HIV & Anti-Retroviral therapy

Question 1

What is UNAIDS 90-90-90?

Answer 1

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

Question 2

What is the cause of HIV and the pathogenesis?

Answer 2

Lentivirus - a type of retrovirus, infecting the immune cells:
(1) CD4+ T helper cells
(2) Macrophages
(3) Dendritic cells

Question 3

What type of virus is lentivirus?

Answer 3

• Group IV
• ssRNA
• Positive sense
• Enveloped

Question 4

What is the difference between HIV-1 and HIV-2

Answer 4

(1) HIV-1

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

Question 5

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

Answer 5

(1) Direct viral killing of infected cells

(2) Increased apoptosis of infected cells

(3) Killing of infected CD4+ T cells by CD8 cytotoxic lymphocytes

Question 6

What does a CD8 cytotoxic lymphocyte do?

Answer 6

Kills infected CD4+ (Helper) T cells

Question 7

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

Answer 7

(1) Increased susceptibility to opportunistic infections

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

Question 8

What are the stages of the HIV life cycle?

Answer 8

Lentivirus binds to CD4 receptor to fuse with host cell membrane

Virus uncoats and viral RNA + proteins enter host cell

Viral DNA is transcribed via reverse transcriptase

Viral DNA enters nucleus
Integrates into host genome using viral integrase

New viral DNA is used as genomic RNA
This is used to make new viral proteins

Question 9

How can HIV enter the body?

Answer 9

Into the bloodstream
or
mucus membranes (vaginal/penis/anus)

Question 10

Where is HIV present in the body once contracted?

Answer 10

semen
vaginal fluids
breast milk
blood
rectal excretions

Question 11

How can HIV be transmitted?

Answer 11

Unprotected sex
mother to baby
IV drug use - needle sharing/needle stick injury
blood transfusions

Question 12

How can HIV spread be prevented?

Answer 12

HIV testing
condoms
post exposure phrophylaxis PEP
pre-exposure phrophylaxis PrEP
Needle exchange programmes & clean needles
blood screening

Question 13

How is HIV diagnosed

Answer 13

ELISA-immunoassay
detection of antibodies for HIV
detection of p24 antigen

Question 14

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

Answer 14

3 months

Question 15

Where can tests be accessed by the public

Answer 15

sexual health clinics
hospitals
GP surgeries
community pharmacies

Question 16

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

Answer 16

-Immunoassay (ELISA) to differentiate between HIV-1 and HIV-2

-HIV NAT (nucleic acid test)

Question 17

When do AIDS symptoms occur following HIV infection?

Answer 17

7.5 years post infection

Question 18

How does HIV lead to death if left untreated?

Answer 18

Progressively destroys all CD4+ (helper) T cell lymphocytes

Question 19

what is seroconversion?

Answer 19

the acute infection stage of HIV infection, flu-like symptoms: fever, headache, rash

Question 20

What is clinical latency?

Answer 20

chronic infection (asymptomatic) stage of HIV infection

Question 21

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

Answer 21

Seroconversion, acute infection stage

Question 21

Are HIV antibodies present in seroconversion?

Answer 21

No, they are only starting to be made

Question 22

When can common infections be seen in an HIV infection?

Answer 22

chronic latency stage

Question 23

What characterises AIDS

Answer 23

Immune system can no longer fight infection
Low CD4+ (helper) lymphocyte count
High viral load

Question 24

When are opportunistic infections observed in HIV infections?

Answer 24

AIDS stage of infection

Question 25

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

Answer 25

DEATH

Question 26

How does AIDS develop?

Answer 26

Untreated HIV infection

Question 27

What is ART and its aims?

Answer 27

antiretroviral therapy Increase CD4+(helper) T lymphocyte count Increase quality of life + life expectancy decrease risk of infections decrease transmission decrease viral load decrease risk progression

Question 28

What are the types of ART?

Answer 28

Entry/fusion inhibitors these drugs block HIV from getting inside healthy cells. RT inhibitors bind to a specific protein so the HIV virus can't make copies of itself. integrase inhibitors These stop HIV from making copies of itself by blocking a key protein that allows the virus to put its DNA into the healthy cell's DNA. protease inhibitors These drugs block a protein that infected cells need to put together new HIV virus particles.

Question 29

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

Answer 29

Stage 1: virus receptor binding stage 2: virus uncoating and entry of RNA and proteins into CD4+ (helper) lymphocyte t cell

Question 30

What stage of the HIV-life cycle does an RT inhibitor affect

Answer 30

Stage 3: viral DNA transcription using reverse transcriptase

Question 31

What stage of the HIV-life cycle does an integrase inhibitor affect?

Answer 31

stage 4: prevents integration of viral DNA into host genome

Question 32

Which stage of the HIV life cycle does a protease inhibitor affect?

Answer 32

stage 5 prevents generation of new viral proteins stage 6 prevents assembly of viral proteins and RNA at the CD4+ (helper) T lymphocyte cell membrane

Question 33

What are the two types of RT inhibitor?

Answer 33

NRTIs causes DNA chain termination, analogue of dNTPs NNRTIs direct inhibitor of HIV reverse transcriptase

Question 34

How can the formation of mature viral particles be prevented?

Answer 34

protease inhibitor drugs

Question 35

What is the first line treatment for HIV

Answer 35

combination therapy 2 NRTIs 1 NNRTI/PI/INI

Question 36

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

Answer 36

Integrase inhibitor drug

Question 37

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

Answer 37

Antenatal screening

Question 38

Who is PrEP medicine intended for?

Answer 38

HIV negative individuals who are at risk of HIV infection, currently only TRUVADA available

Question 39

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

Answer 39

>90%