L27+HIV/AIDS Flashcards
Initial HIV infection symptoms
asymptomatic
sore throat, LAD, mimics Mono
During which stage of infection is there a high risk of transmission?
Early stages when the patient is unaware
Average time from HIV infection to AIDS if left untreated
8 years
Main symptoms of Acute HIV infection
Mouth sores Thrush Fever Weight loss Myalgia Hepatosplenomegaly HA, neuropathy LAD Rash N/V
When is Stage 3 HIV (AIDS) diagnosed?
severe damage to the immune system= CD4 <200
Examples of AIDS defining conditions
Kaposi's sarcoma (HHV-8) Pneumocystis pneumonia (PJP) MAC infection, TB Invasive cervical cancer CMV retinitis Chronic intestinal Cryptosporidiosis Candidiasis Encephalopathy
4 HIV disease course classes
- Fast: <3 years to AIDS
- Average: ~10 years
- Long term non-progressors >10 years, <5% of cases
- Elite controllers: don’t become infected. RARE AF
HIV virus
dsRNA genome
Enveloped
Reverse transcriptase: RNA dependent DNA polymerase inserts DNA copy into human genome, establishes latency
HIV-1
Wide spread form, more common
HIV-2
Form found in West Africa
less easily transmitted, and has a slower progression
resistant to NNRTI antiretrovirals
How did we get AIDs originally?
Zoonotic: Primates: Simian Immunodeficiency Virus
entered into human population in Africa at least 3 times
How long has AIDs been around
Found in human sera as early as the 1950s in retrospective studies
Which cells does HIV-1 infect?
Infection of cells with CD4 and chemokine co-receptor molecule displayed:
Th, Monocytes, Macrophages
Cytopathic effects of HIV
Th cell loss immunosuppression mechanism is uncertain: 1. Direct virus killing 2. Apoptosis of immune cells Formation of "swarms"
Why do you have to use combination therapy for HIV treatment?
Mutates rapidly, prevents swift virus inhibition of antivirals
monitor viral load frequently to ensure virus hasn’t mutated
Labs of primary infection:
High CD4 count
High HIV RNA copies
Viremia
Labs of clinical latency:
CD4 count declines over time
Viremia sharply declines to 0
HIV RNA copies drop and then level off (don’t get to 0)
Labs of reactivation: constitutional symptoms
Lower CD4+ (~300)
Rising HIV RNA and viremia
Labs of reactivation: opportunistic diseases and/or death
Few/No CD4+
Very high HIV RNA and viremia
Detection of HIV
HIV antibody: 2 steps
- EIA screen
- Confirm (+) results with Western blot
Direct tests of HIV detect
presence of virus RNA or protein antigens
Nucleic acid test
PCR: antigen p24, RNA genome
How is donated blood screened for HIV?
Nucleic acid test, as to avoid antibody response lag
Rapid HIV tests
OraQuick Rapid HIV-1/2 Antibody test
takes 20 minutes
identify infected and prevent transmission (doesn’t account for antibody lag though)
Classes of antiretroviral agents
***use in combination***//***not curative*** Reverse transcriptase inhibitors: 1. Nucleoside analogs 2. Non-nucleoside inhibitors Protease inhibitors -stop maturation of viral assembly Fusion-penetration inhibitors
