HIV Flashcards
what kind of virus is HIV
retrovirus
is HIV 1 or 2 more virulent
HIV 1 more virulent
what is the target site for HIV
CD4+ receptors
what is CD4 and give 4 types of cells it is found on
glycoprotein found on surface of
- T helper lymphocytes (CD4 cells)
- dentritic cells
- macrophages
- microglial cells
how long is it between HIV infection and establishment
72 hours
CD4+ T helper lymphocytes are essential for the ____ of the ____ immune response
induction of adaptive immune response
CD4+ T helper cells recognise MHC class _ APCs
II
give 4 functions of CD4+ T helper cells
recognition of MHC-II antigen presenting cells
activation of B-cells
Activation of cytotoxic T cells (CD8+)
cytokine release
what is a normal CD4+ Th cell count
500-1600 cells/mm3
at what count of CD4+ Th cells is there a risk of opportunistic infections
< 200
in HIV CD4 count will be ___ and CD8 count will be ____
CD4 low
CD8 high
why can psoriasis get worse in HIV
overproduction of CD8
when is the most rapid replication of the HIV virus
very early and very late
what is the average time to death without treatment of HIV
9-11 years
baby - 1 year
what are the 3 stages of HIV infection
acute HIV syndrome
clinical latency
symptoms of aids
what happens after the infection of mucosal CD4 cells (langerhans and dendritic cells)
transport to regional lymph nodes
when is the onset of symptoms after primary infection
2-4 weeks
give 5 symptoms of primary HIV infection
fever maculopapular rash myalgia pharyngitis headache
during the primary infection, there is a very low/high risk of transmission
very high
when does the clinical latency period last between
4 weeks - 9+ years
describe what goes on in the clinical latency period
ongoing viral replication, CD4 count depletion and immune activation
is there a risk of transmission during the clinical latency phase
yes
what is an opportunistic infection
an infection caused by a pathogen that does not normally produce disease in a healthy individual
what type of pneumonia is common in HIV
pneumocystis pneumonia
what is the causative organism in pneumocystis pneumonia
pneumocystis jiroveci
what is the CD4 threshold for pneumocystis jiroveci
< 200
what are the symptoms of pneumocystis pneumonia
shortness of breath
dry cough
exercise desaturation
what may a CXR show of pneumocystis pneumonia
may be normal
may be interstitial infiltrates
may be reticulo-nodular markings
how is pneumocystis pneumonia diagnosed
BAL and immunofluorescence +/- PCR
what is the treatment for pneumocystis pneumonia
high dose co-trimoxazole (+/- steroid)
what is the prophylactic treatment of pneumocystis pneumonia
low dose co-trimoxazole
what is the prophylactic treatment of pneumocystis pneumonia
low dose co-trimoxazole
chronic productive cough +/- haemoptysis
fever
night sweats
pulmonary tuberculosis
what is the treatment for tuberculosis
2 RIPE 4 RI
what is the causative organism in cerebral toxoplasmosis
toxoplasma gondii
what is the CD4 threshold for cerebral toxoplasmosis
< 150
what would show on a brain scan of cerebral toxoplasmosis
multiple cerebral abscess
what are some signs/symptoms of cerebral toxoplasmosis
headache fever focal neurology seizures reduced consciousness raised ICP
if you took a brain biopsy and found it to be a toxoplasmic abscess what would your next step be
HIV test
what is a problem in the eye caused by toxoplasma gondii
toxoplasmic chorioretinitis
give 3 things CMV can cause
retinitis
colitis
oesophagitis
how can CMV retinitis present
reduced visual acuity
floaters
how can CMV colitis present
abdominal pain, diarrhoea, PR bleeding
what is the CD4 threshold for CMV
< 150
what should all patients with a CD4 < 150 be offered
ophthalmic screening
give 5 skin infections that occur with HIV
herpes zoster herpes simplex HPV penicilliosis histoplasmosis
state whether the following infections can be reactivated
- tuberculosis
- toxoplasma gondii
- CMV
- JC virus
all yes
what strain of HIV causes HIV associated neurocognitive impairment
HIV-1
what is the CD4 threshold for HIV associated neurocognitive impairment
any - increase in immunosuppression increases incidence
how does HIV associated neurocognitive impairment present
reduced short term memory +/- motor dysfunction
what organism causes progressive multifocal leukoencephalopathy
JC virus
what is the CD4 threshold for JC virus
< 100
how does progressive multifocal leukoencephalopathy present
rapidly progressive focal neurology
confusion
personality change
what might you see in the MRI T2 weighted imaging of progressive multifocal leukoencephalopathy
hyperintensities in the white matter which later spreads to the internal capsule and the other hemisphere
what might you see in the MRI T1 weighted imaging of progressive multifocal leukoencephalopathy
extensive hypodensities corresponding to loss of myelin
what is slim’s disease
HIV associated wasting
what causes HIV associated wasting
severe weight loss/metabolic
chronic diarrhoea/malabsorption
hypogonadism
what causes kaposi sarcoma
human herpes virus 8 (HHV8)