HIV Flashcards
(18 cards)
What is HIV?
A retrovirus that causes AIDS (Acquired immunodeficiency virus)
What is the target of the HIV virus?
CD4 receptors- A glycoprotein found on the surface of a range of cells incl TH cells, dendrites, macrophages and microglial cells
What do CD4 Th cells do?
Recognise MHC2 APC
Activate B cells
Activate CD8
Cytokine release
What effect does HIV have on immune response?
Pooling of cells in lymphoid tissue
Reduced proliferation of CD4 cells
Reduced CD8 activity
Reduced antibody class switching
What value of CD4 count puts you at risk of opportunistic infections?
<200 cells/mm3
Progression of infecction from exposure?
Infection of mucosal CD4 cells (Langerhans and dendrites)
Transport to regional lymph nodes
Infection established within 3 days entry
Dissemination of virus
When do HIV symptoms start to appear?
2-4 weeks after infection
Symptoms of primary HIV infection?
Combination of:
- Fever
- Rash (Maculopapular)
- Myalgia
- Pharyngitis
- Headache/aseptic meningitis
Signs and symptoms of Pneumocystis pneumonia?
Insidious onset
SOB
Dry cough
Exercise desaturation
CXR interstitial infiltrates and reticulonodular markings
Treatment of PCP?
High dose co-trimoxazole +/- steroid
Other complications of HIV?
TB
Cerebral toxoplasmosis
CMV
Causative organism of cerebral toxoplasmosis?
Toxoplasma gondii
Skin infections associated with HIV?
Herpes zoster
Herpes simplex
HPV
What is Slim’s disease?
HIV associated wasting
Which cancers are related to AIDS?
Kaposi Sarcoma- Vascular tumour
NH Lymphoma
Cervical
HIV modes of transmission?
Sexual - main
Parenteral
Mother-child
Which markers are used to test for HIV?
Antibody
Viral RNA
p24 capsule protein antigen
What is the HIV window period?
The time between infection with the virus, seroconversion, and a reliable test result
