Transient dissociation between infectious HIV-1 titer and viral RNA during the early phase of AZT treatment.

The short-term kinetics of infectious HIV titers, HIV copy numbers and p24-antigen during the first 28 days of AZT monotherapy were evaluated. In three of four patients, infectious HIV was culturable and infectious titers rose 2- and 4-fold compared to baseline values. This increase was neither associated with mutations conferring resistance to AZT nor a switch from NSI to SI phenotypes. Two patients showed an increase of plasma infectivity associated with a reduction of HIV copies and p24-antigen. We conclude that transient dissociations of plasma infectivity and HIV copy numbers occur during early AZT monotherapy.