Predictors of CD4 count change over 8 months of follow up in HIV‐1‐infected patients with a CD4 count≥300 cells/μL who were assigned to 7.5 MIU interleukin‐2

BackgroundESPRIT is a randomized trial comparing the clinical impact of interleukin (IL)‐2 plus antiretrovirals vs antiretrovirals alone. Identification of factors that influence the relationship between IL‐2 and CD4 count recovery will enable better personalization of treatment with IL‐2 in HIV‐1‐positive individuals. The IL‐2 induction phase consists of three dosing cycles over 6–8 months (7.5 MIU twice a day, for 5 days every 8 weeks).MethodsWe included patients initiating IL‐2 at the 7.5 MIU dose with an 8‐month CD4 count, measured at least 30 days after their last cycle. We identified baseline predictors of CD4 count changes over 8 months using linear regression.ResultsOf 2090 patients assigned IL‐2, 1673 (80%) were included in the analysis. The median (interquartile range) baseline CD4 count was 461 (370, 587) cells/μL with a median increase of 233 (90, 411) cells/μL at month 8. After adjustments, significant predictors of CD4 count change included CD4 nadir (29.8 cells/μL greater increase per 100 cells/μL higher; P<0.0001), last CD4 count before baseline (mean 36.0 cells/μL greater increase per 100 cells/μL higher; P<0.0001), time from antiretroviral start to baseline (8.3 cells/μL smaller increase per year longer; P=0.001), age (11.7 cells/μL smaller increase per 5 years older; P=0.005) and race (79.7 cells/μL greater increase for black patients vs white patients; P=0.003). A linear relationship existed between total IL‐2 dose in the first cycle and CD4 count change (73.1 cells/μL greater increase per 15 MIU higher; P<0.0001).ConclusionsPrior nadir and current CD4 counts, age and IL‐2 dose are major determinants of CD4 increases induced by with intermittent administration of IL‐2 in HIV‐1‐positive individuals on antiretrovirals. The clinical function of these induced CD4 cells is under study.