Potent combination HIV therapy (commonly called ART or HAART) can significantly prolong life. In high-income countries such as Canada, Australia and the U.S. and regions such as Western Europe, doctors increasingly estimate that young adults diagnosed today and who begin ART shortly thereafter and who take their medicines every day exactly as directed and who have minimal co-existing health conditions have a good chance of living into their 70s.
Scientists in the U.S. have collaborated on a project to study how well ART penetrates the body. They have found that while ART is good at getting into cells in the blood and greatly reduces production of HIV in the blood, HIV-infected cells continue to make viruses deep inside the body. This particularly happens in parts of the immune system called lymph nodes and lymphatic tissues. These findings have many potential implications for the future of HIV therapy and for attempts to try to cure HIV infection. In this CATIE News bulletin, we first give a brief explanation of the immune system and some terms that we will use before detailing the recent U.S. findings.
Cells and systems
One group of cells that helps to fight infections is called lymphocytes. These cells can be divided into two groups as follows:
- T-cells (or T-lymphocytes) – these can help organize the immune response to infection; some T-cells can directly attack infected cells and tumours
- B-cells (or B-lymphocytes) – these make antibodies that can help fight some infections
Some T-cells have a receptor called CD4 and we commonly call these cells CD4+ cells. Other T-cells have another receptor called CD8 and we commonly call these cells CD8+ cells.