1. Immune system and CD4 count (2023)

This chapter looks at the way your body fights infections.  The role of CD4 cells and understanding your CD4 count. Updated 2023.

• 1. 1 and 1.2 Introduction and aims
• 1. 3 Definition of AIDS (SIDA)
• 1. 4 Basic organs of the body
• 1. 5 How the immune system works (before HIV infection)
• 1. 6 How does HIV interact with the immune system?
• 1. 7 CD4 count as a surrogate marker of your immune system
• 1. 8 How quickly does HIV progress without ART?
• 1. 9 Interpreting CD4 results: CD4 count and CD4 percentage
• 1.10 CD4 differences between adults and children
• 1.11 Different stages of HIV infection
• 1.12 CD4 count cut-offs and the risks of OIs
• 1.13 Use of CD4 count for starting therapy (ART)

Last updated: 1 January 2023.