Association of CD8+ T lymphocyte subsets with the most commonly used markers to monitor HIV type 1 infection in children treated with highly active antiretroviral therapy.

In contrast to adults, there is no information about children concerning the effects of the new antiretroviral therapy on the chronic activation and expansion of CD8+ T cells. We have investigated the relationship between blood CD8(+) T cell subsets, with percent CD4+ cells (%CD4), percent CD8+ cells (%CD8), and plasma viral load (VL), in 39 vertically HIV-1-infected children receiving highly active antiretroviral therapy (HAART) (mean age, 7.6 years; range, 2-15.6 years). CD8+ subsets were examined by three-color multiparametric flow cytometry, and VL was quantified by standard assays. There was a strong positive correlation between activated CD8+ T cells and VL. An increase in memory and memory-activated CD8+ T cells correlated with increased VL, whereas nonactivated memory cells and CD28+ CD8+ T cells correlated negatively with VL. Naive and effector cells did not correlate with VL, although the CD8+ CD45RA -CD62L- subset correlated with increased VL. Activated CD8(+) T cells did not correlate with %CD4, but an increase in memory-activated and effector CD8+ T cells was associated with lower %CD4. Increased naive CD8+ and CD28 +CD8+ T cells showed a positive correlation with %CD4 and a negative correlation with %CD8. In conclusion, in HIV-1-infected children receiving HAART, the activation of CD8+ T cells is associated with high VL, whereas CD8 +CD28+ and nonactivated CD8+ memory cells are associated with lower viral load. Naive CD8+ and CD28 +CD8+ T cells are associated with an improved immunological status.

Adenoidal tissue mass as a clinical guide of disease evolution in vertically HIV-1 infected children.

INTRODUCTION: it is known that in early-stage HIV-induced disease there is a discrepancy between the levels of viral burden and virus replication in peripheral blood versus lymphoid organs. HIV disease is active in the lymphoid tissue throughout the period of clinical latency. However, it is not known how long term progression of HIV infection is influenced by short-term changes in the adenoidal size. OBJECTIVE: To assess the reliability of adenoidal-nasopharyngeal (AN) ratio in predicting clinical evolution of pediatric HIV infection. METHODS: lateral radiographs of the nasopharynx in 94 Caucasian children born to HIV-1-infected mothers ranged from 6 months to 15 years (60 children infected with HIV-1 and 34 without HIV infection), and in a control group of 692 normal children were evaluated to obtain the AN ratio in order to identify the relationship of AN profiles with different stages of the disease. Patients were rated regarding their clinical and immunological status according to the Center for Disease Control Classification. RESULTS: statistically significant differences between the groups of HIV-1-infected children, seroreverters and controls in the AN ratio were found (P < 0.001). Moreover, significant differences were also found in individual children that correlated with clinical progression. CONCLUSION: examination of radiographic changes in adenoidal size by AN ratio in relation to clinical status during one year period in the whole group showed strong prognostic value. These findings may have important implications in the design of therapeutic strategies.

[Prognostic markers of survival in infants younger than 12 month of age vertically infected by human immunodeficiency virus]. / Marcadores predictivos de supervivencia en niños menores de 12 meses de edad infectados verticalmente por el virus de la inmunodeficiencia humana.

OBJECTIVES: To assess the immunological and virological markers as potential predictors of progression to death in HIV-1 infected < 12 months of age. PATIENTS AND METHODS: Forty-three HIV-1 infants < 12 months of age were evaluated. None of the children received antiviral treatment, neither their mothers during pregnancy. Plasma viremia was quantified by standardised molecular assay. Virus isolation, evaluation of the non-syncytia-inducing (NSI) or syncytia-inducing (SI) phenotype and kinetic of replication was performed in parallel cultures. RESULTS: Regarding viral load cut off levels of 5 log10 copies/ml appeared to be the best predictors of progression to death. The mean times of progression to death estimated by Kaplan-Meier method were 61.08 months fir children with viral load below that limit, and 19.16 months above this limit (p < 0.013). When the first viral isolate was NSI the mean time of progression to death was of 73.9 months, whereas it was of 26.7 months when was SI (p < 0.003). When the first viral isolate was slow/low (S/L) the mean times of progression to death was 71.8 months, whereas it was of it was of 19.8 months when was rapid/high (R/H) (p < 0.0003). When the first viral isolate was S/L-NSI the mean times of progression to death was of 73.9 months, whereas it was of 19.4 months when was R/H-SI (p < 0.0004). The hazard rate of progression to death in infants with viral load > 5 log10 copies/ml was 4.7, whereas was of 8.07 in those with SI isolates and of 9.32 in those with R/H kinetics. CONCLUSIONS: Initial HIV-1 biological characteristics are better predictors of progression to death than viral load in untreated infants under 12 months of age. Nevertheless, a correlation exists between viral load over 5 log10 copies/ml and progression to death.

