Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medical Microbiology and Virology > HIV 2 > Flashcards

HIV 2 Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards Biology 101 flashcards
1
Q

What is incidence/ prevalence of HIV in UK?

A

5000/ year new diagnosis

100 000 HIV patients in UK
50% gay
25% Black African
25% heterosexual white
IVDU minimal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is HIV incidence decreasing?

A

Earlier diagnosis/ treatment including PEP

PreP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When do we classify HIV as late diagnosis?

A

If diagnosed when CD4 <350

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

HIV positive mother.

What is transmission rate of HIV inutero/ via breast milk?

A

25% transmission in utero

15% transmission via breast milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How much does C-section reduce rate of HIV transmission in pregnancy?

How much does ART reduce risk transmission?

A

C-section reduces rate from 25% to 12%

ART reduces to <1% transmission. Longer duration of cART lower risk of transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which ART drugs are safe pregnancy?

A 
Abacavir
Emtricitabine
Lamivudine
Tenofovir TDF - safe
Tenofovir TAF - 2nd/3rd trimester
Zidovudine

Efavirenza
NEvirapine
Rilpivirine

Atazanavir
Darunavir
Lopinavir
Ritonavir

Raltegravir
Dolutegravir not safe
Elvitegravir not enough data

Almost all common drugs are safe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are risks of using dolutegravir in pregnancy?

A

1 in 2000 neural tube defect

Give extra folic acid

Neural tube closes at 6 weeks, so if presents after 6 weeks, then no need to switch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Maternal HIV new diagnosis, when to check viral load?

When to check CD4 count?

A

Viral load:

  • baseline
  • 4 weeks
  • one every trimester
  • 36 weeks - will determine mode of delivery*
  • at delivery

CD4

  • baseline
  • delivery

*if VL <50/ml can have normal vaginal delivery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

New diagnosis HIV in pregnancy.

When is it recommended to start treatment?

A

Start at beginning of second trimester

If CD4 count <200 or VL >100000, start in first trimester, as need more time to bing down VL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

New HIV pregnancy.

What are treatment options for mother?

A

Tenofovir/ emtricitabine/ atazanavir/ ritonavir

or

Abacavir/ lamivudine/ atazanavir/ efavirenz

If VL >100000 third agent is raltegravir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Possible HIV infected neonate.

What blood tests are required?

A 
baseline - proviral DNA
2 weeks - proviral DNA - only if high risk
6 weeks - proviral DNA
12 weeks - proviral DNA
22-24 months - HIV Ab

If proviral DNA is positive, start prophylactic co-trimoxazole and refer for assessment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Neonate at risk of HIV.

What is prophylaxis for newborn?

Very low risk - mum on ART with undetectable VL on two occassions

Low risk - mum on ART (less than 10 weeks), undetectable VL on one sample

high risk - if risk maternal VL is >50 at time of delivery

A

Very low risk
oral zidovudine 4mg/kg bd 2 weeks

Low risk
oral zidovudine 4mg/kg bd 4 weeks

High risk
oral zidovidine/ lamivudine/ nevirapine
4 weeks

If unable to tolerate oral, zidovudine is only drug available IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

KS caused by HHV8

What is treatment?

A

Minimal lesions - start ART

Intra-lesional chemotherapy if large lesion

Systemic doxorubicin if disseminated disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are oral symptoms of aadvanced HIV?

A 
oral candidiasis
cold sores - HSV1
oral hairy leukoplakia
necrotising gingivitis/ periodonitis
KS - HHV8
oral lymphoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

HIV patient with abnormality of CT head, what is differential diagnosis?

Non-infectious/ infectious

A 
Non-infectious -
CNS tumours
primary CNS lymphoma
IRIS 
Vascular disease - increased risk in HIV

Infectious -
bacterial abscess
tuberculosis
neurosyphilis

CMV
PML

toxoplasmosis
cryptococcosis

candida
aspergillus

If treat infectious cause e.g toxoplasma, CNS lesion can initially increase in size due to IRIS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is HIV viral escape?

A

HIV can hide in sacntuary site e.g brain/ CSF

ART usually has good penetration to CNS. If it does not get good penetration, HIV can replicate in CSF, and then escpae into blood stream, giving detectable viral load

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which ART have excellent CSF penetration?

A

Zidovudine

Dolutegravir

Nevirapine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which ART drugs have poor CSF penetration?

A

Tenofovir

Enfuvirtide

Most other drugs have reasonable penetration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which ARVs are cytochrome p450 inducers?

A

Atazanvir
Darunavir
Ritonavir
Cobicistat

Efavirenz
Nevirapine

20
Q

What is association between PI and corticosteroids?

Includes inhaled steroids

A

Not recommended as PI inhibit steroid metabolism, by inhibiting CYP3A4

Beclomethasone is safest

21
Q

Which anti-coagulants/ platelets can have interactions with ART?

A

Clopidogrel/ ticagrelor and ritonavir

Dabigatran and cobicistat

Warfarin - variable levels with multiple ARVs

22
Q

Why does doultegravir/ ritonavir/ cobicistat increase creatinine levels?

A

Affects transporters involved in renal clearance. So no damage to kidneys, but reduced creatinine clearance

23
Q

Host has restriction factors which are cellular proteins to inhibit virus replication. IFN increases levels of these proteins

What is role of:

TRIM5-alpha

SAMHD1

A

TRIM5-alpha - cytoplasmic protein targets viral capsid proteins with proteasome causing destruction

SAMHD1 - cytoplasmic enzyme hydrolyses dNTPs (deoxyribonucleotide) reducing pool available for replication

HIV2 more sensitive to TRIMalpha than HIV1

24
Q

Host has restriction factors which are cellular proteins to inhibit virus replication.
IFN increases levels of these proteins

What is role of:

APOBEC3

Tetherin interferon-inducible surface protein

A

APOBEC3 - cytosine deaminase incorporated into budding virion upon viral entry, inhibits RT/ INT

Tetherin interferon-inducible surface protein - prevents enveloped virions from detaching from cell surface

25
Q

When to consider HIV2 infection?

