HIV Flashcards
5 routes of transmission for HIV
Sexual intercourse Blood/ Organ transplantation Pregnancy, childbirth, breastfeeding IVDU Occupational exposure
Describe the pathogenesis of HIV
HIV enters CD4 lymphocytes
Reverse transcriptase allows incorporation of HIV genetic material into host genome
Dissemination of virions leads to cell death + eventual T-cell depletion
Initial phase of HIV
Often asymptomatic Or Seroconversion/ acute retroviral syndrome 2-4/52 post. Self-limiting Fever + Night sweats Generalised lymphadenopathy/ rash Sore throat/ ulcers Myalgia Headache Diarrhoea
List the neurological, respiratory, cardiac, haematological, GI and eye pathologies that are direct effects of HIV Infection
Neuro: polyneuropathy, dementia Lung: lymphocytic interstitial pneumonitis Heart: cardiomyopathy, myocarditis Haem: anaemia, thrombocytopaenia GI: anorexia, wasting Eyes: cotton wool spots
What secondary bacterial, viral, fungal, protozoal infections arise from immunodeficiency in HIV?
Bacterial: TB, skin infections, pneumococcal infections
Viral: CMV, HSV, VZV, HPV, EBV
Fungal: pneumocystic jirovecii pneumonia, Cryptococcus, candidiasis, invasive aspergillosis
Protozoal: toxoplasmosis, cryptosporidia
What investigations are required for HIV?
ELISA detects antibodies, confirmed by western blot
p24 antigen viral core protein
Clinical stages of HIV after seroconversion
- Persistent generalised lymphadenopathy
- Unexplained moderate weight loss, recurrent infections
- Unexplained severe weight loss, chronic diarrhoea, persistent fever, persistent/ severe infections, anaemia, neutropenia, thrombocytopenia
- AIDS. Syndrome of secondary diseases resulting from immunodeficiency
At what stages do tests not show false negatives post infection?
ELISA: 4-6 weeks (99% at 12)
p24 antigen: 1 to 3-4 weeks
ELISA + p24: 2-4 weeks
When should testing be performed in an asymptomatic at risk individual?
4 weeks after possible exposure
Repeat at 12 weeks
Further Ix carried out when HIV is detected
HIV RNA viral load
CD4 count
Screen for other STIs/ infections
Principles of tx for HIV
2 nucleoside reverse transcriptase inhibitors (NRTIs) = backbone regimen
+ a 3rd drug: integrase inhibitor (INI), a non-nucleoside reverse transcriptase inhibitor (NNRTI), or boosted protease inhibitor (PI)
Common NRTIs
Emtricitabine + Tenofovir
Abacavir + lamivudine.
Which single tablet regimen has been licences in the UK?
Eviplera
Emtricitabine/ Rilpivirine/ Tenofovir disoproxil
Which suffix is shared by all protease inhibitors?
-navir.
Ritonavir
Which suffix is shared by all integrate inhibitors
-gravir.
Raltegravir
Dolutegravir
Name an entry inhibitor
Maraviroc
4 opportunistic infections/ disorders that may occur with CD4 count 200-500
Oral thrush (Candida albicans) Shingles (Herpes zoster) Hairy leukoplakia (EBV) Kaposi sarcoma (HHV-8)
5 opportunistic infections/ disorders that may occur with CD4 count 100-200
Cerebral toxoplasmosis
Progressive multifocal leukoencephalopathy (JC virus)
Pneumocystis jirovecii pneumonia
HIV dementia
Cryptosporidiosis; usually self-limiting if CD4 200-500 similar to in immunocompetents
4 opportunistic infections/ disorders that may occur with CD4 count 50-100
Aspergillosis (Aspergillus fumigatus)
Oesophageal candidiasis (Candida albicans)
Cryptococcal meningitis
Primary CNS lymphoma (EBV)
5 opportunistic infections/ disorders that may occur with CD4 count <50
Cytomegalovirus retinitis (30-40% of <50cells/mm) Mycobacterium avium-intracellulare infection
NRTI side effects
Peripheral neuropathy
Hypercholesteralaemia
Hypertriglyceridaemia
Hyperglycaemia
NNRTI side effects
Hepatotoxicity
Neuropsychiatric Sx: Nightmares, confusion, insomnia, abnormal thinking/ dreams/ concentration
Nausea
Rash (inc. SJS)
PI side effects
Hyperglycaemia, Hyperlipidaemia, Fat maldistribution, Transaminase elevations / hepatotoxicity
Prolonged PR interval
Rash inc. SJS
Entry inhibitor side effects
Hepatotoxicity Abdominal pain Cough Dizziness MSK Sx Pyrexia Skin rash URTI Orthostatic hypotension
