HIV

Question 1

How does HIV damage the immune system

Answer 1

• Binds via gp120 envelope glycoprotein
• To CD4 receptors on cells
• CD4+ve cells move to lymphoid tissue, where the virus replicates
• Impaired function of infected CD4+ve cells reduces immune function

Question 2

What cells are CD4+ve

Answer 2

• T lymphocytes
• Monocytes
• Macrophages
• Neural cells

Question 3

What predicts the progression of HIV to AIDS

Answer 3

Viral load (number of circulating viruses)

Question 4

Stages of HIV infection

Answer 4

• Seroconversion (primary infection)
• Asymptomatic infection
• Aids-related complex (ARC)

Question 5

Time scales of the stages of HIV to AIDS

Answer 5

HIV>AIDS = ~8yrs
ARC>AIDS = ~2yrs
AIDS>Death = ~2yrs
(Without HAART)

Question 6

3 signs that best correlate to AIDS progression

Answer 6

• Chronic fever
• PGL (persistent generalised lymphadenopathy)
• Cough >1mth

Question 7

Describe the seroconversion stage

Answer 7

• May be accompanied by transient illness for 2-6wks after exposure
• Fever + malaise + myalgia
• Pharyngitis
• Maculopapular rash

Question 8

Define persistent generalised lymphadenopathy

Answer 8

• > 1cm diameter
• 2/> extra-inguinal sites
• 3/> months

Question 9

What are the constitutional symptoms of HIV and what are the referred to as

Answer 9

AIDS-related complex (ARC)

• Temperature
• Night sweats
• Diarrhoea
• Weight loss
• +/- minor opportunistic infections (oral candida)

Question 10

How to diagnose HIV

Answer 10

• Serum/salivary HIV-ab by ELISA

- Serum p24 antigen level

Question 11

What is the limitation of serum/salivary HIV-ab

Answer 11

Takes ~1-3wks post exposure to be +ve (so can miss early exposures)

Question 12

What is given in PEP for HIV

Answer 12

-Tenofovir + Emtricitabine (Truvada)
AND
-Lopinavir + Ritonavir (Kaletra)

Question 13

Early signs of acute seroconversion

Answer 13

• Lymphadenopathy + rash

- Headache + (rarely) meningitis

Question 14

What other condition can HIV cause

Answer 14

• Osteoporosis

- Dementia

Question 15

What part of HIV are HAART thought to be useless in

Answer 15

Dementia, “brain is a sanctuary for HIV”

Question 16

What is the aim of HAART

Answer 16

• Reduce viral load

- Restore immune function

Question 17

What can be given alongside HAART to reduce frequency of resting cell infection

Answer 17

Valproic acid

Question 18

How to monitor a HIV infection

Answer 18

• CD4 T cell count + HIV RNA + U&E, FBC, creatinine, bilirubin/LFTs (every 3-6months)
• Fasting lipid profile + glucose (annually)

Question 19

Indications for initiating HAART

Answer 19

• Hx of AIDS defining illness or CD4 count <350 cells/microL
• Pregnant or HIV associated nephropathy
• High viral load or CD4 count falling rapidly (still above 350)

Question 20

How many different drugs should be used during HAART

Answer 20

3/>

Question 21

When to suspect poor adherence

Answer 21

If viral load rebounds

Question 22

When should you change to a new combination of HAARTs

Answer 22

• When viral load remains high, despite good adherence

- Consistent fall in CD4 count

Question 23

When should there be undetectable viral loads

Answer 23

4 months after starting HAART

Question 24

Example of a HAART regimen

Answer 24

-Efavirenz and Lamivudine + Tenofovir

Question 25

3 types of anti-retrovirals used in HART

Answer 25

• Protease inhibitors
• Nucleoside reverse transcriptase inhibitors (NRTI)
• Non-nucleoside reverse transcriptase inhibitors (NNRTI)

Question 26

2 examples of NRTI

Answer 26

Lamivudine + Tenofovir

Question 27

Example of Protease inhibitor

Answer 27

Ritonavir

Question 28

Example of NNRTI

Answer 28

-Efavirenz

Question 29

2 examples of a once-a-day tablet

Answer 29

Atripla + Stribild