Immune activation is associated with decreased thymic function in asymptomatic, untreated HIV infected individuals
Date
2016-07-28
Journal Title
Journal ISSN
Volume Title
Publisher
AOSIS Publishing
Abstract
Background: Reduced thymic function causes poor immunological reconstitution in human
immunodeficiency virus (HIV)-positive patients on combined antiretroviral therapy (cART).
The association between immune activation and thymic function in asymptomatic HIVpositive
treatment-naive individuals has thus far not been investigated.
Aims and objectives: To optimise a five-colour flow cytometric assay for measurement of
thymic function by measuring recent thymic emigrants (RTEs) in treatment-naive HIV-infected
patients and healthy controls and correlate results with levels of immune activation, CD4
counts and viral load.
Methods: Blood obtained from 53 consenting HIV-positive individuals and 32 controls
recruited from HIV prevention and testing clinic in Cape Town, South Africa. RTEs were
measured (CD3+/CD4+/CD45RA+/CD31+/CD62L+) and levels were correlated with CD4
counts of HIV-infected individuals, log viral load and levels of immune activation (CD8+/
CD38+ T-cells).
Results: HIV-infected individuals had reduced frequencies of RTEs when compared to controls
(p = 0.0035). Levels of immune activation were inversely correlated with thymic function
(p = 0.0403), and the thymic function in HIV-infected individuals showed no significant
correlation with CD4 counts (p = 0.31559) and viral load (p = 0.20628).
Conclusions: There was impaired thymic function in HIV-infected individuals, which was
associated with increased levels of immune activation. The thymic dysfunction was not
associated with CD4 counts and viral load. Immune activation may result in inflammatory
damage to the thymus and subsequent thymic dysfunction, and CD4 counts and viral load
may not necessarily reflect thymic dysfunction in HIV.
Description
CITATION: Manjati, T., Nkambule, B. & Ipp, H. 2016. Immune activation is associated with decreased thymic function in asymptomatic, untreated HIV infected individuals. Southern African Journal of HIV Medicine, 17(1), a445, doi:10.4102/sajhivmed.v17i1.445.
The original publication is available at http://www.sajhivmed.org.za
The original publication is available at http://www.sajhivmed.org.za
Keywords
Human immunodeficiency virus, Antiretroviral therapy, Immune response, Inflammation -- Immunology
Citation
Manjati, T., Nkambule, B. & Ipp, H. 2016. Immune activation is associated with decreased thymic function in asymptomatic, untreated HIV infected individuals. Southern African Journal of HIV Medicine, 17(1), a445, doi:10.4102/sajhivmed.v17i1.445.