Arachidonic acid and docosahexaenoic acid levels correlate with the inflammation proteome in extremely preterm infants

BACKGROUND & AIM

Clinical trials supplementing the long-chain polyunsaturated fatty acids (LCPUFAs) docosahexaenoic acid (DHA) and arachidonic acid (AA) to preterm infants have shown positive effects on inflammation-related morbidities, but the molecular mechanisms underlying these effects are not fully elucidated. This study aimed to determine associations between DHA, AA, and inflammation-related proteins during the neonatal period in extremely preterm infants.

METHODS

A retrospective exploratory study of infants (n = 183) born below 28 weeks gestation from the Mega Donna Mega trial, a randomized multicenter trial designed to study the effect of DHA and AA on retinopathy of prematurity. Serial serum samples were collected after birth until postnatal day 100 (median 7 samples per infant) and analyzed for phospholipid fatty acids and proteins using targeted proteomics covering 538 proteins. Associations over time between LCPUFAs and proteins were explored using mixed effect modeling with splines, including an interaction term for time, and adjusted for gestational age, sex, and center.

RESULTS

On postnatal day one, 55 proteins correlated with DHA levels and 10 proteins with AA levels. Five proteins were related to both fatty acids, all with a positive correlation. Over the first 100 days after birth, we identified 57 proteins to be associated with DHA and/or AA. Of these proteins, 41 (72%) related to inflammation. Thirty-eight proteins were associated with both fatty acids and the overall direction of association did not differ between DHA and AA, indicating that both LCPUFAs similarly contribute to up- and down-regulation of the preterm neonate inflammatory proteome. Primary examples of this were the inflammation-modulating cytokines IL-6 and CCL7, both being negatively related to levels of DHA and AA in the postnatal period.

CONCLUSIONS

This study supports postnatal non-antagonistic and potentially synergistic effects of DHA and AA on the inflammation proteome in preterm infants, indicating that supplementation with both fatty acids may contribute to limiting the disease burden in this vulnerable population.

CLINICAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT03201588).

Factors associated with the increased incidence of necrotising enterocolitis in extremely preterm infants in Sweden between two population-based national cohorts (2004-2007 vs 2014-2016)

OBJECTIVE

To investigate potential risk factors behind the increased incidence of necrotising enterocolitis (NEC) in Swedish extremely preterm infants.

DESIGN

Registry data from two population-based national cohorts were studied. NEC diagnoses (Bell stage ≥II) were validated against hospital records.

PATIENTS

All liveborn infants <27 weeks of gestation 2004-2007 (n=704) and 2014-2016 (n=895) in Sweden.

MAIN OUTCOME MEASURES

NEC incidence.

RESULTS

The validation process resulted in a 28% reduction of NEC cases but still confirmed a higher NEC incidence in the later epoch compared with the earlier (73/895 (8.2%) vs 27/704 (3.8%), p=0.001), while the composite of NEC or death was lower (244/895 (27.3%) vs 229/704 (32.5%), p=0.022). In a multivariable Cox regression model, censored for mortality, there was no significant difference in early NEC (0-7 days of life) between epochs (HR=0.9 (95% CI 0.5 to 1.9), p=0.9), but being born in the later epoch remained an independent risk factor for late NEC (>7 days) (HR=2.7 (95% CI 1.5 to 5.0), p=0.001). In propensity score analysis, a significant epoch difference in NEC incidence (12% vs 2.8%, p<0.001) was observed only in the tertile of infants at highest risk of NEC, where the 28-day mortality was lower in the later epoch (35% vs 50%, p=0.001). More NEC cases were diagnosed with intramural gas in the later epoch (33/73 (45.2%) vs 6/26 (23.1%), p=0.047).

CONCLUSIONS

The increase in NEC incidence between epochs was limited to cases occurring after 7 days of life and was partly explained by increased survival in the most extremely preterm infants. Misclassification of NEC is common.

One-year survival and outcomes of infants born at 22 and 23 weeks of gestation in Sweden 2004-2007, 2014-2016 and 2017-2019

OBJECTIVE

To explore associations between perinatal activity and survival in infants born at 22 and 23 weeks of gestation in Sweden.

DESIGN/SETTING

Data on all births at 22 and 23 weeks' gestational age (GA) were prospectively collected in 2004-2007 (T1) or obtained from national registers in 2014-2016 (T2) and 2017-2019 (T3). Infants were assigned perinatal activity scores based on 3 key obstetric and 4 neonatal interventions.

MAIN OUTCOME

One-year survival and survival without major neonatal morbidities (MNM): intraventricular haemorrhage grade 3-4, cystic periventricular leucomalacia, surgical necrotising enterocolitis, retinopathy of prematurity stage 3-5 or severe bronchopulmonary dysplasia. The association of GA-specific perinatal activity score and 1-year survival was also determined.

RESULTS

977 infants (567 live births and 410 stillbirths) were included: 323 born in T1, 347 in T2 and 307 in T3. Among live-born infants, survival at 22 weeks was 5/49 (10%) in T1 and rose significantly to 29/74 (39%) in T2 and 31/80 (39%) in T3. Survival was not significantly different between epochs at 23 weeks (53%, 61% and 67%). Among survivors, the proportions without MNM in T1, T2 and T3 were 20%, 17% and 19% for 22 weeks and 17%, 25% and 25% for 23 weeks' infants (p>0.05 for all comparisons). Each 5-point increment in GA-specific perinatal activity score increased the odds for survival in first 12 hours of life (adjusted OR (aOR) 1.4; 95% CI 1.3 to 1.6) in addition to 1-year survival (aOR 1.2; 95% CI 1.1 to 1.3), and among live-born infants it was associated with increased survival without MNM (aOR 1.3; 95% CI 1.1 to 1.4).

CONCLUSION

Increased perinatal activity was associated with reduced mortality and increased chances of survival without MNM in infants born at 22 and 23 weeks of GA.

Hyper high haemoglobin content in red blood cells and erythropoietic transitions postnatally in infants of 22 to 26 weeks' gestation: a prospective cohort study

OBJECTIVE

Blood cell populations, including red blood cells (RBC) unique to the extremely preterm (EPT) infant, are potentially lost due to frequent clinical blood sampling during neonatal intensive care. Currently, neonatal RBC population heterogeneity is not described by measurement of total haemoglobin or haematocrit. We therefore aimed to describe a subpopulation of large RBCs with hyper high haemoglobin content, >49 pg (Hyper-He) following EPT birth.

DESIGN

Prospective observational cohort study.

SETTING

Two Swedish study centres.

PARTICIPANTS

Infants (n=62) born between gestational weeks 22+0 to 26+6.

METHODS

Prospective data (n=280) were collected from March 2020 to September 2022 as part of an ongoing randomised controlled trial. Blood was sampled from the umbilical cord, at postnatal day 1-14, 1 month, 40 weeks' postmenstrual age and at 3 months' corrected age.

RESULTS

At birth, there was a considerable inter-individual variation; Hyper-He ranging from 1.5% to 24.9% (median 7.0%). An inverse association with birth weight and gestational age was observed; Spearman's rho (CI) -0.38 (-0.63 to -0.07) and -0.39 (-0.65 to -0.05), respectively. Overall, Hyper-He rapidly decreased, only 0.6%-5.0% (median 2.2%) remaining 2 weeks postnatally. Adult levels (<1%) were reached at corresponding term age.

CONCLUSION

Our results point to gestational age and birth weight-dependent properties of the RBC population. Future work needs to verify results by different measurement techniques and elucidate the potential role of differing properties between endogenous and transfused RBCs in relation to neonatal morbidities during this important time frame of child development.

TRIAL REGISTRATION NUMBER

NCT04239690.

Visual outcome at 2.5 years of age in ω-3 and ω-6 long-chain polyunsaturated fatty acid supplemented preterm infants: a follow-up of a randomized controlled trial

Background

We investigated ophthalmological outcomes at 2.5 years of corrected age in children born extremely preterm (EPT) to evaluate the effects of postnatal enteral supplementation with ω-3 and ω-6 long-chain polyunsaturated fatty acids.

Methods

In the Mega Donna Mega clinical trial, EPT infants born at less than 28 weeks of gestation were randomized to receive an enteral supplementation of docosahexaenoic acid (DHA) and arachidonic acid (AA) from birth to 40 weeks postmenstrual age. In this exploratory follow-up at 2.5 years of corrected age, we assessed visual acuity (VA), refraction, manifest strabismus, and nystagmus. Satisfactory VA was defined as ≥20/63. Multiple imputation (MI) was used to address the issue of missing data.

Findings

Of 178 children in the trial, 115 (with median gestational age (GA) of 25 + 4/7 weeks and median birth weights of 790 g) were ophthalmologically assessed at a median corrected age of 2.7 years (range 2.0-3.9 years). VA assessment was missing in 42.1% (75/178), in 41.7% (35/84) of the AA/DHA supplemented infants, and in 42.6% (40/94) of the control infants. After MI and adjustments for GA, study center, plurality, and corrected age at VA exam, no significant effect of AA/DHA supplementation was detected in VA outcome (≥20/63) (odds ratio 2.16, confidence interval 95% 0.99-4.69, p = 0.053).

