HIV 101 Review Evaluation Center for HIV and Oral Health Boston University School of Public Health Health & Disability Working Group

What is the Immune System? The immune system is the body’s natural guardian against disease. It consists of specialized cells (including CD4 cells) that defend the body against attacks by ‘foreign’ invaders such as bacteria, viruses, fungi, parasites, and cancer. The immune system is continuously working to protect us against these foreign invaders. Without an immune system, we would very quickly succumb to disease

Where is the Immune System?

CD4 T-Cells: Important cells in the human body for mounting the body’s immune defense against infection. These “helper” cells not only fight infection, but recruit other immune cells to the site of infection to help kill infection-causing bacteria and viruses. The HIV uses the CD4 T-cells to make more HIV. By doing this, HIV destroys the CD4 cell. Without CD4 T-cells, the body is not able to defend itself against bacterial and viral infections. DEFINITIONS

Virus is in the bloodstream but also hides in other cells (e.g. lymph nodes) –Drugs don’t reach these sequestered cells* –That’s why there is no cure Virus destroys CD4 cells which lead to: –Immune suppression –Opportunistic infections and AIDS *HIV hides in cells in certain organs which are “protected” by the body: lymph nodes, the brain, reproductive organs. Not enough meds can get to those cells. HIV

DEFINITIONS DNA: The chemical make-up of living things. DNA contains 2 copies of information. RNA: the chemical make up of living things. RNA contains only 1 copy of information and needs another copy to replicate. HIV: A virus that can only survive in host cells. It carries with it RNA, but must make DNA to replicate.

DNA versus RNA

Viral load test shows the amount of HIV RNA in your blood and tells you how active the virus is in your body. Higher numbers mean you have more virus in your body. Opportunistic infections are illnesses caused by different organisms, some of which do not usually cause disease in people with a normal immune system. Opportunistic infections of the lungs, brain, eyes, and other organs can develop in people with HIV infection. DEFINITIONS

One of the most important tests you will take about every 3 months Often considered the critical marker in the management of HIV and AIDS Measures the amount of HIV in your blood Viral load

CD4 cell count Measures the number of CD4 cells (also called T-helper cells) in your body –Tells you the health of your immune system –The more CD4 cells you have, the stronger your immune system may lead to Fewer CD4 cells Increased infections

What are some opportunistic infections (OIs)? Candidiasis (Thrush) is a fungal infection of the mouth, throat, or vagina. CD4 cell range: can occur even with fairly high CD4 cells. Cytomegalovirus (CMV) is a viral infection that causes eye disease that can lead to blindness.CD4 cell range: under 50. Herpes simplex viruses can cause oral herpes (cold sores) or genital herpes. These are fairly common infections, but if you have HIV, the outbreaks can be much more frequent and more severe. They can occur at any CD4 cell count. Malaria is common in the developing world. It is more common and more severe in people with HIV infection.

More Opportunistic Infections Mycobacterium avium complex (MAC or MAI) is a bacterial infection that can cause recurring fevers, general sick feelings, problems with digestion, and serious weight loss. CD4 cell range: under 75. Pneumocystis pneumonia (PCP) is a fungal infection that can cause a fatal pneumonia. CD4 cell range: under 200. Unfortunately this is still a fairly common OI in people who have not been tested or treated for HIV. Toxoplasmosis (Toxo) is a protozoal infection of the brain. T- cell range: under 100. Tuberculosis (TB) is a bacterial infection that attacks the lungs, and can cause meningitis. CD4 cell range: Everyone with HIV who tests positive for exposure to TB should be treated.

What does HAART stand for? HAART: Highly Active Antiretroviral Therapy A combination of HIV medicines from different groups that are taken together to keep HIV levels down

Principles of HAART HIV virus has 1 goal: replication Triple-drug therapy –“Attack” virus in several different ways –Slow down viral replication –Allow immune system to ‘recover’

How do HIV medicines work? HIV medicines slow down the reproduction of the virus at various stages Each HIV medicine group fights HIV in different ways –Main difference: the stage of HIV reproduction that is targeted

Young boy from Indiana…

And his legacy… Before Ryan White, HIV/AIDS was considered a “homosexual problem” and largely ignored by policymakers Four months after White's death, Congress enacted The Ryan White Comprehensive AIDS Resources Emergency (CARE) Act Largest federally funded program for people living with HIV/AIDS