HIV - Part 2

Question 1

How many people have acquired HIV-1 in the last 40 years?

Answer 1

75 million

Question 2

HIV is a member of the which family?

Answer 2

Lentivirus family

Answer 3

Double stranded RNA virus

Question 4

How does the HIV get in?

Answer 4

Binds to CD4 then to the chemokine co-receptor CCR5 and CXCR4

CCR5 more common

Question 5

How does the retrovirus replicate?

Answer 5

Retroviral transcriptase
Viral enzyme integrase

see lecture slide

Question 6

How many lineages of HIV? Where did they come form? When was the initial transmission? Which lineage is the current pandemic?

Answer 6

4 - MNOP

MNO - chimpanzees
OP - gorillas

Initial transmission of M subtype to humans occured in SE Cameroon between South east Cameroon - 1910

M is the pandemic

Question 7

How long is the acute phase?

Answer 7

3-6 months

Question 8

What happens after the 6 month acute phase? What happens to the risk of transmission during this asymptomatic phase?

Answer 8

Asymptomatic phase - risk of transmission is low

Question 9

Heterosexual cases

Answer 9

With the progression of disease, you have enormous viral diversity as the viral load increases, as HIV is very bad at replicating itself accurately. Hence the need for combination therapy.

Answer 10

Viral quasi species

Viral mutation -

Integration of HIV provirus within CD4 cells within 72 hours leads to lifelong memory???

Question 11

From the POV of the T cell

Question 12

Describe CD4+ T cell response to HIV

Answer 12

In tissues, the mucosal CD4 t cells have a profound drop during the acute phase and do not recover afterwards

The CD 4 T cell in teh blood counts in the blood drop, then recover, then drop again over teh asympatomatic period

Answer 13

IgM is created in the acute phase

Neutralising antibodies is created late, by which point the strain of HIV has diversified

A good b-cell response

Complements bring down the viral load

Question 14

Features of untreated HIV immunology

Answer 14

CD4 t cell depletion
Chronic immune activation
Impairment of CD4 and CD8 T cell function
Disruption of lymph node archtecture and impaired ability to generate protective T

Question 15

Which antigens are detected

Answer 15

assays detect p24 antigen, gp41 from HIV1 group O
gp160 - HIV-1 M and gp36 HIV2

Question 16

What comorbidities would you check for when someone is diagnosed with HIV-1?

Answer 16

TB
GORD
DM
BP
Hepatitis B and C
Anxiety
Depression

Question 17

Baseline investigations

Answer 17

FBC
tb
cxr????????

Question 18

HIV-1

Answer 18

HIV-1 genotype to look for drug resistance

HIV-1 tropism to confirm co-receptor use in

Question 19

When do we use anti-retroviral therapy?

Answer 19

Test and treat
to prevent infection - offer to seronegative partners
In pregnancy to prevent transmission to fetus
PreP or PEP

Question 20

Combination of ART

Answer 21

non-nucleotide reverse transcriptors

Question 22

ART

Answer 22

prevents new cells becoming infected but cannot eliminate infection once the HIV has integrated itself into host DNA

Question 23

If ART is stopped, when can HIV be detectable in the blood?

Answer 23

2-3 weeks as

Question 24

new subcut drugs

Answer 24

Capsid inhibitor lenacapavir
Attachment inhibitor - fostemavir

Question 25

Monitoring on ART

Answer 25

monitor liver, kidneys, bone and lipid toxicity

Question 26

If CD4 cell counts less than 300, what kind of TB do you get?

Answer 26

Pulmonary if over 300
Less than 300 - Milliary