Effects of intermittent interleukin-2 therapy on plasma and tissue human immunodeficiency virus levels and quasi-species expression

To characterize the effects of intermittent interleukin (IL)-2 therapy on h uman immunodeficiency virus (HIV), 11 patients underwent detailed virologic al evaluation during a year of IL-2 therapy. Six patients showed a >0.5 log increase in plasma HIV during at least 1 IL-2 cycle, with 2 experiencing a n increase in >50% of cycles. Three of the remaining 5 patients had a >0.5 log decrease during at least 1 IL-2 cycle, and the remaining patients exhib ited <0.5 log changes. No changes in lymphoid (tonsil) levels of HIV were s een during the year. Quasispecies analysis in a separate cohort demonstrate d that the virus induced by IL-2 most commonly resembled pre-IL-2 plasma qu asi species. Thus, intermittent IL-2 does not result in sustained increases in either plasma or tissue levels of HIV and does not result in sustained expression of a previously silent quasi species.