HIV

Question 1

How is AIDS defined?

Answer 1

1. Low CD4+ cell count (cell<200/microL)
2. 1 or more typical opportunistic infections

Question 2

What is the malignancy most associated with HIV?

Answer 2

Kaposi’s sarcoma

Question 3

What is the process of HIV replication?

Answer 3

1. Attachment to CD4+ T helper cells via gp120-TCR bonding, initiating bonding & uncoating of viral RNA
2. Viral DNA formed by reverse transcriptase and integrated into host DNA by integrase
3. Synthesis of new viral parts using new viral DNA & host cell replication machinery
4. Translated proteins move to cell surface and get cleaved by proteases before budding off as newly formed HIV viruses

Question 4

What are the mains serological markers to be detected?

Answer 4

1. p24 antigen (titer decreases >2mths as Ab produced)
2. p24 Ab (IgG)

Question 5

Describe the structure of HIV.

Answer 5

1. gp120 & gp41 on surface membrane
2. p24 capsid
3. Capsid contains integrase, protease & reverse transcriptase

Question 6

How is HIV spread?

Answer 6

1. Vertical transmission
2. Blood transmission
3. Sexual route (chloe prob will kena)

Question 7

How is HIV diagnosed?

Answer 7

1. ELISA serology
2. Confirmatory Western blot test

Question 8

What are the 3 stages on untreated HIV?

Answer 8

1. Primary infection –> burst of viremia, transient decline in CD4+ T cells
2. Latency –> chronic low levels of viremia as immune system fights off virus
3. Progression to AIDS –> CD4+ cell death outweighs production