Search

Background. We sought to determine the safety of treatment interruption (TI) and to identify parameters that would define patients with human immunodeficiency virus (HIV) for whom TI is safer. Methods. AIDS Clinical Trials Group 5170 was a multicenter, 96-week-long, prospective study of HIV-infected patients receiving antiretroviral therapy (ART) who had CD4+ cell counts >350 cells/mm³ and who underwent TI. Results. A total of 167 patients were enrolled. The median nadir in CD4+ cell count was 436 cells/mm³. The initial decrease (i.e., during the first 8 weeks) in CD4+ cell count after ART interruption was 20 cells/mm³/week; the subsequent decrease was 2.0 cells/mm³/week until week 96. Both the CD4+ cell count before enrollment and the increase in CD4+ cell count during ART predicted early decrease; later decrease was predicted by the level of interleukin- 7 at enrollment. A Centers for Disease Control and Prevention (CDC) diagnosis of a category B or C event was made for 2 and 2 patients, respectively (all had CD4+ cell counts >350 cells/mm³). At week 96, 17 patients had CD4+ cell counts ⩽250 cells/mm³, and 46 patients had resumed ART; 5 patients died (unrelated to HIV or acquired immunodeficiency syndrome). In a multivariate analysis, a higher nadir in CD4+ cell count (1400 cells/mm³), a lower HIV load (<50 copies/mL) at the time of TI, and an HIV load ⩽22,000 copies/mL before ART predicted a longer time to the primary end point (CDC category B or C event, death, CD4+ cell count <250 cells/mm³, or resumption of ART). Conclusion. Disease progression after TI was low in this cohort. A higher nadir in CD4+ cell count, a lower HIV load before ART, and an HIV load ⩽50 copies/mL at the time of TI predicted a longer time to the primary end point. [ABSTRACT FROM AUTHOR]