HIV (Human Immunodeficiency Virus) & AIDS (Acquired Immunodeficiency Syndrome)

Question 1

HIV leads to what

Answer 1

immunodeficiency

virus incorporates self into host cells to replicate

Question 2

cmplx of HIV infection

Answer 2

AIDS

Question 3

what virus targets the immune system for HIV

Answer 3

retrovirus

Question 4

how does retrovirus impact DNA

Answer 4

• Usually DNA transcribes into RNA and that forms proteins
• These viruses take RNA and put it into the DNA of the host (work backwards)
• results in profound immunosuppression (develop infection & CA easily)

Question 5

etiology & transmission

Answer 5

• sexually transmitted

- maternal

Question 6

how is it sexually transmitted

Answer 6

semen contains virus & virus carried in blood

Question 7

how is it transmitted maternally

Answer 7

• in utero
• labor & delivery (severed blood vessel & baby contacts blood)
• lactation (through breast milk)

Question 8

3 stages of HIV

Answer 8

1) primary infection
2) latent period
3) overt AIDS

Question 9

(1) primary infection duration

Answer 9

weeks - months

Question 10

(1) primary infection

Answer 10

• seroconversion
• high viral load
• dec CD4 count

Question 11

pt tests negative for HIV in what stage

Answer 11

primary infection (window period – time it takes Abx to form)

Question 12

seroconversion

Answer 12

formation of Abs

Question 13

(2) latent period

Answer 13

• asympt for years
• lymphatic tissue damage
• recurrent respiratory infections

Question 14

why do recurrent respiratory infections occur in latent period (2)

Answer 14

b/c most microbes & viruses enter via inhalation

Question 15

(3) overt AIDS

Answer 15

• ~10 yr (60-70%): typical progressors
• ~5 yrs: rapid progressors
• ~15 yrs: slow progressors
• long-term non-progressors (2-5%): do not develop AIDS
• CD4 count below 200 & have an opportunistic infection = AIDS

Question 16

patho

Answer 16

• targets T helper cells (CD4)
• also targets macrophages & B cells
• destroys immune system (new infections occur d/t latent pathogens)
• many organs affected

Question 17

if T helper cells (CD4) are damaged, what happens

Answer 17

cytokines not generated for immune cells to communicate with e/o –> immune system compromised

Question 18

B cells

Answer 18

Responsible for Ab formation, if these are targeted, then Ab formation inhibited

Question 19

Dx

Answer 19

• clinicl presentation
• ELISA (Ab test) –> Es-linked immunosorbant assay
• western blot assay
• PCR (polymerase chain rxn)
• CD4 counts & viral loads (inversely proportional)
• quick tests (rapid serum & saliva tests)

Question 20

ELISA (Ab test)

Answer 20

Body’s production of Abs measured against entire virus using an enzymatic method

• if test positive, they confirm w/ Western blot assay

Question 21

Western blot assay

Answer 21

Abs produced to a specific part of HIV virus (more specific test)

Question 22

PCR (Polymerase Chain Reaction)

Answer 22

Amplifies genetic material and measures viral particle itself (rarely used)

Question 23

CD4 counts & viral loads

Answer 23

Surface proteins on T helper cells –> CD4 counts measure the number of T helper cells

(if this is low, then the viral load must be high and vice versa)

Question 24

quick tests: new rapid serum & saliva tests

Answer 24

indicates pt might be positive, more specific tests used

• P24 antigen

Question 25

P24 antigen

Answer 25

protein found in the viral core and makes its appearance early (between time of infection and seroconversion, when antibodies are detectable)

Question 26

mnfts

Answer 26

- extensive, involves many body systems - recurrent resp infections - GI infections - NS: dementia, encephalopathy - opportunistic CA

Question 27

why do recurrent resp infections occur

Answer 27

defense is compromised d/t infection impacting resp tract (ex. TB & pneumonia)

Question 28

why do GI infections occur

Answer 28

from normal flora & ingested microbes (in food) | ex. diarrhea, gastroenteritis, etc.

Question 29

why does dementia & encephalopathy occur

Answer 29

impaired CNS Fx d/t various infections & virus presence

Question 30

opportunistic CA

Answer 30

Malignant cells in early stage controlled by immune system - Kaposi's sarcoma - cervical CA - Non-Hodgekin's lymphoma

Question 31

Kaposi's sarcoma

Answer 31

mesenchyme origin (non-epithelial) --> arises in endothelial cells (lining blood vessels), forms malignant lesions (appear in skin, mucosa of mouth, lymph nodes)

Question 32

cervical CA cause

Answer 32

d/t HPV infection (compromised defences)

Question 33

Tx

Answer 33

- incurable - HAART (Highly-Active Anti-Retroviral Therapy) - polypharmacy

Question 34

what drugs used

Answer 34

antiviral agents (at least 3) -- each target diff steps

Question 35

what antivirals used

Answer 35

- reverse transcriptase inhibitors - protease inhibitors - entry inhibitors - integrase inhibitors

Question 36

reverse transcriptase inhibitors

Answer 36

inhibit the viral RNA replicating into DNA, and the multiplication of the virus

Question 37

protease inhibitors

Answer 37

inhibits the enzyme that breaks down proteins --> proteases break up polypeptides in host cells

Question 38

entry inhibitors

Answer 38

inhibit entry into the host cell | if the virus cannot get into the cell then it cannot damage it

Question 39

integrase inhibitors

Answer 39

enzyme inhibited --> prevents the viral particle from integrating its RNA into the host cell’s DNA

Question 40

functions of antivirals

Answer 40

A) Prevents virus from entering host cell B) Presents virus from integrating RNA into DNA C) Prevents virus from dividing