CD4  Cell count

$148.00

CD4 cells are a type of white blood cell that fight infection, and they play an important role in our immune system. They help to identify, attack, and destroy specific bacteria, fungi, and other germs that affect the body. CD4 cells are made in the spleen, lymph nodes, and thymus gland, and they circulate throughout the body in the bloodstream. CD4 cells are a major target for the HIV virus, which binds to the surface of CD4 cells, enters them, and either reproduces immediately, killing them in the process, or remains in a resting state, reproducing later. As the HIV virus gets into the cell and replicates, the number of CD4 cells in the blood gradually declines. As HIV disease progresses, the CD4 count will go down and as treatment reduces the progression, the CD4 count will go back up.

This test measures the number of CD4 cells (also known as T-helper cells) in your blood and assesses the status of your immune system. CD4 cells are a type of white blood cell that fight infection, and they play an important role in your immune system. They help to identify, attack, and destroy specific bacteria, fungi, and other germs that affect the body.

The CD4 count points indicates the immune system strength is, how far HIV disease has advanced (the stage of the disease), and helps predict the risk of complications and debilitating infections. The CD4 count is most useful when it is compared with the count obtained from an earlier test.
The CD4 count is used in combination with the viral load test, which measures the level of HIV in the blood, to determine the staging and outlook of the disease.
The CD4 count is also used to identify possible health problems for which you may be at risk and to determine which medications might be helpful

A CD4 count and a viral load test are ordered when a person is first diagnosed with HIV as part of a baseline measurement. Both tests should be repeated about two to eight weeks after starting or changing anti-HIV therapy. If treatment is maintained, a CD4 count should be performed every three to six months thereafter.
Normal CD4 counts in adults range from 500 to 1,500 cells per cubic millimeter of blood.
In general, the CD4 count goes down as HIV disease progresses. Any single CD4 count value may differ from the last one even though your health status has not changed. You should not place too much importance on any one result. What is more important than any single value is the pattern of CD4 counts over time.
If your CD4 count declines over several months, your doctor may recommend beginning or changing anti-HIV treatment and/or starting preventive treatment for opportunistic infections like Pneumocystis carinii pneumonia (PCP). Your CD4 count should increase or stabilize in response to effective combination anti-HIV therapy.
According to public health guidelines, preventive therapy should be started when an HIV-positive person who has no symptoms registers a CD4 count under 200. Some physicians will opt to consider treatment earlier, at 350. The Centers for Disease Control and Prevention considers HIV-infected persons who have CD4 counts below 200 to have AIDS, regardless of whether they are sick or well.

Because reference values are dependent on many factors, including patient age, gender, sample population, and test method, numeric test results have different meanings in different labs. It Is therefore important to use the same laboratory for serial monitoring of the CD4 count.

The CD4 count tends to be lower in the morning and higher in the evening. Acute illnesses, such as pneumonia, influenza, or herpes simplex virus infection, can cause the CD4 count to decline temporarily. Cancer chemotherapy can dramatically lower the CD4 count. Regardless, it can be used as an effective monitoring tool if the more sensitive HIV viral load test is not available.
The CD4 count does not always reflect how someone with HIV disease feels and functions. For example, some people with higher counts are ill and have frequent complications, and some people with lower CD4 counts have few medical complications and function well.

When AIDS is present and a CD4 count is lower than 200 there is a risk for what are called opportunistic infections due to decreased immune system difenses.

Opportunistic Infections Included in the CDC's Definition of AIDS
 

Pneumocystis Carinii Pneumonia (PCP) Kaposi's Sarcoma (KS) HIV wasting syndrome Non-Hodgkin's lymphoma Cryptococcosis, extrapulmonary HIV encephalopathy (AIDS Dementia) Mycobacterium Avium Intracellulare (MAC or MAI) Candidiasis of the esophagus, trachea, bronchi, or lungs Cryptosporidiosis, chronic intestinal Cytomegalovirus disease (CMV) Tuberculosis (outside of the lungs) Herpes simplex virus infection Progressive Multifocal Leukoencephalopathy (PML) Primary lymphoma of the brain Toxoplasmosis of the brain Histoplasmosis Isoporiasis, chronic intestinal Coccidioidomycosis Salmonella septicemia Bacterial infections, recurrent, <13 years Lymphoid interstitial pneumonia/pulmonary lymphoid hyperplasia, <13 years.  Pulmonary tuberculosis Recurrent bacterial pneumonia (two or more episodes in one year) Invasive cervical cancer

Note that more recent definitions finally include illnesses specific to women with HIV. Although this list has been revised several times since it was first developed, it does not include all of the illnesses experienced by people with HIV-related immune suppression