Omega-3 fatty acids modulate neonatal cytokine response to endotoxin

Essential Fatty Acid Supplementation and Early Inflammation in Preterm Infants: Secondary Analysis of a Randomized Clinical Trial

INTRODUCTION

Postnatal inflammation is associated with increased mortality and adverse outcomes in preterm infants. The essential fatty acids arachidonic acid (ARA) and docosahexaenoic acid (DHA) are precursors of lipid mediators with a key role in resolving inflammation. Our aim was to investigate the effect of ARA and DHA supplementation on systemic inflammation in very preterm infants and to identify clinical factors associated with early inflammation.

METHODS

Secondary analysis of data from a randomized clinical trial (ImNuT study). Infants with gestational age (GA) less than 29 weeks were randomized to receive a daily enteral supplement with ARA 100 mg/kg and DHA 50 mg/kg (ARA:DHA group) or MCT oil (control group) from the second day of life to 36 weeks postmenstrual age. ARA, DHA, and four proinflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α) were analyzed in repeated dried blood samples from birth to day 28 and the area under the curve (AUC) for each variable was calculated.

RESULTS

The intention to treat population included 120 infants with mean (SD) GA 26.4 (1.7). The ARA:DHA group had significantly lower IL-6 levels from day 3 to day 28 compared to the control group, mean difference AUC log10 (95% CI): 0.16 (0.03-0.30) pg/mL, p = 0.018. There was no correlation between ARA or DHA blood concentrations and cytokine levels. Having a low gestational age was independently associated with increased levels of all cytokines during the first 4 weeks of life.

CONCLUSIONS

Enhanced supplementation with ARA and DHA may modulate inflammation in very preterm infants.

Prenatal exposure to multiple metallic and metalloid trace elements and the risk of bacterial sepsis in extremely low gestational age newborns: A prospective cohort study

BACKGROUND

Prenatal exposures to metallic and metalloid trace elements have been linked to altered immune function in animal studies, but few epidemiologic studies have investigated immunological effects in humans. We evaluated the risk of bacterial sepsis (an extreme immune response to bacterial infection) in relation to prenatal metal/metalloid exposures, individually and jointly, within a US-based cohort of infants born extremely preterm.

METHODS

We analyzed data from 269 participants in the US-based ELGAN cohort, which enrolled infants delivered at <28 weeks' gestation (2002-2004). Concentrations of 8 trace elements-including 4 non-essential and 4 essential-were measured using inductively coupled plasma tandem mass spectrometry in umbilical cord tissue, reflecting in utero fetal exposures. The infants were followed from birth to postnatal day 28 with bacterial blood culture results reported weekly to detect sepsis. Discrete-time hazard and quantile g-computation models were fit to estimate associations for individual trace elements and their mixtures with sepsis incidence.

RESULTS

Approximately 30% of the extremely preterm infants developed sepsis during the follow-up period (median follow-up: 2 weeks). After adjustment for potential confounders, no trace element was individually associated with sepsis risk. However, there was some evidence of a non-monotonic relationship for cadmium, with hazard ratios (HRs) for the second, third, and fourth (highest) quartiles being 1.13 (95% CI: 0.51-2.54), 1.94 (95% CI: 0.87-4.32), and 1.88 (95% CI: 0.90-3.93), respectively. The HRs for a quartile increase in concentrations of all 8 elements, all 4 non-essential elements, and all 4 essential elements were 0.92 (95% CI: 0.68-1.25), 1.19 (95% CI: 0.92-1.55), and 0.77 (95% CI: 0.57-1.06). Cadmium had the greatest positive contribution whereas arsenic, copper, and selenium had the greatest negative contributions to the mixture associations.

CONCLUSIONS

We found some evidence that greater prenatal exposure to cadmium was associated with an increased the risk of bacterial sepsis in extremely preterm infants. However, this risk was counteracted by a combination of arsenic, copper, and selenium. Future studies are needed to confirm these findings and to evaluate the potential for nutritional interventions to prevent sepsis in high-risk infants.

