quiz 3 Flashcards
What type of nucleic acids does Hep B have
DNA
What are the markers for Hep A
IgM anti- HAV
When testing for Hep A, if IgM is detected what does this indicate
current infection or recent exposure
When testing for Hep A, if IgG is detected what does this indicate
immunity; have been vaccinated
What are the four ACUTE serological markers
Anti- HAV, HbsAG, Anti-HBc, Anti- HCV
What is anti- HAV directed against
its an IgM antibody directed against Hep A
What is HBsAG
hep B surface antigen
what is anti-HBc directed against
its an IgM antibody directed against hep B core antigen
what is anti-HCV
antibody against hep C
What are antibody markers for hbv
anti- HBc, anti- HBe, anti- HBs
if anti- HBc is present, what does this indicate
current or recent acute infection
What is anti- HBe
antibodies directed against HBeAG
If anti- HBe is present, what does this indicate
recovery from hbv
If HBeAG is present (the antigen), what does this indicate
pt is highly infectious; marker of active viral replication
What markers are on hep b virus surface and in core
core protein, b-e protein, surface antigen (HBsAG)
What does presence of HBsAG indicate
marker for active hbv infection
If positive for HbsAG and anti- HBc IgM, what is the dx
acute hep b infection
What is first hbv marker to appear
core protein
What is second hbv marker to appear
anti- HBc (against core protein)
What is third hbv marker to appear
HBsAG
What is fourth hbv marker to appear
anti- HBs IgG
When is an individual considered chronically infected with hbv
if HBsAG is present for more than six months
Which three markers determine the stage of chronic infection
HBsAG, HBeAG, anti-HBc IgG
Testing which markers determines hbv immunity
anti- HBs (antibody against surface antigen)
What is hbv vaccine contain
surface antigen
Which protein complex is anchored into HIV envelope
gp120/gp41
Which proteins surround the HIV genome
p24 and p17
Which three enzymes are in the HIV nucleocapsid
protease, reverse transcriptase, integrase
Which three encoding genes are in the HIV genome
gag, pol, env
Which co-receptors are required for gp120 to attach to CD4 on host, allowing virus to enter
CXCR4 and CCR5
Asymptomatic stage of HIV
flu like symptoms, lymphadenopathy. test for p24
Seroconversion stage of HIV
detectable antibodies from 2 weeks - 6 months
Latent phase of HIV
lasts up to 10 yrs, CD4 destroyed slowly, viral RNA and Ab detected
Clinical AIDS stage
serious infections
What concentration of CD4 T cells is indicative of HIV
< 200 cells/uL
What is done for HIV screening test and what is detected
ELISA, detects antibodies against gp120
What is confirmatory test for HIV and what is detected
Western blot, detects IgG to HIV
Four types of tests used in dx and monitoring of HIV
CD4 T cell enumeration (see if < 200 cells/ uL)
HIV antibody detection (ELISA and western blot)
HIV antigen detection (early stages)
HIV nucleic acid detection (RT-PCR)
What is principle of ELISA screening for HIV
detects HIV antibody in serum to vital antigens coated onto a solid support
What is principle of western blot
separated HIV antigens, p24, gp41, and gp120/160 on western blot media is treated with pt serum; at least two of the antigens should be detected to call result positive
What is reagin
antibody against cardiolipin; non treponemal antibody
What are nontreponemal tests for syphilis
VDRL, RPR
What do VDRL and RPR detect
reagin
What reaction occurs in VDRL and RPR
flocculation- precipitation that produces clumping of fine cardiolipin particles
What are confirmatory tests for syphilis
most common is FTA-ABS (fluorescent treponemal absorption)– detects antibodies against T. pallidum
Does VDRL display sensitivity in latent patients
no
How is lyme dx
ELISA; if positive confirm with western blot
Which band should be present to identify lyme
41 kD
