Background: Newborns are susceptible to inflammatory diseases due to defects in clearing activated immune cells from tissues. Therefore, mechanisms have likely evolved to protect neonates from leukocyte-mediated cytotoxicity. Bilirubin has antioxidant activity, and it is possible that it also exerts effects on cellular immune responses in jaundiced infants. Objectives: We hypothesize that bilirubin increases expression of antioxidant genes and decreases production of inflammatory proteins in neonatal neutrophils. Methods: Neutrophils were isolated from umbilical cord blood, and from adults for comparison, and treated with bilirubin (10–300 µmol/l, equivalent to unbound bilirubin 3–40 nmol/l), in the presence or absence of lipopolysaccharide (LPS). Expression of genes for antioxidant enzymes [superoxide dismutase (SOD), heme-oxygenase-1 (HO-1)] and heme-dependent enzymes involved in inflammation [NADPH oxidase-1 (NOX-1), cyclooxygenase-2 (COX-2)] was measured by PCR. Inflammatory cytokines were measured by bead array analysis using flow cytometry. Results: We found that LPS induced production of interleukin (IL)-8, IL-1β, and macrophage inhibitory protein-1β (MIP-1β). Bilirubin increased basal production of IL-8 and IL-1β, but downregulated LPS-induced generation of IL-8 and MIP-1β. It also upregulated SOD and HO-1 gene expression. We observed an unexpected bilirubin-induced increase in gene expression of NOX-1 in LPS-activated cells, and of COX-2 in both resting and activated cells. Conclusions: These findings suggest that bilirubin suppresses inflammation and increases antioxidant enzyme generation in activated neonatal neutrophils. The unexpected increases in NOX-1 and COX-2 expression may represent an early response, with physiologic effects mitigated by increased antioxidant activity. Further studies will be needed to define levels of bilirubin that optimize its protective effects, while minimizing potential inflammatory toxicity.

Extremely low birth weight (ELBW; <1,000 g) infantshave poor outcomes, often compromised by bilirubin neurotoxicity. We measured unbound bilirubin (B_f) and unbound free fatty acid (FFA_u) levels in 5 ELBW infants in a trial examining the effects of pharmacologic ductal closure on infants treated with Intralipid infusion (3 g/kg/day). The levels for all infants (mean ± SD) were: total serum bilirubin (TSB) 4.6 ± 1.7 mg/dl, FFA_u 376 ± 496 nM, and B_f 42 ± 30 nM. Of the 3 infants who died, 2 had TSB <5.9 mg/dl but FFA_u >580 nM and B_f >75 nM. Multiple regression revealed a major effect on B_f levels due to FFA_u, indicating that Intralipid elevated levels of FFA_u and B_f. Indomethacin or ibuprofen reduced B_f levels, most likely by reducing FFA_u levels through lipase inhibition. Because displacement of B_f by FFA_u decouples B_f from TSB, phototherapy may not reduce the risk of bilirubin or FFA_u toxicity in Intralipid-treated ELBW infants.

A case is described of a neonate with a four-vessel umbilical cord containing two arteries and two veins. This was due to a rare persistence of the caudal portion of the right umbilical vein. The infant had multiple congenital anomalies including a complete atrioventricular canal, an interrupted inferior vena cava, a double superior vena cava, a left ventricular hypoplasia, dextrocardia, situs ambiguous, and malrotation of the small bowel. The birth of an infant with a four-vessel cord mandates comprehensive work-up for associated anomalies. The literature is reviewed.

OBJECTIVES: The American Academy of Pediatrics National Registry for the Surveillance and Epidemiology of Perinatal coronavirus disease 2019 (COVID-19) (NPC-19) was developed to provide information on the effects of perinatal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: National Registry for the Surveillance and Epidemiology of Perinatal COVID-19 participating centers entered maternal and newborn data for pregnant persons who tested positive for SARS-CoV-2 infection between 14 days before and 10 days after delivery. Incidence of and morbidities associated with maternal and newborn SARS-CoV-2 infection were assessed. RESULTS: From April 6, 2020 to March 19, 2021, 242 centers in the United States centers reported data for 7524 pregnant persons; at the time of delivery, 78.1% of these persons were asymptomatic, 18.2% were symptomatic but not hospitalized specifically for COVID-19, 3.4% were hospitalized for COVID-19 treatment, and 18 (0.2%) died in the hospital of COVID-related complications. Among 7648 newborns, 6486 (84.8%) were tested for SARS-CoV-2, and 144 (2.2%) were positive; the highest rate of newborn infection was observed when mothers first tested positive in the immediate postpartum period (17 of 125, 13.6%). No newborn deaths were attributable to SARS-CoV-2 infection. Overall, 15.6% of newborns were preterm: among tested newborns, 30.1% of polymerase chain reaction-positive and 16.2% of polymerase chain reaction-negative were born preterm (P &lt; .001). Need for mechanical ventilation did not differ by newborn SARS-CoV-2 test result, but those with positive tests were more likely to be admitted to a NICU. CONCLUSIONS: Early in the pandemic, SARS-CoV-2 infection was acquired by newborns at variable rates and without apparent short-term effects. During a period that preceded widespread availability of vaccines, we observed higher than expected numbers of preterm births and maternal in-hospital deaths.

Lower Sirt1 in TA leukocytes is associated with the development of BPD or death in premature infants. Dex use had no effect on Sirt1.