Blood work:
Two common tests to use for
monitoring HIV disease

January 2008     View PDF     En español

CD4 cell counts and when to start therapy

There’s no single, right answer to the question of when to start anti-HIV treatment. A cautious approach suggests checking CD4 cell counts more often when a person is not on therapy. A more aggressive approach suggests offering therapy. In spite of the actual CD4 cell count, therapy may be justified if there’s a dramatic falling trend in the CD4 cell count over time.

Research shows that anti-HIV therapy benefits people with CD4 cell counts below 200, best started when counts fall to 200. Other research suggests that therapy may benefit people when their CD4 cell counts are 200–350. In this range, thinking about other factors like viral load, falling trends in CD4 cell counts and overall general health may persuade a person to start therapy when his or her CD4 cell count is above 200. It’s unknown if starting therapy when CD4 cell counts are above 350 will provide a person with long-term results that outweigh concerns from short- and long-term side effects of anti-HIV therapies.