Neonatal screening of ABO/RhD blood group and direct antiglobulin Coombs test. Experience of a single institution.

BACKGROUND: Evaluating the ABO/RhD blood group and the direct antiglobulin Coombs test (DAT) at birth is recommended good practice, but there is variability in its universal implementation. This study aims to show the comparative results in various variables of clinical impact during the hospital stay of neonates with positive DAT compared with those with negative DAT, based on the systematic detection of the ABO/RhD group and DAT at birth. METHODS: Newborns between 2017 and 2020 in a high-risk pregnancy care hospital were included. The ABO/RhD and DAT group was determined in umbilical cord samples or the first 24 hours of life. Demographic, maternal, and neonatal variables were recorded. The association between the variables was estimated using the odds ratio (OR). RESULTS: 8721 pairs were included. The DAT was positive in 239 newborns (2.7%), with the variables associated with positive PDC being maternal age > 40 years (OR: 1.5; 95% CI: 1.0 to 2.3), birth by cesarean section (1.4; 1.1-2.0), mother group O (6.4; 3.8-11.8), prematurity (3.6; 2.6-5.0), birth weight < 2500 g (2.1; 1.6-2.8), newborn group A (15.7; 10.7-23.1) and group B (17.6; 11.4-27.2), hemoglobin at birth < 13.5 g/dl (4.5; 2.8-7.1) and reticulocytosis > 9% (1.9; 1.2 to 3.1). DISCUSSION: The frequency of neonatal positive PDC was 2.7%, with a significant association with maternal/neonatal incompatibility to the ABO and RhD group, with a substantial impact on various neonatal variables. These results support the policy of universal implementation at the birth of the ABO/RhD and DAT determination.

INTRODUCCIÓN: La determinación del grupo sanguíneo ABO/RhD y la prueba directa de Coombs (PDC) al nacimiento son una práctica recomendada, pero existe variabilidad en su implementación universal. Se presentan los resultados de la determinación al nacimiento del grupo ABO/RhD y la PDC en una cohorte institucional. MÉTODOS: Se incluyeron los recién nacidos entre 2017 y 2020 en un hospital de atención a embarazos de alto riesgo. Se determinó el grupo ABO/RhD y se realizó la PDC en muestras de cordón umbilical o en las primeras 24 horas de vida. Se registraron las variables demográficas, maternas y neonatales. Se estimó la asociación entre las variables mediante la razón de probabilidad (OR). RESULTADOS: Se incluyeron 8721 binomios. La PDC fue positiva en 239 recién nacidos (2.7%), siendo las variables asociadas a la PDC positiva la edad materna > 40 años (OR: 1.5;IC95%: 1.0-2.3), el nacimiento por vía cesárea (1.4; 1.1-2.0), la madre del grupo O (6.4; 3.8-11.8), la prematuridad (3.6; 2.6-5.0); el peso al nacer < 2500 g (2.1; 1.6-2.8); el neonato del grupo A (15.7; 10.7-23.1) o del grupo B (17.6; 11.4-27.2), la hemoglobina al nacer < 13.5 g/dl (4.5; 2.8-7.1) y la reticulocitosis > 9% (1.9; 1.2 a 3.1). DISCUSIÓN: La frecuencia de PDC positiva neonatal es del 2.7%, con asociación significativa la incompatibilidad materna/neonatal al grupo ABO y RhD, con impacto significativo en diversas variables neonatales. Estos resultados apoyan la política de implementación universal al nacimiento de la determinación de ABO/RhD y PDC.

Disturbances in the IgG Antibody Profile in HIV-Exposed Uninfected Infants Associated with Maternal Factors.

Over the last 20 years, the incidence of vertical HIV transmission has decreased from 25%-42% to less than 1%. Although there are no signs of infection, the health of HIV-exposed uninfected (HEU) infants is notoriously affected during the first months of life, with opportunistic infections being the most common disease. Some studies have reported effects on the vertical transfer of antibodies, but little is known about the subclass distribution of these antibodies. We proposed to evaluate the total IgG concentration and its subclasses in HIV+ mothers and HEU pairs and to determine which maternal factors condition their levels. In this study, plasma from 69 HEU newborns, their mothers, and 71 control pairs was quantified via immunoassays for each IgG isotype. Furthermore, we followed the antibody profile of HEUs throughout the first year of life. We showed that mothers present an antibody profile characterized by high concentrations of IgG1 and IgG3 but reduced IgG2, and HEU infants are born with an IgG subclass profile similar to that of their maternal pair. Interestingly, this passively transferred profile could remain influenced even during their own antibody production in HEU infants, depending on maternal conditions such as CD4+ T-cell counts and maternal antiretroviral treatment. Our findings indicate that HEU infants exhibit an altered IgG subclass profile influenced by maternal factors, potentially contributing to their increased susceptibility to infections.

Impaired T helper cell responses in human immunodeficiency virus-exposed uninfected newborns.