[Relationship between T-cells subsets and prognostic markers in HIV-1-infected children]. / Relación de las subpoblaciones de linfocitos T con los marcadores pronósticos de la infección pediátrica por el virus de la inmunodeficiencia humana.

BACKGROUND: To investigate the relationship between peripheral blood T-cell subsets and both CD4+ T-cell percentage and viral load (VL) in HIV-1-infected children. PATIENTS AND METHOD: We studied 50 HIV-1-infected children on antiretroviral therapy. T-cell subsets were determined by flow cytometry. The VL was quantified using standardized molecular methods. RESULTS: Memory (CD45RO+), activated memory (CD45RO+HLA-DR+) and CD45RA-CD62L+ (memory cells expressing L-selectin) CD4+ and CD8+ T-cells correlated positively with the VL and negatively with the percentage of CD4+ T-cells. Inversely, naive CD4+ and CD8+ T-cells (CD45RA+CD62L+) correlated positively with the percentage of CD4+ T-cells and negatively with the VL. HLA-DR+, CD38+ or HLA-DR+CD38+CD4+ and CD8+ T-cells correlated also positively with the VL and negatively with the percentage of CD4+ T-cells (with the exception of CD4+CD38+ which did not show any association with the VL). CD8+CD28+ T-cells correlated positively with the percentage of CD4+ T-cells and negatively with the VL, whereas CD8+ CD57+ and CD8+CD28-CD57+ exhibited an opposite association. CONCLUSIONS: Our data suggest a relationship between the different lymphocyte subsets (memory, naïve, activated and effector T-cells) and the most commonly used markers in clinical practice, namely the viral load and the CD4+ T-cell percentage. Some of these subsets may be useful to determine the virologic and immunologic status in HIV-1-infected children.

[Prognostic markers of progression to AIDS in infants vertically infected by human immunodeficiency virus type-1]. / Marcadores predictivos de progresión a sida en niños infectados por transmisión vertical por el virus de la inmunodeficiencia humana tipo 1.

BACKGROUND: To study the prognostic AIDS progression value of the percentage of CD4+, CD8+, and plasma viral load (VL) (copies/ml) in HIV-1-vertically infected children. PATIENTS AND METHOD: We study a cohort of 115 HIV-1 infected children older than 12 months of age. The VL was quantified using standard molecular assay. CD4 and CD8 T lymphocytes were determined by flow cytometry. RESULTS: The children with a median of VL > 4.5 log10 (p < 0.001) and percentage of CD8+ < 25% (p = 0.05) during follow-up, progressed faster to AIDS than children with a median of VL < 4.5 log10 and CD8 > 25%. The relative risk (RR) of AIDS progression was 7-fold higher in children with median VL above 4.5 log10. When considering VL as a continuous variable, risk of progression to AIDS is 3.5-fold higher for each increase of one log10 of VL. The percentage of CD8+ T-cells had a RR of AIDS progression of 0.95/% CD8+ at entry to the study and of 0. 19/% CD8+ during follow-up, indicating protection against progression to AIDS. CONCLUSIONS: Our results indicate that each basal values at entry in the study and during the follow-up of the percentage of CD8+ and VL helps to determine the risk of AIDS progression in HIV-1-infected children. More interestingly, the use of the two predictive markers together had higher predictive value.

[Expression of different HIV-1 phenotypic subpopulations through the natural history of the infection]. / Expresión de diferentes subpoblaciones fenotípicas del virus de la inmunodeficiencia humana tipo 1 a lo largo de la historia natural de la infección.

