Age and viral replication, not vertical HIV acquisition, drive inflammation and T-cell dysfunction in heavily treatment experienced: data from the Prestigio Registry.

Heavily treatment-experienced (HTE) individuals carry a high inflammatory burden, which is potentially increased in those with vertical HIV transmission (VT), due to lifelong viral exposure. We assessed inflammation and T-cell activation/exhaustion/senescence in HTE with VT or horizontal transmission (HT). Interleukin-6 (IL-6) was lower in VT and positively correlated with age. T-cell dysfunction was greater in HTE than people without HIV (PWOH), mainly driven by viremic VT and HT. Age and viral replication, rather than transmission mode, underlie immune dysregulation in HTE.