What is a CD4 count?
The CD4 count is a blood test that measures the number of CD4 cells in a blood sample. CD4 cells are a type of white blood cell. They are also called CD4 T cells or "helper T cells." That's because they help fight the infection by activating theirimmune systemto destroy viruses, bacteria, and other germs that can make you sick.
A CD4 count is mainly used to check the health of your immune system when you are infected withHIV(Human immunodeficiency virus).
HIV attacks and destroys CD4 cells. Without treatment, HIV can destroy so many CD4 cells that your immune system has trouble fighting the infection. HIV is the virus that causes AIDS (Acquired Immune Deficiency Syndrome). AIDS is the most serious stage of HIV infection. If you have AIDS, your CD4 count is low enough to develop it.severe infectionsVonvirus,bacteria, omushroomsThey do not normally cause problems in healthy people. These are called "opportunistic infections" and can be fatal. AIDS also increases the risk of developing certain types of cancer.
Most people with HIV do not have AIDS.And if they get theirsHIV medicationas prescribed, they can never develop AIDS.
If you have HIV, a CD4 count can help your doctor control your risk of serious infections. A CD4 count can also be used to diagnose and monitor other conditions that affect your immune system.
Other names: CD4 cell count, CD4+ count, T4 count, helper T cell count, CD4 percentage
What is this used for?
If you have HIV, a CD4 count can be used to:
- See how HIV affects your immune system.The CD4 count can help monitor your risk of developing opportunistic infections or certain types of cancer. If your risk increases, your doctor may give you treatment to prevent infection.
- Help check that HIV treatment is working.A CD4 count is used with a test calledlatest HIV virus testto see if the HIV medicine is working. A viral load test measures the amount of HIV in your blood.
- diagnosed with AIDS.Without treatment, HIV can result in a very low CD4 count, which means you have AIDS.
A CD4 count can also be used to:
- Supervise treatment after aorgan transplant.If you have had an organ transplant, you will need to take medicine to prevent your immune system from attacking the new organ. These drugs are called "anti-rejection drugs" or immunosuppressants. You can also take these drugs to treat certain medical conditions.Autoimmune diseases🇧🇷 A low CD4 count means the medicine is working.
- Help diagnose different types of lymphoma.A CD4 count may be used along with other tests to find out what type of immune cells is causing the lymphoma. The test results help choose the right treatment.
- help in diagnosisDiGeorge Syndrome.This is a rare inherited condition that often causes immune problems and other health problems that begin at birth.
Why do I need a CD4 count?
Your provider may request a CD4 count when you are first diagnosed with HIV. You will likely be retested every few months to see if your levels have changed since the first test.
If you take HIV medicines, your doctor may order regular CD4 counts with an HIV viral load test to see how well your medicine is working.
What happens during a CD4 count?
A health professional will take a blood sample from a vein in your arm with a small needle. After the needle is inserted, a small amount of blood is collected in a test tube or vial. You may feel a slight sting as the needle enters or exits. This usually takes less than five minutes.
Do I have to prepare for the exam?
You do not need any special preparation for a CD4 count.
Are there any risks with the test?
The risk from a blood test is very small. You may have mild pain or bruising where the needle was inserted, but most symptoms go away quickly.
What do the results mean?
CD4 results are generally reported as the number of cells per cubic millimeter of blood. But labs may have different ways of describing "normal" CD4 counts. What is normal for you will depend on your age, other health conditions, and the medications you are taking. That's why it's important to talk to your doctor about what your test results mean.
CD4 values can change even if your health has not changed. Therefore, your provider will usually look at some test results over time to see if there is a trend in your CD4 counts.
In general, the CD4 count ranges are:
- Normal CD4 count for healthy adults and adolescents:500 to 1200 cells per cubic millimeter
- Low CD4 count:Less than 500 cells per cubic millimeter
- if you have hiv, a low CD4 count means that HIV has weakened your immune system. A CD4 count of200 or less cells per cubic millimeterit means you have AIDS. With AIDS, there is a high risk of developing life-threatening infections or cancer.
- If you do not have HIV, a low CD4 count may be due to an infection.cancer chemotherapyand medicines that weaken your immune system can also cause low CD4 counts. In some cases, the cause of a low CD4 count is unknown, but this is rare.
- High CD4 count:Values above the normal range could be a sign of infection or blood cancer.
While there is no cure for HIV, there are several medications you can take to control the virus and protect your immune system. In fact, CD4 levels often rise with these drugs, helping you stay healthy. If you areliving with HIV, it is important to take the medication as prescribed and have regular blood tests, including CD4 count.
learn more aboutLaboratory tests, reference ranges and understanding the results.
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