Long-Chain Polyunsaturated Fatty Acid Status at Birth and Development of Childhood Allergy: A Systematic Review

The associations of fetal fatty acids status to immune-related health parameters later in life are unclear. Our aim is to collect all available information on the relationship between fatty acid status at birth and allergy in childhood. Systematic literature search was performed on Ovid MEDLINE, Cochrane Library, and Embase. The search retrieved 897 articles without duplicates; 14 articles remained after excluding those that did not fit into our inclusion criteria. When the dichotomous parameter of suffering or not from allergic condition in childhood was analyzed, cord blood eicosapentaenoic acid (EPA) values proved to be significantly lower in allergic than non-allergic children in four comparisons from three studies. When the linear parameters of odds ratios and relative risks for allergy were taken into consideration, high cord blood EPA, but also high docosahexaenoic acid (DHA) and high total n-3 long-chain polyunsaturated fatty acid values were associated to clinically relevant reduction (at least 38%) in eight comparisons from five studies. Within the cord blood samples, higher EPA, docosapentaenoic acid, and DHA values were significantly and negatively associated in eight correlation analyses from three studies with laboratory parameters considered to reflect allergic trait. The data reported here may provide information for defining optimal fatty acid intakes for pregnant women.

Impact of Docosahexaenoic acid supplementation on proinflammatory cytokines release and the development of Necrotizing enterocolitis in preterm Neonates: A randomized controlled study

INTRODUCTION

Preterm neonates have under-developed immune-regulatory system; consequently, there is a risk for developing chronic inflammation. Necrotizing enterocolitis (NEC) is an acute devastating neonatal intestinal inflammatory disorder. Due to the obscure multifactorial etiology, early diagnosis and effective treatment of NEC are limited. Consequently, effective strategies in the prevention of NEC, including nutritional approaches, are critically needed. The current study was conducted to assess the potential immunomodulatory effect of Docosahexaenoic Acid (DHA) supplementation in preterm neonates at neonatal intensive care unit (NICU) and subsequently its effect on preventing or reducing NEC incidence.

METHODS

This was a prospective randomized controlled study. A total of 67 neonates, with gestational age equal or less than 32 weeks at birth and weight less than or equal 1500 g, were randomly assigned to either DHA group or the control group. Modified Bell's staging criteria for NEC was used as an objective tool for diagnosis and staging of NEC. Levels of Interleukin 1 beta (IL-1β) were measured at baseline and after 10 days. Mortality and NICU length of stay (LOS) were also monitored.

RESULTS

Thirty neonates of each group completed the study. A statistically significant difference was observed between the two groups regarding diagnosis and staging of NEC (p = 0.0001). There was also a statistically significant difference between DHA group 22(73.3), 95% CI [55.9, 86.5] and the control group 8 (26.7), 95% CI [13.5, 44.1] in the percentage change in IL-1β levels (p = 0.0001).A statistically significant association was found between IL and 1 β change and NEC diagnosis (p = 0.001). NICU LOS was significantly lower among DHA group 21.63 ± 6.67 compared to the control group 25.07 ± 4.67 (p = 0.025). Mortality n (%) among the control group 4 (11.8) was higher than DHA group 3 (9.1), however, no significant difference was detected (p = 1.0).

CONCLUSION

Findings of this study suggest that enteral DHA supplementation can reduce NEC incidence in preterm neonates through its immunoregulatory effect that modulates production of regulatory cytokines.Trial registration: Registered at clinical trials.gov (NCT03700957), 6 October 2018.

H. Smith L, Puttonen H, Fyhr IM, Sävman K, Nilsson AK, Klevebro S. Docosahexaenoic Acid and Arachidonic Acid Levels Are Associated with Early Systemic Inflammation in Extremely Preterm Infants

Fetal and early postnatal inflammation have been associated with increased morbidity in extremely preterm infants. This study aimed to demonstrate if postpartum levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) were associated with early inflammation. In a cohort of 90 extremely preterm infants, DHA and AA in cord blood, on the first postnatal day and on postnatal day 7 were examined in relation to early systemic inflammation, defined as elevated C-reactive protein (CRP) and/or interleukin-6 (IL-6) within 72 h from birth, with or without positive blood culture. Median serum level of DHA was 0.5 mol% (95% CI (confidence interval) 0.2–0.9, P = 0.006) lower than the first postnatal day in infants with early systemic inflammation, compared to infants without signs of inflammation, whereas levels of AA were not statistically different between infants with and without signs of inflammation. In cord blood, lower serum levels of both DHA (correlation coefficient −0.40; P = 0.010) and AA (correlation coefficient −0.54; p < 0.001) correlated with higher levels of IL-6. Levels of DHA or AA did not differ between infants with and without histological signs of chorioamnionitis or fetal inflammation. In conclusion, serum levels of DHA at birth were associated with the inflammatory response during the early postnatal period in extremely preterm infants.

