HIV & Hepatitis

Question 1

HIV genome

Answer 1

2 copies ssRNA, negative-sense

Question 2

HIV - 2 important glycoproteins

Answer 2

gp41 & gp120

Question 3

HIV - 3 important enzymes

Answer 3

Protease, RT, integrase

-all in nucleocapsid

Question 4

HIV - 3 genes and what each encodes

Answer 4

gag - p24 (capsid), p17, p6
pol - RT (p51), p66
env - gp41, gp120

Question 5

This HIV appears early in the infection. Why is it not a good confirmatory protein?

Answer 5

p24

p24 disappears because host develops immunity to it

Question 6

HIV - spread mainly through… Anything covered in ___ is more infectious

Answer 6

Sexual contact

Blood
-HIV in all bodily fluids, but blood is especially infectious

Question 7

Healthcare workers can be exposed to HIV through

Answer 7

Prick

• 1 in 300 workers
• also splash, exposure, etc

Question 8

Why does having an preexisting STD increase likelihood for HIV?

Answer 8

Lots of inflammation and CD+ cells in the area

Question 9

HIV binds to this receptor… Requires these co-receptors

Answer 9

CD4

CXCR4 = T cells
CCR2 & CCR5 = macrophages

Question 10

HIV - Where does integrase cut the host genome?

Answer 10

Anywhere

Question 11

Why is it hard to make vaccines for HIV?

Answer 11

Antigenic variation

-HIV is an RNA virus, lacks proofreading mechanism

Question 12

HIV - clinical manifestations

Answer 12

Hypergammaglobulinemia

Increase p24 (initially)

Decreased CD4 - less lymphocytes

<200 cells / ul

Question 13

HIV - screening & confirmatory tests

Answer 13

ELISA for gp120

Western blot for at least 2 out of 3 bands

Question 14

A patient has HIV when their CD4+ cell count drops below… What’s the normal CD4:CD8 ratio? What’s the ratio for an HIV+ person?

Answer 14

<200 cells / ul

2:1

<1:1

Question 15

What kind of HIV testing should be performed on an infant?

Answer 15

RT-PCR

Question 16

HIV - What are some downsides of using ELISA testing?

Answer 16

False positive or false negative

-expired kits, handling, pre-analytical, patient in window period

Question 17

Process for confirmation HIV+ patient

Answer 17

ELISA for gp120
Second ELISA to confirm
Western blot for 2/3 of these proteins - p24, gp41, gp120/gp160

Question 18

Advanced liver disease results in…

Answer 18

Cirrhosis (scarring)

-cannot be reversed

Question 19

Liver disease - clinical presentations

Answer 19

Jaundice

Urine/feces color change

Appetite loss

Cold/flu-like symptoms

Liver tenderness

Hepatomegaly

Question 20

Why does liver damage cause dark urine?

Answer 20

Bilirubin from broken down RBCs

• highly toxic
• brain damage if accumulates

Question 21

Liver disease - lab findings (3)

Answer 21

Elevated Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), Bilirubin

Question 22

Hepatitis - how many types are there? Which ones are DNA and which ones are RNA?

Answer 22

5
A through E

B is DNA, rest are RNA

Question 23

Antibodies are needed against Hepatitis B to ___ the virus

Answer 23

Neutralize

Question 24

A recent Hepatitis infection shows elevated levels of ___. After 6 months, elevated levels of ___ are detected

Answer 24

IgM

IgG & IgA

Question 25

Vaccinating against Hep B also protects you from…

Answer 25

Hep D

Question 26

Hep B and Hep D infecting at the same time is called… Hep D infecting after Hep B is called

Answer 26

Coinfection

Superinfection - high chance of chronicity

Question 27

Hep A - acute infection marker is…

Answer 27

anti-HAV - IgM antibody directed against Hepatitis A (HAV)

Question 28

What are the antibody markers for Hep B?

Answer 28

anti-HBc

anti-HBe

anti-HBs

Question 29

Hep B - the two core proteins are

Answer 29

Core protein

E protein

Question 30

Hep B - markers that appear in the blood in order

Answer 30

HBs Ag - surface antigen

HBe Ag - E protein

HBc Antibody

HBe Antibody

HBs Antibody

-mnemonic = “seces” (pronounced sexist)

Question 31

anti-HBc IgG in the blood indicates what?

Answer 31

Person had a Hep B infection, but not a Hep B vaccination

• vaccination targets HBs
• IgG indicates recovery from disease & an infection that happen awhile ago

Question 32

HBe and HBs antigens in the blood after 6 months indicates what?

Answer 32

Infected person never recovered from acute infection. Infection becomes chronic
-anti-HBc IgM and total anti-HBc do develop

Question 33

High HBe antigens with no anti-HBe antibodies in the blood indicates what?

Answer 33

Infected person is not recovering. Very severe

• HBe = indicates high degree of infectivity
• anti-HBe = person is recovering

Question 34

Vaccinated people only have this antibody in their blood

Answer 34

anti-HBs antibody only

Question 35

anti-HBs antibody in the blood indicates what?

Answer 35

Person is infected, resolved their infection, or had a vaccination

Question 36

Chances of developing chronic liver disease when infected with Hep B? Hep C?

Answer 36

The younger you are when you get a Hep B infection, the more likely you will get cirrhosis or chronicity later in life

Hep C = 90% will develop chronic liver disease regardless of age

Question 37

Hep B monitoring panel consists of 4 things

Answer 37

HBs Ag
anti-HBs antibody
HBe Ag
anti-HBe antibody

-screen, diagnose, monitor

Question 38

Which two Hep B markers are acute markers?

Answer 38

HBs antigen
HBe antigen
-both appear and decline < 6 months

Question 39

Once this antibody appears during an acute Hep B infection, the person is considered “protected”

Answer 39

anti-HBs

-anti-HBe will develop around same time to resolve infection in blood

Question 40

Hep C - acute infection marker is

Answer 40

anti-HCV

Question 41

Hepatitis transmission routes

Answer 41

Hep A, Hep E = oral-fecal
-mnemonic = “AtE”

Hep B, Hep C, Hep D = parenteral