Why You Need to Know your CD4 Count Now

Studies have shown that people who are just diagnosed with HIV might be able to better manage their treatment by learning their CD4-cell count as soon as possible.

CD4, a protein on the surface of certain white blood cells, is sought out by the virus seeking cells to infect. A study of 516 people with HIV that appeared in the medical journal AIDS Research and Human Retroviruses shows that early tabulation of CD4 counts can help doctors better determine when patients should begin antiretroviral therapy.

The virus's infiltration of the cells leads to a drop in CD4 cell count, then a small wave of recovery, followed by a slow decline in CD4 count over time. Once the CD4 count falls below 350 cells per microliter of blood, doctors usually prescribe antiretroviral drugs. Once a person falls below 200 cells per microliter, he or she is considered to have AIDS.

Those considered fast progressors — people who develope AIDS within 7.5 years of contracting HIV — had lower peak CD4 cell counts earlier in their infection than slower progressors did. According to the study's authors, quick, permanent loss of CD4 proteins shows signs of long-term immune system damage in people who were classified as fast progressors.

Researchers caution that further study must be done to see if fast progressors' protein levels may recover after beginning antiretroviral therapy, but the results of more research may help doctors better evaluate who needs antiretroviral treatment sooner than others.