Neonatal Jaundice: The Other Side of the Coin in the Development of Allergy

Neonatal jaundice and associated factors in public hospitals of southern Ethiopia: A multi-center cross-sectional study

Background

Neonatal jaundice is one of the most prevalent problems, affecting over a million newborns globally every year. It increases the likelihood of hospitalization, lifetime disability, and death, particularly in low and middle-income countries. Despite its impact and diverse risk factors, neonatal jaundice remains underappreciated in developing nations such as Ethiopia. As a result, this study aimed to determine the magnitude and associated factors of jaundice in newborns admitted to public hospitals in south Ethiopia.

Methods

A facility-based cross-sectional study was conducted among 417 newborns from October 1, 2020, to April 30, 2021. The data was collected using pretested interviewer-administered questionnaire and checklist. Jaundice and its severity were assessed using the physician's diagnosis and the Kramer scale. Open data kit tools and Stata version 16.0 were used for data collection and analysis, respectively. Bivariable and multivariable analyses were used to identify factors associated with neonatal jaundice. An odds ratio with a 95 % confidence interval was used to assess the direction and strength of the association.

Results

Out of the newborns, 24.46 % [95 % CI: 20.42-28.88] encountered neonatal jaundice. Being male [AOR: 1.81, 95 % CI: 1.06, 3.12], birth injuries [AOR: 3.01, 95 % CI: 1.27, 7.12], perinatal asphyxia [AOR: 2.10, 95 % CI: 1.18, 3.76], hyaline membrane disease [AOR: 2.16, 95 % CI: 1.16, 4.00], sepsis [AOR: 3.30, (95 % CI: 1.67, 6.54], the combined effect of low birth weight and prematurity [AOR: 1.88, 95 % CI: 1.06, 3.35], and maternal alcohol abuse during pregnancy [AOR: 2.46, 95 % CI: 1.02, 5.94] were significantly associated with neonatal jaundice.

Conclusion

The burden of neonatal jaundice was high in the hospitals studied. Early detection and treatment of neonatal problems, counseling pregnant women to avoid consuming any level of alcohol, strict monitoring of labor and delivery, improving antenatal care utilization, and pre-discharge universal bilirubin screening of newborns are essential to reduce the incidence and complications of jaundice. The findings of this study will be used as input to initiate interventions and conduct further studies.

Blue-Green (~480 nm) versus Blue (~460 nm) Light for Newborn Phototherapy-Safety Considerations

We have previously shown that the phototherapy of hyperbilirubinemic neonates using blue-green LED light with a peak wavelength of ~478 nm is 31% more efficient for removing unconjugated bilirubin from circulation than blue LED light with a peak wavelength of ~452 nm. Based on these results, we recommended that the phototherapy of hyperbilirubinemic newborns be practiced with light of ~480 nm. Aim: Identify and discuss the most prominent potential changes that have been observed in the health effects of phototherapy using either blue fluorescent- or blue LED light and speculate on the expected effects of changing to blue-green LED light phototherapy. Search the phototherapy literature using the terms neonate, hyperbilirubinemia, and phototherapy in the PubMed and Embase databases. Transitioning from blue fluorescent light to blue-green LED light will expose neonates to less light in the 400-450 nm spectral range, potentially leading to less photo-oxidation and geno-/cytotoxicity, reduced risk of cancer, and decreased mortality in extremely low-birthweight neonates. The riboflavin level may decline, and the increased production and retention of bronze pigments may occur in predisposed neonates due to enhanced lumirubin formation. The production of pre-inflammatory cytokines may rise. Hemodynamic responses and transepidermal water loss are less likely to occur. The risk of hyperthermia may decrease with the use of blue-green LED light and the risk of hypothermia may increase. Parent-neonate attachment and breastfeeding will be positively affected because of the shortened duration of phototherapy. The latter may also lead to a significant reduction in the cost of phototherapy procedures as well as the hospitalization process.

Association of Neonatal Jaundice with Gut Dysbiosis Characterized by Decreased Bifidobacteriales

Neonatal jaundice, caused by excess serum bilirubin levels, is a common condition in neonates. Imbalance in the gut microbiota is believed to play a role in the development of neonatal jaundice. Thus, we aimed to reveal the gut microbiota characteristics in neonates with jaundice. 16S rRNA gene sequencing was performed on stool samples collected on day 4 from 26 neonates with jaundice (serum total bilirubin > 15.0 mg/dL) and 17 neonates without jaundice (total serum bilirubin < 10.0 mg/dL). All neonates were born full term, with normal weight, by vaginal delivery, and were breastfed. Neonates who were administered antibiotics, had serum direct bilirubin levels above 1 mg/dL, or had conditions possibly leading to hemolytic anemia were excluded. The median serum bilirubin was 16.0 mg/dL (interquartile range: 15.5-16.8) and 7.4 mg/dL (interquartile range: 6.8-8.3) for the jaundice and non-jaundice groups, respectively. There was no difference in the alpha diversity indices. Meanwhile, in the jaundice group, linear discriminant analysis effect size revealed that Bifidobacteriales were decreased at the order level, while Enterococcaceae were increased and Bifidobacteriaceae were decreased at the family level. Bifidobacteriaceae may act preventatively because of their suppressive effect on beta-glucuronidase, leading to accelerated deconjugation of conjugated bilirubin in the intestine. In summary, neonates with jaundice had dysbiosis characterized by a decreased abundance of Bifidobacteriales.

The Effects of Bilirubin and Lumirubin on Metabolic and Oxidative Stress Markers

For severe unconjugated hyperbilirubinemia the gold standard treatment is phototherapy with blue-green light, producing more polar photo-oxidation products, believed to be non-toxic. The aim of the present study was to compare the effects of bilirubin (BR) and lumirubin (LR), the major BR photo-oxidation product, on metabolic and oxidative stress markers. The biological activities of these pigments were investigated on several human and murine cell lines, with the focus on mitochondrial respiration, substrate metabolism, reactive oxygen species production, and the overall effects on cell viability. Compared to BR, LR was found to be much less toxic, while still maintaining a similar antioxidant capacity in the serum as well as suppressing activity leading to mitochondrial superoxide production. Nevertheless, due to its lower lipophilicity, LR was less efficient in preventing lipoperoxidation. The cytotoxicity of BR was affected by the cellular glycolytic reserve, most compromised in human hepatoblastoma HepG2 cells. The observed effects were correlated with changes in the production of tricarboxylic acid cycle metabolites. Both BR and LR modulated expression of PPARα downstream effectors involved in lipid and glucose metabolism. Proinflammatory effects of BR, evidenced by increased expression of TNFα upon exposure to bacterial lipopolysaccharide, were observed in murine macrophage-like RAW 264.7 cells. Collectively, these data point to the biological effects of BR and its photo-oxidation products, which might have clinical relevance in phototherapy-treated hyperbilirubinemic neonates and adult patients.