HIV2 RNA testing performed in Birmingham

A

West African
Atypical serological results
CD4 decline if undetectable HIV1 RNA

26
Q

What drugs is HIV2 intrinsically resistant to?

A

all NNRTIs

Fusion inhibitor - enfuvirtide

27
Q

HIV2

Little studies about when to start treatment, so start as soon as possible to prevent disease transmission

What are initial treatment regimens?

A

Two NRTIs + INT

Two NRTIs + PI

e.g

Tenofovir/ emtricitabine/ dolutegravir

Tenofovir/ emtricitabine/ darunavir

abacavir/ lamivudine/ dolutegravir

28
Q

When to perform HIV resistance testing?

Assay checks point mutations using NGS

A

New diagnosis - baseline

Pregnancy

Treatment failure - if suspect drug resistance

29
Q

What is process of NGS identifying resistance in HIV?

A

Extract nucleic acid

RT and PCR

Sequence genes using overlapping primers

Generate data compare to database of known resistance mutations

30
Q

Why does HIV persist without eradication?

A

DNA incorporated into reservoir of memory B cells, which can live for 50-70 years

“Berlin patient” had HIV, and developed AML. Had extensive chemo/radiotherapy, and bone marrow transplant. No HIV found in blood/ tissues

31
Q

What are differences between these drugs?

Tenofovir disoproxil TDF

Tenofovir alafenamide TAF

A

TAF -

longer plasma half life, and more stable in plasma.

Less nephrotoxicity – reduced creatinine reabsorption

Less bone disease

Safe first trimester

32
Q

New medication Biktarvy is suitable as less renal disease, less bone disease, suitable for pregnancy. Good results, with little side effects

What drugs does it include?

A

Tenofovir alafenamide TAF

Emtricitabine

Bictegravir (not available on its own)

33
Q

New medication Doravirine is a NNRTI.

What are its benefit?

A

Less susceptible resistance compared to other NNRTI

No interaction PPI

Less site effects e.g diarrhoea, headache

34
Q

New long acting injection forms are available

Initial treatment to get patient undetectable VL.

What drugs can be given?

A

carbotegravir and rilpivirine

Give IM, every month

35
Q

What are examples of entry and fusion inhibitors?

What receptors do they block?

A

Inhibitors of entry -

  • Marviroc binds CCR5 - need check tropism
  • Ibalizumab binds CD4 (post-attachment inhibitor)
  • Fostemsavir binds gp120 attachment inhibitor

Fusion
- Enfuvirtide

36
Q

New treatments may include neutralising monoclonal antibodies.

What are examples of how do they work?

A

Bind to CD4 binding site, inhibiting fusion

Bind to V3 loop of gp120, inhibiting fusion

37
Q

HIV Ag/Ab combo test on Architect

What are the targets?

A

p24 antigen

gp41 antibody HIV1
gp36 HIV2

38
Q

HIV PEP

Truvada + Raltegravir

What are common side effects?

A 
The most common side-effects were 
fatigue (37%)
diarrhoea (25%)
nausea (24%)
flatulence (24%)
abdominal cramps (21%)
bloating (16%)
headache (15%)
vivid dreams (15%)
depression (10%)
thirst (10%).

Raltegravir can often cause a hypersensitivity reaction e.g rash/ fever

39
Q

HIV PEP truvada and raltegravir

Patient experiencing side effects of of these drugs or
has poor renal function

What are other options for PEP?

A

Replace NRTI backbone with -
Lamivudine 150mg BD
Zidovudine 250mg BD

Replace INT with INT -
Dolutegravir

Replace INT with PI -
Lopinavir/ ritonavir (kaletra)
Darunavir/ ritonavir
Atazanavir/ ritonavir

40
Q

Why is loperamide often prescribed with PEP?

A

NRTI/ INT can both cause diarrhoea

if having to switch to PI - this has even higher risk of diarrhoea

41
Q

Patient has positive HIV Ag/Ab test. CD4 count is low
But undetectable viral load.

What are explanations?

A

Problem with test -

  • pre-analytical - wrong patient sampled
  • false positive Ag/Ab test
  • other cause for CD4 lymphopenia
  • HIV1 with rare group (N, O, P) or recombinant circulating form not detected by current viral load assay
  • HIV1 with elite controller status

Other -
- HIV2 positive, needs RNA VL sent to Birmingham

42
Q

What new drug is available as an injectable?

A

Cabotegravir/ Rilpivirine combination injection

tablets or injection

Integrase inhibitor/ NNRTI

Only if HIV VL undetectable, and known to have no NNRTI mutations

43
Q

Cabotegravir/ rilpivirine injections

What is dosing schedule?

A

injection once a month

each drug into a different gluteal muscle

44
Q

Cabotegravir/ rilpivirine injections

What groups should we be cautious of using in?

A

Do not use if known NNRTI mutation

Do not use if detectable VL

Caution if high BMI

45
Q

Mutations documentation

What does the mutation mean: K65R

A

K - amino acid wild-type. K is abbreviation of Lysine

65 - amino acid position

R - amino acid substitution conferring resistance. R is abbreviation or arginine

46
Q

With HIV diagnostics, what is meant by the eclipse period, and window period

A

Eclipse period - early infection in which virus cannot be readily obtained from the host. e.g a viral load may be negative

Window period - time until first detection of a marker. e,g p24 or antibody

Medical Microbiology and Virology (60 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions