HIV

Question 1

Normal CD4 lymphocyte count

Answer 1

500-1500 cells/mm3

Question 2

Pathophysiology of HIV

Answer 2

HIV virus has a surface glycoprotein (gp120) which binds to CD4 glycoprotein on the surface of host cells, esp T helper lymphocytes that have CD4 receptor

• -> infects and destroys it
• -> progressive destruction of the CD4+ lymphocyte population
• -> immune deficiency + infection susceptibility

Question 3

HIV often asymptomatic until CD4 count drops below what

Answer 3

<200 cells/mm3