[T-cell subsets variation during clinical and immunological progression in vertically HIV-infected children]. / Variacion de las subpoblaciones de células T según la progresión clínica e inmunológica en niños infectados verticalmente por HIV-1.

We have investigated the relationship among peripheral blood T-cell subsets with immunological and clinical categories, and viral load (VL) in 65 HIV-1-infected children on stable antiretroviral therapy (ART): 26 (40%) children on combination therapy with 2 nucleoside inhibitors, and 39 (60%) children on highly active antiretroviral therapy (HAART). T-cell subsets were determined by flow cytometry. VL was quantified using a standardized molecular method. Naïve CD4+ T-cells (CD45RA+CD62L+) were lower in children with low %CD4+ T-cells, but neither in children with advanced stage of illness nor with high VL. By contrast, naïve CD8+ T-cells were lower in children with low %CD4+ T-cells, advanced stage of illness and high VL. Memory (CD45RO+) and activated (CD38+, HLA-DR+ and CD38+HLA-DR+) CD4+ and CD8+ T-cells were higher in children with low %CD4+ T-cells, advanced stage of illness and high VL. However, CD4+CD38+ T-cells were higher in HIV-children with CD4+ > 25% than in the control group (p < 0.001) and were diminished in children with low %CD4+ T-cells. Naïve and memory CD4+ and CD8+ T-cells are more tightly dependent on the immunological category than on clinical category or plasma VL. Furthermore, our data indicate an association between low %CD4+ T-cells, high VL and high expression of cellular activation markers, although not with advanced clinical stage, possibly due to ART.

Variacion de las subpoblaciones de células T según la progresión clínica e inmunológica en niños infectados verticalmente por HIV-1. / [T-cell subsets variation during clinical and immunological progression in vertically HIV-infected children]

We have investigated the relationship among peripheral blood T-cell subsets with immunological and clinical categories, and viral load (VL) in 65 HIV-1-infected children on stable antiretroviral therapy (ART): 26 (40

) children on combination therapy with 2 nucleoside inhibitors, and 39 (60

) children on highly active antiretroviral therapy (HAART). T-cell subsets were determined by flow cytometry. VL was quantified using a standardized molecular method. Na´ve CD4+ T-cells (CD45RA+CD62L+) were lower in children with low

CD4+ T-cells, but neither in children with advanced stage of illness nor with high VL. By contrast, na´ve CD8+ T-cells were lower in children with low

CD4+ T-cells, advanced stage of illness and high VL. Memory (CD45RO+) and activated (CD38+, HLA-DR+ and CD38+HLA-DR+) CD4+ and CD8+ T-cells were higher in children with low

CD4+ T-cells, advanced stage of illness and high VL. However, CD4+CD38+ T-cells were higher in HIV-children with CD4+ > 25

than in the control group (p < 0.001) and were diminished in children with low

CD4+ T-cells. Na´ve and memory CD4+ and CD8+ T-cells are more tightly dependent on the immunological category than on clinical category or plasma VL. Furthermore, our data indicate an association between low

CD4+ T-cells, high VL and high expression of cellular activation markers, although not with advanced clinical stage, possibly due to ART.

[Primary infection in vertically infected HIV-1 infants: biological characteristics of isolated virus, viral load and CD4 t-lymphocytes]. / Infección primaria en niños VIH-1 infectados verticalmente: características biológicas de los aislados virales, carga viral y linfocitos T CD4+.

OBJECTIVE: Our aim was to study the relationship between virological and/or immunological markers during the first month of life in vertically HIV-1 infected infants without prior antiviral treatment. PATIENTS AND METHODS: Thirty HIV-1 infected infants that had not received prior antiviral therapy, nor had their mother during pregnancy, were studied. Viral load was quantified using standard molecular assays. Viral isolation and phenotype were carried out by using viral co-cultures. Subpopulations of lymphocytes were determined by flow cytometry. RESULTS: We have found an inverse correlation between log10 CD4+ cells/mm3, as well as CD4+ percentage with log10 viral load, with a slope of -0.266 (CI95%: -0.459 to -0.074) and -6.648 (CI95%: -12.815 to -0.471), respectively. When the influence of viral phenotype on the log10 viral load or the percent of CD4+ T cells standardized according to age (Z-score) with the log10 of the viral load was determined, it was found that infants having syncytium inducing (SI) virus had 12.355% (CI95%: 2.336 to 22.373) less CD4+ cells and 4.530 standard deviations (IC95%: 0.448 to 8.613) than infants with non syncytium inducing (NSI) isolates. CONCLUSIONS: Our results suggest that a particular biological phenotype of viral isolates (SI and those with rapid/high replication) and high plasma viral loads have a statistically significant tendency to be associated. Viral load is the marker that shows the best inverse correlation with the level of CD4+ cells normalized according to the infant's age. This correlation shows a different value in infants with SI and NSI isolates.

