Antimicrobial Peptides (AMPs) and the Microbiome in Preterm Infants: Consequences and Opportunities for Future Therapeutics.

Antimicrobial peptides (AMPs) are crucial components of the innate immune system in various organisms, including humans. Beyond their direct antimicrobial effects, AMPs play essential roles in various physiological processes. They induce angiogenesis, promote wound healing, modulate immune responses, and serve as chemoattractants for immune cells. AMPs regulate the microbiome and combat microbial infections on the skin, lungs, and gastrointestinal tract. Produced in response to microbial signals, AMPs help maintain a balanced microbial community and provide a first line of defense against infection. In preterm infants, alterations in microbiome composition have been linked to various health outcomes, including sepsis, necrotizing enterocolitis, atopic dermatitis, and respiratory infections. Dysbiosis, or an imbalance in the microbiome, can alter AMP profiles and potentially lead to inflammation-mediated diseases such as chronic lung disease and obesity. In the following review, we summarize what is known about the vital role of AMPs as multifunctional peptides in protecting newborn infants against infections and modulating the microbiome and immune response. Understanding their roles in preterm infants and high-risk populations offers the potential for innovative approaches to disease prevention and treatment.

Association of ApoE Genotypes and Recovery From Intracerebral Hemorrhage in Very Low Birth Weight Infants.

BACKGROUND AND PURPOSE: Associations of APOE genotypes with intracerebral hemorrhage (ICH) in preterm infants were previously described. In adults, APOE-ε4 genotype has been proposed as susceptibility factor for impaired recovery after cerebral insult. We here aim to determine APOE genotype-specific neurological consequences of neonatal ICH at school age. METHODS: In this multicenter observational cohort study, very low birth weight (<1500 g, <32 weeks gestational age) children were studied for cerebral palsy (CP) after ultrasound diagnosed ICH stratified by APOE genotype. Follow-up examination was done at the age of 5 to 6 years. Study personnel were blinded for perinatal information and complications. Participants were born between January 1, 2009 and December 31, 2013 and enrolled in the German Neonatal Network. Of 8022 infants primarily enrolled, 2467 children were invited for follow-up between January 1, 2014 and December 31, 2019. Univariate analyses and multivariate logistic regression models were used to assess the impact of APOE genotype (APOE-ε2, APOE-ε3, APOE-ε4) on CP after ICH. RESULTS: Two thousand two hundred fifteen children participated at follow-up, including 363 children with ultrasound diagnosed neonatal ICH. In univariate analyses of children with a history of ICH, APOE-ε3 carriers had lower frequencies of CP (n=33/250; 13.2 [95% CI, 9.4%-17.8%]), as compared to APOE-ε2 (n=15/63; 23.8 [14.6%-35.3%], P=0.037) and -ε4 carriers (n=31/107; 29.0 [21.0%-38.0%], P<0.001), respectively. Regression models revealed an association of APOE-ε4 genotype and CP development (odds ratio, 2.77 [1.44-5.32], P=0.002) after ICH. Notably, at low-grade ICH (grade I) APOE-ε4 expression resulted in an increased rate of CP (n=6/39; 15.4 [6.7-29.0]) in comparison to APOE-ε3 (n=2/105; 1.9 [0.4%-6.0%], P=0.002). CONCLUSIONS: APOE-ε4 carriers have an increased risk for long-term motor deficits after ICH. We assume an effect even after low-grade neonatal ICH, but more data are needed to clarify this issue.

Vancomycin-induced ototoxicity in very-low-birthweight infants.

BACKGROUND: Vancomycin is an extensively used anti-infective drug in neonatal ICUs. However, exposure-toxicity relationships have not been clearly defined. OBJECTIVES: To evaluate the risk profile for hearing deficits in vancomycin-exposed very-low-birthweight infants (VLBWI). METHODS: In a large cohort study of the German Neonatal Network (GNN; n = 16 967 VLBWI) we assessed the association of vancomycin treatment and pathological hearing tests at discharge and at 5 year follow-up. We performed audits on vancomycin exposure, drug levels, dose adjustments and exposure to other ototoxic drugs in a subgroup of 1042 vancomycin-treated VLBWI. RESULTS: In the GNN cohort, 28% (n = 4739) were exposed to IV vancomycin therapy. In multivariable logistic regression analysis, vancomycin exposure proved to be independently associated with pathological hearing test at discharge (OR 1.18, 95% CI 1.03-1.34, P = 0.016). Among vancomycin-treated infants, a cumulative vancomycin dose above the upper quartile (>314 mg/kg bodyweight) was associated with pathological hearing test at discharge (OR 2.1, 95% CI 1.21-3.64, P = 0.009), whereas a vancomycin cumulative dose below the upper quartile was associated with a reduced risk of pathological tone audiometry results at 5 years of age (OR 0.29, 95% CI 0.1-0.8, P = 0.02, n = 147). CONCLUSIONS: Vancomycin exposure in VLBWI is associated with an increased, dose-dependent risk of pathological hearing test results at discharge and at 5 years of age. Prospective studies on long-term hearing impairment are needed.

Prevalence of Congenital CMV Infection and Antiviral Therapy in Very-Low-Birth-Weight Infants: Observations of the German Neonatal Network.

