Uncovering the Hidden Players: Double-negative T Cells in Pediatric HIV and Their Impact on Disease Progression

BACKGROUND: Immune reconstitution in pediatric HIV infection under antiretroviral therapy (ART) is monitored by CD4 + T-cell counts and the CD4/CD8 ratio, whereas the role of double-negative T cells (DNTs; CD3 + CD4 - CD8 - ) is poorly defined. We aimed to characterize CD4 + /CD8 + T-cell dynamics and age-dependent DNT patterns. METHODS: In this retrospective cohort, 30 children were followed for 12 months after ART initiation. Flow cytometry was used to measure CD3 + , CD4 + , CD8 + and DNT subsets and the CD4/CD8 ratio; demographic, clinical and coinfection data were abstracted from medical records. RESULTS: The cohort comprised 30 children (20 boys, 10 girls; mean age 10.4 years). ART increased CD4 + and decreased CD8 + T-cell percentages, with the CD4/CD8 ratio rising from 0.73 to 1.09 and normalizing (≥1.0) in 63.3% of children. Baseline DNT levels were elevated (mean 7.0%) but declined significantly, normalizing (