltrationof lymphocytes PKLS ,urthle cells
-omplications:
Permanent hypothyroidism (occursin 2-29* of young pts)
Rarely+ thyroid lymphoma
-
7/24/2019 Pem Lab h Tiroid
29/40
Thyroid 3unction Tests
TS, Thyro!ine (T") (free 1 total)
Ttriiodothyronine (T) (free 1 total)
Thyroid Antibodies= Autoimmune
thyroid disease is detected bycirculating antibodies against TP andTg%
:maging
Thyroid Lltrasound scan
Thyroid :sotope Scan
-
7/24/2019 Pem Lab h Tiroid
30/40
uidelines The diagnosis of primary hypothyroism
reuires the measurement of both TS, andT" Patients $ith type-2 diabetes should ha#e a
chec. of thyroid function included in their
annual re#ie$% Patients $ith type-4 diabetes
should ha#e their function chec.ed atdiagnosis but routine annual thyroid functiontesting is not recommended
Patients stabilised on long term thyro!ine
treatment should ha#e TS, chec.ed annually
-
7/24/2019 Pem Lab h Tiroid
31/40
uidelines The thyroid status of hypothyroid patients
should be chec.ed $ith TS, ? T" during eachtrimester:deally the follo$ing seuence of T3T should be
performed in the hypothyroid $omen duringpregnancy
Before conception At time of diagnosis of pregnancy At antenatal boo.ing At least once in 4ndand rdtrimester Again after deli#ery at 4 " $ee.s post partum
>e$ly diagnosed hypothyroid $ill need testinge#ery " 7 $ee.s until stable
-
7/24/2019 Pem Lab h Tiroid
32/40
Thyroid Antibodies
Thyroid Pero!idase(thyroid microsomal)
100% in Hashimato thyroiditis
87% with graves disease
Thyroglobulin Antibody 76% of Graves Disease
Thyroid receptor antibody
Normally resent in 1! "18 % offemale o#lation
6 TS,
-
7/24/2019 Pem Lab h Tiroid
33/40
6easure TS,
Ele#ated
>ormal
6easure unbound T" Pituitary disease
suspected
>ormal yes>oKo$
6ild
hypothyroidism
Primaryhypothyroidi
sm
>o
furthertest
6easure
unboundT"
TP Ab(?)or
symptomatic
TP Ab(-)
or no
symptoms
TPAb(?)
TPAb (-)
>o
furthertest
>ormal
Ko$
Rule out drug e'ects+sic. euthyroid
syndrome+ then
E#aluate anterior
Rule out othercauses of
hypothyroidismAutoimmune
hypothyroidismT" treatment
Annual follo$up T" treatment
Application of TS, e!amination
-
7/24/2019 Pem Lab h Tiroid
34/40
I-%s. /01
ioassayary insensitiityInconinient
RI%sSensitiity 1m$-ross reaction . 15Hypothyroid
IR%sSensitiity
1/ + 2// x RI%s Hypo 6e$thyroid
HyperthyroidTSH /0/7 + /011m$
8$thyroid/04 9 40/
Hypothyroid4 m
!etection
Imm$noassayI : 7 9 ; m
II: /01 9 /02
Imm$noassayIII:/0/1 9 /0/2
I: /0//1 9 /0//2
I II
Application of TS, e!amination
Autoimmune Thyroiditis (A:T)
-
7/24/2019 Pem Lab h Tiroid
35/40
AutoimmuneThyroiditis (A:T)
Anti Tg
Cytoplasma
follicular
Complemen
t acti#ation
(-)
Anti TP
29 .Ja+ microsomal
Thyroid pero!idase
enNyme
Pos correlation= anti TP
< PPTJ
Complement acti#ation
(?)
AntiTS,-R
,yperthyroid
,ypothyroid :n J
Ab bispeciMc= Ab TP more freuent < higher than ant
nly anti TP (?)= rare
Anti TP < anti Tg in J= not established (discussion)
Routine detection Ab thyroid= only anti TP
-
7/24/2019 Pem Lab h Tiroid
36/40
Ab
bispeciMcPPTJ= 27 *
> population= 2%"
*
Pre#alence of anti
TPPPTJ (post partum
thyroiditis)= 27 *
ra#eDs disease= "%7 *
,asimoto thyroiditis= "%9 *Anti TP < A:T
Clinical rele#ancy= not clearly
Correlation $ith acti#e clinical
disease
Strong correlation $ith ris. of
-
7/24/2019 Pem Lab h Tiroid
37/40
Anti TP for predict PPTJ
ariation of sensiti#ity < speciMcity
Jepend on $hen anti TP e!amined
PPTJ (-) $hen anti TP (-)
Screening anti TP in early pregnancy
-
7/24/2019 Pem Lab h Tiroid
38/40
-
7/24/2019 Pem Lab h Tiroid
39/40
Serum Tg E!amination
>ot distinguished= PPTJ < J
:nterference= serum anti Tg
(reaction of anti Tg ? anti Tg
antibody in immunoassay .it)+
e!amination simultaneously Tg? anti Tg
-
7/24/2019 Pem Lab h Tiroid
40/40