BACKGROUND: Multiple viral subpopulations coexist in an HIV infected patient with dynamics of selection established between them. In order to get insight on the phenotype of these subpoblations, and its relation with disease progression, we have studied the biological variability of HIV-1 in 113 patients. Variability was related with CD4+ T lymphocyte counts, clinical status, way of viral transmission and antiretroviral treatment. PATIENTS AND METHODS: 113 patients (80 adults and 33 children) were studied for HIV-1 isolation in cocultures of infected and non infected lymphocytes. Viral replication was evaluated as rapid (R)/slow (S) or high (H)/low (L). Syncytia formation was estimated in MT2 cell line (SI/NSI). The tropism toward lymphocytes and monocytes (LM) was studied on H9 and U937 cell lines. RESULTS: Up to 86.7% of viral isolates were R, 56.6% were H and 49.6% were SI. These percentages increased with disease progression. Eight viral strains were R/H/NSI cocultivated in MT2 cells and SI in cocultured lymphocytes (NSI/SI), which may be considered as a new phenotype. All the SI isolates and all the R/H (SI and NSI) isolates were LM. Three categories were established: R/H/SI/LM, R/H/NSI/LM and S/L/NSI/NLM. The first two categories corresponded to patients with CD4+ T lymphocytes <200 x 10(6)/I (56%, 50%). The third category corresponded to patients with > 500 x 10(6)/I (53.3%). CONCLUSIONS: Viral replication and SI phenotype, independently, are useful markers for severity of HIV infection. The biological differences among NSI of the 3 viral phenotype categories, including the new subgroup NSI/SI, may indicate the existence of more pathogenic NSI subpopulations.

Autoimmune phenomena in children with human immunodeficiency virus infection and acquired immunodeficiency syndrome.

We have studied sera from 44 children with Human Immunodeficiency Virus infection and Acquired Immunodeficiency Syndrome using immunoblotting, radioimmunoassay, enzymoimmunoassay and indirect immunofluorescence. We have detected a low incidence of antinuclear (2.9%), anti-reticulin (2.9%) and anti-smooth muscle (14.7%) antibodies by indirect immunofluorescence. By enzymoimmunoassay we have detected anti-dsDNA (20.5%) and anti-ENA [anti-nRNP (61.3%), anti-Sm (29.5%), anti-Ro (47.7%) and anti-La (18.1%)] antibodies. Tests for anti-dsDNA by radioimmunoassay were negative, suggesting the presence of low-avidity anti-DNA antibodies. By immunoblotting we have detected anti-C (nRNP) (33.3%), anti-BB' (Sm) (33.3%), anti-Ro (60 KD) (4.5%) and anti-La (11.3%) antibodies. The presence of anti-Ro antibodies was associated with progressive neurological disease. Long-term follow-up studies with larger numbers of patients are necessary to evaluate the clinical significance of the presence of anti-dsDNA and anti-ENA antibodies in children infected with Human Immunodeficiency Virus.

Role of antiretroviral therapies in mucocutaneous manifestations in HIV-infected children over a period of two decades.

BACKGROUND: Human immunodeficiency virus (HIV) infection causes a severe cellular immunodeficiency, which results in a greater susceptibility to infectious, inflammatory and malignant conditions. Among these, pathologies of the skin seem to be those most frequently observed in HIV+ patients. However, there are few reports on how antiretroviral therapy affects skin disorders in HIV-infected children. OBJECTIVE: To study the incidence and prevalence of skin disorders in a cohort of HIV-infected children, in relation to the antiviral therapy [nontreated, monotherapy, combined therapy and highly active antiretroviral therapy (HAART)] received, and their impact on immunological and virological markers. The treatments were those available in different calendar periods in the history of antiviral treatment. MATERIALS AND METHODS: A retrospective, observational study in a cohort of 210 HIV-infected children was carried out. These children were followed up every 3 months throughout 22 years. The viral load (HIV RNA copies mL(-1)) was quantified using reverse transcriptase-polymerase chain reaction and the viral phenotype of HIV-1 isolates was determined by in vitro culture. T-lymphocyte subsets in peripheral blood were quantified by flow cytometry. RESULTS: Mucocutaneous manifestations were diagnosed in 17% of the untreated infected children. Of the treated children in different treatment periods, 22% in the monotherapy period, 25% in the combined therapy period but only 10% on HAART had some type of mucocutaneous manifestation, concordant with a higher number of CD4+ T cells, a lower viral load and less cytopathic virus in the last group. Mucocutaneous manifestations of infectious aetiology were most frequently observed; they were detected in 13% of the children during the first calendar period (untreated children), 16% during the second and third periods (monotherapy and combined therapy) and only 5% in the last period (HAART). Interestingly, syncytium-inducing virus was present in 69% of all children with mucocutaneous manifestations of infectious aetiology. CONCLUSION: Only in the last calendar period (HAART) was a significant decrease observed in the prevalence of mucocutaneous manifestations with HIV infection associated with an increase in CD4+ T cells. In addition, we found a strong association between children who had mucocutaneous manifestations with an infectious aetiology and a more cytopathic (X4/SI) viral phenotype.

