Unit 9: Minor 1 HIV

Question 1

What is gastrointesinal disturbance?

Answer 1

Any symptons involving the GI tract, including IBD, nausea, gas, bloating a diarrhea

Question 2

What are rigors?

Answer 2

A sudden feeling of cold with shivering accompanied by a rise in core temperature

Question 3

What is pyrexia?

Answer 3

Elevation in core body temperature

Question 4

What is viral load?

Answer 4

Amount of virus in a blood sample

Question 5

What is the pathophysiology of night sweats?
What conditions is it common in?

Answer 5

Is repeated episodes of sweating during sleep, common in chronic TB, HIV, abscesses and endocarditis
At night basal body temperature drops, infection means set point is higher than normal, shivers (involuntary muscle contraction) to increase body temp, rapid rise in temp results in sweating

Question 6

What is the link between fever and non-bloody non foul diarrhea and HIV/AIDs?

Answer 6

Symptoms of opportunist infection

Question 7

What is HIV wasting syndrome?

Answer 7

Significant and rapid weight loss in AIDs.
Causes by opportunistic infections, hypermetabolic state, damage to gut causing malabsorption.

Question 8

Describe how HIV affects the GIT.

Answer 8

GALT - damage to GALT as T cells infected - leads to immunocompromised and inflammation
Normal microflora (also altered by ART) - more suspecitibly to opportunsitic infections - trigger chronic inflammation
Combines to create decreased levels of mucosal repair and regeneration

Question 9

Describe how HIV affects the cardiovascular system?

Answer 9

Indirectly through chronic systemic inflammation
Infects myocardial dendritic cells
Causes endothelial cell dysfunction
Can cause ischemic conditions

Question 10

How does HIV affect the nervous system?

Answer 10

May infect glia cells which contain the CCR5 co-receptor - indirect damage from inflammation
Enters CNS - associated with low grade chronic inflammation

Question 11

MOA of tenofovir Disporxol Fumarate

Answer 11

Pro drug converted into active substance tenofovir diphosphate
Tenofovir - NRTI

Question 12

MOA of emtricitabine

Answer 12

NRTI
Cytidine analogue
Inhibits HIV reverse transcriptase
Prevents converion of RNA to DNA

Question 13

MOA of dolutegravir

Answer 13

Integrase inhibitor - stops HIV DNA being incorporated into the host genome

Question 14

What are the immediate management priorities for a new HIV patient?

Answer 14

New diagnosis: refer urgently to a HIV clinic, to be seen within 48hrs to 2 weeks,
provide sources of information and support, advise on ways to prevention transmission to others,
arrange a follow up within few days to answer any questions and confirm specialist appointment date

Question 15

How would you manage acute HIV problems?

Answer 15

Admit to hospital if acutely unwell
- respiratory symptoms (TB, pneumonia)
- visual symptoms
- neurological symptoms
- cancers such as Kaposi sarcoma
- life threatening adverse effects of ART (lactic acidosis, bone marrow suppression)

Question 16

How to manage an established HIV patient?

Answer 16

Review in primary care
Ensure is attending specialist services - to monitor CD4 count and viral load
Check adherence to ART
Check for side effects of ART

Question 17

What conditions should be screened for in a HIV patient?

Answer 17

Cancers - kaposci, cervical and non-hodgkin lymphoma - normally by biopsy, smear or imaging
Hepatitis B - transmitted by blood, increased risk of liver complications in HIV patients
Opportunistic pathogens - stool sample, sputum sample (when symptoms present)
Mental health screening

Question 18

Why does a reduced CD4+ count make more suscpetible to infection?

Answer 18

Secondary immunodeficiency
Unable to activate a T cell response - no activation of B cells so no antibody production - reduced memory response
Systemic immunoprivledged sites
Indicate depleted T helper, DCs, NK cells

Question 19

What are the different mechanism that pathogens use to develop resistance to drugs?

Answer 19

1. Have inactivating enzymes that destory the drug
2. Decrease drug accumulation
3. Alter the binding site of the drug
4. Develop alternative metabolic pathways that are not affected by the drug

Question 20

What are the different ways that resistance can spread between pathogens?

Answer 20

1. Appears by spontaneous mutation
2. Some bacteria possess the ability to exchange genes with bacteria in the same species and different species, normally by the exchange of plasmids.
3. Phage - virus infects bacteria and transfers DNA

Question 21

What is the principle of genotypic screening?

Answer 21

Add probe to DNA sample, look for specific mutation - bind and identifiable - often flourescant

PCR - add a primer for a sequence, set time to replicate, measure amount of DNA present compare to expected, can show if homozygous or heterozygous