HIV Flashcards
what are the target sites of HIV?
CD4+ receptors
what effect does HIV have on the immune response?
Sequestration of cells in lymphoid tissues
Reduced circulating CD4+ cells
Reduced proliferation of CD4+ cells
Reduction CD8+ (cytotoxic) T cell activation
Dysregulated expression of cytokines
Increasing susceptibility to viral infections (including HIV!)
Reduction in antibody class switching
Reduced affinity of antibodies produced
Chronic Immune Activation (microbial translocation)
what are the normal parameters of CD4+ Th cells?
how low are they when you are at risk of an oppertunistic infection?
Normal: 500-1600 cells/mm3
Risk of opportunistic infections: <200 cells/mm3
what is the time frame of a primary HIV infection?
What are the main symptoms?
Onset average 2-4 weeks after infection
Combination of
Fever
Rash (maculopapular)
Myalgia
Pharyngitis
Headache/aseptic meningitis
what type of lung infection is commonly seen in HIV?
How does it present?
What investigations would you do?
How is it diagnosed?
How is it treated?
Organism: Pneumocystis jiroveci
CD4 threshold: <200
Symptoms: insidious onset
SOB
Dry cough
Signs: exercise desaturation
CXR: May be normal
Interstitial infiltrates, reticulonodular markings
Diagnosis: BAL and immunofluorescence +/- PCR
Treatment: high dose co-trimoxazole (+/- steroid)
Prophylaxis: low dose co-trimoxazole
why would you provide opthalmic screening for patients with CD4+<50?
Cytomegalovirus
Causes retinitus- reduction in acuity and causes floaters
also causes
colitis, and oesophagitis
what cerebral conditions are common with HIV
Organism: Toxoplasma gondii
CD4 threshold: <150
Reactivation of latent infection
Multiple cerebral abscess
(Chorioretinitis)
Symptoms/signs
Headache
Fever
Focal neurology
Seizures
Reduced consciousness
Raised intracranial pressure
HIV-associated neurocognitive impairment (HIV-1)
Progressive multifocal leukoencephalopathy (JC virus)
name the very common cancer that appears on mucosa epithelium and vicera?
What organims causes it?
Kaposi’s sarcoma
Organism: Human herpes virus 8 (HHV8)
Affected up to 40% pre-ART era
Pathology: vascular tumour
CD4 threshold: Any. ↑ incidence with ↑ immunosuppression
Presentation:
Cutaneous
Mucosal
Visceral – pulmonary, GI
Treatment:
HAART
Local therapies
Systemic chemotherapy
list common AIDS cancers?
Cervical
Non-Hodgkins lymphoma
Kaposi’s sarcoma
what proportion of babies will contract HIV from an untreated mother?
What proportion of these babies will die (without treatment)
1 in 4
1 in 3
