Flashcards in HIV Deck (25):
What is the main HIV group globally?
others: N, O
Where is HIV-2 mainly found?
West Africa, SE Asia
What enzymes are coded for by pol
RT, protease, integrase
Env codes for a polypeptide that is cleaved to form _____ and ____ on the viral envelope
What does gag code for?
proteins that make up the viral core
List 8 steps in HIV viral replication
1. attachment of gp120 to CD4 and a co-receptor
2. fusion of viral envelope, release of genome into host cell
3. RT converts viral RNA to DNA which goes to the nucleus
4. Integrase inserts viral genome into host genome
5. transcription and translation of viral genome
6. viral protease cleaves polyproteins
7. viral assembly
8. budding/ acquisition of envelope and glycoproteins
Innumerable HIV ______ exist within each infected individual
** due to compact genome, error prone RT, replication kinetics
After crossing the mucosal barrier, _____ cells transport HIV to regional lymph nodes and CD4+ cells in the paracortical regions of the node interact with HIV
Widespread dissemination of HIV to the CNS, reticuloendothelial system, and GALT occurs within _____ days of infection
primary viremia, but asymptomatic
The hallmark of HIV disease is:
occurs in GI tract over first 2-3 weeks of infection (loss of 80% of CD4 T cells)
List components of the immune system that are dysregulated in HIV infection
lymphoid tissue- distorted architecture
B cells- hypergammaglobulinemia
Neutrophils- impaired opsonizing activity
Monocytes/ macrophages- reservoir for virus, role in CNS disease
_____________ serve as reservoirs for HIV and play a prominent role in CNS disease via infection of microglial cells
HIV immunosuppression involves not only intracellular
pathogens and malignancies (for which we rely on the _______) but also common bacterial
pathogens for which we rely on the _________ defenses
CMI for intracellular pathogens/ malignancies
humoral and neutrophil for bacterial pathogens
Why do antibodies against HIV fail to provide high levels of neutralizing capacity?
- genetic diversity of viral isolates
balance at viral set point correlates with development of HIV specific antibodies
Chronic immune system ______ is harmful over time, as the ability to respond to any specific antigen is lessened and a broad response to other antigens is compromised
The massive depletion of GI tract CD4+ T lymphocytes can lead to _________ across the GI mucosa, which has been shown to drive immune activation
products of bacterial translocation
What is the most common mode of HIV transmission worldwide? What are other notable modes of transmission?
MTC, IDU, transfusion/ transplantation, accidental needle stick
Why is the acute antiretroviral syndrome so clinically significant?
most transmission occurs by those who just acquired the virus themselves
Viral load is very high during this time
What are the most common presenting symptoms of somebody experiencing primary antiretroviral syndrome? Which are (relatively) specific to HIV as compared to other infections?
fever, fatigue, rash, adenopathy, pharyngitis, myalgia, night sweats, thrombocytopenia, luekopenia, diarrhea, aseptic meningitis, oral or genital ulcers
specific: rash, aseptic meningitis, ulcers
What other infections should be on the differential for acute HIV infection?
One manifestation of chronic symptomatic infection is _____, which is a manifestation of EBV on the sides of the tongue
oral hairy leukoplakia
Describe the immune reconstitution inflammatory syndrome
Immune reconstitution due to antiretroviral therapy can lead to the expression of opportunistic
infectious processes because now the immune system can react to latent organisms that have been present, but not previously recognized due to immune system dysfunction
What prophylaxis should be offered against opportunistic infections and at what CD4 count should they be initiated?
pneumocystis- TMP/SMX at CD4=200
toxoplasmosis TMP/SMX at CD4= 100
M avium azithromycin at CD4=50
Describe phenotypic and genotypic drug resistance testing
genotypic resistance testing: provides a list of detected mutations that have
occurred in the viral genome that are associated with drug resistance.
phenotypic resistance testing: compares the concentration of
antiretroviral medications required to inhibit the patient’s virus to that of wild type virus.