The Biology Project: Immunology

HIV and AIDS Problem Set

Problem 1: HIV+ patient and AIDS

Tutorial to help answer the question

Which HIV+ patient is most likely to have AIDS?

A. A person who engaged in high-risk sexual behavior three months ago
B. A person who engaged in high-risk sexual behavior ten years ago
C. A recently infected person whose drug therapies include reverse transcription inhibitors and protease inhibitors
D. A person who has an almost normal number of helper T cells detected in her blood sample


AIDS (acquired immunodeficiency syndrome) is caused by HIV infection. HIV infects helper T cells, specialized white blood cells which regulate the body's antigen-specific immune response. These vital cells are killed by HIV infection, and by cytotoxic T cells which kill infected helper T cells. Although initially the body can replace damaged helper T cells, over years, the helper T cell population is eventually depleted. When too many helper T cells are lost, the body can no longer launch a specific immune response and becomes susceptible to many opportunistic infections. HIV+ individuals are considered to have AIDS when their helper T cell counts below 200 cells/mm3 and they suffer from opportunistic infections.

Today drug therapies including reverse transcription inhibitors and protease inhibitors can greatly reduce the progression of HIV infection. HIV+ individuals receiving treatment can live many years without suffering from AIDS.




The Biology Project
The University of Arizona
Monday, April 3, 2000
Contact the Development Team
All contents copyright © 2000. All rights reserved.