HIV Flashcards
3 enzymes HIV must have in packaging
reverse transcriptase, integrase and protease
HIV Type in USA
HIV-1B
Is incidence of disease going up or down?
the incidence is decreasing overall, but increasing in places like china and russia
GP41/120 proteins in HIV
outer transmembrane membrane proteins, important for attachment and entry of virus
P24 protein in HIV
important for capsid of HIV surrounding nucleus
P17 protein in HIV
matrix protein
two interactions for HIV entry into cell?
CD4 and chemokines (CCR5 and CXCR5)
CD4 interaction
primary interaction, with T cells, macrophages and microglial cells
CCR5 interaction and type of HIV
usually in macrophages, called M-tropic HIV (M5 virus)
associated with virus transmission
CXCR4 interaction and type of HIV
in T cells and called T-tropic HIV (X4 virus)
associated with disease progression…usually later in infection
binding of Dual mixed virus
CXCR4 and CCR5
Steps of reverse transcription
make ssDNA, destroy RNA, make dsDNA, integrate
classes of antiretroviral meds
reverse transcriptase inhibitors
protease inhibitors
fusion/entry inhibitors
integrase inhibitors
Zidovudine information
NRTI
drug for infants
IV
Abacavir information
NRTI
serious hypersensitivity…blood test prior
Lamivudine and Emtricitabine information
NRTI
treats hep B and HIV
combo with Zidovudine
Tenofovir information
NRTI, very common, Hep B and HIV
less toxic
given for HIV PREP
Lopinavir/ritonavir information
protease inhibitor
Raltegravir information
integrase inhibitor
Maraviroc information
unique class that inhibits co receptor…may not always work
two types of prophylaxis with HIV
pre (prep) and post exposure (PEP)
common classes in HAART treatment of HIV
NRTI, integrase and protease inhibitors
correlation between plasma viral load and CD4 levels?
if high plasma HIV load…typically lowering CD4 count
Cells that encounter HIV first
langerhans in vagina and foreskin
macrophages, dendritic and NKs in subepithelium
Components of adaptive response to HIV
antibodies develop against core antigens
CD8 t cells become activated
CD4 cells activated, but lose these
what happens when HIV virus has tons of mutations?
fitness of the host and virus actually decreases so it decreases the likelihood of transmission
What cells have the CCR5 receptors?
mainly dendritic, macros, and T cells in GALT, other T cells only about 20-30% have the CCR5
DC sign
on dendritic cells…can recognize HIV too
What do APCs do once they have the HIV virus?
present to CD4 cells around it and travel to nodes to present
acute HIV infection has what effect on mucosal CD4 cells?
knocks these out!!!
acute HIV infection effect on CD4 cells?
causes a large decrease in CD4 cells
AIDs effect on CD4 cells?
causes large decrease in CD4 cells
asymptomatic HIV phase effect on CD4 cells?
CD4 cells are actually increasing during this time
how do CD4 cells increase during asymptomatic HIV?
CD8 cells are activated and killing of virus
Viral load changes in acute, asymptomatic phase of HIV and AIDs
high in acute, decline and steady in asymptomatic, then increases again in AIDs
Acute HIV presentation and onset
usually symptomatic with fever sore throat lymphadenopathy and rash
couple weeks after infection
What is the best test for early acute phase HIV diagnosis?
P24 antigen testing
What is the HIV viral set point? and what does it mean for progression of AIDs?
it is the viral load of a patient
the higher it is, the more likely for the progression to AIDs
Two main adaptive T cells for HIV immune response
CD4 HIV specific, need for presentation with APCs and CD8 activation
CD8 HIV specific,
3 ways CD8 HIV specific cells can fight HIV
- lead to lysis of infected cells before virus released
- inhibit viral reproduction with IFN-gamma
- inhibit viral entry into surrounding cells by blocking CCR5
Two main steps in CD4 cell loss in HIV?
virus leads to lysis of the CD4 cells….virus prevents replacement of CD4 cells by inhibiting thymus, bone marrow
Which leads to AIDS faster, CXCR4 or CCR5 or Dual?
dual and CXCR4 lead to AIDs faster because all T cells have the CXCR4 receptor whereas not all T cells have the CCR5 receptor
Chronic latency or asymptomatic period of HIV characteristics
clinical latency, but no viral latency…the virus is still replicating inside cells and killing some CD4 cells
up to date HIV test name
4th generation HIV 1/2 immunoassay
tests for HIV Antigen and antibody comobination
HIV tests for HIV antibody
ELISA and western blot
best test for acute inflammation? When to test?
avoid latent period of about a week, but after that test for p24 antigen
is there an oral rapid HIV test?
yea, and actually not a bad test but has concerns
what is HIV DNA PCR important for and why?
diagnosing infant, and because you cant do the antibody testing in an infant because will have Moms
characteristics of Initial T cell response to HAART?
rapid increase in T cells, mainly memory cells, so will have forgotten pathogens
characteristics of later T cell response to HAART?
more naive T cell growth, can develop new T cell repertoires and specificities, unlike initial response
IRIS name
immune reconstitution inflammatory syndrome
IRIS disease progression
usually right after HAART treatment was started and as immune system is recovering you have an increased inflammatory response to a pathogen
Most common way of perinatal transmission of HIV, a big risk for it, and how to prevent?
during delivery
if mother contracts disease during pregnancy
HAART is best way to prevent transmission
common clinical signs and symptoms of HIV/AIDS
recurrent bacterial and viral infections, thrush, hepatomegaly and splenomegaly, lack of growth, developmental delay, lymphadenopathy, opportunistic infections
autoimmune disease and malignancy
Why are herpes simplex virus and Zoster rashes more recurrent in HIV?
because the T cells are diminished and they can come back easily
infections in individuals with CD4 count over 200?
have more true pathogen infections than usual…
common true pathogen infections in HIV
strep pneumo, M tuberculosis, Herpes simplex, shingles, syphilis, salmonella, staph aureus
TB and HIV presentation
often an abnormal presentation…nothing in chest X ray, PPD test may be negative because diminished immune response
Pneumocystis Jirovecu pneumonia in HIV
most common opportunistic AIDS pathogen
shortness of breath and low Oxygen saturation
CD4 count less than 200
fungal infections in AIDS patients
PJP, candida, and cryptococcus
common viral infections with AIDS patients
cytomegalovirus, herpes simplex 1/2, human herpes 8, JC virus
CMV and AIDS presentation
very low CD4 count less than 50, leads to retinitis!!
Kaposis Sarcoma and HIV
these are vascular nodules in skin in immune suppressed individuals with CD4 counts less than 200
Causative agent of Kaposis Sarcoma
Human Herpes Virus 8…sex spread
Other common infections with AIDS
toxoplasma, cryptosproidia, mycobacterium avium complex
Mycobacterium Avium complex presentation in AIDS
low CD4 count,
fevers and night sweats with diarrhea and weight loss
also anemia!
3 AIDS infections with CNS effects
toxoplasmosis, primary CNS lymphoma, and JC virus
drug to prevent pneumocystis pneumonia?
bactrim and septra
drug to prevent mycobacterium avium?
azithromycin
NABC clinical diagnosis of HIV
N is asymptomatic
A is mild
B is moderate
C is severe
123 clinical diagnosis of CD4 cell count
1 is no suppression (greater than 25)
2 is mild (15-25)
3 is extreme (less than 15)
Should you give HIV kids vaccines?
they do have lower CD4 cell counts, and likely less antiibodies and CD8 cells but still thought to be effective
