HIV

Question 1

What is the target site for HIV?

Answer 1

CD4+ receptors

Question 2

Where are CD4+ receptors found?

Answer 2

On the surfaces of:
T helper lymphocytes (“CD4+ cells”)
Dentritic cells
Macrophages
Microglial cells

Question 3

What do CD4+ lymphocytes do?

Answer 3

Essential for the adaptive immune system:
Recognition of MHC2 antigen-presenting cell
Activation of B-cells
Activation of cytotoxic T-cells (CD8+)
Cytokine release

Question 4

What infections does HIV leave a patient susceptible to?

Answer 4

Viral infections
Fungal infections
Mycobacterial infections
Infection-induced cancers

Question 5

Give two examples of mycobacterium infections.

Answer 5

Tuberculosis

Leprosy

Question 6

What is the normal range of CD4+ T cells?

Answer 6

500-1600 cells/mm3

Question 7

At what level of CD4+ T cells does someone become susceptible to opportunistic infection?

Question 8

How does HIV enter the body?

Answer 8

Infects CD4 mucosal cells (Dendritic and Langerhans cells)
Transport to regional lymph nodes
Dissemination of virus

Question 9

How many days before HIV infection is established?

Answer 9

Within 3 days of entry

Question 10

When does primary HIV infection tend to occur?

Answer 10

2-4 weeks after entry of virus

Question 11

What are the symptoms of primary HIV infection?

Answer 11

Fever
Rash (maculopapular)
Myalgia
Pharyngitis
Headache/aseptic meningitis

Question 12

What is the risk of transmission during the primary HIV infection?

Answer 12

Very high risk

Question 13

What is the prophylaxis and treatment regime of pneumocystis pneumonia?

Answer 13

Prophylaxis: low-dose trimoxazole
Treatment: high-dose trimoxazole

Question 14

What are the symptoms of cerebral toxoplasmosis?

Answer 14

Headache
Fever
Focal neurology
Seizures
Reduced consciousness
Raised intracranial pressure

Question 15

What is the causal bacteria of cerebral toxoplasmosis?

Answer 15

Toxoplasma gondii

Question 16

At which CD4 count does toxoplasmosis become a threat?

Question 17

At which CD4 count does cytomegalovirus become a threat?

Question 18

How does cytomegalovirus present?

Answer 18

Reduced visual acuity
Floaters
Abdo pain, diarrhoea, PR bleeding

Question 19

What is ‘Slim’s disease’?

Answer 19

HIV-associated wasting/cachexia

Question 20

What are the factors contributing to HIV-associated wasting?

Answer 20

Metabolic (chronic immune activation)
Anorexia (multifactorial)
Malabsorption/diarrhoea
Hypogonadism

Question 21

What is the causal virus of Kaposi’s sarcoma?

Answer 21

Human herpes virus 8

Question 22

What is a Kaposi’s sarcoma?

Answer 22

A vascular tumour occurring with immunosuppression

Question 23

What factors increase the risk of transmission of HIV?

Answer 23

Anoreceptive sex
Trauma
Genital ulceration
Concurrent STI

Question 24

When can mother-to-baby HIV transmission occur?

Answer 24

In utero/trans-placental
Delivery
Breast-feeding

Question 25

What is the definition of highly active antiretroviral therapy?

Answer 25

A combination of three drugs from at least 2 drug classes to which the virus is susceptible

Question 26

What are the targets for antiretroviral therapy?

Answer 26

``` Reverse transcriptase Integrase Protease Entry: - Fusion - CCR5 receptor Maturation ```

Question 27

What is the best way to prevent drug resistance in HIV?

Answer 27

Adherence to the regime

Question 28

Which antiretrovirals are potent liver enzyme inhibitors?

Answer 28

Protease inhibitors | NNRTIs

Question 29

What steps are taken to avoid mother to baby transmission of HIV?

Answer 29

``` HAART during pregnancy Vaginal delivery if undetected viral load Caesarean section if detected viral load 4/52 PEP for neonate Exclusive formula feeding ```

Question 30

Which anti-retroviral is a protease inhibitor?

Answer 30

Indinavir

Question 31

Which anti-retrovirals are NRTIs?

Answer 31

Zidovudine | Abacivir