Interpretation

In this randomized controlled trial follow-up, postnatal supplementation with enteral AA/DHA to EPT children did not significantly alter VA at 2.5 years of corrected age. Due to the high loss to follow-up rate and the limited statistical power, additional studies are needed.

Funding

The Swedish Medical Research Council #2020-01092, The Gothenburg Medical Society, Government grants under the ALF agreement ALFGBG-717971 and ALFGBG-971188, De Blindas Vänner, Knut and Alice Wallenberg Foundation - Wallenberg Clinical Scholars, NIHEY017017, EY030904BCHIDDRC (1U54HD090255 Massachusetts Lions Eye Foundation) supported the study.

The development of blood protein profiles in extremely preterm infants follows a stereotypic evolution pattern

BACKGROUND

Preterm birth is the leading cause of neonatal mortality and morbidity. Early diagnosis and interventions are critical to improving the clinical outcomes of extremely premature infants. Blood protein profiling during the first months of life in preterm infants can shed light on the role of early extrauterine development and provide an increased understanding of maturation after extremely preterm birth and the underlying mechanisms of prematurity-related disorders.

METHODS

We have investigated the blood protein profiles during the first months of life in preterm infants on the role of early extrauterine development. The blood protein levels were analyzed using next generation blood profiling on 1335 serum samples, collected longitudinally at nine time points from birth to full-term from 182 extremely preterm infants.

RESULTS

The protein analysis reveals evident predestined serum evolution patterns common for all included infants. The majority of the variations in blood protein expression are associated with the postnatal age of the preterm infants rather than any other factors. There is a uniform protein pattern on postnatal day 1 and after 30 weeks postmenstrual age (PMA), independent of gestational age (GA). However, during the first month of life, GA had a significant impact on protein variability.

CONCLUSIONS

The unified pattern of protein development for all included infants suggests an age-dependent stereotypic development of blood proteins after birth. This knowledge should be considered in neonatal settings and might alter the clinical approach within neonatology, where PMA is today the most dominant age variable.

Proteomics identifies lipocalin-2 in neonatal inflammation associated with cerebrovascular alteration in mice and preterm infants

Staphylococcus (S.) epidermidis is the most common nosocomial coagulase-negative staphylococci infection in preterm infants. Clinical signs of infection are often unspecific and novel markers to complement diagnosis are needed. We investigated proteomic alterations in mouse brain after S. epidermidis infection and in preterm infant blood. We identified lipocalin-2 (LCN2) as a crucial protein associated with cerebrovascular changes and astrocyte reactivity in mice. We further proved that LCN2 protein expression was associated with endothelial cells but not astrocyte reactivity. By combining network analysis and differential expression approaches, we identified LCN2 linked to blood C-reactive protein levels in preterm infants born <28 weeks of gestation. Blood LCN2 levels were associated with similar alterations of cytokines and chemokines in both infected mice and human preterm infants with increased levels of C-reactive protein. This experimental and clinical study suggests that LCN2 may be a marker of preterm infection/inflammation associated with cerebrovascular changes and neuroinflammation.

Modification of serum fatty acids in preterm infants by parenteral lipids and enteral docosahexaenoic acid/arachidonic acid: A secondary analysis of the Mega Donna Mega trial

BACKGROUND & AIM

Preterm infants risk deficits of long-chain polyunsaturated fatty acids (LCPUFAs) that may contribute to morbidities and hamper neurodevelopment. We aimed to determine longitudinal serum fatty acid profiles in preterm infants and how the profiles are affected by enteral and parenteral lipid sources.

METHODS

Cohort study analyzing fatty acid data from the Mega Donna Mega study, a randomized control trial with infants born <28 weeks of gestation (n = 204) receiving standard nutrition or daily enteral lipid supplementation with arachidonic acid (AA):docosahexaenoic acid (DHA) (100:50 mg/kg/day). Infants received an intravenous lipid emulsion containing olive oil:soybean oil (4:1). Infants were followed from birth to postmenstrual age 40 weeks. Levels of 31 different fatty acids from serum phospholipids were determined by GC-MS and reported in relative (mol%) and absolute concentration (μmol l-1) units.

RESULTS

Higher parenteral lipid administration resulted in lower serum proportion of AA and DHA relative to other fatty acids during the first 13 weeks of life (p < 0.001 for the 25th vs the 75th percentile). The enteral AA:DHA supplement increased the target fatty acids with little impact on other fatty acids. The absolute concentration of total phospholipid fatty acids changed rapidly in the first weeks of life, peaking at day 3, median (Q1-Q3) 4452 (3645-5466) μmol l-1, and was positively correlated to the intake of parenteral lipids. Overall, infants displayed common fatty acid trajectories over the study period. However, remarkable differences in fatty acid patterns were observed depending on whether levels were expressed in relative or absolute units. For example, the relative levels of many LCPUFAs, including DHA and AA, declined rapidly after birth while their absolute concentrations increased in the first week of life. For DHA, absolute levels were significantly higher compared to cord blood from day 1 until postnatal week 16 (p < 0.001). For AA, absolute postnatal levels were lower compared to cord blood from week 4 throughout the study period (p < 0.05).

CONCLUSIONS

Our data show that parenteral lipids aggravate the postnatal loss of LCPUFAs seen in preterm infants and that serum AA available for accretion is below that in utero. Further research is needed to establish optimal postnatal fatty acid supplementation and profiles in extremely preterm infants to promote development and long-term health.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov, identifier: NCT03201588.

[Survival and prematurity-related neonatal diagnoses among children born before 24 gestational weeks in Sweden 2007-2018]

Children born before 24 gestational weeks had high neonatal morbidity and a majority had one or more neurodevelopmental disorders in addition to somatic diagnoses in childhood. Active Swedish perinatal care of infants with gestational age <24 weeks has resulted in a survival rate of more than 50 percent. Resuscitation of these immature infants is controversial, and some countries offer comfort care only. In a retrospective review of medical files and registries of 399 Swedish infants born before 24 gestational weeks, a majority had severe prematurity-related neonatal diagnoses. In childhood (2-13 years), 75 percent had at least one neurodevelopmental disorder and 88 percent had one or more prematurity-related somatic diagnosis (permanent or transient) that was likely to affect their quality of life. Long-term consequences for surviving infants should be considered in general recommendations as well as in parental information.

Retrospective evaluation of ophthalmological and neurological outcomes for infants born before 24 weeks gestational age in a Swedish cohort

OBJECTIVES

To retrospectively evaluate ophthalmological and neurological outcomes in a Swedish cohort of infants born before 24 weeks gestational age (GA) and explore risk factors for visual impairment.

SETTING

Eye and paediatric clinics in Sweden.

PARTICIPANTS

Infants screened for retinopathy of prematurity (ROP) (n=399), born before 24 weeks GA, 2007-2018. Cases were excluded if ophthalmological follow-up records could not be traced.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes were ophthalmological, including visual acuity (VA), refractive error, strabismus, nystagmus and cerebral visual impairment (CVI). Secondary outcomes comprised neonatal and neurological morbidities. Data were retrospectively retrieved from medical records.

RESULTS

The 355 assessed children had a median GA of 23 weeks and 2 days and a median birth weight of 565 g. At the last available ophthalmological examination, the median age was 4.8 years (range 0.5-13.2 years). Nystagmus was recorded in 21.1%, strabismus in 34.8%, and 51.0% wore spectacles. Seventy-three of 333 (21.9%) were visually impaired, defined as being referred to a low vision clinic and/or having a VA less than 20/60 at 3.5 years of age or older. ROP treatment was a significant risk factor for visual impairment (OR 2.244, p=0.003). Visually impaired children, compared with children without visual impairment, more often had neurological deficits such as intellectual disability 63.8% versus 33.3% (p<0.001), epilepsy 21.1% versus 7.5% (p=0.001) and autism spectrum disorders 32.8% versus 20.9% (p=0.043). Nine of the 355 children had been diagnosed with CVI.

CONCLUSIONS

Children born before 24 weeks GA frequently had visual impairment in association with neurological deficits. CVI was rarely diagnosed. A multidisciplinary approach for the evaluation and habilitation of these vulnerable infants is warranted. National follow-up guidelines need to be developed and implemented.

National cohort of infants born before 24 gestational weeks showed increased survival rates but no improvement in neonatal morbidity

AIM

To describe survival and neonatal morbidities in infants born before 24 weeks of gestation during a 12-year period.

METHODS

Data were retrieved from national registries and validated in medical files of infants born before 24 weeks of gestation 2007-2018 in Sweden. Temporal changes were evaluated.

RESULTS

In 2007-2018, 282 live births were recorded at 22 weeks and 460 at 23 weeks of gestation. Survival to discharge from hospital of infants born alive at 22 and 23 weeks increased from 20% to 38% (p = 0.006) and from 45% to 67% (p < 0.001) respectively. Caesarean section increased from 12% to 22% (p = 0.038) for infants born at 22 weeks. Neonatal morbidity rates in infants alive at 40 weeks of postmenstrual age (n = 399) were unchanged except for an increase in necrotising enterocolitis from 0 to 33% (p = 0.017) in infants born at 22 weeks of gestation. Bronchopulmonary dysplasia was more common in boys than girls, 90% versus 82% (p = 0.044). The number of infants surviving to 40 weeks doubled over time.

