Predictive value of the ultrasensitive HIV viral load assay in clinical practice.

The aim of this study was to determine whether an HIV viral load of <50 copies/ml (c/ml), in the first available plasma sample to have shown a viral load of <400 c/ml, in patients on antiretroviral therapy, is correlated with longer term suppression of viral load (at <400 c/ml) compared to a viral load of 50-399 c/ml, and secondly, to compare the results obtained by ultrasensitive and standard viral load assays carried out on the same sample. A total of 98 HIV-positive patients on antiretroviral therapy with a viral load of <400 c/ml and at least one subsequent viral load measurement, were selected. For each patient, the first available specimen showing a viral load of <400 c/ml was tested using the Roche Amplicor ultrasensitive viral load assay, and patients were followed up subsequently for a median period of 52 weeks.