Objectives: Most 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.
Methods: This 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.
Results: PIRs 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.
Conclusions: The two PIR subgroups are different in terms of immune characteristics and the response to prolonged HAART.
Keywords: Long-term HAART; Poor immunological responders; Subdivision; Thymic output.
Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.