Posttreatment controllers: what do they tell us?

Abstract

The posttreatment controllers (PTCs), as described for the Viro-Immunological Sustained COntrol after Treatment Interruption patients, are able to maintain durable HIV control after interruption of early antiretroviral therapy (ART). They are different from spontaneous HIV controllers who achieve HIV control without prior ART. PTCs provide proof-of-concept that prolonged ART-free remission is possible. PTCs support the idea that early treatment could be especially beneficial. They show that a stable equilibrium between a small HIV reservoir and HIV-1-specific immune responses can be achieved. PTCs occur at a frequency of 5 and 15% of patients with early combination ART interruption, which might be considered too infrequent to support early combination ART in all individuals. However, it will be necessary to use more potent ART, with good penetration into lymphoid tissues, initiated earlier and maintained for at least 4 years to see if this frequency might be increased. Understanding the mechanisms underlying durable HIV control among PTCs will provide critical insights into how this might be achieved in others. PTCs give hope that the objective of durable HIV remission is a realistic goal in the medium term.