Characterizing the immune system after long-term undetectable viral load in HIV-1-infected children

The pattern and magnitude of T cell subsets reconstitution during ten years of ART with viral suppression in HIV-infected patients

BACKGROUND

The extent of immune reconstitution in human immunodeficiency virus (HIV) infected persons receiving long-term antiretroviral therapy (ART) with controlled viral load has been controversial. We studied the extent and speed of T cell subsets retrieval after long-term antiretroviral treatment.

METHODS

662 HIV-infected patients followed at least 2 years whose plasma HIV-1 RNA load <50 copies/mL were evaluated for longitudinal and functional phenotypic indices of immune restoration. Determinants of change in magnitude and importance of recovery have been evaluated using mixed linear regression models.

RESULTS

Almost all robust immune restorations achieved occurred after 2-3 years of ART. The median CD4 lymphocyte count increased 449 cells/μl (IQR 303-604) from 226 cells/μl (IQR 83-336) at baseline during the third year (P < 0.001); CD4+T lymphocyte rises during the sixth and tenth years were not significant. Naive and memory CD4+T cells'reconstitution occurred in the sixth and eighth years of ART but no significant change thereafter. The change of CD45RA+Naïve and CD45RA-memory CD4+T cell reconstitution is different in baseline CD4+T cell counts <100 cells/μl group and in baseline CD4+T cell counts >100 cells/μl group. Activation antigen expression (CD38 or HLA-DR) on CD8 lymphocytes declined mostly during the first till second year, and after 4 years, activation antigen expression on patient lymphocytes showed no significant change. The proportion of CD4 cells expressing CD28 climbed during the first years and reached normal levels in the second year.

CONCLUSIONS

Immune restoration was dependent on the capacity of immune system during the first 2-3 year of ART. But the significant change of CD4 and compartments of CD4+T cells could persist until 6-8 years. The pattern of CD38+CD8+, HLA-DR+CD8+, CD28+CD4+ T cells could quickly return to normal level and no significant change after sufficient time of ART. In general, the immune response compared to the baseline status may be the overall effect from the age and time of antiretroviral treatment.

Profiling of Inflammatory Proteins in Plasma of HIV-1-Infected Children Receiving Antiretroviral Therapy

Treatment of HIV-1-infected patients results in improved clinical and immunological conditions, but severe non-AIDS-related conditions still persist. Novel proteomic platforms have identified inflammatory proteins where abundance is dysregulated in adult treated patients, whereas limited data are available in treated HIV-1 infection of children. Using a proteomic plasma profiling approach comprising 92 inflammation-related molecules, we analyzed specimens from 43 vertically HIV-1-infected children receiving antiretroviral treatment (ART) and matched controls in Ethiopia. The infected children were analyzed as a group and separately, according to age of treatment initiation. Proteins displaying a significantly different abundance between groups were hierarchically clustered and presented in heat maps. Random forest analysis was performed to pin-point proteins discriminating between groups; five proteins (STAMBP, CD5, TFG-α, TRANCE, AXIN1) were the strongest prediction factors for treated HIV-1 infection. TRANCE was previously linked to reduced bone mass levels in HIV-1-infected children. CCL4 chemokine, ligand to HIV-1 co-receptor CCR5, was the most critical protein for successful classification between children who initiated ART at different time points. Our data provide evidence that a dysregulated expression of proteins linked to immunological abnormalities and bone metabolism can be found in HIV-1-infected children with prolonged exposure to ART.

Hepatitis B Virus Vaccination in HIV-1-Infected Young Adults: A Tool to Reduce the Size of HIV-1 Reservoirs?

