Relationship Between CD4+ T-Cell Counts/HIV-1 RNA Plasma Viral Load and AIDS-Defining Events Among Persons Followed in the ACTG Longitudinal Linked Randomized Trials Study

Abstract

AIDS-defining events (ADEs) decreased in the era of highly active antiretroviral therapy but still lead to hospitalizations and deaths. Understanding factors related to ADEs is important to mitigate events. We examined the relationship between demographics, behaviors, comorbidities, laboratory, clinical measurements, and ADEs diagnosed among subjects randomized to antiretroviral treatments (ART)/strategies and followed prospectively. Logistic regression models using generalized estimating equations generated odds ratios (ORs) focusing on the relationship between current CD4 T-cell count (CD4)/HIV-1 RNA viral load (VL) and ADEs in the subsequent 16-week study period. Among the 2948 subjects in the analysis, overall incidence of ADEs was 1.53 per 100 person-years. Multivariate regression models adjusted for demographics, body mass index, and ADE history. A 6-level time-varying variable examined VL (>100,000 copies/mL, < or =100,000) at CD4 levels (0-50, 51-200, >200 cells/microL); reference level was CD4 >200/VL < or =100,000. Among ART naives, odds of having an ADE in the subsequent 16-week interval were greater among subjects with lower CD4 counts; this relationship was modified by VL level (CD4 < or =50/VL >100,000: OR 37.2; CD4 < or =50/VL < or =100,000: OR 30.5; CD4 51-200/VL >100,000: OR 13.0; CD4 51-200/VL < or =100,000: OR 4.5; all P values <0.001). Similar results were seen among ART-experienced subjects. Recent CD4 and VL values are closely associated with development of ADEs even after examining a multitude of potential factors.