(PM3A) HIV & Anti-Retroviral Therapy Flashcards Preview

Part 3 – PM3A > (PM3A) HIV & Anti-Retroviral Therapy > Flashcards

Flashcards in (PM3A) HIV & Anti-Retroviral Therapy Deck (73)
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1
Q

How many people have died from HIV?

A

33 million

2
Q

How many people in the world are living with HIV?

A

38 million

3
Q

Where is HIV most prevalent?

A

Africa - 2/3 of total HIV cases

4
Q

How many people die from HIV every year?

A

700,000

5
Q

How many new HIV infections are there every year?

A

1.7 million

6
Q

How many people have access to anti-retroviral therapy?

A

25.4 million

7
Q

How many people in the UK are living with HIV?

A

105,000

8
Q

What age range is affected most by HIV infection?

A

35-49

9
Q

What is UNAIDS 90-90-90?

A

A global target set for countries to have:

(1) ≥90% HIV+ to be diagnosed
(2) ≥90% HIV+ to be on ART
(3) ≥90% HIV+ to have viral load depressed

10
Q

What is ART

A

Anti-retroviral therapy

11
Q

What does HIV stand for?

A

Human Immuno-deficiency Virus

12
Q

What is the cause of HIV?

A

Lentivirus - a type of retrovirus

13
Q

What type of virus is lentivirus?

A
  • Group IV
  • ssRNA
  • Positive sense
  • Enveloped
14
Q

How does lentivirus cause HIV?

A

Infects immune cells

15
Q

What are the immune cells infected by lentivirus to cause HIV?

A

(1) CD4+ T helper cells
(2) Macrophages
(3) Dendritic cells

16
Q

What is a CD4+ T cell also known as?

A

Helper T cell

17
Q

What is a helper T cell also known as?

A

CD4+ T Cell

18
Q

(1) What is most commonly caused by lentivirus?

(2) What is also caused by lentivirus?

A

(1) HIV-1

(2) HIV-2 - less virulent and less infective

19
Q

How does the infection of immune cells by lentivirus lead to low levels of helper T cells?

A

(1) Direct viral killing of infected cells
(2) Increased apoptosis of infected cells
(3) Killing of infected CD4+ T cells by CD8 cytotoxic lymphocytes

20
Q

What does a CD8 cytotoxic lymphocyte do?

A

Kills infected CD4+ (Helper) T cells

21
Q

What white blood cell kills CD4+ (Helper) T cells?

A

CD8 cytotoxic lymphocytes

22
Q

What effect does increased death of CD4+ (Helper) T cells have?

A

(1) Increased susceptibility to opportunistic infections

(2) Susceptibility increases as CD4+ (Helper) T cell count falls below critical level

23
Q

What is the 1st stage of the HIV life cycle?

A

Lentivirus binds to CD4 receptor to fuse with host cell membrane

24
Q

What is the 2nd stage of the HIV life cycle?

A

Virus uncoats and viral RNA + proteins enter host cell

25
Q

What is the 3rd stage of the HIV life cycle?

A

Viral DNA is transcribed via reverse transcriptase

26
Q

What is the 4th stage of the HIV life cycle?

A

Viral DNA enters nucleus

Integrates into host genome using viral integrase

27
Q

What is the 5th stage of the HIV life cycle?

A

New viral DNA is used as genomic RNA

This is used to make new viral proteins

28
Q

What is the 6th stage of the HIV life cycle?

A

Viral RNA and viral proteins gather at the cell membrane

29
Q

What is the 7th stage of the HIV life cycle?

A

Budding leads to a mature viral particle being released from the cell

30
Q

How many stages are there in the HIV life cycle?

A

7 stages

31
Q

How can HIV enter the body?

A

(1) Into the bloodstream

2) Mucous membranes (vagina/ penis/ anus

32
Q

Where is HIV present in the body once contracted?

A
  • Semen
  • Vaginal fluids
  • Breast milk
  • Blood
  • Rectal excretions
33
Q

How can HIV be transmitted?

A

(1) Unprotected sex
(2) Mother-to-baby
(3) IV drug use - needle sharing/ needle stick injury
(4) Blood transfusions

34
Q

How can HIV spread be prevented?

A

(1) HIV testing
(2) Condoms
(3) Post-exposure prophylaxis (PEP)
(4) Pre-exposure prophylaxis (PrEP)
(5) Needle exchange programmes + clean needles
(6) Blood screening

35
Q

How is HIV diagnosed?

A

ELISA - immunoassay

Detection of antibodies for HIV

Detection of p24 antigen

36
Q

What is the period for which HIV+ patients may test negative with older tests?

A

3 months

37
Q

Where can tests be accessed by the public?