During anti-retroviral therapy (ART) HIV-1 persists in cellular reservoirs, mostly represented by CD4+ memory T cells. Several approaches are currently being undertaken to develop a cure for HIV-1 infection through elimination (or reduction) of these reservoirs. Few studies have so far been conducted to assess the possibility of reducing the size of HIV-1 reservoirs through vaccination in virologically controlled HIV-1-infected children. We recently conducted a vaccination study with a combined hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccine in 22 HIV-1-infected children. We assessed the size of the virus reservoir, measured as total HIV-1 DNA copies in blood cells, pre- and postvaccination. In addition, we investigated by immunostaining whether the frequencies of CD4+ and CD8+ T cells and parameters of immune activation and proliferation on these cells were modulated by vaccination. At 1 month from the last vaccination dose, we found that 20 out of 22 children mounted a serological response to HBV; a majority of children had antibodies against HAV at baseline. The number of HIV-1 DNA copies in blood at 1 month postvaccination was reduced in comparison to baseline although this reduction was not statistically significant. A significant reduction of HIV-1 DNA copies in blood following vaccination was found in 12 children. The frequencies of CD4+ (naïve, effector memory) and CD8+ (central memory) T-cell subpopulations changed following vaccinations and a reduction in the activation and proliferation pattern of these cells was also noticed. Multivariate linear regression analysis revealed that the frequency of CD8+ effector memory T cells prior to vaccination was strongly predictive of the reduction of HIV-1 DNA copies in blood following vaccination of the 22 HIV-1-infected children. The results of this study suggest a beneficial effect of vaccination to reduce the size of virus reservoir in HIV-1-infected children receiving ART. A reduced frequency of activated CD4+ cells and an increase in central memory CD8+ T cells were associated with this finding. Further studies should assess whether vaccination is a possible tool to reduce HIV-1 reservoirs.

Incident Hepatitis B Virus Infection in HIV-Infected and HIV-Uninfected Men Who Have Sex With Men From Pre-HAART to HAART Periods: A Cohort Study

BACKGROUND

Men who have sex with men (MSM) are at high risk for hepatitis B virus (HBV) infection. Data on the effect of highly active antiretroviral therapy (HAART) on incident HBV infection in HIV-infected and HIV-uninfected MSM are limited.

OBJECTIVE

To determine predictors of incident HBV infection in MSM during pre-HAART and HAART periods.

DESIGN

Observational cohort study.

SETTING

Cohort of MSM who have, or are at risk for, HIV infection.

PATIENTS

2375 HBV-uninfected MSM in the Multicenter AIDS Cohort Study.

MEASUREMENTS

Poisson regression was used to compare incidence rates of HBV infection in the pre-HAART and HAART eras and to identify factors associated with incidence of HBV infection.

RESULTS

In 25,322 person-years of follow-up, 244 incident HBV infections occurred. The unadjusted incidence rate was higher in HIV-infected MSM than in HIV-uninfected MSM (incidence rate ratio [IRR], 1.9 [95% CI, 1.5 to 2.4]) and was significantly lower in the HAART era than in the pre-HAART era among HIV-infected (IRR, 0.2 [CI, 0.1 to 0.4]) and HIV-uninfected (IRR, 0.3 [CI, 0.2 to 0.4]) MSM. Age younger than 40 years (IRR, 2.3 [CI, 1.7 to 3.0]), more than 1 recent sexual partner (IRR, 3.1 [CI, 2.3 to 4.2]), and HIV infection (IRR, 2.4 [CI, 1.8 to 3.1]) were independently associated with higher incidence of HBV infection, whereas HBV vaccination was protective (IRR, 0.3 [CI, 0.2 to 0.4]). Highly active antiretroviral therapy with HIV RNA levels less than 400 copies/mL was associated with protection (IRR, 0.2 [CI, 0.1 to 0.5]), but HAART in those with HIV RNA levels of 400 copies/mL or greater was not.

LIMITATION

The observational nature limits inferences about causality.

CONCLUSION

Effective HAART is associated with lower incidence of HBV infection; however, even in the HAART era, incidence of HBV infection remains high among MSM.

PRIMARY FUNDING SOURCE

National Institute of Allergy and Infectious Diseases.

Changes in cellular immune activation and memory T-cell subsets in HIV-infected Zambian children receiving HAART

BACKGROUND

Increased exposure to a broad array of pathogens in children residing in sub-Saharan Africa may lead to heightened immune activation and increased proportions of memory T cells. Changes in the size of these cellular subsets have implications for restoration of normal immune function after treatment with highly active antiretroviral therapy (HAART) and are not well characterized in young sub-Saharan African children.

METHODS

CD4⁺ and CD8⁺ T-cell subsets were measured by flow cytometry in 157 HIV-infected Zambian children before and at 3-month intervals during HAART for up to 30 months and in 34 control children at a single study visit.

RESULTS

Before HAART, HIV-infected children had higher levels of activated and effector memory (EM) CD4⁺ and CD8⁺ T cells, and lower levels of naive T cells and CD8⁺ T cells expressing IL-7Rα, compared with control children. The median duration of follow-up was 14.9 months (interquartile range, 6.4-23.2) among 120 HIV-infected children with at least 1 study follow-up visit. Levels of immune activation and EM CD4⁺ T cells declined within 6 months of HAART, but the percentages of EM CD4 T cells and effector CD8⁺ T cells remained elevated through 30 months of HAART. IL-7Rα-expressing CD8⁺ T cells increased with HAART, suggesting expansion of memory capacity.

