<20ml/copies VL detected

Question

I have had patients with CD4 counts in the 800/1000 range with detected VL <20 cop/ml.. Asymptomatic with no recent illness. Why at times are they detected? Then the next check up the VL taken at the same lab shows <20 not detected?

Answer

There are probably two aspects to this finding. First, is assay variability below the quantifiable limit of 20 copies/mL. Second, there may also be some intermittent HIV replication from some sites in the body.