HIV

Question 1

What is the main HIV group globally?

Answer 1

M

others: N, O

Question 2

Where is HIV-2 mainly found?

Answer 2

West Africa, SE Asia

Question 3

What enzymes are coded for by pol

Answer 3

RT, protease, integrase

Question 4

Env codes for a polypeptide that is cleaved to form _____ and ____ on the viral envelope

Answer 4

pg120, gp41

Question 5

What does gag code for?

Answer 5

proteins that make up the viral core

Question 6

List 8 steps in HIV viral replication

Answer 6

1. attachment of gp120 to CD4 and a co-receptor
2. fusion of viral envelope, release of genome into host cell
3. RT converts viral RNA to DNA which goes to the nucleus
4. Integrase inserts viral genome into host genome
5. transcription and translation of viral genome
6. viral protease cleaves polyproteins
7. viral assembly
8. budding/ acquisition of envelope and glycoproteins

Question 7

Innumerable HIV ______ exist within each infected individual

Answer 7

quasispecies

** due to compact genome, error prone RT, replication kinetics

Question 8

After crossing the mucosal barrier, _____ cells transport HIV to regional lymph nodes and CD4+ cells in the paracortical regions of the node interact with HIV

Answer 8

dendritic

Question 9

Widespread dissemination of HIV to the CNS, reticuloendothelial system, and GALT occurs within _____ days of infection

Answer 9

4-11

primary viremia, but asymptomatic

Question 10

The hallmark of HIV disease is:

Answer 10

CD4 depletion

occurs in GI tract over first 2-3 weeks of infection (loss of 80% of CD4 T cells)

Question 11

List components of the immune system that are dysregulated in HIV infection

Answer 11

lymphoid tissue- distorted architecture
CD8 cells
B cells- hypergammaglobulinemia
NK cells
Neutrophils- impaired opsonizing activity
Monocytes/ macrophages- reservoir for virus, role in CNS disease

Question 12

_____________ serve as reservoirs for HIV and play a prominent role in CNS disease via infection of microglial cells

Answer 12

monocytes/ macrophages

Question 13

HIV immunosuppression involves not only intracellular
pathogens and malignancies (for which we rely on the _______) but also common bacterial
pathogens for which we rely on the _________ defenses

Answer 13

CMI for intracellular pathogens/ malignancies

humoral and neutrophil for bacterial pathogens

Question 14

Why do antibodies against HIV fail to provide high levels of neutralizing capacity?

Answer 14

• genetic diversity of viral isolates

balance at viral set point correlates with development of HIV specific antibodies

Question 15

Chronic immune system ______ is harmful over time, as the ability to respond to any specific antigen is lessened and a broad response to other antigens is compromised

Answer 15

hyperactivation

Question 16

The massive depletion of GI tract CD4+ T lymphocytes can lead to _________ across the GI mucosa, which has been shown to drive immune activation

Answer 16

products of bacterial translocation

Question 17

What is the most common mode of HIV transmission worldwide? What are other notable modes of transmission?

Answer 17

Sexual transmission

MTC, IDU, transfusion/ transplantation, accidental needle stick

Question 18

Why is the acute antiretroviral syndrome so clinically significant?

Answer 18

most transmission occurs by those who just acquired the virus themselves
Viral load is very high during this time

Question 19

What are the most common presenting symptoms of somebody experiencing primary antiretroviral syndrome? Which are (relatively) specific to HIV as compared to other infections?

Answer 19

fever, fatigue, rash, adenopathy, pharyngitis, myalgia, night sweats, thrombocytopenia, luekopenia, diarrhea, aseptic meningitis, oral or genital ulcers

specific: rash, aseptic meningitis, ulcers

Question 20

What other infections should be on the differential for acute HIV infection?

Answer 20

influenza
mono
measles
hepatitis
rubella
secondary syphilis

Question 21

One manifestation of chronic symptomatic infection is _____, which is a manifestation of EBV on the sides of the tongue

Answer 21

oral hairy leukoplakia

Question 22

Describe the immune reconstitution inflammatory syndrome

Answer 22

Immune reconstitution due to antiretroviral therapy can lead to the expression of opportunistic
infectious processes because now the immune system can react to latent organisms that have been present, but not previously recognized due to immune system dysfunction

Question 23

What prophylaxis should be offered against opportunistic infections and at what CD4 count should they be initiated?

Answer 23

pneumocystis- TMP/SMX at CD4=200
toxoplasmosis TMP/SMX at CD4= 100
M avium azithromycin at CD4=50

Question 24

Describe phenotypic and genotypic drug resistance testing

Answer 24

genotypic resistance testing: provides a list of detected mutations that have
occurred in the viral genome that are associated with drug resistance.

phenotypic resistance testing: compares the concentration of
antiretroviral medications required to inhibit the patient’s virus to that of wild type virus.

Question 25

What are the goals of HAART?

Answer 25

Clinical well being

Achieve maximal and durable viral suppression

Achieve maximal and durable immune reconstitution