CROI 2009: No Clinical Benefit of CD4 Cells Generated by Interleukin-2

February 11, 2009 (Montreal, Canada) — Investigators were stunned to find that there was no clinical benefit from the additional CD4+ cells generated using interleukin (IL)-2 in conjunction with highly active antiretroviral therapy (HAART) when the ESPRIT study was unblinded a month ago. The first full results of both the ESPRIT trial and the SILCAAT study, a parallel trial that was stopped at the same time, were presented here at the 16th Conference on Retroviruses and Opportunistic Infections (CROI).

Higher CD4+ cell counts have been associated with better clinical outcomes in HIV infection and, in fact, are used as a surrogate marker in treating the disease. More than a decade ago, investigators became intrigued by the fact that IL-2 could robustly increase CD4+ count. The ESPRIT and SILCAAT trials were launched to determine whether those cells provided protection from disease progression and death.