The Effect of Maternal Diet with Fish Oil on Oxidative Stress and Inflammatory Response in Sow and New-Born Piglets

Pregnancy is an oxidative stress and immune challenge for the mother. Fish oil is rich in EPA and DHA, which can partly inhibit aspects of inflammation and restore antioxidant capacity. In the present study, we investigated the effect of maternal diet with fish oil during the late gestation period on oxidative stress and inflammatory response in sows and their progenies. Twelve second-parity sows were allocated equally into two groups. Sows were fed either the soybean oil diet (SD) or soybean oil+fish oil diet (FD) during the gestation period. The plasma of sows, cord blood, and new-born piglets were collected. Full-term placentas and livers of new-born piglets were also sampled. The activities of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) in the plasma of sows on farrowing day were higher, and the concentrations of interleukin-6 (IL-6) and prostaglandin-endoperoxide synthase 2 (PGE2) in the plasma of sows on farrowing day and interleukin-1β (IL-1β) in the plasma of cord blood were lower in the FD group than those in the SD group (P < 0.05). The FD downregulated the expression of SOD, IL-1β, IL-6, and transforming growth factor-β-activated kinase 1 binding protein 1 (TAB1) mRNA but upregulated the expression of lipoxygenase enzyme 5 (ALOX5) and interleukin-10 (IL-10) mRNA in placentas (P < 0.05). The FD downregulated the protein expression level of p-JNK/JNK in placentas (P < 0.05). In the livers of new-born piglets, the FD upregulated the expression of ALOX5 (P < 0.05) and G-protein-coupled receptor 120 (GPR120) (P < 0.05) mRNA. Our results suggest that the maternal diet with fish oil might alleviate oxidative stress in sows on farrowing day and modulate inflammatory response in full-term placentas by inhibiting the JNK signal pathway. Moreover, the maternal diet with fish oil might partly regulate the neonatal immune response of their progenies.

Beneficial Effects of Enteral Docosahexaenoic Acid on the Markers of Inflammation and Clinical Outcomes of Neonates Undergoing Cardiovascular Surgery: An Intervention Study

BACKGROUND

Neonates undergoing surgery are at risk for uncontrolled inflammatory response and adverse clinical outcomes. Docosahexaenoic acid (DHA) ameliorates inflammation, improving clinical outcomes. However, its effect has not been evaluated in neonates undergoing surgery. We evaluated the effect of DHA on markers of inflammation and clinical outcomes in neonates undergoing surgery.

METHODS

A double-blind clinical trial evaluated the effect of enteral DHA (DHA group) versus sunflower oil (SO group) perioperatively administered in neonates scheduled for cardiovascular surgery. Inflammation was evaluated by percentage of cells+ for cytokines and CD69 in mononuclear cells at baseline, 24 h and 7 days post surgery. Clinical outcomes measured were sepsis, organ dysfunctions (ODs), length of stay in intensive care and bleeding. Repeated measures analysis of variance and logistic regression were applied.

RESULTS

Sixteen neonates received DHA and 18 received SO. Cells+ from neonates in the DHA group showed an early increase in receptor antagonist of interleukin (IL)-1+ (IL-1ra+) and IL-10+ and a late decrease in IL-6+. IL-1β+ and IL-10+ changes were different between groups. After adjusting for confounders, less cells from DHA group were IL-1β+, IL-6+, IL-1ra+ and IL-10+. DHA group presented less sepsis, ODs and shorter stay, but no difference in CD69+CD4+ cells or bleeding between groups.

CONCLUSIONS

Administration of enteral DHA ameliorates markers of inflammation and improves clinical outcomes in surgical neonates.