CONCLUSIONS

HAART significantly reduced levels of immune activation and EM CD4⁺ T cells, and promoted reconstitution of naive T cells and IL-7Rα-expressing CD8⁺ T cells. However, persistently high levels of EM CD4⁺ T cells in HIV-infected children may reflect chronic perturbations in T-cell subset composition.

Immunologic basis for revaccination of HIV-infected children receiving HAART

With increasing access to antiretroviral therapy for children infected with HIV, especially in sub-Saharan Africa, better understanding of the development and maintenance of memory T- and B-cell responses to pathogens after immune reconstitution is needed to assess the risk of infection. Knowledge of long-term immune responses after starting HAART is of particular importance for policies on revaccination of HIV-infected children, who may lose protective immunity to prior infections and immunizations. We review normal development of T- and B-cell memory responses to viruses and vaccines against viral pathogens, and contrast the immunological effects of perinatal HIV transmission with HIV infection acquired later in life. We then explore the potential benefits of antiretroviral therapy and revaccination, using measles virus as a model.

CD57+ T lymphocytes and functional immune deficiency

CD57(+) expression in T lymphocytes has been recognized for decades as a marker of in vitro replicative senescence. In recent years, accumulating evidences have pointed on the utility of this marker to measure functional immune deficiency in patients with autoimmune disease, infectious diseases, and cancers. We review here the relevant literature and implications in clinical settings.

The Distribution and Immune Profile of T Cell Subsets in HIV-Infected Children from Uganda

Abstract T cell activation is an important mechanism in HIV-associated immune depletion. We have previously demonstrated an association between the hyperactivation of CD4(+) and CD8(+) T cells and low CD4 status in HIV-infected Ugandan children. In this study, we explore differences in activation between naive and memory T cells in HIV-infected Ugandan children. A significant correlation between CD4- and CD8-mediated immune activation and CD4 status was observed only in the memory T cells. Antiretroviral (ART) untreated and treated HIV-positive and HIV-negative children displayed similar profiles of activation and distribution within the CD4(+) naive T cells. In contrast, significantly higher immune activation of the memory CD4(+) T cell subset was seen in ART-untreated children when compared to ART-treated or HIV-negative children. ART-mediated viral suppression led to the correction of CD4(+) immune activation to levels seen in uninfected children but did not increase the size of the memory CD4(+) T cell population. High levels of CD8(+) immune activation were also found in both naive and memory cell subsets. Antiretroviral treatment led to the normalization of CD8(+) T cell activation but did not correct the distribution of naive CD8(+) T cells. We also assessed PD-1 expression on CD8(+) T cells as a measure of immune dysfunction. Upregulation of PD-1 was highest in untreated children but persisted in ART-treated children compared to uninfected children. The mechanisms of immunopathogenesis in pediatric HIV infection likely involve distinct contributions from individual naive and memory T cells subsets.

Antiretroviral therapy corrects HIV-1-induced expansion of CD8+ CD45RA+ CD2-) CD11a(bright) activated T cells

BACKGROUND

HIV infection decreases thymic output and induces chronic T-cell activation.

OBJECTIVE

To examine the reconstitution of naive and activated T cells.

METHODS

Extended immune phenotyping of CD4(+) and CD8(+) T-cell subsets was combined with T-cell receptor rearrangement excision circle (TREC) levels and measures of T-cell receptor repertoire perturbations in CD8(+) T-cell subpopulation to define the global effect of HIV-1 on T-cell dynamics. Evaluations before and after therapy were performed in HIV-infected children and compared with those in healthy individuals.

RESULTS

Ten HIV-infected children and adolescents with a broad range of pretherapy CD4(+) T-cell counts were compared with healthy individuals. Pretherapy late activated CD8(+) T cells (CD3(+)CD8(+)CD45RA(+)CD27(-)CD11a(bright) cells) were expanded among HIV-infected subjects. Successful antiretroviral therapy increased the proportion of naive T cells (CD3(+)CD4(+)CD45RA(+)CD27(+)CD28(+) and CD3(+)CD8(+)CD45RA(+)CD27(+)CD11a(dim) cells), with a significant decrease in late activated CD8(+) T cells. The proportion of naive CD4(+) and CD8(+) T cells significantly predicted log(10) TREC copies/10(6) PBMCs in infected children and healthy control subjects, with a negative correlation in late activated CD8(+) T cells and activated CD4(+) T cells. Treatment re-established Gaussian distributions and decreased oligoclonal expansion within the Vbeta repertoire of CD8(+)CD45RA(+) T cells, but compared with that seen in healthy children, the proportion of late activated CD8(+) T cells remained increased.

