diagnostic vhb

7/30/2019 Diagnostic VHB

1/23

DIAGNOSTIC DE LABORATOR

IN HEPATITA CU V.H.B


2/23

ALGORITM DE DIAGNOSTIC IN

HEPATITE

1. Tablou clinic

2. Teste biochimice Markerii necrozei hepatocitare (transaminaze, LDH)

Markeri colestaza (FAL, GGT, bilirubina)

Markeri ai incapacitatii de sinteza la nivel hepatic (proteine serice,colesterol, trigliceride)

3. Date epidemiologice: cale transmitere, contactinfectant, per. incubatie, vaccinuri

4. Diagnostic etiologic = detectia markerilorvirali:

antigene virale (ag)

anticorpi antivirali (anti)


3/23

Tablou clinic

Icter sclerotegumentar

Astenie fizica

Apetit scazut Febra

Diaree

Urini hipercrome

Scaune decolorate

Nu toate persoanele au tablou clinic manifest.

Adultii si tinerii au manifestari clinice mai frecvent decat copiii.


4/23

AInfectious

Serum

Viralhepatitis

Entericallytransmitted

Parenterallytransmitted

other

E

NANB

B

D

C

HEPATITE VIRALE

PERSPECTIVA ISTORICA


5/23

Source of

virus

Feces

25d (15-50)

blood/

blood-derivedbody fluids

blood/


blood/


Feces

40d (15-60)

Route oftransmission

fecal-oralpercutaneous

permucosal

percutaneouspermucosal

percutaneous

permucosal

fecal-oral

Chronicinfection no yes yes yes no

Prevention pre/post-exposure

Immunization

pre/post-exposure

Immunization

blood donorscreening;

risk behaviormodification

pre/post-exposure

immunization;risk behavior

modification

ensure safedrinking

water

Viral Hepatitis - An Overview

Type of Hepatitis

A B C D E


6/23

Diagnostic V.H.B.


7/23

Structura VHB

ADN/VHB

AgHBc (antigen de centru)

AgHBe(marker deinfectivitate)

AgHBs (antigen desuprafata)

clivare


8/23

Sisteme antigenice VHB

Ag HBs Ac antiHBS

Ag HBc Ac antiHBc

Ag HBe Ac antiHBe


9/23

ETAPE

1. Incubare ser pacient 1h la 37C2. Spalare

3. Incubare conjugat 30min la 37C4. Spalare5. Incubare substrat 20 min la t.camerei6. Citire la spectrofotometru

ELISA de detectie a Ag virale

Ag HBs

Anti HBs

Anti HBs cuplatcu o enzima =conjugat


10/23

Stadii ale infectieio cu V.H.B

Acute Hepatitis B

Chronic Persistent Hepatitis (AgHBe negativ)

Chronic Active Hepatitis (Ag HBe pozitiv)

> Cirrhosis> Hepatocellular Carcinoma

{


11/23

Simptome

AgHBeADN/VHB

anti-HBe

anti-HBc totali

anti-HBc IgM anti-HBsAgHBs

0 4 8 12 16 20 24 28 32 36 52 100

Infectia acuta cu VHB evolutie spre vindecare

Saptamini post expunere


12/23

IgM anti-HBc

Total anti-

HBc

HBsAg

Acute(6 months)

HBeAg

Chronic(Years)

anti-HBe

0 4 8 12 16 20 24 28 32 36 52 Years

Weeks after Exposure

Infectia cronica cu VHB

ALGORITHM OF LABORATORY DIAGNOSIS


13/23

ALGORITHM OF LABORATORY DIAGNOSIS

HBsAg-

ELISA

Positive=contactwith HBV

negativeAnti-HBc IgM

Positive=

acute

hepatitis B

Negative = must

detect Anti-HBcIgG

Negative =posible

HBsAg

carrier,investigate

Positive=

chronichepatitis B must

detect HBeAg

Positive=

chronic active

hepatitis Negative= chronicpersistent hepatitis

positive=

acutehepatitis B

Negative=nohepatitis B


14/23

Diagnostic molecular in

infectia V.H.B

AMPLIFICAREA TINTEI- PCR

AMPLIFICAREA SEMNALULUI- B-DNA (branched DNA)


15/23

PCRMetoda utilizata pentru detectia ADN-ului de orice tip.

PCR A lifi T t d


16/23

PCR Amplifies a Targeted

SequenceTarget Sequence

DNA Strand

Double Helix

DNA StrandSupercoiled

DNA Strand

Chromosome


17/23

PCR C l St 1


18/23

PCR Cycle - Step 1 -

Denaturation by Heat

Target Sequence

Target Sequence


19/23

PCR Cycle - Step 2 - Primer Pair

Anneals to Ends of Target Sequence


20/23

End of the 1st PCR Cycle - Results in Two

Copies of Target Sequence


21/23

Target Amplification

No. of No. AmpliconCycles Copies of

Target

1 2

2 4

3 8

4 16

5 32

6 64

20 1,048,576

30 1,073,741,82

1 cycle = 2 Amplicon








22/23

Monitorizarea evolutiei naturale /subtratament a hepatitei virale B

Riscul de ciroza creste cu nivelul iv, atat pt persoanele

AgHBe negative, cat si pt cele AgHBe pozitive

Initiere tratamentului pt hepatita cronica BLa persoanele AgHBe negative, iv >10.000 copii/ml indica

infectie activa (marker de infectivitate virala). Tratamentul

este initiat pe baza

PBH iv

Transaminaze serice


23/23

Virus si test Riscrezidual

prin triaj

serologic

Risc rezidual

prin testare

acizi nucleici

Reducere

a riscului

Cost

Per test

(USD)

VHB - ADN/PCR 15.83 9.12 42.4% 30

VHC

ARN/Rt- PCR9.7 2.72 72.0% 200

HIV - Ag p24

2.03

1.48 27.3% 5

HIV - ADN/PCR 1.48 27.3% 50HIV

ARN/Rt-PCR1.01 50.0% 200

Reducerea riscului rezidual asociat transfuziilor

diagnostic vhb

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