CONCLUSION

Increased survival of infants born before 24 weeks of gestation resulted in increasing numbers of very immature infants with severe neonatal morbidities likely to have a negative impact on long-term outcome.

Neurodevelopmental disorders and somatic diagnoses in a national cohort of children born before 24 weeks of gestation

AIM

This study investigated childhood diagnoses in children born extremely preterm before 24 weeks of gestation.

METHODS

Diagnoses of neurodevelopmental disorders and selected somatic diagnoses were retrospectively retrieved from national Swedish registries for children born before 24 weeks from 2007 to 2018. Their individual medical files were also examined.

RESULTS

We studied 383 children born at a median of 23.3 (range 21.9-23.9) weeks, with a median birthweight of 565 (range 340-874) grams. Three-quarters (75%) had neurodevelopmental disorders, including speech disorders (52%), intellectual disabilities (40%), attention deficit hyperactivity disorder (30%), autism spectrum disorders (24%), visual impairment (22%), cerebral palsy (17%), epilepsy (10%) and hearing impairment (5%). More boys than girls born at 23 weeks had intellectual disabilities (45% vs. 27%, p < 0.01) and visual impairment (25% vs. 14%, p < 0.01). Just over half of the cohort (55%) received habilitation care. The majority (88%) had somatic diagnoses, including asthma (63%) and failure to thrive/short stature (39%).

CONCLUSION

Most children born before 24 weeks had neurodevelopmental disorders and/or additional somatic diagnoses in childhood and were referred to habilitation services. Clinicians should be aware of the multiple health and developmental problems affecting these children. Resources are needed to identify their long-term support needs at an early stage.

Serum docosahexaenoic acid levels are associated with brain volumes in extremely preterm born infants

BACKGROUND

Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for fetal brain growth and development. Our aim was to evaluate the association between serum DHA and AA levels and brain volumes in extremely preterm infants.

METHODS

Infants born at <28 weeks gestational age in 2013-2015, a cohort derived from a randomized controlled trial comparing two types of parenteral lipid emulsions, were included (n = 90). Serum DHA and AA levels were measured at postnatal days 1, 7, 14, and 28, and the area under the curve was calculated. Magnetic resonance (MR) imaging was performed at term-equivalent age (n = 66), and volumes of six brain regions were automatically generated.

RESULTS

After MR image quality assessment and area under the curve calculation, 48 infants were included (gestational age mean [SD] 25.5 [1.4] weeks). DHA levels were positively associated with total brain (B = 7.966, p = 0.012), cortical gray matter (B = 3.653, p = 0.036), deep gray matter (B = 0.439, p = 0.014), cerebellar (B = 0.932, p = 0.003), and white matter volume (B = 3.373, p = 0.022). AA levels showed no association with brain volumes.

CONCLUSIONS

Serum DHA levels during the first 28 postnatal days were positively associated with volumes of several brain structures in extremely preterm infants at term-equivalent age.

IMPACT

Higher serum levels of DHA in the first 28 postnatal days are positively associated with brain volumes at term-equivalent age in extremely preterm born infants. Especially the most immature infants suffer from low DHA levels in the first 28 postnatal days, with little increase over time. Future research is needed to explore whether postnatal fatty acid supplementation can improve brain development and may serve as a nutritional preventive and therapeutic treatment option in extremely preterm infants.

Galectin-3 modulates microglia inflammation in vitro but not neonatal brain injury in vivo under inflammatory conditions

Microglia may contribute to injury but may also have neuroprotective properties. Galectin-3 has immunomodulatory properties that may affect the microglia phenotype and subsequent development of injury. Galectin-3 contributes to experimental hypoxic-ischemic (HI) injury in the neonatal brain, but it is unclear if galectin-3 has similar effects on infectious and sterile inflammation. Thus, we investigated the effect of galectin-3 on microglia in vitro under normal as well as infectious and sterile inflammatory conditions, and the effect of galectin-3 on neonatal brain injury following an infectious challenge in vivo. Conditions mimicking infectious or sterile inflammation were evaluated in primary microglia cell cultures from newborn mice, using LPS (10 ng/mL) and TNF-α (100 ng/mL). The response to galectin-3 was tested alone or together with LPS or TNF-α. Supernatants were collected 24 h after treatment and analyzed for 23 inflammatory mediators including pro- and anti-inflammatory cytokines and chemokines using multiplex protein analysis, as well as ELISA for MCP-1 and insulin-like growth factor (IGF)-1. Phosphorylation of proteins (AKT, ERK1/2, IκB-α, JNK, and p38) was determined in microglia cells. Neonatal brain injury was induced by a combination of LPS and HI (LPS + HI) in postnatal day 9 transgenic mice lacking functional galectin-3 and wild-type controls. LPS and TNF-α induced pro-inflammatory (9/11 vs. 9/10) and anti-inflammatory (6/6 vs. 2/6) cytokines, as well as chemokines (6/6 vs. 4/6) in a similar manner, except generally lower amplitude of the TNF-α-induced response. Galectin-3 alone had no effect on any of the proteins analyzed. Galectin-3 reduced the LPS- and TNF-α-induced microglia response for cytokines, chemokines, and phosphorylation of IκB-α. LPS decreased baseline IGF-1 levels, and the levels were restored by galectin-3. Brain injury or microglia response after LPS + HI was not affected by galectin-3 deficiency. Galectin-3 has no independent effect on microglia but modulates inflammatory activation in vitro. The effect was similar under infectious and sterile inflammatory conditions, suggesting that galectin-3 regulates inflammation not just by binding to LPS or toll-like receptor-4. Galectin-3 restores IGF-1 levels reduced by LPS-induced inflammation, suggesting a potential protective effect on infectious injury. However, galectin-3 deficiency did not affect microglia activation and was not beneficial in an injury model encompassing an infectious challenge.

Effect of Enteral Lipid Supplement on Severe Retinopathy of Prematurity: A Randomized Clinical Trial

IMPORTANCE

Lack of arachidonic acid (AA) and docosahexaenoic acid (DHA) after extremely preterm birth may contribute to preterm morbidity, including retinopathy of prematurity (ROP).

OBJECTIVE

To determine whether enteral supplementation with fatty acids from birth to 40 weeks' postmenstrual age reduces ROP in extremely preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

The Mega Donna Mega trial, a randomized clinical trial, was a multicenter study performed at 3 university hospitals in Sweden from December 15, 2016, to December 15, 2019. The screening pediatric ophthalmologists were masked to patient groupings. A total of 209 infants born at less than 28 weeks' gestation were tested for eligibility, and 206 infants were included. Efficacy analyses were performed on as-randomized groups on the intention-to-treat population and on the per-protocol population using as-treated groups. Statistical analyses were performed from February to April 2020.

INTERVENTIONS

Infants received either supplementation with an enteral oil providing AA (100 mg/kg/d) and DHA (50 mg/kg/d) (AA:DHA group) or no supplementation within 3 days after birth until 40 weeks' postmenstrual age.

MAIN OUTCOMES AND MEASURES

The primary outcome was severe ROP (stage 3 and/or type 1). The secondary outcomes were AA and DHA serum levels and rates of other complications of preterm birth.

RESULTS

A total of 101 infants (58 boys [57.4%]; mean [SD] gestational age, 25.5 [1.5] weeks) were included in the AA:DHA group, and 105 infants (59 boys [56.2%]; mean [SD] gestational age, 25.5 [1.4] weeks) were included in the control group. Treatment with AA and DHA reduced severe ROP compared with the standard of care (16 of 101 [15.8%] in the AA:DHA group vs 35 of 105 [33.3%] in the control group; adjusted relative risk, 0.50 [95% CI, 0.28-0.91]; P = .02). The AA:DHA group had significantly higher fractions of AA and DHA in serum phospholipids compared with controls (overall mean difference in AA:DHA group, 0.82 mol% [95% CI, 0.46-1.18 mol%]; P < .001; overall mean difference in control group, 0.13 mol% [95% CI, 0.01-0.24 mol%]; P = .03). There were no significant differences between the AA:DHA group and the control group in the rates of bronchopulmonary dysplasia (48 of 101 [47.5%] vs 48 of 105 [45.7%]) and of any grade of intraventricular hemorrhage (43 of 101 [42.6%] vs 42 of 105 [40.0%]). In the AA:DHA group and control group, respectively, sepsis occurred in 42 of 101 infants (41.6%) and 53 of 105 infants (50.5%), serious adverse events occurred in 26 of 101 infants (25.7%) and 26 of 105 infants (24.8%), and 16 of 101 infants (15.8%) and 13 of 106 infants (12.3%) died.

CONCLUSIONS AND RELEVANCE

This study found that, compared with standard of care, enteral AA:DHA supplementation lowered the risk of severe ROP by 50% and showed overall higher serum levels of both AA and DHA. Enteral lipid supplementation with AA:DHA is a novel preventive strategy to decrease severe ROP in extremely preterm infants.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03201588.

Analysis of Brain Injury Biomarker Neurofilament Light and Neurodevelopmental Outcomes and Retinopathy of Prematurity Among Preterm Infants

IMPORTANCE

Circulating levels of neurofilament light (NfL) and glial fibrillary acidic protein (GFAP) are important in the course of brain injury in adults, but longitudinal postnatal circulating levels in preterm infants have not been investigated.

