HIV & AIDS

Question 1

AIDs Overveiw

Answer 1

SYNDROME!
prolonged clinical latency, ineffective immunity, & ability of the virus to infect others
often opportunistic infections

Question 2

HIV epidemiology

Answer 2

majority in Africa

large % from homosexual intercourse, IV drug use etc

Question 3

HIV transmission

Answer 3

Blood transfusions
Perinatal
Fluids containing high levels of HIV - breast milk, blood, semen

Question 4

HIV Structure

Answer 4

2 copies of ssRNA w/ reverse transcriptase

protein capsid & surrounded w/ lipid membrane

Question 5

HIV gene structure

Answer 5

Gag - viral capsid
Pol- enzymatic proteins
Evn- surface glycoproteins

Question 6

Gag protein

Answer 6

HIV viral capsid protein

antibodies against p24 are commonly made during infection!

Question 7

Pol Protein

Answer 7

P51 is the reverse transcriptase that catalyzes the reverse transcription of RNA to DNA & inserts into the host DNA = PROVIRUS

Question 8

Env Protein

Answer 8

surface glycoproteins GP120/41

mediate viral attachment to host membrane & promote viral entry

Question 9

HIV-1 replication cycle

Answer 9

1. viron attachment - macrophages & CD4+ t cells
viral gp160 & CD4 chemokine receptor 
CCR5 & CXCR4 are coreceptors 
2. viral fusion to host cells
3. viral entry
4. reverse transcriptase
5. provirus
6. viral synthesis
7. assembly & release

Question 10

Acute HIV

Answer 10

2-4 weeks after primary infection flu like symptoms
viremia - 100 mil/mL in serum
dip in CD4+ cells

Question 11

Latency HIV

Answer 11

‘low’ #s of virions (10-100 k/mL of serum)

appearance of antibodies - seroconversion

Question 12

AIDs

Answer 12

CD4+ cells fall below 200/uL

or diseases characteristic of severely immunocompromised individuals

Question 13

Fungal infections associated with AIDs

Answer 13

thrush

cryptococcal menigitis -fatal infection of the brain

Question 14

Protozoan infections associated with AIDs

Answer 14

cryptosporidiosis

Question 15

Bacterial Infections seen in AIDs

Answer 15

M. TB- #1 cause of death of HIV infected people
MAC
enteric pathogens

Question 16

Viral infections seen in AIDs

Answer 16

cytomegalovirus- 75% of HIV infected people are carriers

Question 17

Cancer’s associated with AIDs

Answer 17

Kaposi’s sarcoma- most common cancer in HIV +
caused by herpesvirus 8
malignancy of blood vessels

Question 18

seroconversion

Answer 18

the appearance of antibodies & occurs up to 3 months after initial infections
antibodies against gp120, gp 41, p 24

Question 19

Types of Lab testing for HIV

Answer 19

nucleic acid testing - quantitative PCR
antigen testing - viral specific proteins
serology - antibodies to HIV
CD4:CD8 t cell enumeration - flow cytometry

Question 20

Nucleic acid HIV testing

Answer 20

can detect a virus as early as 1 week post infection
expensive
determines viral load

Question 21

Antigen Testing for HIV

Answer 21

p24 capsid protein is the most readily detectable HIV protein in the serum

Question 22

Antibody testing for HIV

Answer 22

rapid test, enzyme immunoassay, immunoblot/western blot

use AFTER seroconversion

Question 23

CD4+ t cell enumeration

Answer 23

CD4:CD8 ratio is 2:1 in healthy individual
HIV: CD4:CD8 ratio is smaller 0.5:1