HIV-1-infected children on HAART: immunologic features of three different levels of viral suppression.
BACKGROUND
HIV-1-infected children show changes of blood lymphocyte subpopulations. We have, therefore, investigated how highly active anti-retroviral therapy (ART) alter these subsets. Blood samples were taken from 41 HIV-1-infected children on ART who were divided into groups showing good, partial and poor responses to ART on the basis of viral load (VL) measurement in blood. The observations were compared to those seen in 20 uninfected children.


METHODS
The samples were studied using 4-color flow cytometry for "naïve", central memory and effector memory cells as well as for CD38 expression as the sign of activation within both the CD4+ and the CD8+ T cell populations. HIV-1 infected children were also evaluated for the presence and the titers of antibodies induced by vaccination against childhood infections in our patients while on HAART.


RESULTS
Lymphocyte counts were lower in the "poor" viral load responding (VLR) group when compared with partial and good VLRs. Poor VLRs had lower total and naïve CD4+ T cell counts. HIV-1-infected children from all three groups had high CD8+ T cell counts. Central memory CD4+ and CD8+ T cell percentages were particularly low in the poor VLR group while in the poor VLR group the percentages of effector memory CD4+ and CD8+ T cells were higher when compared with the control group. Higher cellular activation of CD8+ T cells was observed in HIV-1-infected children, particularly when analyzed for the intensity of CD38 expression in the poor VLR group. CD5 expression on B cells was higher among all HIV-1-infected children. Antibodies to tetanus, diphtheria, measles, rubella, and hepatitis B were present in a large proportion of children but the titers were similarly low for all three groups of HIV-infected children.


CONCLUSIONS
Children with different levels of viral response to HAART present immune phenotype characteristics that tend to place the children with partial and good virological responses into the same group. These children are still moderately deficient in their immune responses but show better recovery than seen with children in the poor VLR group. These observations indicate that the proportions of central memory cells among the CD4+ T cells and the intensity of the expression of CD38 activation antigen on CD8+ T cells provide more informative parameters for monitoring children on HAART than the absolute numbers of CD4+ and CD8+ T cells alone.
Zaccarelli-Filho
Carlos Alberto
CA
Division of Pediatric Infectious Diseases, Federal University of São Paulo, rua Pedro de Toledo 781-9 andar, 04039-032 São Paulo, SP, Brazil.
Ono
Erika
E
Machado
Daisy Maria
DM
Brunialti
Milena
M
Succi
Regina Célia de Menezes
RC
Salomão
Reinaldo
R
Kallás
Esper Georges
EG
de Moraes-Pinto
Maria Isabel
MI
D016915:AIDS Vaccines / Q000276:immunology; D000906:Antibodies / Q000097:blood; D015703:Antigens, CD / Q000276:immunology; D023241:Antiretroviral Therapy, Highly Active; D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology / Q000821:virology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology / Q000821:virology; D018956:CD5 Antigens / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology / Q000821:virology; D002452:Cell Count; D002648:Child; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000276:immunology* / Q000472:pathogenicity; D006801:Humans; D016130:Immunophenotyping; D039001:Integrin alpha Chains / Q000276:immunology; D007694:Killer Cells, Natural / Q000166:cytology / Q000473:pathology / Q000821:virology; D007962:Leukocytes / Q000276:immunology / Q000473:pathology / Q000821:virology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology / Q000821:virology; D019562:Viral Load
D016915:AIDS Vaccines; D000906:Antibodies; D015703:Antigens, CD; D018956:CD5 Antigens; D039001:Integrin alpha Chains; C091367:alpha E integrins