[Directory of diagnostic tests in primary immunodeficiencies]. / Directorio de pruebas diagnósticas de las inmunodeficiencias primarias.

The clinical and immunological characteristics that suggest diverse forms of primary immunodeficiency are discussed. Data on the hospitals that perform immunological, molecular and genetic tests for the diagnosis of most of the primary immunodeficiencies in Spain are presented.

[Clinical manifestations and biological markers in the natural history of HIV-1 infection in vertically infected children. Longitudinal study]. / Manifestaciones clínicas y marcadores biológicos en la historia natural de la infección por el VIH-1 en niños infectados verticalmente. Estudio longitudinal.

OBJECTIVE: To study the relationship among clinical symptoms and biological markers as predictive value of progression to death in HIV-1 vertically infected infants. PATIENT AND METHODS: We carry out a prospective study in 43 HIV-1 infants with a mean age of 4.27 (range: 0-11.8 months). None of the infants' mothers had received any antiviral treatment during pregnancy. None of the infants were breastfed. They were routinely assessed for clinical symptoms during follow-up. RESULTS: Cox regression analysis was used to study the hazard ratio (HR) of progression to death. For the median viral load > 5 log10, the HR was 6.42 (95% CI, 1.28-32.03) (p = 0.023) and 6.84 (95% CI, 1.52-30,69) (p = 0.012) for biological phenotype of viral isolates with rapid replication and high titter (R/H-X4). We also study the predictive value of the clinical symptoms and we observe that the symptoms with more HR of progression to death were the progressive encephalopathy (3.60 [95% CI, 0.92-14.06; p = 0.065]) and the cardiopathy (6.29 [95% CI, 1.59-24.85; p = 0.008]). CONCLUSIONS: Our data indicate that viral load > 5 log10 and biological phenotype R/H-X4 of virus isolates along the study are predictive markers of progression to death. In addition, the progressive encephalopathy and cardiopathy were also markers of progression death.

[Correlation between high plasma viral load and levels of TNF-alpha and cICAM-1 in HIV-1 infected children]. / Correlación entre carga viral elevada y concentraciones de TNF-alpha y cICAM-1 en el plasma de niños infectados por el VIH-1.

AIM: To assess the relationship among plasma TNF-a and cICAM-1 levels and plasma viral load (VL) in HIV-infected children and to compare these values with those of healthy non-HIV infected children. PATIENTS AND METHODS: We studied 44 HIV-infected children and 38 non-HIV-infected children. The VL was quantified using standard molecular assay. CD4 and CD8 lymphocyte subpopulations were determined by flow cytometry. TNF-a and cICAM-1 were quantified using commercially available specific enzyme-linked immunosorbent assay (ELISA). RESULTS: Levels of TNF-a and cICAM-1 were higher in HIV-infected children than in non-HIV infected children. HIV-infected children with VL > 50000 copies/ml had higher levels of TNF-a (12.83; 95% CI: 24.71 to 0.95 pg/ml) and cICAM-1 (248.94; 95% CI: 419.01 to 78.84 ng/ml) than HIV-infected children with VL < 50000 copies/ml. Interestingly, we found an increase of 6.57 pg/ml of TNF-a and 119.97 ng/ml of cICAM-1 levels for each log10 of VL. CONCLUSIONS: HIV-infected children had higher levels of TNF-a and cICAM-1 than healthy controls. Our data indicate a positive correlation among plasma TNF-a and cICAM-1 and VL levels.

Clinical relevance of cytokine production in HIV-1 infection in children on antiretroviral therapy.

