Different profiles of immune reconstitution in children and adults with HIV-infection after highly active antiretroviral therapy.
BACKGROUND
Recent advances in characterizing the immune recovery of HIV-1-infected people have highlighted the importance of the thymus for peripheral T-cell diversity and function. The aim of this study was to investigate differences in immune reconstitution profiles after highly active antiretroviral therapy (HAART) between HIV-children and adults.


METHODS
HIV patients were grouped according to their previous clinical and immunological status: 9 HIV-Reconstituting-adults (HIV-Rec-adults) and 10 HIV-Reconstituting-children (HIV-Rec-children) on HAART with viral load (VL) <or=400 copies/ml and CD4+ >or=500 cells/microL at least during 6 months before the study and CD4+ <or=300 cells/microL anytime before. Fifteen healthy-adults and 20 healthy-children (control subjects) were used to calculate Z-score values to unify value scales between children and adults to make them comparable.


RESULTS
HIV-Rec-children had higher T-cell receptor excision circles (TREC) and lower interleukin (IL)-7 levels than HIV-Rec-adults (p < 0.05). When we analyzed Z-score values, HIV-Rec-children had higher TREC Z-score levels (p = 0.03) than HIV-Rec-adults but similar IL-7 Z-score levels. Regarding T-cell subsets, HIV-Rec-children had higher naïve CD4+ (CD4+CD45RA hi+CD27+), naïve CD8+ (CD8+CD45RA hi+CD27+), and memory CD8+ (CD8+CD45RO+) cells/microl than HIV-Rec-adults, but similar memory CD4+ (CD4+CD45RO+) counts. HIV-Rec-children had lower naïve CD8+ Z-score values than HIV-Rec-adults (p = 0.05).


CONCLUSIONS
Our data suggest that HIV-Rec-children had better thymic function than HIV-Rec-adults and this fact affects the peripheral T-cell subsets. Thus, T-cell recovery after HAART in HIV-Rec-adults could be the consequence of antigen-independent peripheral T-cell expansion while in HIV-Rec-children thymic output could play a predominant role in immune reconstitution.
Resino
Salvador
S
Laboratorio de Inmuno-Biología Molecular, Hospital General Universitario Gregorio Marañón, Madrid, Spain. sresino.hgugm@salud.madrid.org
Seoane
Elena
E
Pérez
Alicia
A
Ruiz-Mateos
Ezequiel
E
Leal
Manuel
M
Muñoz-Fernández
Maria A
MA
D000293:Adolescent; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D015415:Biomarkers / Q000032:analysis; D002648:Child; D003430:Cross-Sectional Studies; D006678:HIV / Q000187:drug effects; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology* / Q000821:virology; D006801:Humans; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology; D019562:Viral Load
D015415:Biomarkers