HIV Flashcards
What is the target site for HIV?
CD4+ receptors
What is the function of CD4+ T cells?
Recognise the antigen-presenting cell and activate the adaptive immune response
Give some effects of HIV infection on immune response
Reduced circulating CD4+ cells
Dysregulated CD8+ cell activation
Reduced antibody class switching
CD4+ T cells should always be above what value?
500 cells/mm
At what level of CD4+ T cells is there risk of opportunistic infections?
<200 cells/mm
What occurs in the primary infection stage of HIV?
Huge amount of virus causes a rapid depletion in CD4 count
After primary infection, why does CD4 count start to rise?
As immune cells are produced against HIV
What is the average time to death if not treated for HIV?
9-11 years
Give some symptoms seen in primary HIV infection
Fever Rash Myalgia Pharyngitis Headache
What occurs in asymptomatic HIV infection?
Ongoing viral replication causes CD4 to reduce
Give some examples of opportunistic infections seen in HIV
Pneumocystic pneumonia TB (certain types) Cerebral toxoplasmosis CMV Herpes simplex/zoster Progressive multifocal leukoencephalopathy
What is the most common opportunistic infection in HIV?
Pneumocystis pneumonia
How is pneumocystis pneumonia treated?
Co-trimoxazole
Give some signs of cerebral toxoplasmosis
Headache Fever Focal neurology Seizures Raised ICP
How does CMV present?
Reduced visual acuity
Floaters
Abdo pain, diarrhoea and PR bleeding
Which virus causes progressive multifocal leukoencephalopathy?
JC virus
Give some examples of AIDS-related cancers
Kaposi’s sarcoma
Non-Hodgkins lymphoma
Cervical cancer
How does Kaposi’s sarcoma present?
Cutaneous/mucosal vascular tumour
Which virus causes non-Hodgkins lymphoma?
Epstein-Barr virus
Why does cervical cancer commonly occur in AIDS?
As there is persistence of HPV infection
Give some clinical features seen in “asymptomatic” HIV
Mucosal candidiasis Seborrhoeic dermatitis Diarrhoea Fatigue Lymphadenopathy Worsening psoriasis
What is the main mode of transmission of HIV?
Sex
Give some factors which increase transmission risk?
Anoreceptive sex
Trauma
Genital ulceration
STI
How else may someone acquire HIV?
Injection drug use
Infected blood products
Mother-to-child
What is the risk of mother to child transmission of HIV in the UK when viral load is undetectable?
<0.1%
Which population group have the highest % of people living with undiagnosed HIV?
Heterosexual men
Which population group have the highest proportion of HIV?
MSM
What markers of HIV are tested for?
Viral RNA
Antigen
Antibody
How is HIV most commonly tested for?
Test for combined antibody-antigen
Why is it better to test for combined antibody-antigen rather than antibody?
As it shortens the window period where infection may not be detected
What test can be used to test for HIV rapidly?
POCT
Give some targets for anti-retroviral drugs
Reverse transcriptase
Integrase
Protease
What strategy is used to treat HIV?
HAART - highly active anti-retroviral therapy
What is HAART?
A combination of 3 drugs from at least 2 drug classes to which the virus is susceptible
How can a patient prevent drug resistance in HIV?
Adherence
Lifestyle changes
Avoiding drug-drug interactions
Give some common side effects of HAART therapy
Diarrhoea Rash Psychosis Proximal renal tubulopathy Osteomalacia Anaemia
What effect does protease inhibitors have on liver enzymes?
They inhibit them
What effect does NNRTIs have on liver enzymes?
They induce them
Are HIV patients legally required to notify their partner?
No
What are the best ways to prevent onward HIV transmission sexually?
Condom use
STI screening
Pre/post-exposure prophylaxis
An undetectable viral load means the virus is still transmissible. True/false?
False - undetectable viral load = untransmissable virus
What method of delivery is done if viral load is detected in a pregnant mother?
Caesarean section
Why are all HIV patients treated even if they are not symptomatic?
As it means they cannot transmit the virus
Which patients are eligible for pre-exposure prophylaxis?
HIV+ partner with detectable viral load
MSM or transwoman that has UPAI >2 partners in last year
