AUTHOR=Helguera-Repetto Addy Cecilia , Villegas-Mota Isabel , Arredondo-Pulido Guadalupe Itzel , Cardona–Pérez Jorge Arturo , León-Juárez Moises , Rivera-Rueda Maria Antonieta , Arreola-Ramírez Gabriela , Mateu-Rogell Paloma , Acevedo-Gallegos Sandra , López-Navarrete Gloria Elena , Valdespino-Vázquez María Yolotzin , Martínez-Salazar Guadalupe , Rodríguez-Bosch Mario , Coronado-Zarco Irma Alejandra , Castillo-Gutiérrez María del Rosario , Cuevas-Jiménez Carlos Alberto , Moreno-Verduzco Elsa Romelia , Espino-y-Sosa Salvador , Cortés-Bonilla Manuel , Irles Claudine TITLE=Cord Blood SARS-CoV-2 IgG Antibodies and Their Association With Maternal Immunity and Neonatal Outcomes JOURNAL=Frontiers in Pediatrics VOLUME=10 YEAR=2022 URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2022.883185 DOI=10.3389/fped.2022.883185 ISSN=2296-2360 ABSTRACT=

Passive transplacental immunity is crucial for neonatal protection from infections. Data on the correlation between neonatal immunity to SARS-CoV-2 and protection from adverse outcomes is scarce. This work aimed to describe neonatal seropositivity in the context of maternal SARS-CoV-2 infection, seropositivity, and neonatal outcomes. This retrospective nested case-control study enrolled high-risk pregnant women with a SARS-CoV-2 RT-PCR positive test who gave birth at the Instituto Nacional de Perinatología in Mexico City and their term neonates. Anti-SARS-CoV-2 IgG antibodies in maternal and cord blood samples were detected using a chemiluminescent assay. In total, 63 mother-neonate dyads (mean gestational age 38.4 weeks) were included. Transplacental transfer of SARS-CoV-2 IgG occurred in 76% of neonates from seropositive mothers. A positive association between maternal IgG levels and Cycle threshold (Ct) values of RT-qPCR test for SARS-CoV-2 with neonatal IgG levels was observed. Regarding neonatal outcomes, most seropositive neonates did not require any mechanical ventilation, and none developed any respiratory morbidity (either in the COVID-19 positive or negative groups) compared to 7 seronegative neonates. Furthermore, the odds of neonatal respiratory morbidity exhibited a tendency to decrease when neonatal IgG levels increase. These results add further evidence suggesting passive IgG transfer importance.