Antiretroviral therapy (ART) has improved survival into adulthood for young people with perinatally acquired HIV-1 (yp-PaHIV), but
long-term prognosis remains unclear. We hypothesized that on-going immune activation, re
fl
ected in the failure of CD4:CD8 ratio
normalization would be observed in yp-PaHIV, despite ART.
A cross-sectional study of routinely collected clinical data from a cohort of yp-PaHIV (
≥
16 years).
Data were collected from records of individuals attending a specialist clinic for yp-PaHIV transitioning to adult care. CD4:CD8 ratio
and proportion with CD4:CD8 ratio
≥
1, demographic data and viral parameters, including HIV-1 viral load (VL) and human
cytomegalovirus (CMV) IgG, were analyzed with IBM SPSS Statistics v22.
A total of 115 yp-PaHIV, median (IQR) age 22.0 (20.0
–
24.0) years, were studied, of whom 59 were females, and the majority were
Black African 75/115 (65.2%). Where measured, CMV antibodies were frequently detected (71/74, 95.9%) and CMV IgG titre was
inversely associated with CD4:CD8 ratio, (Rho

0.383,
P
=
.
012). Of those taking ART, 69 out of 90 (76.7%) yp-PaHIV had
suppressed HIV viremia (
<
50 RNA copies/mL) and recovery of CD4:CD8 ratio to
≥
1 was seen in 26 out of 69 (37.7%)
with suppressed HIV viremia. Persistence of low CD4:CD8 ratio was observed even in those with a CD4 count
≥
500cells/
m
L, where
28/52 (53.8%) had a CD4:CD8 ratio
<
1. Of those with suppressed viremia, the median (IQR) age for starting ART was 8.0 (5.0
–
12.8)
years and CD4:CD8 ratio was inversely associated with age at ART start, Rho

0.348, (
P
=
.
028).
In this cohort of yp-PaHIV, despite lifelong HIV infection and widespread CMV coinfection, CD4:CD8 ratio recovery rate was
comparable to adults treated in acute infection. Where persistence of CD4:CD8 ratio abnormality was observed, on-going immune
activation may have signi
fi
cance for non-AIDS outcomes. Taken together our
fi
ndings indicate immune resilience to be a feature of
these adult survivors of perinatally acquired HIV infection, which can be supported with early antiretroviral therapy.