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What’s in a Number? : CD4 vs. Viral Load

Viral Load and CD4 Count

If you’re beginning HIV testing or treatment, you’ll learn
to keep a sharp eye on your viral load and CD4 count. These two counts speak
volumes about your HIV and immune system health. They provide important information
on virus progression, therapy response, and help determine whether to begin HIV

See a list of 37 HIV prescription medications »

The Human Immune Alarm Bell

CD4 cells, also called T-cells, are like the alarm bells of
the immune system. They alert the immune system to invading viruses and
bacteria. Certain receptors on the CD4 cell make them a prime target for HIV infection. Infection
lowers CD4 count. Lower CD4 count means a weaker immune system.

A normal CD4 count ranges from 500-1,000 cells/mm3. According to, a count of
fewer than 200 cells/mm3 is one of the qualifications for an AIDS diagnosis.

Measuring HIV

Viral load is the best gauge of the level of HIV in the body.
It is measured as the number of copies of HIV-1 per milliliter of blood plasma (copies/mL).
According to the U.S.
Department of Health and Human Services (HRSA), the lowest levels of detectable
viral load are about 40-75 copies/mL. The highest measure can be over 500,000

Low viral load means lower amounts of HIV activity. The goal
of HIV therapy is to lower the viral load to levels below 40-75 copies/mL. It’s
important to know that just because viral load
may fall below these levels, does not mean HIV is gone from the body.

When Therapy Begins

CD4 count, the measure of immune system health, is the major
factor in deciding whether to begin HIV therapy. Treatment guidelines recommend
that therapy should begin when CD4 counts fall below 350 cells/mm3.

Treatment may also be considered for patients with CD4
counts up to 500 cells/mm3 if they have a high viral load, or if they are
experiencing a rapid drop in CD4 cell count.

Types of Therapy

HIV therapy is called antiretroviral therapy (ART) or highly
active antiretroviral therapy (HAART). It consists of the combination of at
least three antiretroviral drugs (ARV) to keep the virus from spreading.

Slowing the spread of HIV gives the immune system and CD4
count time to recover. Three drugs are used in order to reduce the likelihood
of the virus developing resistance.

Numbers Can Fluctuate

Be careful of attaching emotions to single test results. Numbers
can often vary. For example, after initial HIV infection, viral load peaks. The
immune system then responds and lowers the number to a base level.

CD4 levels can also vary. The time of day, illness, infection, and
recent vaccinations can all affect CD4 and viral load count. This is why trends
in results matter much more than individual test results.

Early Treatment and Transmission

Recent studies cited by the World
Health Organization (WHO) show the benefits
of beginning therapy early. This is when CD4 counts are higher than 350

According to the studies, starting ART when above 350
cells/mm3 reduces the risk of AIDS and tuberculosis. It also reduces the risk of
developing non-AIDS-defining illnesses, such as liver failure and heart disease.
Another trial
showed that earlier treatment can reduce the risk of sexual transmission of HIV
to non-infected partners.

Don’t Forget Your Vitamins

Nutrition and food safety are vital to living well with HIV.
And fortunately, some studies have shown that nutritional supplements can help
increase CD4 counts for patients.

In a study published by the Journal
of Acquired Immune Deficiency Syndromes, researchers found micronutrient/vitamin
supplements could significantly improve CD4 cell count in HIV patients who are also
taking HAART.

A separate study showed that probiotic yogurt may
help increase CD4 count slightly in HIV/AIDS patients by limiting
gastrointestinal infections.

Checking The Numbers

notes that CD4 and viral load monitoring happen about every three to six
months. The schedules of each may differ slightly. Viral load requires more
frequent monitoring. Viral load and CD4 monitoring increases when treatment
begins. When treatment becomes effective, monitoring becomes less frequent.

HIV treatment has come a long way in recent years. An
effective ART and attention to healthy living will help to keep your CD4 count
high and viral load count low.

Posted by: Dr.Health

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