HIV Flashcards
(68 cards)
What are the key receptors involved in thee infection of CD4 cells by the HIV virus?
Viral gp120 attaches to CD4 receptor then binds to CCR5 or CXCR4 coreceptors. viral gp41 is exposed and facilitates fusion and viral entry.
Mortality in HIV/AIDS is usually secondary to….
opportunistic infections,
wasting,
cancer
in a HIV infected pregnant woman, Caesarian delivery is indicated if….
viral load >1000
what is the typical course of HIV infection?
- Primary HIV infection
- Asymptomatic HIV infection
- Symptomatic HIV infection
- Full-blown AIDS
The combination of these two tests in confirming a HIV diagnosis yields an overall sensitivity and specificity of >99%….
ELISA and Western Blot
Phase I: Primary HIV infection
mononucleosis-like syndrome 2-4 weeks after HIV exposure
Duration is brief: 3days-2 weeks
Nonspecific symptoms
High false negative rate due to pre-seroconversion
Phase 2: Asymptomatic HIV infection
Seropositive
No clinical evidence of HIV infection
CD4 counts are normal
Longest Phase: lasts 4-7 years if untreated
Phase 3: Symptomatic HIV infection
first evidence of immune system dysfunction
Phase lasts 1-3 years with out treatment
Characterized by generalized lymphadenopathy, fungal infections, oral hairy leukoplakia, seborrheic dermatitis, constitutional symptoms
Phase 4: Full-blown AIDS
CD4 count
if CD4 count is >500, immune system is…
essentially normal
CD4 level between 200-500
Increased risk of HIV related problems: herpes zoster TB lymphoma bacterial pneumonia kaposi sarcoma
CD4 count
most opportunistic infections occur at this level
Target goal for HIV viral load
want undetectable viral load
How often should viral load and CD4 count be measured?
At time of diagnosis and every 3-4 months afterward
Pro and Con to p24 antigen assay for diagnosing HIV infection
test is less expensive
but it is less sensitive than viral load testing
Patients with acute (primary) HIV infection have very high…
levels of viremia
what is the leading cause of death in AIDS?
Pneumocystis Pneumonia (PCP)
Treatment of PCP
TMP-SMX (trimethoprim/sulfamethoxazole) for three weeks
*If hypoxic or elevated A-a gradient, give steroids
What is the recommended prophylaxis treatment for PCP?
oral TMP-SMX 1 dose daily
TB, CMV, MAC infections are more likely when….
CD4 count
Seroconversion
When patient is positive for HIV antibody
Occurs 3-7 weeks after infection
Confirms HIV diagnosis
IF HIV ELISA is positive, what is the next step?
Confirm with Western Blot Test
HIV Patient with subtle memory impairment and cognitive deficits, followed by changes to mental status, aphasia, and motor abnormalities should be evaluated for….
AIDS dementia
HIV patient with CNS symptoms and head imaging findings of contrast-enhanced mass lesions in basal ganglia and subcortical white matter should be suspected of having…
reactivation of latent toxoplasmosis
