In order for you and your health care provider to know how best to fight your HIV infection, you will need to have some blood tests on a regular basis. This will help you closely monitor your health and any possible damage that HIV or the drugs you're taking might cause. In addition to common blood tests like a Complete Blood Count (CBC), and a Chem-Screen (CS), you will need to do two more tests that help measure the progression of HIV disease:
CD4 cell Count: As HIV disease progresses, the CD4 cell count goes down from a normal count of 500-1500 cells in a cubic millimeter of blood (a drop, more or less) down to as low as zero. When the CD4 cell count goes below 200, there is an increased risk of opportunistic infections, and when the CD4 cell count drops below 50, the risk rises dramatically. Remember: a high CD4 cell count is good, and a low CD4 cell count is bad. The CD4 count is also one of the most important tests when figuring out when to start HIV treatment.
Viral Load Count: A test known as a viral load count, a viral burden count, or an HIV RNA count, measures the amount of HIV in a drop of blood. If only a small amount of virus is present (say, less than 50-200 copies depending on the test), then the test cannot detect the virus. This is what is meant when a viral load count comes back with a result of "undetectable." It doesn't mean that there is no virus present, but that the amount is so low that the test cannot measure it. As HIV disease progresses, the viral load count tends to rise, so that someone who starts with a very low viral load count (say 5,000 copies of virus per drop) may rise to a very high viral load count (say, several hundred thousand or even more than a million copies of virus per drop of blood). While viral load isn't frequently used when figuring out when antiretroviral therapy should be started, it is a very important test for those currently on treatment. When using HIV medications, the ultimate goal is to make the viral load go undetectable. If treatment isn't able to do this, or a viral load becomes detectable again while taking ARVs, it may be necessary to switch your treatment.
Generally your health care provider will order a routine set of blood tests every three or four months (although it may be more or less frequent depending on how far your HIV disease has progressed and what medicines you're taking). Usually the results of these blood tests come back on complicated forms that list the results of lots of different tests together. For more information about understanding your blood test results, click on the following lesson links:
AIDSmeds.com also has a handy interactive program that allows you to track & graph these and any other lab test results
. It's called "Graph My Labs," and it's a great way to become more involved with monitoring your own health. Check it out by clicking here.