HIV

Question 1

What is HIV?

Answer 1

Human immunodeficiency virus

Question 2

How is HIV spread?

Answer 2

• Sexual transmission - Injection drug misuse - Blood products - Vertical transmission - Organ transplant

Question 3

Can we test unconscious patients for HIV?

Answer 3

Unconscious patients can be tested if you think it is in the patient’s interest to have the test (Having had a negative HIV test does not affect insurance premiums)

Question 4

How does HIV infection affect the immune system?

Answer 4

• HIV infects and destroys cells of the immune system especially the T-Helper cells that are CD4+ (have a CD4 receptor on their surface) - CD4 receptors are not exclusive to lymphocytes – they are also present on the surface of macrophages and monocytes, cells in the brain, skin, and probably many other sites.

Question 5

What is the natural history of the HIV infection?

Answer 5

CD4 count declines & HIV viral load increases (severity of these illnesses is greater the lower the CD4 count (normal CD4 > 500))

Question 6

What are the features of Clinical stage 1?

Answer 6

Asymptomatic Persistent generalised lymphadenopathy

Question 7

What are the features of clinical stage 2?

Answer 7

Weight loss <10% Herpes zoster, within last 5 years

Question 8

What are the features of clinical stage 3?

Answer 8

Weight loss >10% Unexplained chronic diarrhoea Unexplained prolonged fever

Question 9

What are the features of clinical stage 4?

Answer 9

HIV wasting syndrome Pneumocystic pneumonia Toxoplasmosis of the brain

Question 10

What is the trend in reduction of CD4 and the level of opportunistic infection?

Answer 10

reduction of CD4 increased opportunistic infection

Question 11

What is the difference between HIV and AIDS?

Answer 11

Certain infections and tumours that develop due to a weakness in the immune system are classified as AIDS illnesses. If you have no symptoms then you have HIV infection only.

Question 12

What is the correlation between CD4 level and mortality?

Answer 12

Lower the CD4 the higher the mortality risk

Question 13

What is the natural history of HIV?

Answer 13

Acute infection (seroconversion) - asymptomatic - HIV-related illness - AIDS defining illness - Death

Question 14

What are the notable features of primary HIV?

Answer 14

Approximately 30 - 60% of patients have a seroconversion illness (when HIV antibodies first develop) Abrupt onset 2 – 4 weeks post exposure, self limiting 1 – 2 weeks Symptoms are generally non-specific

Question 15

What are the symptoms of primary HIV?

Answer 15

• Flu-like illness - Fever - Malaise and lethargy - Pharyngitis - Lymphadenopathy - Toxic exanthema

Question 16

What is ART?

Answer 16

Anti-retroviral therapy

Question 17

When is the best time to start ART?

Answer 17

As soon as they know CD4 is dropping (diagnosis of HIV is suspected)

Question 18

How has treatment for HIV evolved in the last 10 years?

Answer 18

Multiple medications to now one tablet

Question 19

What is the action of antiretroviral therapy?

Answer 19

• Different classes of drugs acting on different stages in HIV lifecycle - Combination antiretroviral therapy (cART) means at least 3 drugs from at least 2 groups

Question 20

What level of adherence is required for successful therapy?

Answer 20

Adherence needs to be over 90% - support patient

Question 21

How does cART effect life?

Answer 21

On cART can lead to a normal life but side effects can be significant eg metabolic, lipodystrophy

Question 22

At what sites do these ART treatments act?

Answer 22

1. Binding and entry 2. Reverse transcription 3. Integration 4. Transcription 5. Assembly 6. Release and Protease

Question 23

When do we start ART therapy?

Answer 23

Consider starting all patients at diagnosis regardless of CD4

Question 24

What are the current life expectancy’s of patients diagnosed aged 20?

Answer 24

<100 : 52 100-200 : 62 >200 : 72

Question 25

How long does treatment last?

Answer 25

Lifelong

Question 26

Why do treatment’s fail at points in time?

Answer 26

*Poor adherence leads to viral mutation and resistance* - Inadequate potency - Inadequate drug levels - Inadequate adherence - Pre-existing resistance

Question 27

Nucleoside reverse transcriptase inhibitor features?

Answer 27

Marrow toxicity, neuropathy, lipodystrophy

Question 28

Non-nucleoside reverse transcriptase inhibitor features?

Answer 28

Skin rashes, hypersensitivity, drug interactions

Question 29

Protease inhibitors features?

Answer 29

Drug interactions, diarrhoea, lipodystrophy and hyperlipidaemia.

Question 30

Integrase inhibitors features?

Answer 30

rashes

Question 31

How can we prevent HIV?

Answer 31

• Behaviour change and condoms - Circumcision - Treatment as prevention: VL undetectable = untransmissable (pregnancy) - Pre-exposure prophylaxis (PrEP) - Post-exposure prophylaxis for sexual exposure (PEPSE)