How important is undectectable

Mar 1, 2008

Hello,

I take Atripla and have no resistances. When I went to the doctor in October 2007, the numbers were CD4: 574/31%, vl: 151 and in Feb. 2008: CD4: 589/31%, vl: <50. I asked my doctor who is an experienced ID clincian, what she would do if the vl increased but remained below 500. She said if the medication were well-tolerated and being taken as perscribed, then she would do nothing. She said that a vl of <500 had no significantly increased chance of resistance. My question is if that is accurate. Everything I read talks about a vl less than 50 and people seem obsessed with getting the vl to that level. Is my doctor wrong? I got the impression that she feels that <50 is an arbitrary number because the vl tests can now detect down to that point where as years ago the vl tests couldn't detect less than 500. What do you think?

Response from Dr. Holodniy

I agree with your doctor. It certainly is better to have consistently undetectable viral loads. however, data from several studies indicate that blips up to 500 or so in viral load are not associated with antiviral failure, particularly if the viral load alternates between undetectable and low positive. Most of these blips are associated with assay variability and not failure. If however the viral load stays positive and begins to creep above 1,000 or so, then it is likely that treatment failure has occurred.