Evaluation of Human Immunodeficiency Virus (HIV) Type 1 Load, CD4 T Cell Level, and Clinical Class as Time‐Fixed and Time‐Varying Markers of Disease Progression in HIV‐1–Infected Children

Human immunodeficiency virus (HIV) type 1 RNA load, CD4 T cell level, and Centers for Disease Control and Prevention (CDC) clinical class history were measured as potential correlates of a CDC class C diagnosis or death in 165 HIV-1-infected children followed from birth. These covariates were assessed at fixed "landmark" ages from 6 to 24 months and were also assessed as time-varying values. Virus load was associated with progression in all analyses, even after adjusting for immunologic and clinical status. This confirms its importance for monitoring pediatric disease progression. CD4 T cell level was associated with disease progression in time-varying but not in adjusted landmark analysis, suggesting that CD4 cells reflects immediate risk more than long-term risk. The distinction between clinical class B and lower classes is prognostic during the first 18 months of life; class C versus classes N/A/B becomes more important as the patient ages. Virologic, immunologic, and clinical status all provide information regarding disease progression risk.