Flashcards in Aquired Immunodeficiency Syndrome Deck (12):
What fluids are associated with HIV transmission?
Why is IV exposure much more transmissible than genital exposure?
Genital has mucosal barriers of intact epithelium, pH, adaptive mucosal immunity
Are uncircumcised or circumcised men at a higher risk for HIV?
Uncircumcised - inner mucosa of the foreskin has less keratinization (deposition of fibrous protein) and a higher density of target cells for HIV infectio
Why are individuals with HSV infections more like to become infected even if there are no actual ulcers at the time of exposure?
HSV creates a better target environment for HIV, submucosal T cells are activated and much more likely to take up HIV and become infected.
Describe an acute HIV infection.
The time period following infection during which HIV virus can be detected in blood but antibodies to HIV are not present. Appears 1-4 weeks after exposure, 40-90% are asymptomatic, usually lasts about 14 days. Have a high risk of transmission during this time.
What will HIV tests look like with an acute HIV infection?
Positive HIV-1 RNA test
Negative HIV antibody test
Explain why HIV is considered a "slippery" virus.
People make neutralizing antibodies against their own HIV virus but they only work against the virus that was there a few months ago because HIV is always changing.
How does HIV blunt the humoral response?
Uses conformational masking:
Lack of broad neutralization
Shielding of highly-conserved co-receptor binding regions by hyper variable loops
Surface glycosylation -- focused changes in glycan packing prevents neutralizing antibody binding but not receptor binding
What is the main reason that HIV cannot be cured?
It integrates into the host genome and establishes a latent reservoir in resting CD4+ cells.
How many visions are produced a day?
10^9 - 10^10
with one error each time the genome is replicated -- lots of mutations
Explain Immune Reconstitution Inflammatory Syndrome (IRIS).
Paradoxical deterioration in clinical status after initiating antiretroviral therapy. Due to the recovery of the immune system to latent or subclinical infections or non-infectious processes. Takes about 8 wks to develop.