OBJECTIVES

To examine postnatal longitudinal serum levels of NfL and GFAP in preterm infants during the first 15 weeks of life and to explore possible associations between these biomarkers, neonatal morbidities, and neurodevelopmental outcomes at 2 years.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from 3 clinical studies, including 221 infants born before 32 weeks gestational age (GA) from 1999 to 2015; neurodevelopmental outcomes were evaluated in 120 infants. Data were collected at tertiary-level neonatal intensive care units in Gothenburg, Lund, and Uppsala, Sweden. Data analysis was conducted from January to October 2020.

EXPOSURE

Preterm birth.

MAIN OUTCOMES AND MEASURES

Serum NfL and GFAP levels, retinopathy of prematurity (ROP), intraventricular hemorrhage, and Bayley Scales of Infant Development II and III at 2 years of age, analyzed by multivariate logistic regression measured by odds ratio (OR), and receiver operating characteristic curve (ROC) analysis. Area under the curve (AUC) was also measured.

RESULTS

The 221 included infants (108 [48.9%] girls) had a mean (SD) GA at birth of 26.5 (2.1) weeks and a mean (SD) birth weight of 896 (301) grams. NfL levels increased after birth, remaining high during the first 4 weeks of life before declining to continuously low levels by postnatal age 12 weeks (median [range] NfL level at birth: 58.8 [11.5-1371.3] ng/L; 1 wk: 83.5 [14.1-952.2] ng/L; 4 wk: 24.4 [7.0-306.0] ng/L; 12 wk: 9.1 [3.7-57.0] ng/L). In a binary logistic regression model adjusted for GA at birth, birth weight SD score, Apgar status at 5 minutes, and mode of delivery, the NfL AUC at weeks 2 to 4 was independently associated with any ROP (OR, 4.79; 95% CI, 2.17-10.56; P < .001). In an exploratory analysis adjusted for GA at birth and sex, NfL AUC at weeks 2 to 4 was independently associated with unfavorable neurodevelopmental outcomes at 2 years corrected age (OR per 10-unit NfL increase, 1.07; 95% CI, 1.02-1.13; P = .01). Longitudinal GFAP levels were not significantly associated with neonatal morbidity or neurodevelopmental outcome.

CONCLUSIONS AND RELEVANCE

In this study, high NfL levels during the first weeks of life were associated with ROP and poor neurodevelopmental outcomes at 2 years of age. Associations between NfL and later neurovascular development in infants born prematurely should be investigated further.

Decreased Platelet Counts and Serum Levels of VEGF-A, PDGF-BB, and BDNF in Extremely Preterm Infants Developing Severe ROP

INTRODUCTION

Thrombocytopenia has been identified as an independent risk factor for retinopathy of prematurity (ROP), although underlying mechanisms are unknown. In this study, the association of platelet count and serum platelet-derived factors with ROP was investigated.

METHODS

Data for 78 infants born at gestational age (GA) <28 weeks were included. Infants were classified as having no/mild ROP or severe ROP. Serum levels of vascular endothelial growth factor A, platelet-derived growth factor BB, and brain-derived neurotrophic factor were measured in serum samples collected from birth until postmenstrual age (PMA) 40 weeks. Platelet counts were obtained from samples taken for clinical indication.

RESULTS

Postnatal platelet counts and serum concentrations of the 3 growth factors followed the same postnatal pattern, with lower levels in infants developing severe ROP at PMA 32 and 36 weeks (p < 0.05-0.001). With adjustment for GA, low platelet counts and low serum concentrations of all 3 factors at PMA 32 weeks were significantly associated with severe ROP. Serum concentrations of all 3 factors also strongly correlated with platelet count (p < 0.001).

CONCLUSION

In this article, we show that ROP, platelet counts, and specific pro-angiogenic factors correlate. These data suggest that platelet-released factors might be involved in the regulation of retinal and systemic angiogenesis after extremely preterm birth. Further investigations are needed.

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.

Expression of S100A Alarmins in Cord Blood Monocytes Is Highly Associated With Chorioamnionitis and Fetal Inflammation in Preterm Infants

Background: Preterm infants exposed to chorioamnionitis and with a fetal inflammatory response are at risk for neonatal morbidity and adverse outcome. Alarmins S100A8, S100A9, and S100A12 are expressed by myeloid cells and have been associated with inflammatory activation and monocyte modulation.

Aim: To study S100A alarmin expression in cord blood monocytes from term healthy and preterm infants and relate results to clinical findings, inflammatory biomarkers and alarmin protein levels, as well as pathways identified by differentially regulated monocyte genes.

Methods: Cord blood CD14+ monocytes were isolated from healthy term (n = 10) and preterm infants (<30 weeks gestational age, n = 33) by MACS technology. Monocyte RNA was sequenced and gene expression was analyzed by Principal Component Analysis and hierarchical clustering. Pathways were identified by Ingenuity Pathway Analysis. Inflammatory proteins were measured by Multiplex ELISA, and plasma S100A proteins by mass spectrometry. Histological chorioamnionitis (HCA) and fetal inflammatory response syndrome (FIRS) were diagnosed by placenta histological examination.

Results: S100A8, S100A9, and S100A12 gene expression was significantly increased and with a wider range in preterm vs. term infants. High S100A8 and S100A9 gene expression (n = 17) within the preterm group was strongly associated with spontaneous onset of delivery, HCA, FIRS and elevated inflammatory proteins in cord blood, while low expression (n = 16) was associated with impaired fetal growth and physician-initiated delivery. S100A8 and S100A9 protein levels were significantly lower in preterm vs. term infants, but within the preterm group high S100A gene expression, spontaneous onset of labor, HCA and FIRS were associated with elevated protein levels. One thousand nine hundred genes were differentially expressed in preterm infants with high vs. low S100A alarmin expression. Analysis of 124 genes differentially expressed in S100A high as well as FIRS and HCA groups identified 18 common pathways and S100A alarmins represented major hubs in network analyses.

Conclusion: High expression of S100A alarmins in cord blood monocytes identifies a distinct clinical risk group of preterm infants exposed to chorioamnionitis and with a fetal inflammatory response. Gene and pathway analyses suggest that high S100A alarmin expression also affects monocyte function. The connection with monocyte phenotype and inflammation-stimulated S100A expression in other cell types (e.g., neutrophils) warrants further investigation.

Morphine affects brain activity and volumes in preterms: An observational multi-center study

OBJECTIVE

We hypothesized that morphine has a depressing effect on early brain activity, assessed using quantitative aEEG/EEG parameter and depressed activity will be associated with brain volumes at term in extremely preterm infants.

STUDY DESIGN

174 preterm infants were enrolled in 3 European tertiary NICUs (mean GA:26 ± 1wks) and monitored during the first 72 h after birth with continuous 2 channel aEEG. Six epochs of aEEG recordings were selected and minimum amplitude of aEEG (min aEEG), percentage of time amplitude <5 μV (% of time < 5 μV), spontaneous activity transients (SATrate) and interSAT interval (ISI) were calculated. For infants receiving morphine, the cumulative morphine dosage was calculated. In a subgroup of 58 infants, good quality MRI at term equivalent age (TEA) and the cumulative morphine dose until TEA were available. The effects of morphine administration and cumulative dose on aEEG/EEG measures and on brain volumes were investigated.

RESULTS

Morphine administration had a significant effect on all quantitative aEEG/EEG measures, causing depression of early brain activity [longer ISI (β 2.900), reduced SAT rate (β -1.386), decreased min aEEG (β -0.782), and increased % of time < 5 μV (β 14.802)] in all epochs. A significant effect of GA and postnatal age on aEEG/EEG measures was observed. Cumulative morphine dose until TEA had a significant negative effect on total brain volume (TBV) (β -8.066) and cerebellar volume (β -1.080).

CONCLUSIONS

Administration of sedative drugs should be considered when interpreting aEEG/EEG together with the negative dose dependent morphine impact on brain development.

Neonatal clinical blood sampling led to major blood loss and was associated with bronchopulmonary dysplasia

AIM

Studies indicate that reduced foetal haemoglobin levels are related to increased neonatal morbidity rates. This study investigated the relationships between sampling-related blood loss and adult blood transfusions administered during postnatal days 1-14 and the development of severe neonatal morbidities in extremely preterm infants born before 28 weeks of gestation.

METHODS

The medical files of 149 extremely preterm infants born at two university hospitals in Sweden from 2013 to 2018 were investigated.

RESULTS

Blood sampling resulted in a 58% depletion of the endogenous blood volume postnatal days 1-14 (median 40.4 mL/kg, interquartile range 23.9-53.3 mL/kg) and correlated with the adult erythrocyte transfusion volume (r_S  = 0.870, P < .001). Sampling-related blood loss on postnatal days 1-7, adjusted for gestational age at birth and birth weight standard deviation score, was associated with the development of bronchopulmonary dysplasia (BPD) (odds ratio by a 10-unit increase 2.4, 95% confidence interval 1.1-5.4) (P = .03). No associations were found between blood sampling and intraventricular haemorrhage or necrotising enterocolitis in the full statistical model. The largest proportion of sampling-related blood was used for blood gas analyses (48.7%).

