Two types of poor immunological responder showing distinct responses to long-term HAART

Abstract

ObjectivesMost previous studies on poor immunological responders (PIRs) have been performed on one cohort at one time-point following highly active antiretroviral therapy (HAART). The aim of this study was to investigate whether there are different subtypes of PIR and whether a certain population might achieve better immune reconstitution following longer HAART. MethodsThis study was designed as an ambispective cohort study, including a 4–5-year retrospective study and a 2-year prospective follow-up investigation. Thymic output, activated T cell and regulatory T cell (Treg) subset frequencies, expression levels of interferon-stimulated genes, and plasma concentrations of neopterin were determined at 4–5 years and 6–7 years following HAART initiation. ResultsPIRs were subdivided into two populations after 4–5 years of HAART, according to the kinetics of T cell recovery. Type II PIRs exhibited a significantly lower percentage of naïve CD4+ T cells and CD31+ naïve CD4+ T cells compared with type I PIRs. After an additional 2 years of HAART treatment, type I PIRs showed a better outcome than type II PIRs. Furthermore, it was found that 2 years of additional HAART could persistently improve thymic output. ConclusionsThe two PIR subgroups are different in terms of immune characteristics and the response to prolonged HAART.