CONCLUSION

HIV infection strikingly shifts the proportion of naive and late activated CD45RA(+)CD8(+) T cells. Homeostasis within this T-cell population reflects TREC levels and the extent of T-cell receptor Vbeta perturbations.

Immune reconstitution in human immunodeficiency virus type 1-infected children with different virological responses to anti-retroviral therapy

Immune repopulation, despite virological failure, often occurs in children under highly active anti-retroviral therapy (HAART). The aim of this study was to analyse the characteristics of immune repopulation and activation in children with and without virological response to HAART. Fourteen human immunodeficiency virus type 1 (HIV-1)-infected children with suppression of HIV-1 plasma viraemia (virological responders, VR) and 16 virological non-responders (VNR) to therapy were studied at baseline and after approximately 2 years of HAART. During therapy, CD4+ T cells increased in both groups, but were higher in the VR than in the VNR group. All CD4+ T cell subsets (naive, central memory, effector/memory and CD38+) increased significantly in VR children, while there was a significant increase only in naive cells in VNR children. Naive CD8+ T cells and T cell receptor rearrangement excision circles (TREC), an indicator of thymic output, increased in both VR and VNR children. Activated CD8+ CD38+ T cells decreased in VR but remained high in VNR children. Levels of circulating lipopolysaccharide (LPS), an indicator of microbial translocation, further increased in VNR children. In conclusion, HAART induced an increase in naive cells in all children, regardless of their virological response. However, the persistence of viraemia resulted in an impaired expansion of memory CD4+ T cells susceptible to HIV-1 infection, and together with the microbial translocation sustained the persistence of a high level of immune activation.

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) ≤400 copies/ml and CD4⁺ ≥500 cells/μL at least during 6 months before the study and CD4⁺ ≤300 cells/μL 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/μl 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).

Conclusion

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.

Virologic, immunologic, and clinical benefits from early combined antiretroviral therapy in infants with perinatal HIV-1 infection

OBJECTIVE

To investigate the impact of early versus deferred combined antiretroviral treatment (ART) in asymptomatic or moderately symptomatic [Centers for Disease Control and Prevention (CDC) category N, A or B] infants with perinatal HIV-1 infection.

METHODS

A multi-centre nationwide case-control study was conducted. Data from 30 infants treated with combined ART with three or more drugs before 6 months of age were compared with data from 103 infants starting ART with three or more drugs after 6 months of age. The median follow-up time was 4.1 years (range, 1.0-6.5 years).

RESULTS

No difference was evident in the first available viral load and CD4 T-lymphocyte percentage between the two groups of children. Early-treated infants showed significantly lower viral loads than infants receiving deferred treatment at all the follow-up periods. A higher proportion of early-treated infants than infants receiving deferred treatment (73.3% versus 30.1%; P < 0.0001) reached an undetectable viral load. Higher CD4 T-lymphocyte percentages were found in early-treated infants at 13-24 (P < 0.0001), 25-36 (P < 0.0001), and 37-48 (P = 0.003) months of age. No early-treated infant versus 20 of 103 (19.4%) infants receiving deferred ART (P = 0.02) showed a CD4 T-lymphocyte percentage of less than 15% at one time point during follow-up. No CDC category A, B or C clinical event occurred in early-treated infants over the follow-up period while 44 of 103 (42.7%) infants receiving deferred treatment presented a decline in the CDC category. Kaplan-Meier analyses revealed significant differences in CDC category A (P = 0.0002), B (P = 0.0003), and C (P = 0.0018) event-free survivals.

CONCLUSION

The data suggest virologic, immunologic, and clinical benefits from early administration of ART.

HIV-1 seronegativity in a child with proved perinatal HIV infection on HAART

OBJECTIVES

To report the unexpected absence of HIV-1 antibodies and provirus in the peripheral blood of a 4 year old with previously diagnosed perinatal HIV infection.

METHODS

Case study including review of clinic and laboratory records and confirmation of results of HIV-1 enzyme linked immunosorbent assay (ELISA), western blot, and HIV-1 DNA PCR from reference laboratory.