CONCLUSION

Diagnostic blood sampling led to major endogenous blood loss replaced with adult blood components and was associated with the development of BPD.

[Children born too soon and outcomes]

Advances in perinatal intensive care have resulted in increased survival of the most immature preterm infants (born before 28 gestational weeks) and these new survivors are now entering school. While the clear majority of all children born preterm have a normal development, the extremely preterm infant is at a considerable risk for long term disabilities and rates of adverse development increase at lower gestational ages. Lung function is commonly affected in children born extremely preterm, and many have treatment for obstructive symptoms. The incidences of major neuromotor impairments, i.e. cerebral palsy, are low, but there is an increasing awareness of common cognitive and neuropsychiatric problems in extremely preterm children and their special needs in school. Extremely preterm children therefore need follow up of lung function and neurodevelopment at least until school start.

Association of Retinopathy of Prematurity With Low Levels of Arachidonic Acid: A Secondary Analysis of a Randomized Clinical Trial

Importance

Mice with oxygen-induced retinopathy fed matched diets except for ω-3 long-chain polyunsaturated fatty acids (LC-PUFAs) vs ω-6 LC-PUFAs demonstrate relative antiangiogenic and neuroprotective associations of ω-3 LC-PUFAs. However, supplementing preterm infants with LC-PUFAs has been inconsistent in reducing major preterm morbidities. However, few studies measured serum lipid levels after supplementation.

Objective

To examine the associated risk of retinopathy of prematurity (ROP) from the levels of circulating ω-3 and ω-6 LC-PUFAs.

Design, Setting, and Participants

This longitudinal clinical study was a further analysis of serum lipid levels from a randomized controlled trial cohort of 90 infants born at gestational age (GA) less than 28 weeks. From April 4, 2013, to September 22, 2015, cord blood samples, followed by venous blood samples, were obtained at birth and at 1, 7, 14, and 28 days after birth and then at postmenstrual age (PMA) 32, 36, and 40 weeks at the neonatal intensive care unit at Sahlgrenska University Hospital in Göteborg, Sweden.

Main Outcomes and Measures

Serum phospholipid fatty acids were transmethylated and measured by gas chromatography-mass spectrometry. Mann-Whitney test, logistic regression Spearman rank correlation, and receiver operating characteristic curve analysis were used to compare differences between infants with no ROP and infants who developed ROP.

Results

Serum levels from 78 infants (43 male [55%]; mean [SD] GA, 25.5 [1.4] weeks) with a known ROP outcome were evaluated. Lower area under the curve (AUC) of arachidonic acid (AA) (20:4 ω-6) was seen in infants with a later diagnosis of ROP compared with infants with no ROP in the first month of life (mean, 34.05 [95% CI, 32.10-36.00] vs 37.15 [95% CI, 34.85-39.46]; P < .05). In addition, lower levels of AA at 32 weeks' PMA were seen in infants with later severe ROP compared with in those without ROP (mean, 7.06 [95% CI, 6.60-7.52] vs 8.74 [95% CI, 7.80-9.67]; P < .001). In logistic modeling, low postnatal serum levels of AA and GA at birth identified with a sensitivity greater than 90% of infants who developed ROP.

Conclusions and Relevance

Low postnatal levels of the ω-6 LC-PUFAs (AA) are strongly associated with ROP development. Evaluating postnatal AA fraction after birth in addition to GA may be useful for ROP prediction.

Trial Registration

clinicaltrials.gov Identifier: NCT02760472.

Erythropoietin serum levels, versus anaemia as risk factors for severe retinopathy of prematurity

BACKGROUND

Preterm infants with anaemia are treated with recombinant human erythropoietin (rhEPO). It is debated whether rhEPO treatment is a risk factor for retinopathy of prematurity (ROP). We evaluated longitudinal EPO and haemoglobin levels, blood transfusions and neonatal morbidities as risk factors for severe ROP.

METHOD

This prospective study included 78 Swedish infants, born <28 weeks gestational age (GA), screened for ROP. We tested serum EPO levels on postnatal days 1, 7, 14 and 28 and at postmenstrual ages 32, 36 and 40 weeks. Haemoglobin levels and blood transfusions were recorded during postnatal weeks 1-4. Anaemia was defined as haemoglobin ≤110 g/L.

RESULTS

During postnatal week 1, infants with severe ROP requiring treatment (28%) more frequently developed anaemia (42.9% versus 8.0%, P = 0.003) and had higher mean EPO levels (postnatal day 7: 14.2 versus 10.8 mIU/mL, P = 0.003) compared to infants with no or less severe ROP not requiring treatment. In multivariable analyses, GA and anaemia during week 1 remained significant risk factors, but elevated EPO level postnatal day 7 was no longer significant.

CONCLUSIONS

Among infants born <28 weeks GA, anaemia during week 1 was a significant risk factor for severe ROP requiring treatment but not elevated EPO levels.

C-peptide suppression during insulin infusion in the extremely preterm infant is associated with insulin sensitivity

CONTEXT

Little is known about the individual response of glucose-regulating factors to administration of exogenous insulin infusion in extremely preterm infants.

OBJECTIVE

To evaluate longitudinal serum concentrations of insulin, C-peptide, and plasma glucose levels in a high frequency sampling regimen in extremely preterm infants treated with insulin due to hyperglycemia.

DESIGN

Prospective longitudinal cohort study.

SETTING

Two university hospitals in Sweden between December 2015 and September 2016.

PATIENTS AND INTERVENTION

Serum samples were obtained from nine extremely preterm infants, gestational age between 22(+3) and 26(+5) weeks(+days), with hyperglycemia (plasma-glucose >10 mmol/L) at the start of insulin infusion, at 12, 24, and every 24 hours thereafter during ongoing infusion, and 12, 24, and 72 hours after the end of insulin infusion.

MAIN OUTCOME MEASURES

Longitudinal serum concentrations of insulin and C-peptide and plasma glucose levels.

RESULTS

During insulin infusion, the serum C-peptide concentrations decreased compared to at start of infusion (p = 0.036), and then increased after ending the infusion. Individual insulin sensitivity based on the non-fasting plasma glucose/insulin ratio at the start of insulin infusion correlated with the initial decrease in serum ΔC-peptide[After 12h] (p = 0.007) and the degree of lasting decrease in serum ΔC-peptide[After end of infusion] (p = 0.015).

CONCLUSION

Exogenous insulin infusion suppressed the C-peptide concentration to individually different degrees. In addition, the effect of insulin infusion on β-cells may be linked to individual insulin sensitivity, where a low insulin sensitivity resulted in a more pronounced decrease in C-peptide during insulin infusion.

Long-chain polyunsaturated fatty acids decline rapidly in milk from mothers delivering extremely preterm indicating the need for supplementation

AIM

Our aim was to perform an in-depth analysis of the composition of fatty acids in milk from mothers delivering extremely preterm babies. We investigated longitudinal changes in milk fatty acid profiles and the relationship between several types of fatty acids, including omega-3 and omega-6.

METHODS

Milk samples were collected at three stages of lactation from 78 mothers who delivered at less than 28 weeks of pregnancy at the Sahlgrenska University Hospital, Gothenburg, Sweden, from April 2013 to September 2015. Fatty acid composition was analysed by gas chromatography-mass spectrometry.

RESULTS

A reduction in long-chain polyunsaturated fatty acids (LCPUFAs) was observed during the lactation period. The concentrations of arachidonic acid and docosahexaenoic acid declined from medians of 0.34 to 0.22 mol% and 0.29 to 0.15 mol%, respectively, between postnatal day 7 and a postmenstrual age of 40 weeks. Strong correlations were found between the intermediates of several classes of fatty acids, including omega-3, omega-6 and omega-9.

CONCLUSION

A rapid reduction in LCPUFA content in the mother's milk during the lactation period emphasises the importance of fatty acid supplementation to infants born extremely preterm, at least during the period corresponding to the third trimester, when rapid development of the brain and adipose tissue requires high levels of LCPUFAs.

Influence of Human Milk and Parenteral Lipid Emulsions on Serum Fatty Acid Profiles in Extremely Preterm Infants

Background

Infants born prematurely are at risk of a deficiency in ω‐6 and ω‐3 long‐chain polyunsaturated fatty acids (LC‐PUFAs) arachidonic acid (AA) and docosahexaenoic acid (DHA). We investigated how fatty acids from breast milk and parenteral lipid emulsions shape serum LC‐PUFA profiles in extremely preterm infants during early perinatal life.

Methods

Ninety infants born < 28 weeks gestational age were randomized to receive parenteral lipids with or without the ω‐3 LC‐PUFAs eicosapentaenoic acid (EPA) and DHA (SMOFlipid: Fresenius Kabi, Uppsala, Sweden, or Clinoleic: Baxter Medical AB, Kista, Sweden, respectively). The fatty acid composition of infant serum phospholipids was determined from birth to postmenstrual age 40 weeks, and in mother's milk total lipids on postnatal day 7. Enteral and parenteral intake of LC‐PUFAs was correlated with levels in infant serum.