In order to investigate the correlation among cytokine production and antiretroviral therapy (ART), viral load, CD4(+) and CD8(+) T lymphocytes, 55 human immunodeficiency virus (HIV)-1-infected children on ART or not, and 16 uninfected controls were studied. Peripheral blood mononuclear cells (PBMCs) of HIV-1-infected children and controls were cultured and spontaneous and mitogen-stimulated cytokines production was quantified in the supernatants. Viral load was quantified using standard molecular assay. CD4 and CD8 T-lymphocyte counts were determined by flow cytometry. Cytokine production by mitogen-stimulated PBMCs showed different profiles in HIV-1 children whether treated or not. The tumour necrosis factor (TNF)-alpha production was higher and the interleukin (IL)-10 production was lower in the HIV-1-untreated group than in the HIV-1-treated children and controls. The IL-2 production was reduced and the RANTES production was higher in both HIV-1 groups compared with the controls. The interferon (IFN)-gamma and the IL-5 production was significantly reduced in the HIV-1-treated children compared to the controls. Interestingly, the analysis of the correlation of HIV-1 phenotype with cytokine production indicated an increased RANTES production in relation to nonsyncytium-inducing viral phenotype with slow/low replication profile, whereas decreased IL-10 levels was associated to syncytium-inducing (SI) strains and rapid/high replication. Our findings suggest that AVT changes on the cytokine and chemokine production play an important role in the HIV pathogenesis.

Disruption in cytokine and chemokine production by T-cells in vertically HIV-1-infected children.

UNLABELLED: This study measured cytokine production by mitogen-stimulated peripheral blood mononuclear cells (PBMCs) from 55 human immunodeficiency virus (HIV)-infected children born to HIV-infected mothers, and compared it with vertically exposed but uninfected age-matched children. A significant defect was observed in Th1 cytokine production [interferon-gamma and interleukin-2 (IL-2)] in HIV-infected children compared with controls, but without a concomitant increase in Th2 cytokines. Indeed, IL-5 and IL-10 production was even lower in HIV-infected children than in controls, with the decrease in IL-5 being the best predictive marker of immunodeficiency. In addition, an increased release of tumour necrosis factor-alpha (TNF-alpha) that correlated well with CD4+ levels, and a positive correlation of the TNF-alpha/IL-10 ratio with disease progression was observed. A correlation between AIDS-free status and higher %CD4+ and %CD8+ T-lymphocytes and RANTES (regulated on activation, normal T-cell expressed and secreted) production was also found. CONCLUSION: A dysfunctional cytokine production of PBMCs was observed in HIV-infected children in both Th1 and Th2 cytokines due to quantitative and qualitative defects induced by HIV-1. An important observation was an increased RANTES production associated with viral isolates of NSI/R5 phenotype and S/L kinetics.

Predictive markers of clinical outcome in vertically HIV-1-infected infants. A prospective longitudinal study.

We have investigated the relationship between disease progression and several immunologic and virologic markers of HIV infection. Plasma samples from infants born to HIV-1-infected mothers were collected at birth and at 1, 2, 4, 6, 9, 12, 15, and 18 mo of age and subsequently were assayed every 6 mo for viral load, viral phenotype, and lymphocyte populations. A cutoff level of 25% indicative of a preserved immunologic status, both of CD4+ and CD8+ blood T cells, was associated with significant differences in disease progression (p = 0.04 and 0.02, respectively). Infants with median CD4+ T cells <25% had a relative risk of progression to AIDS 3.35-fold higher than those with CD4+ above this level (p = 0.05). The relative risk of progression to AIDS for infants with median CD8+ <25% was 4.95-fold higher than for those with CD8+ percent above this threshold (p = 0.03). Similarly, a cutoff level of viral load of 5.5 log10 copies/mL was indicative of a worse prognosis. Infants with median viral load >5.5 log10 copies/mL had a relative risk of progression to AIDS 23.72-fold higher (p = 0.0001) than those with median viral load below this threshold. Interestingly, changes from a slow replication and low titer to a rapid replication and high titer of virus and from nonsyncytium-inducing to syncytium-inducing viral phenotype were indicative of progression to AIDS. Our results indicate that biologic phenotype of viral isolates and CD8+ T-lymphocyte percentages in peripheral blood as well as viral load and CD4+ T-lymphocyte percentages could predict rapid progression to advanced HIV-1 disease in HIV-1-infected infants.

Recovery of T-cell subsets after antiretroviral therapy in HIV-infected children.

