Hi Keith, I began taking Atripla after initial lab results of CD4 720 and VL 2000. My viral load quickly became undetectable and over the next year my CD4 steadily increased to 900+ Everything seemed to be going well, but my last 3 results have seen my CD4 fall to 640. My doctor isn't worried about this - but should i be? I lead a relatively healthy lifestyle, eat well and exercise regularly.

Are falling CD4 counts something to worry about if they remain above 500 or so?

Thanks )

The key variable to assess the effectiveness of an HIV regimen is the viral load (your Atripla is doing fine there). The CD4 count usually will go up over time but less so if starting at a high level. Also, the CD4 count is highly variable with wider absolute fluctuations (even in HIV negative patients) when the count is high (> 500). From the clinical standpoint a CD4 count appears protective from most HIV-related problems-still under study what is advantage to have CD4 count >> 500. KH