Results

Infants administered parenteral ω‐3 LC‐PUFAs received 4.4 and 19.3 times more DHA and EPA, respectively, over the first 2 weeks of life. Parenteral EPA but not DHA correlated with levels in infant serum. We found linear relationships between dietary EPA and DHA and infant serum levels in the Clinoleic (Baxter Medical AB) group. The volume of administered SMOFlipid (Fresenius Kabi) was inversely correlated with serum AA, whereas Clinoleic (Baxter Medical AB) inversely correlated with serum EPA and DHA.

Conclusions

There appears to be no or low correlation between the amount of DHA administered parenterally and levels measured in serum. Whether this observation reflects serum phospholipid fraction only or truly represents the amount of accreted DHA needs to be investigated. None of the parenteral lipid emulsions satisfactorily maintained high levels of both ω‐6 and ω‐3 LC‐PUFAs in infant serum.

Prediction of neonatal respiratory morbidity by quantitative ultrasound lung texture analysis: a multicenter study

BACKGROUND

Prediction of neonatal respiratory morbidity may be useful to plan delivery in complicated pregnancies. The limited predictive performance of the current diagnostic tests together with the risks of an invasive procedure restricts the use of fetal lung maturity assessment.

OBJECTIVE

The objective of the study was to evaluate the performance of quantitative ultrasound texture analysis of the fetal lung (quantusFLM) to predict neonatal respiratory morbidity in preterm and early-term (<39.0 weeks) deliveries.

STUDY DESIGN

This was a prospective multicenter study conducted in 20 centers worldwide. Fetal lung ultrasound images were obtained at 25.0-38.6 weeks of gestation within 48 hours of delivery, stored in Digital Imaging and Communication in Medicine format, and analyzed with quantusFLM. Physicians were blinded to the analysis. At delivery, perinatal outcomes and the occurrence of neonatal respiratory morbidity, defined as either respiratory distress syndrome or transient tachypnea of the newborn, were registered. The performance of the ultrasound texture analysis test to predict neonatal respiratory morbidity was evaluated.

RESULTS

A total of 883 images were collected, but 17.3% were discarded because of poor image quality or exclusion criteria, leaving 730 observations for the final analysis. The prevalence of neonatal respiratory morbidity was 13.8% (101 of 730). The quantusFLM predicted neonatal respiratory morbidity with a sensitivity, specificity, positive and negative predictive values of 74.3% (75 of 101), 88.6% (557 of 629), 51.0% (75 of 147), and 95.5% (557 of 583), respectively. Accuracy was 86.5% (632 of 730) and positive and negative likelihood ratios were 6.5 and 0.3, respectively.

CONCLUSION

The quantusFLM predicted neonatal respiratory morbidity with an accuracy similar to that previously reported for other tests with the advantage of being a noninvasive technique.

Increase of neuronal injury markers Tau and neurofilament light proteins in umbilical blood after intrapartum asphyxia

AIM

Compare the levels of the brain injury biomarkers Tau and neurofilament light protein (NFL) in cases of asphyxia with those in controls.

MATERIALS AND METHODS

We analyzed the neuronal proteins Tau and NFL in umbilical blood of 10 cases of severe-moderate intrapartum asphyxia and in 18 control cases.

RESULTS

The levels of both Tau and neurofilament were significantly higher after asphyxia and it appeared to be a correlation between the levels of the biomarkers and the severity of the insult.

DISCUSSION

Future studies are warranted to support or refute the value of Tau/NFLin clinical practice.

CONCLUSION

Fetal asphyxia remains a clinical problem resulting in life-long neurological disabilities. We urgently need more accurate early predictive markers to direct the clinician when to provide neuroprotective therapy.

Effects of a lipid emulsion containing fish oil on polyunsaturated fatty acid profiles, growth and morbidities in extremely premature infants: A randomized controlled trial

BACKGROUND & AIMS

The purpose of the study was to compare the effects of the parenteral emulsion SMOFlipid^®, with 15% fish oil, with Clinoleic^® on retinopathy of prematurity (ROP) and other morbidities and growth, and to compare their impact on longitudinal serum levels of fatty acids. Retinopathy of prematurity, other morbidity and growth were correlated with each parenteral lipid supplement.

METHODS

Ninety infants born at gestational age <28 weeks were randomized to treatment with SMOFlipid^® or Clinoleic^®. Two thirds (66%) of the infants received parenteral nutrition for up to 14 days birth (median 8, range 2-14 days), and additional 25% of the infants received for up to 28 days after birth (median 21, range 15-28 days). Cord blood samples and then venous blood samples were obtained at ages 1, 7, 14, and 28 days and at postmenstrual age (PMA) 32, 36, and 40 weeks. Breastmilk was collected at postnatal day 7, and at PMA 32 and 40 weeks. Serum phospholipid and breastmilk total fatty acids were analyzed by gas chromatography-mass spectrometry. Treatment groups were compared with regard to ROP, bronchopulmonary dysplasia, necrotizing enterocolitis, patent ductus arteriosus sepsis and growth between birth and 36 weeks.

RESULTS

Infants on SMOFlipid^® had higher fractions of omega-3 LCPUFA eicosapentaenoic acid (EPA) and slightly higher omega-3 LCPUFA docosahexaenoic acid (DHA) fraction and a decreased arachidonic acid (AA) to DHA ratio from one week after birth up to 32 postmenstrual weeks compared to infants on Clinoleic^®. Treatment groups did not differ in morbidities or growth.

CONCLUSION

Supplementation with SMOFlipid^® containing 15% fish oil during parenteral nutrition increased EPA substantially, DHA marginally, reduced AA and decreased AA to DHA ratio. It did not reduce morbidity or affect growth. Since extremely preterm infants accumulate a large deficit of DHA and AA, studies on more prolonged or different levels of DHA and AA supplementation are warranted.

Temporal Characterization of Microglia/Macrophage Phenotypes in a Mouse Model of Neonatal Hypoxic-Ischemic Brain Injury

Immune cells display a high degree of phenotypic plasticity, which may facilitate their participation in both the progression and resolution of injury-induced inflammation. The purpose of this study was to investigate the temporal expression of genes associated with classical and alternative polarization phenotypes described for macrophages and to identify related cell populations in the brain following neonatal hypoxia-ischemia (HI). HI was induced in 9-day old mice and brain tissue was collected up to 7 days post-insult to investigate expression of genes associated with macrophage activation. Using cell-markers, CD86 (classic activation) and CD206 (alternative activation), we assessed temporal changes of CD11b⁺ cell populations in the brain and studied the protein expression of the immunomodulatory factor galectin-3 in these cells. HI induced a rapid regulation (6 h) of genes associated with both classical and alternative polarization phenotypes in the injured hemisphere. FACS analysis showed a marked increase in the number of CD11b⁺CD86⁺ cells at 24 h after HI (+3667%), which was coupled with a relative suppression of CD11b⁺CD206⁺ cells and cells that did not express neither CD86 nor CD206. The CD11b⁺CD206⁺ population was mixed with some cells also expressing CD86. Confocal microscopy confirmed that a subset of cells expressed both CD86 and CD206, particularly in injured gray and white matter. Protein concentration of galectin-3 was markedly increased mainly in the cell population lacking CD86 or CD206 in the injured hemisphere. These cells were predominantly resident microglia as very few galectin-3 positive cells co-localized with infiltrating myeloid cells in Lys-EGFP-ki mice after HI. In summary, HI was characterized by an early mixed gene response, but with a large expansion of mainly the CD86 positive population during the first day. However, the injured hemisphere also contained a subset of cells expressing both CD86 and CD206 and a large population that expressed neither activation marker CD86 nor CD206. Interestingly, these cells expressed the highest levels of galectin-3 and were found to be predominantly resident microglia. Galectin-3 is a protein involved in chemotaxis and macrophage polarization suggesting a novel role in cell infiltration and immunomodulation for this cell population after neonatal injury.

Cord blood neutrophils display a galectin-3 responsive phenotype accentuated by vaginal delivery

BACKGROUND

Term neonates are at increased risk of infections due to undeveloped immune mechanisms, and proper neutrophil function is important for perinatal immune defence. Galectin-3, an endogenous β-galactoside-binding lectin, is emerging as an inflammatory mediator and we have previously shown that primed/activated, but not resting, adult neutrophils respond to this lectin by production of reactive oxygen species (ROS). We investigated if galectin-3 is of importance in perinatal immune defence, focusing on plasma levels and neutrophil responsiveness.

METHODS

Neutrophils were isolated from peripheral blood of healthy adults and cord blood (CB) after elective Caesarean section (CSCB) and vaginal delivery (VDCB). ROS production was measured by chemiluminescence, L-selectin expression by flow cytometry, and interleukin-8 (IL-8) and galectin-3 concentrations by ELISA. Statistical evaluations were performed using the Mann-Whitney test.

RESULTS

In response to galectin-3, CSCB neutrophils showed a small but clear ROS production not evident in adult cells, signifying that neonatal neutrophils exist in a primed state. IL-8 production was elevated in CSCB cells while L-selectin exposure was equal to adult cells. Comparing CSCB to VDCB neutrophils, the latter showed an extensive galectin-3 responsiveness, indicating that the degree of priming is dependent on mode of delivery. VDCB neutrophils were increasingly prone to shed L-selectin, while the amount of IL-8 was similar to CSCB cells. The endogenous galectin-3 levels were higher in neonatal as compared to adult plasma, unaffected by mode of delivery.