BACKGROUND: Variation of percentageCD4+ T cells may accurately reflects the kinetics of a comprehensive immune recovery independently of the antiretroviral (ART) regimen. To test this we have investigated the relationship among peripheral blood T-cell subsets with the variation of percentageCD4+ T cells during follow up in 49 HIV-infected children. METHODS: Children were divided into two groups according to the sign of slope percentageCD4+ T cell during follow up: Ps-group (positive slope) and Ns-group (negative percentageCD4 slope) indicative of immunological recovery or not, respectively. CD4+ and CD8+ T-cell subset percentages were examined by three-colour flow cytometry. RESULTS: We found higher memory CD4+ and CD8+ T-cell percentages in the Ns-group than in the Ps-group, and inversely, higher naive CD4+ and CD8+ T cells in the Ps-group than in the Ns-group. CD4+ and CD8+ subsets in the Ps-group expressed higher levels of CD38+ and lower levels of HLA-DR+ compared with the Ns-group. We found a very strong positive correlation among the slope of percentageCD4+, CD4+ CD38+, whereas a negative correlation among the slope of percentageCD4+, the CD8+ CD28+ CD57+ and CD8+ CD57+ T-cell subsets. CONCLUSION: Recovery of the CD4+ T-cell percentage induced by ART reflects a reduction in the chronic immune activation and a measurable reconstitution of the immune system and depends on naive CD4+ T cells.

IgG antibodies: in vitro blocking activity of IgE mediated reactions.

Sera from 177 atopic patients treated by immunotherapy were screened in order to detect IgD antibodies against a purified fraction of Lollium perenne (fractions C). IgD antibodies were found in 23% of the subjects. Eight of these sera were selected and their IgD isolated by means of immunoabsorption. The in vitro biological activity of the IgD antibodies against fraction C was tested by three methods: basophil degranulation, histamine release and RAST inhibition test. In all these assays, the data obtained indicated a possible blocking effect of the IgD antibodies upon the IgE in vitro mediated reactions.

Correlation of viral load and CD8 T-lymphocytes with development of neurological manifestations in vertically HIV-1-infected infants. A prospective longitudinal study.

To assess the predictive power of immunological and virological markers for the development of neurological syndromes, 39 HIV-1-infected infants with a mean age of 4.05+/-0.5 months and without neurological manifestations at enrolment were studied. They had neither been previously treated with antiretroviral therapy, nor had their mothers been given such treatment during pregnancy. They were routinely assessed for signs of neurological impairment during follow-up (19.54+/-3.37 months). Cox regression analysis was used to evaluate the risk of appearance of neurological signs, associated to viral load and T-lymphocyte subsets. A HR > 1 for viral load, and <1 for CD8+, but not for CD4+T-lymphocyte percentage, was observed, indicating that higher viral load and lower CD8+ T-lymphocytes percentages are risk factors for developing neurological signs. By applying the Kaplan-Meier method we found that infants with viral load > 5 1og10 copies/ ml or <20% CD8+T lymphocyte had higher relative risk for developing neurological impairment than those with these two parameters below or above these values, respectively. Finally, CD8+ T lymphocyte had a stronger prognostic value to predict neurological manifestations than viral load. Our data strongly suggest that in the early postnatal period viral load and CD8+ percentages are useful markers in predicting neurological impairment. To our knowledge, this is the first time that CD8+ T-lymphocyte levels are related to development of neurological disorders in AIDS.

Dynamics of progression markers in a non-study population of human immunodeficiency virus-1 vertically infected infants with different antiretroviral treatments.

UNLABELLED: Treatment with highly active antiretroviral therapy (HAART) has been shown to modify viral replication dynamics and lead to a significant recovery of CD4+ T-cells. A retrospective multicentre observational study was performed in a non-study population of 151 HIV-1-infected children, categorized into four groups according to therapy: untreated (NT), on monotherapy (MT) with a nucleoside inhibitor, on combination therapy (CT) with two nucleoside inhibitors, and on HAART, protease inhibitor containing regimens, to assess the "real-life" effectiveness of these different therapies on plasma viral load (VL) and CD4+ T-cells. VL was quantified using a standard molecular assay. CD4+ and CD8+ T-cells subsets were determined by flow cytometry. The HAART group showed the highest relative proportion (RP) of increases in 5, 10, 15 and 20% of CD4+ T-cells over baseline, and the earliest fall-off of VL (0.5, 1, 1.5 and 2 log10 copies ml-1). The RP of the fall-off of 0.5, 1, 1.5 and 2 log10 VL below baseline was 3-fold higher in HAART group than in the MT and CT groups. However, no differences were found among the groups of treated children in reaching undetectable VL. CONCLUSION: A better evolution of VL and CD4+ T-cells was evident in children on HAART, indicating a positive effect on the immune system and clinical status, inhibiting HIV-1 replication and enabling the recovery of CD4+ T-cell counts.