RESULTS

This child had high plasma viral load at the initiation of highly active antiretroviral therapy (HAART) at 10 months of age. Following undetectable HIV viraemia continuously for a 3 year period, he had normal CD4 and immunoglobulin levels. When retested at the request of the parent, HIV-1 ELISA, western blot, and HIV DNA PCR were all negative, raising the question of misdiagnosis and the parental misperception of a "cure." A rebound increase in viral load on cessation of therapy led to these diagnostic tests becoming positive again, with better parental acceptance of the diagnosis and treatment plan.

CONCLUSIONS

Patients and providers should exercise caution in interpreting negative serological tests in children on HAART.

Predictors of immunologic long-term nonprogression in HIV-infected children: implications for initiating therapy

BACKGROUND

Early markers that predict immunologic long-term nonprogression in infants with perinatally acquired HIV infection might assist in subsequent antiretroviral treatment decisions.

OBJECTIVES

We sought to identify early markers of immunologic long-term HIV disease nonprogression.

METHODS

We analyzed immunologic and virologic characteristics at 1 and 2 months of age in HIV-infected children who were enrolled in the Women and Infants Transmission Study and born before 1995, comparing immunologic long-term nonprogressors (ILTNPs; n = 10) with non-ILTNPs (n = 127). ILTNPs were children who survived to 8 years or older with CD4 percentages of 25% or greater and counts of 500 cells/mm 3 or more without receiving highly active antiretroviral therapy. Non-ILTNPs were defined as all other HIV-infected children. Receiver operating characteristic curve analysis was used to assess combined sensitivity and specificity for each of these characteristics and to determine potential threshold values to discriminate between ILTNPs and non-ILTNPs.

RESULTS

Characteristics in the first 2 months of life associated with ILTNP status in univariate analysis included higher CD4 percentages, lower CD8 + percentages, lower CD8 + HLA-DR + percentages, and lower HIV-1 RNA PCR values. In receiver operating characteristic analysis CD8 + HLA-DR + percentage had the best combined sensitivity and specificity for discriminating between ILTNPs and non-ILTNPs. CD8 + HLA-DR + percentages of 5% or less predicted ILTNP status with 80% sensitivity and 80% specificity. In multivariate analysis CD8 + HLA-DR+ percentage of 5% or less remained a significant predictor of ILTNP status after adjusting for CD3 + CD4 + percentage and HIV-1 RNA PCR value (odds ratio, 15.4; 95% CI, 1.9-124.7).

CONCLUSION

CD8 + HLA-DR + T-lymphocyte percentage of less than 5% at 1 to 2 months of age might be predictive for ILTNP status but should not be used at this time to make treatment-deferral decisions. Immune activation in HIV-infected infants might herald more disease progression. Further study of the use of this subpopulation in early infancy to predict ILTNP status is warranted.

Immunological changes after highly active antiretroviral therapy with lopinavir-ritonavir in heavily pretreated HIV-infected children

We evaluated the effect of salvage antiretroviral therapy with lopinavir/ritonavir (LPV/r) on the immune system of heavily antiretroviral pretreated HIV-infected children. We carried out a longitudinal study in 20 antiretroviral experienced HIV-infected children to determine the changes in several immunological parameters (T cell subsets, thymic function) every 3 months during 18 months of follow-up on salvage therapy with LPV/r. Statistical analyses were performed with the Wilcoxon test, taking as a reference the basal value at the entry in the study. HIV-infected children showed an increase of CD4+ T cells, a decrease in CD8+ T cells, and an increase in T cell rearrangement excision circle (TRECs) levels. The percentage of HIV children with undetectable viral load (VL < or = 400 copies/ml) increased significantly (p = 0.007) and the percentage with SI viral phenotype decreased significantly (p = 0.002) at the end of the study. Thus, the viral phenotype changed to NSI/R5 after salvage therapy with LPV/r. Interestingly, we observed a significant decrease of memory (CD4+ CD45RO+) and a moderate decrease of activated (CD4+ HLA-DR+, CD4+ HLA-DR+CD38, CD4+, CD45RO+HLA-DR+) CD4+ T cells during the follow-up. On the other hand, memory (CD8+ CD45RO+ and CD8+ CD45RO+CD38+), activated (CD8+ HLA-DR+CD38+, CD8+ HLA-DR+, CD8+ CD38+), and effector (CD8+ CD57+, CD8+ CD28(-)CD57+) CD8+ T cells had a very significant decrease during follow-up. Our data indicate an immune system reconstitution in heavily pretreated HIV-infected children in response to salvage therapy with LPV/r as a consequence of a decrease in immune system activation and an increase in thymic function.