CONCLUSIONS

Neutrophils enter a pre-primed state already in the fetus. Upon exposure to the inflammatory stimuli that are associated with labor, the neutrophils develop a reactive phenotype with extensive priming features.

The association between histological chorioamnionitis, funisitis and neonatal outcome in women with preterm prelabor rupture of membranes

OBJECTIVE

To determine the impact of histological chorioamnionitis (HCA) and funisitis on neonatal outcome in preterm prelabor rupture of membranes (PPROM) pregnancies.

METHODS

Women with PPROM between 24 + 0 to 36 + 6 weeks of gestation, admitted to the Department of Obstetrics and Gynecology at the University Hospital Hradec Kralove in the Czech Republic, between July 2008 and October 2010, were enrolled in the study (n = 231).

RESULTS

The incidence of early-onset sepsis (EOS) differed significantly in neonates born to women with and without HCA, after adjustment for gestational age (11% versus 1%, p = 0.011). The incidence of EOS in neonates was also significantly different, after adjustment for gestational age, in cases with and without funisitis (18% versus 4%, p = 0.002). The same was also found for retinopathy of prematurity (ROP) cases with and without funisitis (23% versus 4%, p = 0.014), after adjustment for gestational age.

CONCLUSIONS

HCA and funisitis increase the risk of adverse perinatal outcome in PPROM pregnancies.

Microglia/macrophage-derived inflammatory mediators galectin-3 and quinolinic acid are elevated in cerebrospinal fluid from newborn infants after birth asphyxia

Activation of microglia/macrophages is important in neonatal hypoxic–ischemic (HI) brain injury. Based on experimental studies, we identified macrophage/microglia-derived mediators with potential neurotoxic effects after neonatal HI and examined them in cerebrospinal fluid (CSF) from newborn infants after birth asphyxia. Galectin-3 is a novel inflammatory mediator produced by microglia/macrophages. Galectin-3 is chemotactic for inflammatory cells and activates nicotinamide adenine dinucleotide phosphate (NADPH) oxidase resulting in production and release of reactive oxygen species (ROS). Matrix metalloproteinase-9 (MMP-9) is a tissue-degrading protease expressed by activated microglia in the immature brain after HI. Both galectin-3 and MMP-9 contribute to brain injury in animal models for neonatal HI. Quinolinic acid (QUIN) is a neurotoxic N-methyl-d-aspartate (NMDA) receptor agonist also produced by activated microglia/macrophages. Galectin-3 and MMP-9 were measured by ELISA and QUIN by mass spectrometry. Asphyxiated infants (n = 20) had higher levels of galectin-3 (mean (SEM) 2.64 (0.43) ng/mL) and QUIN (335.42 (58.9) nM) than controls (n = 15) (1.36 (0.46) ng/mL and 116.56 (16.46) nM, respectively), p < 0.05 and p < 0.01. Infants with septic infections (n = 10) did not differ from controls. Asphyxiated infants with abnormal outcome had higher levels of galectin-3 (3.96 (0.67) ng/mL) than those with normal outcome (1.76 (0.32) ng/mL), p = 0.02, and the difference remained significant in the clinically relevant group of infants with moderate encephalopathy. MMP-9 was detected in few infants with no difference between groups. The potentially neurotoxic macrophage/microglia-derived mediators galectin-3 and QUIN are increased in CSF after birth asphyxia and could serve as markers and may contribute to injury.

Galectin 3 aggravates joint inflammation and destruction in antigen-induced arthritis

OBJECTIVE

Galectin 3, an endogenous β-galactoside-binding lectin, plays an important role in the modulation of immune responses. The finding that galectin 3 is present in the inflamed synovium in patients with rheumatoid arthritis suggests that the protein is associated with the pathogenesis of this disease. We undertook this study to investigate the influence of galectin 3 deficiency in a murine model of arthritis.

METHODS

Wild-type (WT) and galectin 3-deficient (galectin 3(-/-) ) mice were subjected to antigen-induced arthritis (AIA) through immunization with methylated bovine serum albumin. The concentration of serum cytokines (interleukin-6 [IL-6] and tumor necrosis factor α [TNFα]) and antigen-specific antibodies was evaluated using a cytometric bead array platform and enzyme-linked immunosorbent assay (ELISA). Cellular IL-17 responses were examined by flow cytometry, ELISA, and enzyme-linked immunospot assay.

RESULTS

The joint inflammation and bone erosion of AIA were markedly suppressed in galectin 3(-/-) mice as compared with WT mice. The reduced arthritis in galectin 3(-/-) mice was accompanied by decreased levels of antigen-specific IgG and proinflammatory cytokines. The frequency of IL-17-producing cells in the spleen was reduced in galectin 3(-/-) mice as compared with WT mice. Exogenously added recombinant galectin 3 could partially restore the reduced arthritis and cytokines in galectin 3(-/-) mice.

CONCLUSION

Our findings show that galectin 3 plays a pathogenic role in the development and progression of AIA and that the disease severity is accompanied by alterations of antigen-specific IgG levels, systemic levels of TNFα and IL-6, and frequency of IL-17-producing T cells. To our knowledge, this is the first report of in vivo evidence that galectin 3 plays a crucial role in the development of arthritis.

Profile of blood cells and inflammatory mediators in periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome

Background

This study aimed to profile levels of blood cells and serum cytokines during afebrile and febrile phases of periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome to advance pathophysiological understanding of this pediatric disease.

Methods

A cohort of patients with a median age of 4.9 years experiencing 'typical PFAPA' episodes participated in this study. Blood cells and serum cytokines were analyzed by CBC analysis and multiplex ELISA.

Results

Oscillations in the concentration of blood cells during the afebrile and febrile phases of typical PFAPA syndrome were observed; novel findings include increased monocytes and decreased eosinophils during a febrile episode and increased thrombocytes in the afebrile interval. Relatively modest levels of pro-inflammatory cytokines were present in sera. IFNγ-induced cytokine IP10/CXCL10 was increased after the onset of fever while T cell-associated cytokines IL7 and IL17 were suppressed during afebrile and febrile periods.

Conclusions

Identification of dysregulated blood cells and serum cytokines is an initial step towards the identification of biomarkers of PFAPA disease and/or players in disease pathogenesis. Future investigations are required to conclusively discern which mediators are associated specifically with PFAPA syndrome.

Mortality rates of children aged under five in Henan province, China, 2004-2008

To analyse the mortality rates, causes of death and trends over time in children aged under five years in Henan province and to provide preventive advice to attempt to decrease the mortality rates of these children, a retrospective study was conducted, analysing the vital statistics data from 2004 to 2008 from the annual report of maternal and child health in Henan. The early neonatal (<7 days), neonatal (<28 days), infant (<1 year) and children under-five mortality rates were calculated for each year. The child mortality rates decreased in all age groups (early neonatal, neonatal, infants and children <5 years) from 2004 (7.44 per thousand, 9.81 per thousand, 12.08 per thousand and 14.04 per thousand, respectively) to 2008 (4.86 per thousand, 5.50 per thousand, 7.08 per thousand and 8.81 per thousand, respectively). The changes were more pronounced in the rural areas. However, child mortality remained higher in the rural areas (5.00 per thousand, 5.62 per thousand, 7.22 per thousand and 9.06 per thousand) than urban areas (3.98 per thousand, 4.74 per thousand, 6.21 per thousand and 7.30 per thousand). Infants and neonates accounted for a large proportion of deaths in the under-fives (84.5% and 67.9%). The first five leading causes of death in the under-fives were: disorders relating to short gestation and low birthweight, birth asphyxia, congenital anomalies, accidents and pneumonia. The leading causes of death in different age groups varied between rural and urban areas. Reducing early newborn death, especially in the rural areas, is a key step to further decreasing mortality in the under-fives. Attention should be paid to perinatal care to prevent preterm birth and congenital anomalies.

Treating neonatal brain injury - promise and inherent research challenges

In this review we discuss current challenges faced by researchers and clinician-scientists in the pursuit of therapeutics to treat hypoxic-ischemic (HI) brain injury in term infants. At present, there is an absence of neuroprotective drugs that are safe and effective for the protection of neonates from neurological sequels after HI. We discuss secondary neurotoxic processes elicited by HI that may be targets for therapeutic interventions with a specific focus on inflammatory mechanisms. Advances in research to unravel these cellular processes and molecular mechanisms that drive injurious processes after HI have traditionally been plagued by conflicting results when assessing different times for intervention, different models for brain injury, and the adult versus neonate brain. We attribute impeded drug development in part to such disparate results and general difficulties to conduct a stringent, comprehensive analysis of candidate drugs prior to clinical trials. It will be imperative to implement changes in the clinic and laboratory in order for future drug initiatives to achieve success. We also provide a brief discussion on the pursuit of anti-inflammatory molecules and monitoring methods that are the focus of current patents and that, in our opinion, may lead to important new developments in the treatment of HI brain injury in newborn infants.

