More than 80% of HIV-positive adults experience a CD4-cell rebound of at least 50 cells -- and most an increase much higher than that -- within the first few weeks of antiretroviral therapy, researchers report in the March edition of the journal AIDS Research and Human Retroviruses.

The researchers followed 170 adults who began antiretroviral therapy between 1997 and 2003 to evaluate the extent of immune system recovery shortly after anti-HIV drugs were prescribed. They confirmed that four out of five treatment-naive HIVers posted at least a 50-cell CD4-cell count rebound shortly after beginning treatment. CD4-cell rebounds were highest among those who began treatment with HIV viral loads about 100,000 copies, suggesting that individuals with the highest viral levels benefit the most from treatment.