[Viral load quantification for the early diagnosis of perinatal human immunodeficiency virus 1 (HIV-1) infection]. / Determinación de la carga viral para el diagnóstico precoz de la infección perinatal por el virus de la inmunodeficiencia humana tipo 1 (VIH-1).

OBJECTIVE: The aim of this study was to compare the sensitivity and specificity of polymerase chain reaction (DNA-PCR) and virus cultures with HIV-RNA assays (viral load) in the early diagnosis of vertically transmitted HIV-1 infection. PATIENTS AND METHODS: One hundred and six infants born to HIV-1 seropositive mothers were divided into three groups: A) Nineteen newborns (24-26 hours of age): B) Twenty-three infants between 1 and 2 months of age; and C) Sixty-four infants older than 2 months. HIV-1 RNA was measured in plasma and HIV proviral DNA was determined in peripheral blood mononuclear cells after amplification by DNA-PCR. The HIV was isolated by a microculture technique. RESULTS: In the samples obtained during the neonatal period (less than 96 hours of age), 75% of the infants were positive by viral load analysis, 50% by proviral DNA-PCR and only 25% by culture assay. In group B, 100% of the infants were positive by viral load analysis and 85.7% by proviral DNA-PCR and culture assays. Viral load, proviral DNA-PCR and cultures were positive in all infants older than 2 months of age. CONCLUSIONS: Our results indicate that the 3 techniques, viral load, DNA-PCR and culture, have 100% sensitivity after 2 months of age. However, the viral load technique, which is not routinely used, was found to have a higher sensitivity than proviral DNA-PCR and viral culture in infants younger than 2 months. We conclude that viral load is a useful technique to diagnose HIV infection in newborns.

[Early diagnosis of HIV infection in children born to seropositive mothers]. / Diagnóstico temprano de infección por VIH en niños nacidos de madres seropositivas.

We have studied 70 children, born to HIV seropositive mothers, since the first trimester of life and every three months thereafter. The virological markers we used in the diagnosis included: 1) p24 antigen detection. 2) Autochthonous production of antibodies detected by Western Blot technique. 3) HIV isolation. 4) Specific determination of IgM antibodies. In infected children under 15 months of age, p24 antigen was positive in 78%, HIV was isolated in 75% and autochthonous production of antibodies occurred in 50%. IgM specific antibodies were detected in 92%, but these were also detected in the 33% of the children who seroreverted. In seroreverted children, the other three virological markers were negative. The problems due to the low sensitivity in p24 antigen detection, HIV isolation and the detection of autochthonous production of antibodies, as well as the low specificity of the IgM detection, means that it is necessary to simultaneously use several techniques in the diagnosis of these children.

[HIV infection in infants under 15 months of age. Value of the p-24 antigen as a prognostic marker]. / Infección por el virus de la inmunodeficiencia humana en niños menores de 15 meses. Valoración del antígeno p-24 como marcador pronóstico.

We have studied 65 children, born to HIV seropositive mothers, during the first quarter of life and afterwards every three-months. During this time, ten of the children (13%) became infected with the virus. The study of p24 antigen during the first 15 months of life showed an inverse relationship between the permanent presence of P24 antigen in the serum and the absence of anti-p24 antibodies. Since both markers were related to a bad prognosis, it is useful to carry-out the routine study of p24 antigen and its level in serum. Of the infections detected, 3 cases were early onset and the other 7 cases later onset. The three children from the first group died between 4 and 8 months of life, while the second group had a much more stable clinical situation. The children with early onset infections had T4 lymphocytes lower than 500 cell/mm3, detectable p24 antigen, and a fatal progression of the disease.

[Evaluation of the western blot test in the follow up of children born to HIV seropositive mothers]. / Valoración del western blot en el seguimiento de niños nacidos de madres seropositivas al Virus de la Inmunodeficiencia Humana.

We have made a follow-up study of 65 children born to HIV seropositive mothers. These children were studied during the first quarter of life and subsequently every three months thereafter to measure the usefulness of the Western Blot technique in the detection of the gradual development of seroreversion, as well as in HIV infection. The study of 25 mother-child pairs allowed us to anticipate seroreversion up to three months, showing an earlier and quicker finding than by indirect immunofluorescence. In the HIV diagnosis during the first 15 months of life, the sequential study of serum by Western Blot is able to detect the reappearance of new bands, indicating the endogenous production of antibodies in the child. The circunstance is observed in 7 out of 10 infected children, showing the reappearance of bands corresponding to antibodies against p-31 and/or p-55 proteins between the second and fourth quarter of life.