Reducing CD4 monitoring in children on antiretroviral therapy with virologic suppression

Background: Ongoing CD4 monitoring in patients on antiretroviral therapy (ART) with viral suppression has been questioned. We evaluated the probability of CD4 decline in children with viral suppression and CD4 recovery after 1 year on ART. Methods: We included children from 8 South African cohorts with routine HIV-RNA monitoring if (1) they were "responders" [HIV-RNA < 400 copies/mL and no severe immunosuppression after ≥1 year on ART (time 0)] and (2) ≥1 HIV-RNA and CD4 measurement within 15 months of time 0. We determined the probability of CD4 decline to World Health Organization-defined severe immunosuppression for 3 years after time 0 if viral suppression was maintained. Follow-up was censored at the earliest of the following dates: the day before first HIV-RNA measurement >400 copies/mL; day before a >15-month gap in testing and date of death, loss to follow-up, transfer out or database closure. Results: Among 5984 children [median age at time 0: 5.8 years (interquartile range: 3.1-9.0)], 270 children experienced a single CD4 decline to severe immunosuppression within 3 years of time 0 with probability of 6.6% (95% CI: 5.8-7.4). A subsequent CD4 measurement within 15 months of the first low measurement was available for 63% of children with CD4 decline and 86% showed CD4 recovery. The probability of CD4 decline was lowest (2.8%) in children aged 2 years or older with no or mild immunosuppression and on ART for <18 months at time 0. This group comprised 40% of children. Conclusions: This finding suggests that it may be safe to stop routine CD4 monitoring in children older than 2 years and rely on virologic monitoring alone.