CD4+ Cell Count 6 Years after Commencement of Highly Active Antiretroviral Therapy in Persons with Sustained Virologic Suppression

Abstract

Sustained suppression of the human immunodeficiency virus (HIV) type 1 RNA load with the use of highly active antiretroviral therapy (HAART) results in immunologic improvement, but it is not clear whether the CD4(+) cell count increases to normal levels or whether it reaches a less-than-normal plateau. We characterized the increase in the CD4(+) cell count in patients in clinical practice who maintained sustained viral suppression for up to 6 years. All patients were from the Johns Hopkins HIV Clinical Cohort, a longitudinal observational study of patients receiving primary HIV care in Baltimore, Maryland, who were observed for >1 year while receiving HAART and who had sustained suppression of the HIV RNA load at <400 copies/mL. We analyzed annual change in the CD4(+) cell count for up to 6 years after the start of HAART, stratified by baseline CD4(+) cell counts of < or =200, 201-350, >350 cells/microL, and we assessed the development of clinical events (death and new acquired immunodeficiency syndrome-defining illness) by Kaplan-Meier analysis. A total of 655 patients were observed for a median of 46 months (range, 13-72 months). The median change from baseline to most recent CD4(+) cell count was +274 cells/microL, with 92% of patients having an increase in CD4(+) cell count. By 6 years, the median CD4(+) cell count was 493 cells/microL among patients with baseline CD4(+) cell counts < or =200 cells/microL, 508 cells/microL among those with baseline CD4(+) cell counts of 201-350 cells/microL, and 829 cells/microL among those with baseline CD4(+) cell counts >350 cells/microL. In addition to baseline CD4(+) cell count, injection drug use and older age were associated with a lesser CD4(+) cell count response, and duration of therapy was associated with a greater CD4(+) cell count response. Only patients with baseline CD4(+) cell counts >350 cells/microL returned to nearly normal CD4(+) cell counts after 6 years of follow-up. Significant increases were observed in all CD4(+) cell count strata during the first year, but there was a lower plateau CD4(+) cell count at lower baseline CD4(+) cell strata. These data suggest that waiting to start HAART at lower CD4(+) cell counts will result in the CD4(+) cell count not returning to normal levels.