• HIV - stands for Human Immunodeficiency Virus. A virus that weakens a patient’s immune system over time.
  • HIV-1 - the most common type of HIV worldwide.
  • CD4+ T-cell -  a type of cell that helps fight infections. Called CD4+ because of a type of receptor on the surface of the cell
  • combination antiretroviral therapy -  the combination of medicines, or regimen, used to treat HIV infection
  • R5 HIV 1 This type of HIV uses the coreceptor CCR5 (R5 for short) as a coreceptor to blind to and infect human cells.
  • T Cell Count  measurement of the amount of T-cells found in a sample of blood. 
  • CCR5-tropic HIV-1 - the type of HIV-1 that uses the CCR5 coreceptor to attach to CD4+ T-cells.
  • CD4+ T-cell count - the number of CD4+ T-cells in every cubic millimeter of blood.
  • Coreceptor – on the surface of CD4+ T-cells; used by HIV, along with the CD4 receptor, to attach to CD4+ T-cells.
  • Tropism – refers to the type of coreceptor that HIV uses to attach to CD4+ T-cells.
  • Tropism test or tropism assay – test done to determine which type of coreceptor a patient’s HIV uses to attach to a CD4+ T-cell.
  • AIDS – stands for Acquired Immunodeficiency Syndrome. The most severe phase of HIV infection. People with AIDS have such badly damaged immune systems that they get an increasing number of severe illnesses, called opportunistic illnesses
  • Opportunistic infections - infections that occur more frequently and are more severe in individuals with weakened immune systems, including people with HIV
Not an actual HIV-1 patient.



Understanding HIV-1 and how medicines work.

If you’ve been living with HIV for a while, chances are you know more than a few things about the condition. It can never hurt to review the basics, though. During discussions with your doctor, this knowledge may help you as you consider your game plan for treatment.

What are HIV and AIDS?

  • HIV stands for Human Immunodeficiency Virus. It’s the virus that causes AIDS.
  • AIDS means Acquired Immunodeficiency Syndrome. AIDS is the most advanced stage of HIV infection.
  • HIV is transmitted (spread) through the blood, semen, genital fluids, or breast milk of a person infected with HIV. Having unprotected sex or sharing needles and syringes with a person infected with HIV are the most common ways HIV is transmitted.

An infected person can have different amounts of the HIV virus in his or her blood. The amount of HIV in an infected person’s blood is called the viral load.

How HIV Affects Your Body

  • Your body has a type of white blood cell called a CD4+ T-cell. CD4+ T-cells help protect you from infection. They are a big part of your immune system. HIV destroys these cells.
  • HIV enters the body's CD4+ T-cells and uses these cells to make copies of itself. This process is called the HIV life cycle. This process of replication also destroys the CD4+ T-cell.

When HIV has killed too many CD4+ T-cells, your body can no longer fight off certain infections. These infections are called opportunistic infections.

What does CCR5-tropic mean?

First, it's important to know that each person's HIV-1 may be different. One way each patient's virus is different is in how it attaches to and makes its way into the CD4+ T-cell.

  • First, HIV-1 attaches to the CD4+ receptor on the outside of CD4+ T-cells.
  • Then, HIV-1 attaches to what is called a coreceptor.
  • There are two different coreceptors: CCR5 and CXCR4.
  • Some HIV-1 will use only 1 of these coreceptors, and some can use either.

SELZENTRY helps inhibit the entry of only CCR5-tropic HIV-1 into white blood cells called CD4+ T-cells.

SELZENTRY is used with other HIV medicines to treat only CCR5-tropic HIV-1. SELZENTRY is not approved or effective for patients infected with CXCR4-tropic, dual-tropic, or mixed-tropic HIV-1.

HIV Treatment

  • HIV-1 medicines help stop HIV from using the CD4+ T-cell’s machinery to make more copies of the virus. The different HIV-1 medicines do this by interfering with different steps of the HIV life cycle.
  • The use of multiple HIV-1 medicines is called combination antiretroviral therapy, or ART.
  • ART may reduce the viral load and increase the number of infection-fighting CD4+ T-cells in a person’s blood.

HIV and CCR5:

What’s the connection? 

Getting Support

Have more questions about HIV-1 and treatment? Use the list of resources below to continue to take an active role in your treatment.

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