EXPERIMENT 16 Flashcards
is an enveloped flavivirus
Hepatitis C virus
It is small, enveloped, single – stranded RNA virus.
Hepatitis C virus
Hepatitis C, previously called (?), was regarded as a diagnosis of exclusion because of the absence of specific serologic markers and unknown viral origin.
non – A, non – B (NANB) hepatitis
This also the reason why we are not testing the presence of antigen but the presence of the (?).
antibody
The HCV is most commonly caused
transfusion associated hepatitis
Since antibody is being tested, we should wait or the (?) is very important.
timing of testing
During (?), HCV pinaka nakikitang cause through blood transfusion
90s and 2000s
The general method of detecting infection with HCV is to observe the presence of (?) to the virus in human serum
antibodies
REAGENTS:
Test kit (cassette) for anti – HCV
SAMPLE:
Plasma or serum (should be free form contamination, hemolysis and lipemia)
PRINCIPLE:
IMMUNOCHROMATOGRAPHY
The assay starts with a sample applied to the sample well to which a sample diluent is immediately added.
IMMUNOCHROMATOGRAPHY
= 1 for sample, 1 for diluent
HCV antigen – 2 well
The (?) embedded in the sample pad reacts with the HCV antibody present in serum or plasma sample forming conjugate – HCV antibody complex.
HCV antigen – colloidal gold conjugate
PATIENT SAMPLE:
HCV antibody
As the mixture is allowed to migrate along the test strip, the conjugate – HCV antibody complex is captured by an antibody – binding protein immobilized on a membrane forming a (?)in the test region.
colored test band
A (?) does not produce a test line due to the absence of colloidal gold conjugate – HCV antibody complex.
negative sample
The antigens used in the test are (?) corresponding to highly immunoreactive regions of HCV.
recombinant proteins
A (?) in the control region appears at the end of the test procedure regardless of the result.
colored control band
is the result of colloidal gold conjugate binding to anti – HCV antibody immobilized on the membrane.
colored control band
indicates that the colloidal gold conjugate is functional.
control line
The absence of the control band indicates that the test is
invalid
: Facilitate the reaction and ensure the proper mixing of our reagent and sample.
Diluent
REPORTED AS
REACTIVE
INTERPRETED AS
Since it has two lines
POSITIVE
But if no line in TEST AREA (T) =
NONREACTIVE
PROCEDURE: (SAME AS HEPATITIS B PROCEDURE BUT WITH THE ADDITION OF A DILUENT)
1. Bring the kit components and specimen to room temperature before testing
2. Remove the test card from the sealed foil pouch. Once opened, the test card must be used immediately.
3. Label the test card with patient’s identity
4. Dispense (?) of the sample to the center of the sample well (marked as “S”) of the test card using the plastic dropper provided
5. Add (?) of sample diluent to the diluent well (marked as “D”) immediately after the specimen is added
6. Read and interpret the results
1 drop (10 μL)
2 drops
If there are two lines=
Positive; Reactive
One line under the control=
Negative; Nonreactive
If (?), try another one
invalid
High sensitivity
SCREENING TESTS
RIBA (Recombinant immunoblot assay
CONFIRMATORY TESTS
use recombinant HCV antigens that are fixed to a solid substrate). They are more specific than ELISA testing.
RIBA (Recombinant immunoblot assay
WESTERN BLOT
CONFIRMATORY TESTS
HVC VIRAL LOAD
MONITORING TESTS
TO CONFIRM CHRONIC INFECTION
HVC VIRAL LOAD
HCV PCR/VIRAL LOAD
CONFIRMATORY TESTS
DONE BY NRL AND OTHER HOSPITALS
CONFIRMATORY TESTS
LIVER BIOPSY
CONFIRMATORY TESTS
GENOTYPING
CONFIRMATORY TESTS
Category 1 (ELISA)
SCREENING TESTS
Category 2 (RAPID TESTS)
SCREENING TESTS
Detection of Anti-HCV
SCREENING TESTS
HCV – Testing the presence of the.
antibodies
Unlike in B, antibodies with the presence of.
antigen
They are more specific than ELISA testing and they have been used to confirm un gating positive na ELISA
HEPATITIS C VIRUS (HCV) ANTIBODY RAPID TEST
– detect for the presence of the virus mismo or the HCV
CONFIRMATORY TEST
Only done by national reference laboratories and other hospitals
CONFIRMATORY TEST
QUESTION: Pag may nag positive po ba tayo na result for Hepatitis C, kailangan pa natin siya iconfirm sa NRL?
YES, we are going to send the sample of the patient in manila.
– to detect the viral load and monitor the course of theraphy
MONITORING TEST
PRINCIPLES AND CLINICALLY SIGNIFICANT RESULTS OF OTHER SEROLOGIC TESTS
For the confirmatory testing by (?) is helpful in some clinical situations.
immunoblotting
The positive EIA anti-HCV reactivity could represent the following: (kaya natin siya kinokonfirm via RIBA)
False-positive reaction
(pwede mag positive sa EIA/ELISA ang) Recovery from hepatitis C
False-positive reaction
Viral infection with levels of virus too low to be detected
False-positive reaction
can detect low levels of HCV RNA in serum
PCR amplification technique
Testing for HCV RNA is a reliable way of demonstrating that hepatitis C infection is present and is the most specific test for infection.
Polymerase Chain Reaction
The best confirmatory assay to confirm a diagnosis of hepatis C is to test for the HCV RNA
Polymerase Chain Reaction
Testing for HCV RNA by a PCR assay is particularly useful in the following situations:
Transaminase levels are normal or only slightly elevated.
Anti-HCV is not present.
It will take time to produce antibodies. Tendency to be negative
Anti-HCV is not present.
Eh paano kung talagang malkas yung diagnosis or assessment ni physician na may hepatitis C si patient. Medical technologists:
perform HCV RNA via PCR Testing
Several causes of liver disease are possible.
- common among travelers
Type A
Route of transmission is Fecal Oral Route- travelers are into food trip
Type A
- will not occur if the patient does not have hepatitis B
Type D
It will serve as a coinfection with Hep B
Type D
- post-transfusion hepatitis
Type C
No serological markers to test; no antigen
Type C
Most common cause of post transfusion hepatitis
Type C
