Have you ever heard of a ``CD4 cell count'' or a ``T-cell test''? Maybe your doctor has talked about it, or you may have heard these words somewhere. Although it may seem a bit complicated, let's try to understand it simply. Because this is a test that tells us a lot of important information about the health of our immune system.
What is CD4 cell count?
Simply put, a CD4 cell count is a blood test that measures the number of a specific type of white blood cell in a small amount of your blood. Doctors use it to see how HIV has affected your immune system and how effective treatments like antiretroviral therapy (ART) are. It is also sometimes used to monitor other diseases.
Did you know that HIV is a lifelong viral infection that directly destroys our CD4 cells (also known as helper T-cells or CD4+ T-cells). So when these T-cells are low, our body's ability to fight germs is also low.
What is CD4 percentage?
Your doctor can also use the ``CD4 percentage'' to get an idea of the health of your immune system. This is calculated by dividing the number of ``CD4+ T cells'' by the total number of ``lymphocytes'' (another type of white blood cell) and multiplying the result by 100.
In some cases, just looking at the `(CD4 cell count)` may not be very reliable. For example, if you have a disease that affects your total `(lymphocyte)` count, or for people like young children, pregnant women, or people over the age of 65, the `(CD4 percentage)` may be more useful.
What can we learn from the CD4 count?
CD4 counts give doctors important information about your immune system. If this count is above normal, it can indicate infections, other illnesses, or the progression of HIV infection.
But there's one thing to remember. Your CD4 count can vary slightly from day to day. This can be due to things like when you donated blood, whether you had an infection at the time, etc. Your age, other health conditions, and the medications you take can also affect this count. That's why doctors look at your total count and how it changes over time.
What is CD4 count used for?
Now let's see what this test is mainly used for.
If you have HIV:
If you are infected with HIV, doctors use CD4 counts to:
- Determine the stage of the HIV infection (i.e. how far the disease has progressed).
- Monitor how well the treatment called ``Antiretroviral Therapy - ART'' works .
- Assess your risk of developing ``Opportunistic Infections'' (serious infections that develop easily when immunity is weakened).
In other cases:
The T-cell test is sometimes used for things like:
- After an organ transplant, monitor anti-rejection medications.
- Monitor treatment for certain autoimmune diseases.
- Identify some types of lymphoma (a cancer of the lymphatic system) and diseases such as DiGeorge syndrome.
When are these T-cell tests done?
When you are first diagnosed with HIV, your doctor will check your CD4 count. After that, they will continue to do this test to see how well you are doing and how well your medication is working.
When you start ART, you may need to have your CD4 cell count checked every three to six months at first. Over time, your doctor may change this to every six to twelve months . They will also do a separate test to check your HIV viral load.
How is a CD4 cell count test done?
It's very simple. A lab technician uses a sample of your blood to find your ``CD4 count.'' They count the ``T-cells'' in your blood sample using a special technique called ``Flow Cytometry.'' In this, the cells are marked with special labels.
How should I prepare for this test?
No special preparation is required. You can eat and take your medications as normal.
What should I expect during the test?
A doctor or nurse will take a blood sample by inserting a small needle into a vein in your arm. You may feel some pain or discomfort when the needle is inserted and removed, but it will only be for a short time. The blood sample will then be sent to a lab for testing.
What are the risks of the CD4 count test?
The risks of this test are very low. Sometimes it can be a little difficult if you have to poke the needle several times to find a vein. There are some minor risks when taking blood, such as:
- Feeling a little dizzy or faint.
- A large bruise or collection of blood under the skin (hematoma).
- Getting an infection.
- Persistent bleeding (this happens very rarely).
What kind of results do we get?
CD4 counts are usually expressed as the number of cells per cubic millimeter (a cubic millimeter is about the size of a drop of blood). This is usually written as “mm³” or “mcL” (microliters) after the number. Sometimes you will also see CD4 counts as a percentage of lymphocytes (white blood cells).
The results may look like this:
- Normal CD4 count: 500mm³ to 1,200mm³
- Low CD4 count: less than 500mm³
- High CD4 count: greater than 1,200mm³
The values for these "normal" levels, especially the upper limit, may vary slightly in some labs. So check the normal range on your report.
What does a low CD4 count mean?
If you have HIV, a low CD4 count means that the virus has destroyed many of your white blood cells and weakened your immune system. This puts you at greater risk of developing infections, some of which can be life-threatening. If your CD4 count is 200mm³ or less, it means you have stage 3 HIV, which is the stage of AIDS.
If you don't have HIV, a low CD4 count can be caused by:
- Another infection.
- Chemotherapy is a treatment for cancer.
- Drugs that weaken the immune system (immunosuppressants).
What are the causes of an increased CD4 count?
Some infections and blood cancers can cause the CD4 count to be higher than the normal range.
How long does it take to know the results?
Ask your doctor when you will get your CD4 count results and how you will get them (e.g. will the doctor call you or send you a report). Most of the time, the blood is drawn and tested within 24 hours, but it may take longer for the results to arrive.
What happens if my CD4 count is low?
If your test results are not what your doctor expected, he or she may ask you to repeat the test. Depending on your results, your doctor may do things like:
- Your treatment plan will remain the same, and you will be asked to take your next CD4 count sooner than the previously scheduled date.
- If your immune system is significantly weakened, you may be prescribed antibiotics or antifungals to help prevent infections.
- It is recommended that you change the type of ``Antiretroviral - ART'' medication you are currently taking.
When should I see the doctor?
If you have any questions about your test results, talk to your doctor. If you have signs of infection (e.g., pain, swelling, pus, fever), go to the emergency room immediately.
How can I increase my CD4 count?
Antiretroviral therapy (ART) is often very effective in reducing the amount of HIV in your body (viral load) and increasing your CD4 count. However, you need to take this medicine exactly as prescribed. If you are having any difficulty taking your ART, talk to your doctor about it.
In some cases - for people who don't have HIV, for example someone who has had an organ transplant and is taking immunosuppressive medications - a low CD4 count may mean that their medication is working properly. So, ask your doctor what to expect based on your situation.
Finally, remember this (Take-Home Message)
CD4 counts are a way for your doctor to see how HIV has affected your immune system and how well your treatment is working. Sometimes other things can affect the results, so don't be alarmed if you see an unexpected number. Talk to your doctor about what the results mean and whether you need to make any changes to your treatment plan. Taking antiretroviral therapy (ART) regularly can help prevent HIV from damaging your immune system and keep your T-cell count healthy.
` CD4 count, HIV, immunity, T-cells, blood tests, ART, treatment
💬 අදහස් (0)
තවමත් කිසිදු අදහසක් පළ කර නොමැත. ඔබේ අදහස පළමු වරට මෙහි එක් කරන්න.
ඔබේ අදහස එක් කරන්න