[Changes in CD4+ and CD8+ T-cell subsets in HIV-infected children differently correlate with viral replication and thymic function]

BACKGROUND AND OBJECTIVE

We intended to study the relationship between T-cell subsets with plasmatic detectable viral load (VL) and T-receptor excision circles (TREC).

PATIENTS AND METHOD

Twenty HIV-infected children on highly active antiretroviral therapy (HAART) were recruited in a 1-year longitudinal retrospective study. We analyzed the relationship between changes in peripheral blood T-cell subsets, VL and TREC markers by lineal regression.

RESULTS

Memory and activated CD4+ T-cells increases had a negative association with log10 TRECs increases. However, naive CD4+ T-cells increases had a positive association with log10 TRECs increases. In contrast, memory, activated and effector CD8+ T-cells increases positively correlated with log10 VL increases. On the other hand, naive CD8+ T-cells increases had a negative association with log10 VL increases.

CONCLUSIONS

CD4+ and CD8+ T-cells subsets change in a different way as a response to the changes produced by HAART in HIV vertically infected children. CD4+ T-cells are more dependent on thymic function and CD8+ T-cells are more dependent on viral replication. Thus, the decline in cellular activation would allow the production of more naive T-cells by the thymus.

Impact of highly active antiretroviral therapy on CD4+ T cells and viral load of children with AIDS: a population-based study

In this study, we sought to characterize the changes over time at the population level on CD4(+) T cells and plasma viral load (VL) levels of HIV-1-infected children with or without AIDS. We carried out a retrospective study in 114 HIV-infected children during the calendar period that a highly active antiretroviral therapy (HAART) protocol was used. The HAART protocol consisted of three drugs: nucleoside analogue HIV-1 reverse transcriptase inhibitors, and/or HIV protease inhibitors, and/or nonnucleoside analogue HIV-1 reverse transcriptase inhibitors. The mean of CD4(+) T cells percentage and log(10) VL per calendar year were stratified by AIDS diagnostic. As new HAART strategies become available, an increase of CD4(+) T cells and a decrease of VL were observed over time, in children with and without AIDS. In 2001, children with AIDS reached values of CD4(+) T cells and VL similar to children without AIDS. In conclusion, our study shows that the generalized use of HAART has permitted improvement in immunological and virological status of HIV-infected children without AIDS, and more importantly in children with AIDS.

Subpoblaciones de células T CD8+ en niños asintomáticos infectados verticalmente por el VIH-1

BACKGROUND AND OBJECTIVE

HIV-infection has distinct patterns of disease progression with heterogeneous manifestations. We analyzed the subsets of CD8+ T cells in a group of long term asymptomatic (LTA) HIV-1-infected children who had stable CD4+ T cell counts (> 600/l).

PATIENTS AND METHODS

Cross-sectional study in HIV-1-vertically infected children older than 7 years who were rated into two groups according to the clinical and immunological classification: a) LTA: 7 asymptomatic HIV-1-infected children in A1, and b) rapid progressor (PR): 14 age-matched C3 HIV-1-infected children. Controls included 17 age-matched uninfected children. Characterization of CD8+ T-cell subsets was done by three-color flow cytometry.

RESULTS

LTA children displayed similar values of memory CD8+ T cells (CD8+CD45RO+, CD8+CD45RA-CD28+, CD8+ CD45RA-CD62L+) as controls but lower than PR children. LTA patients also showed similar values of naïve CD8+ T cells (CD8+CD45RA+CD62L+, CD8+CD45RA+CD28+, CD8+CD45RA+, CD8+CD28+ and CD8+CD62L+) as controls but higher values than PR children. The values of CD8+CD38+ T cells were similar in LTA and controls but lower in PR. However, LTA children had higher values of CD8+HLA-DR+CD38+ and CD8+HLA-DR+ T cells than controls. Additionally, LTA patients had higher values of pre-effector CD8+ T cells than controls yet the values of effector CD8+ T-cells were similar in both LTA and controls. Moreover, the LTA group had lower values of CD8+CD11b+ T cells than controls.

CONCLUSIONS

Asymptomatic HIV-1 infected children have an almost normal CD8+ subset distribution, with the exception of activated and pre-effector CD8+ T cells which were higher.