INTRODUCTION: HIV-exposed uninfected (HEU) newborns suffer from higher risks of opportunistic infections during the first months of life compared to HIV-unexposed uninfected (HUU) newborns. Alterations in thymic mass, amounts of T helper (Th) cells, T-cell receptor diversity, and activation markers have been found in HEU newborns, suggesting alterations in T cell ontogeny and differentiation. However, little is known about the ability of these cells to produce specialized Th responses from CD4+ T cells. METHOD: To characterize the Th cell profile, we evaluated the frequency of Th1 (CD183+ CD194- CD196- /CXCR3+ CCR4- CCR6- ), Th2 (CD183- CD194+ CD196- /CXCR3- CCR4+ CCR6- ), Th17 (CD183- CD194+ CD196+ /CXCR3- CCR4+ CCR6+ ), and CD4+ CD25++ blood T-cell phenotypes in 50 HEU and 25 HUU newborns. Early activation markers on CD4+ T cells and the Th cytokine profile produced from mononuclear cells under polyclonal T cell stimulation were also studied. Additionally, we probed the ability of CD4+ T cells to differentiate into interferon (IFN)-γ-producing Th1 CD4+ T cells in vitro. RESULTS: Lower percentages of differentiated Th1 , Th2 , Th17, and CD4+ CD25++ T cells were found in blood from HEU newborns than in blood from HUU newborns. However, polyclonally stimulated Th cells showed a similar ability to express CD69 and CD279 but produced less secreted interleukin (IL)-2 and IL-4. Interestingly, under Th1 differentiation conditions, the percentages of CD4+ IFN-γ+ T cells and soluble IFN-γ were higher in HEU newborns than in HUU newborns. CONCLUSION: HEU neonates are born with reduced proportions of differentiated Th1 /Th2 /Th17 and CD4+ CD25++ T cells, but the intrinsic abilities of CD4+ T cells to acquire a Th1 profile are not affected by the adverse maternal milieu during development.

Análisis de la frecuencia y factores de riesgo asociados a la retinopatía del prematuro en neonatos de muy bajo peso al nacer / Retinopathy of prematurity, frequency and risk factors in very low birth weight infants

Resumen Introducción: La retinopatía del prematuro (ROP) es una de las principales causas de ceguera infantil. La inmadurez y la exposición a oxígeno son algunos factores de riesgo. El objetivo de este artículo fue analizar la frecuencia y los factores de riesgo de ROP en una cohorte de recién nacidos menores de 1,500 g. Métodos: Se llevó a cabo un estudio de casos (con ROP) y controles (sin ROP) de recién nacidos menores de 1,500 g. Se analizaron variables prenatales y neonatales, y para su comparación se utilizaron las pruebas estadísticas t de Student, χ2 y U de Mann-Whitney. Resultados: Se analizaron 282 recién nacidos: 152 (53.9%) con ROP y 130 (46.1%) sin ROP. La mayor frecuencia se encontró en los estadios 1 y 2, con 139 pacientes (91.4%), seguidos de los estadios 3 a 5, con 13 pacientes (8.5%). En los pacientes con ROP, el peso al nacer fue menor (902.7 vs. 1037.9 g; p < 0.0001), así como la edad gestacional (28.2 vs. 29.6 semanas de gestación; p < 0.0001). Los días de ventilación (32.8 vs. 16.1; p < 0.00001) y los días de oxígeno requerido durante la estancia hospitalaria (87.7 vs. 62.6; p < 0.0001) fueron mayores en los pacientes con ROP. La displasia broncopulmonar, la hemorragia intraventricular y la sepsis tardía fueron comorbilidades significativas para el desarrollo de ROP. Conclusiones: En este estudio, la frecuencia de ROP fue mayor que la reportada en la población mexicana, con una baja proporción de formas graves. La vigilancia estrecha del manejo de los neonatos con menor peso y menos edad gestacional es fundamental para lograr disminuir esta enfermedad.

Abstract Background: Retinopathy of prematurity (ROP) is the principal cause of blindness during childhood. The objective of this study was to analyze the frequency of ROP and risk factors associated with ROP in a cohort of very low birth weight infants. Methods: A cases (ROP) and controls (no ROP) study of infants less than 1500 g was conducted. Perinatal and neonatal variables were analyzed. For the statistical analysis, χ2 test, Student’s t-test and Mann-Whitney’s U-test were used. Results: For the study, 282 neonates were included: 152 (53.9%) with ROP and 130 (46.1%) without ROP. The most frequent stages observed were stage 1 and 2, with 139 (91.4%) patients, and stages 3 to 5, with only 13 patients (8.5%). In those neonates with ROP compared with neonates without ROP, the birth weight was less (902.7 vs. 1037.9 g) and the difference was significant (p < 0.0001). Also, the difference with gestational age (28.2 vs. 29.6; p < 0.0001), total ventilation days (32.8 vs. 16.1; p < 0.00001) and total oxygen days (87.7 vs. 62.6; p < 0.0001) was significant in neonates with ROP and neonates without the disease. Bronchopulmonary dysplasia, intraventricular hemorrhage and late onset sepsis were significant with patients with ROP. Conclusions: The frequency of ROP reported here is higher than the reported in Mexican population, with less cases of severe ROP. The neonatal surveillance in babies with less birth weight and gestational age is important to decrease the incidence of ROP.