A

ø Sexual health clinics
ø Hospitals
ø GP surgeries
ø Community pharmacies

38
Q

What tests are undertaken by the patient following an HIV positive diagnosis?

A

(1) Immunoassay (ELISA) to differentiate between HIV-1 and HIV-2
(2) HIV NAT (Nucleic Acid Test)

39
Q

When do AIDS symptoms occur following HIV infection?

A

7.5yrs post-infection

40
Q

How does HIV lead to death if left untreated?

A

Progressively destroys all CD4+ (Helper) T cell lymphocytes

41
Q

What is the acute infection stage of HIV infection called?

A

Seroconversion

42
Q

What is seroconversion?

A

The acute infection stage of HIV

43
Q

What is the chronic infection (asymptomatic) stage of HIV infection called?

A

Clinical latency

44
Q

What is clinical latency? What are its symptoms?

A

The chronic infection stage of HIV

Presents as asymptomatic

45
Q

(1) What are the potential symptoms of initial HIV infection?
(2) What is this initial infection stage called?

A

(1) Flu-like symptoms: Fever, headache, rash

(2) Seroconversion - Acute infection stage

46
Q

Are HIV antibodies present in the acute infection stage (seroconversion)?

A

No

They are only starting to be made

47
Q

When does the body’s CD4+ (Helper) T lymphocyte count begin to decline in an HIV infection?

A

Acute infection stage - Seroconversion

48
Q

When can common infections be seen in an HIV infection?

A

(1) Clinical latency stage - chronic infection stage

49
Q

What characterises AIDS?

A

(1) Immune system can no longer fight infection
(2) Low CD4+ (Helper) T lymphocyte count
(3) High viral load

50
Q

When are opportunistic infections observed in HIV infections?

A

AIDS stage of infection

51
Q

What happens if an HIV infection (AIDS) is left untreated?

A

Death

52
Q

How is AIDS developed?

A

Untreated HIV infection

53
Q

What is ART?

A

Anti-retroviral therapy

54
Q

What are the aims of ART?

A
  • Increase CD4+ (Helper) T lymphocyte count
  • Increase quality of life + life expectancy
  • Decrease risk of infections
  • Decrease transmission
  • Decrease viral load
  • Decrease risk progression
55
Q

What are the types of ART?

A

(1) Entry/ fusion inhibitors
(2) RT (reverse transcriptase) inhibitors
(3) Integrase inhibitors
(4) Protease inhibitors

56
Q

What stage(s) of the HIV-life cycle does an entry/ fusion inhibitor affect?

A

Stage 1: Virus receptor binding

Stage 2: Virus uncoating and entry of RNA and proteins into CD4+ (Helper) T cell

57
Q

What stage(s) of the HIV life-cycle does an RT inhibitor affect?

A

Stage 3: Viral DNA transcription using reverse transcriptase

58
Q

Which stage(s) of the HIV life-cycle does an integrase inhibitor affect?

A

Stage 4: Prevents integration of viral DNA into host genome

59
Q

Which stage(s) of the HIV life-cycle does a protease inhibitor affect?

A

Stage 5: Prevents generation of new viral proteins

Stage 6: Prevents assembly of viral proteins and RNA at the CD4+ (Helper) T cell membrane

60
Q

What are the types of reverse transcriptase inhibitor?

A

(1) NRTIs

(2) NNRTIs

61
Q

What is an NRTI?

A
  • Cause DNA chain termination

- Analogue of dNTPs

62
Q

What is an NNRTI?

A
  • Direct inhibitor of HIV reverse transcriptase
63
Q

How can the formation of mature viral particles be prevented?

A

Protease inhibitor drugs

64
Q

How can host integration be prevented?

A

Integrase inhibitor drugs

65
Q

What is the 1st line treatment for HIV?

(2) What drug(s) are included in the first line treatment for HIV?

A

(1) Combination therapy

2
ø 2 NRTIs
ø + 1 NNRTI/ PI/ INI

66
Q

How can viral load be decreased in HIV infections in pregnancy?

A

Integrase inhibitor drug

67
Q

How is transmission of an HIV infection from mother to child prevented?

A

Antenatal screening

68
Q

What does PrEP stand for?

A

Pre-exposure prophylaxis

69
Q

What is currently the only PrEP on the market?

A

Truvada

70
Q

Who is PrEP medicine intended for?

A

HIV negative individuals who are at risk of HIV infection

71
Q

How much, as a %, does PrEP treatment reduce HIV infection risk by?

A

> 90%

72
Q

What PEP (also known as PEPSE) stand for?

A

Post-exposure prophylaxis

73
Q

When is PEP treatment implemented?

A

Following a high-risk exposure to HIV, e.g. sex/ needle-stick