Respiratory Syncytial Virus Seropositivity at Birth is Associated with Adverse Neonatal Respiratory Outcomes.

Manti, Sara; Esper, Frank; Alejandro-Rodriguez, Marilyn; Leonardi, Salvatore; Betta, Pasqua; Cuppari, Caterina; Lanzafame, Angela; Worley, Sarah; Salpietro, Carmelo; Perez, Miriam K; Rezaee, Fariba; Piedimonte, Giovanni

BACKGROUND More than 60 years since the discovery of the Respiratory Syncytial Virus (RSV), the effects of prenatal exposure to this virus remain largely unknown. In this investigation, we sought to find evidence of RSV seroconversion in cord blood and explore its clinical implications for the newborn. METHODS Offspring from 22 pregnant women with a history of viral respiratory infection during the third trimester of pregnancy (RVI group) and 40 controls were enrolled in this study between September 1, 2016 and March 31, 2019. Cord blood sera were tested for anti-RSV antibodies by indirect fluorescent antibody assay. RSV seropositivity was defined as the presence of anti-RSV IgM or IgA, in addition to IgG in cord blood serum at ≥1:20 dilution. RESULTS Anti-RSV IgG was present in all cord blood serum samples from infants born to RVI mothers (95% CI=82-100%), with 16 samples also having elevated titers for either anti-RSV IgA or IgM (73%; 95% CI=52-87%). No controls had evidence of anti-RSV antibodies. Eight (50%) seropositive newborns developed at least one respiratory tract finding, including RDS (N=8), respiratory failure (N=3), and pneumonia (N=1). RSV seropositive newborns also required more days on oxygen, had leukocytosis and elevated C-reactive protein (p=0.025, p=0.047 and p<0.001, respectively). CONCLUSIONS This study provides evidence of acute seropositivity against RSV in cord blood of newborns delivered from mothers with a history of upper respiratory tract illness in the third trimester. Cord blood seropositivity for anti-RSV IgA or IgM was associated with adverse clinical and laboratory outcomes in newborns. This article is protected by copyright. All rights reserved.