Converging molecular pathways in human neural development and degeneration

Animal studies suggest that phosphorylation of microtubule-associated protein tau is a physiological way of destabilizing axons in the developing brain, promoting synaptic plasticity, while in the adult human brain tau phosphorylation is a specific sign of Alzheimer's disease. We here show, for the first time, that newborn human infants have extremely high levels of phosphorylated tau in their cerebrospinal fluid, and that these levels decrease during the first years of life. Tau phosphorylation in Alzheimer's disease may be a physiological response to Alzheimer-associated synaptotoxicity.

Expression of cytokines and chemokines in cervical and amniotic fluid: relationship to histological chorioamnionitis

OBJECTIVE

To correlate cervical and amniotic fluid cytokines and macrophage-related chemokines to the development of histological chorioamnionitis (HCA) in patients with preterm labor (PTL) and preterm prelabor rupture of the membranes (PPROM).

STUDY DESIGN

Cervical and amniotic fluid interleukin (IL)-6, IL-8, IL-18, monocyte chemotactic protein (MCP)-1, MCP-2, and MCP-3 from pregnant women (at <or=34 weeks of gestation) in PTL (N = 42) were analyzed and related to the subsequent occurrence of HCA or inflammatory signs in the placenta. For the patients with PPROM (N = 30) only amniotic fluid proteins were analyzed.

RESULTS

Intra-amniotic levels of IL-6, IL-8, IL-18, MCP-1, and MCP-3 were significantly higher in PTL cases with HCA compared to non-HCA controls, whereas no such relationship was obtained in the PPROM group. Cervical IL-8 and IL-6 (but not IL-18, MCP-1, MCP-2, and MCP-3) in PTL patients was associated with HCA, and at a cut-off level of 10.0 ng/mL cervical IL-8 was a strong predictor of HCA in the PTL cases (sensitivity 100%, specificity 67%, positive predictive value 63%, negative predictive value 100%). The cytokine and chemokine levels in the group with inflammatory signs were generally higher than in controls but lower compared to the concentrations in the HCA group.

CONCLUSIONS

The amniotic levels of IL-6, IL-8, IL-18, and the CC-chemokines MCP-1 and MCP-3 in PTL patients all predicted HCA, whereas only IL-8 was a clinically useful marker of HCA in the cervical fluid. In addition there is indication that the levels of inflammatory proteins are related to the degree of inflammatory infiltration in placental tissue samples.

Pasteurization of mother's own milk reduces fat absorption and growth in preterm infants

AIM

A randomized study was conducted to evaluate whether pasteurized milk (Holder pasteurization 62.5 degrees C, 30 min) reduces fat absorption and growth in preterm infants.

METHODS

Preterm infants (825-1325 g) born with gestational age < or =30 weeks were randomized into two groups, of which one started with pasteurized own mother's milk for 1 week and continued with raw milk the following week, and a second group was fed in reverse order. By using this design the infants served as their own controls. At the end of each week, a 72-h fat balance was performed and growth was monitored.

RESULTS

We found, on an average, 17% higher fat absorption with raw as compared to pasteurized milk. Infants gained more weight and linear growth assessed as knee-heel length was also greater during the week they were fed raw milk as compared to the week they were fed pasteurized milk.

CONCLUSION

Feeding preterm infants pasteurized as compared to raw own mother's milk reduced fat absorption. When the infants were fed raw milk, they gained more in knee-heel length compared to when they were fed pasteurized milk.

Matrix metalloproteinase-9 gene knock-out protects the immature brain after cerebral hypoxia-ischemia

Inhibition of matrix metalloproteinase-9 (MMP-9) protects the adult brain after cerebral ischemia. However, the role of MMP-9 in the immature brain after hypoxia-ischemia (HI) is unknown. We exposed MMP-9(-/-) [MMP-9 knock-out (KO)] and wild-type (WT) mice to HI on postnatal day 9. HI was induced by unilateral ligation of the left carotid artery followed by hypoxia (10% O2; 36 degrees C). Gelatin zymography showed that MMP-9 activity was transiently increased at 24 h after HI in the ipsilateral hemisphere and MMP-9-positive cells were colocalized with activated microglia. Seven days after 50 min of HI, cerebral tissue volume loss was reduced in MMP-9 KO (21.8 +/- 1.7 mm3; n = 22) compared with WT (32.3 +/- 2.1 mm3; n = 22; p < 0.001) pups, and loss of white-matter components was reduced in MMP-9 KO compared with WT pups (neurofilament: WT, 50.9 +/- 5.4%; KO, 18.4 +/- 3.1%; p < 0.0001; myelin basic protein: WT, 57.5 +/- 5.8%; KO, 23.2 +/- 3.5%; p = 0.0001). The neuropathological changes were associated with a delayed and diminished leakage of the blood-brain barrier (BBB) and a decrease in inflammation in MMP-9-deficient animals. In contrast, the neuroprotective effects after HI in MMP-9-deficient animals were not linked to either caspase-dependent (caspase-3 and cytochrome c) or caspase-independent (apoptosis-inducing factor) processes. This study demonstrates that excessive activation of MMP-9 is deleterious to the immature brain, which is associated with the degree of BBB leakage and inflammation. In contrast, apoptosis does not appear to be a major contributing factor.

Effect of lipopolysaccharide on global gene expression in the immature rat brain

To improve the understanding of the molecular mechanisms whereby lipopolysaccharide (LPS) affects the immature brain, global gene expression following LPS exposure was investigated in neonatal rats. Brains (n = 5/time point) were sampled 2, 6, and 72 h after LPS and compared with age-matched controls. The mRNA from each brain was analyzed separately on Affymextrix GeneChip Rat Expression Set 230. The number of genes regulated after LPS were 847 at 2 h, 1564 at 6 h, and 1546 genes at 72 h. Gene ontology analysis demonstrated that, at both 2 and 6 h after LPS, genes associated with protein metabolism, response to external stimuli and stress (immune and inflammatory response, chemotaxis) and cell death were overrepresented. At 72 h, the most strongly regulated genes belonged to secretion of neurotransmitters, transport, synaptic transmission, cell migration, and neurogenesis. Several pathways associated with cell death/survival were identified (caspase-tumor necrosis factor alpha [TNF-alpha]-, p53-, and Akt/phosphatidylinositol-3-kinase (PI3 K)-dependent mechanisms). Caspase-3 activity increased and phosphorylation of Akt decreased 8 h after peripheral LPS exposure. These results show a complex cerebral response to peripheral LPS exposure. In addition to the inflammatory response, a significant number of cell death-associated genes were identified, which may contribute to increased vulnerability of the immature brain to hypoxia-ischemia (HI) following LPS exposure.

Non-protein-bound iron in brain interstitium of newborn pigs after hypoxia

Oxidative damage is implied in perinatal hypoxic-ischemic brain injury, most importantly in white matter. Nonprotein-bound iron (NPBI) catalyzes the formation of toxic hydroxyl radicals. We measured the extracellular level of NPBI through microdialysis in the cortex, striatum, and periventricular white matter before, during and after severe hypoxia in newborn pigs. NPBI was analyzed by a new spectrophotometric method in which ferrous iron is chelated by bathophenanthroline. NPBI was present in all brain areas under baseline conditions and increased in white matter from 0.97 (0.69) to 2.75 (1.85) micromol/l (not corrected for recovery rate) during early reoxygenation. NPBI may contribute to oxidative injury after perinatal hypoxic insults.

Cytokine response in cerebrospinal fluid from preterm infants with posthaemorrhagic ventricular dilatation

AIM

Posthaemorrhagic ventricular dilatation (PHVD) is closely associated with white matter damage and neurological disability in the preterm infant. Proinflammatory cytokines have been implicated in the pathogenesis of white matter injury and subsequent cerebral palsy. The aim of this study was to determine the levels of proinflammatory cytokines in cerebrospinal fluid (CSF) from preterm infants with PHVD and to correlate the levels to white matter damage and neurodevelopmental outcome.

METHODS

CSF samples were obtained from 24 preterm infants with expanding PHVD and 19 preterm infants with normal ultrasound. Tumour necrosis factor-alphaa (TNF-alpha ), interleukin-1beta (IL-1beta), interleukin-8 (IL-8) and interferon-gamma (IFN-gamma) in CSF were measured by enzyme-linked immunosorbent assay, and IL-6 was measured by bioassay.

RESULTS

The concentrations of TNF-alpha, IL-1beta, IL-6 and IL-8 were significantly elevated in CSF from infants with PHVD. TNF-alpha was detected in 43% of PHVD infants and 11% of controls (p = 0.04). IL-1beta was detected in 67% of PHVD infants and 0% of controls (p < 0.0001). The concentrations of IL-6 were 368 (145-460) pg ml(-1) in the PHVD group and 30 (25-41) pg ml(-1) in the control group (p < 0.0001), and those of IL-8 were 3000 (1620-3400) pg ml(-1) in the PHVD group and 35 (0-230) pg ml(-1) in the control group (p < 0.0001). Cytokine concentrations did not correlate with white matter lesions on ultrasound, shunt dependence or neurological outcome within the PHVD group.

CONCLUSION

There was an intense and prolonged inflammatory reaction in CSF from preterm infants with PHVD and a high risk for subsequent white matter injury and permanent neurological impairment.