BACKGROUND: To determine the prevalence of congenital CMV infection (cCMV) in very-low-birth-weight infants (VLBWI) and to evaluate epidemiological characteristics of VLBWI with antiviral therapy (AT). METHODS: CMV-specific PCR in umbilical cord tissue was performed (n=3330). Univariate analyses and logistic regression models were used to identify associations with outcome. RESULTS: 22/3330 VLBWI received AT (0.66%). 4 of these (0.12%) were PCR positive, with 2 VLBWI showing pathological screening for hearing loss. VLBWI with AT and negative PCR had significantly reduced mean birth weight (BW) and higher rates of small-for-gestational-age (SGA). Clinical sepsis, bronchopulmonary dysplasia (BPD), use of reserve antibiotics (RA) and treatment for retinopathy of prematurity were significantly increased. We further observed a higher need of transfusion of red blood cells (RBC), fresh frozen plasma and platelets. Logistic regression (controlled for gender, gestational age, SGA and BW) showed associations for AT and BPD (OR 3.4 [1.2-10.1], p=0.024), RA (OR 20.4 [4.2-98.9], p≤0.001), transfusions of RBC (OR 11.9 [1.3-105.7], p=0.026) and platelets (OR 8.7 [2.9-26.4], p≤0.001). DISCUSSION: All VLBWI with positive PCR received AT. We hypothesize from our data by assuming a postnatal aquired CMV infection in VLBWI with AT and negative PCR that VLBWI born SGA have a different risk profile. CONCLUSION: Further prospective studies concerning postnatal transmission should take VLBWI born SGA into account and should study the impact of infection on short- and long-term complications in this supposed vulnerable group.

Intermediate Follow-up of Pediatric Patients With Hemolytic Uremic Syndrome During the 2011 Outbreak Caused by E. coli O104:H4.

BACKGROUND.: In 2011 Escherichia coli O104:H4 caused an outbreak with >800 cases of hemolytic uremic syndrome (HUS) in Germany, including 90 children. Data on the intermediate outcome in children after HUS due to E. coli O104:H4 have been lacking. METHODS.: Follow-up data were gathered retrospectively from the medical records of patients who had been included in the German Pediatric HUS Registry during the 2011 outbreak. RESULTS.: Seventy-two of the 89 (81%) patients were included after a median follow-up of 3.0 (0.9-4.7) years. Hypertension and proteinuria were present in 19% and 28% of these patients, respectively. Of 4 patients with chronic kidney disease (CKD) > stage 2 at short-term follow-up, 1 had a normalized estimated glomerular filtration rate, and 3 (4%) had persistent CKD > stage 2. In 1 of these patients, CKD improved from stage 4 to 3; 1 who had CKD stage 5 at presentation received kidney transplantation; and 1 patient required further hemodialysis during follow-up. One patient (1.4%) still had major neurological symptoms at the latest follow-up. Dialysis during the acute phase (P = .01), dialysis duration (P = .01), and the duration of oligo-/anuria (P = .005) were associated with the development of renal sequelae. Patients treated with eculizumab (n = 11) and/or plasmapheresis (n = 13) during the acute phase of HUS had comparable outcomes. CONCLUSIONS.: The overall outcome of pediatric patients after HUS due to E. coli O104:H4 was equivalent to previous reports on HUS due to other types of Shiga toxin-producing E. coli (STEC). Regular follow-up visits in patients are recommended after STEC-HUS.

A simplified intravenous artesunate regimen for severe malaria.

BACKGROUND: We compared a conventional empirically derived regimen with a simplified regimen for parenteral artesunate in severe malaria. METHODS: This was a randomized, double-blind, placebo-controlled comparison to assess the noninferiority of a simplified 3-dose regimen (given at 0, 24, and 48 hours) compared with the conventional 5-dose regimen of intravenous artesunate (given at 0, 12, 24, 48, and 72 hours) in African children with Plasmodium falciparum malaria with a prespecified delta of 0.2. The total dose of artesunate in each group was 12 mg/kg. The primary end point was the proportion of children clearing ≥ 99% of their admission parasitemia at 24 hours. Safety data, secondary efficacy end points, and pharmacokinetics were also analyzed. RESULTS: In 171 children (per protocol), 78% of the recipients (95% confidence interval [CI], 69%-87%) in the 3-dose group achieved ≥ 99% parasite clearance 24 hours after the start of treatment, compared with 85% (95% CI, 77%-93%) of those receiving the conventional regimen (treatment difference, -7.2%; 95% CI, -18.9% to 4.4%). Dihydroartemisinin was cleared slightly more slowly in those children receiving the higher 3-dose regimen (7.4 vs 8.8 L/h for a 13-kg child; P 5 .008). CONCLUSIONS: Pharmacodynamic analysis suggests that 3 doses of artesunate were not inferior to 5 doses for the treatment of severe malaria in children. CLINICAL TRIALS REGISTRATION: NCT00522132.

Antimicrobial skin peptides in premature infants: Comparison with term infants and impact of perinatal factors.

Introduction: Preterm infants have an immature epidermis barrier function that may lead to an increased permeability to pathogens. On the surface of the human skin, antimicrobial peptides (AMPs) are important molecules of the innate immune system, have broad antimicrobial properties, and provide an essential role in integrity of the microbiome. Given the marked susceptibility of preterm infants to infection, we hypothesize a decreased expression of AMPs on the skin of preterm infants. Materials and methods: In a prospective single-center study with 35 preterm and 20 term infants, we analyzed skin rinsing probes for the presence of the AMPs psoriasin (S100A7) and ribonuclease 7 (RNase 7) via enzyme-linked immunosorbent assay. Samples were taken from preterm infants < 34 0/7 weeks gestational age (mean ± SD gestational age, 28.8 ± 2.4 weeks) on days 0, 7, 14, and 28 after birth. Term infants (> 36 6/7 weeks) (controls) were washed on days 0 and 28. Results: Psoriasin and RNase 7 were both expressed on skin of preterm and term infants and increased in concentration significantly over time. RNase 7 was more expressed in term infants on day 0 [preterm = 1.1 (0.7-2.9) vs. term = 2.0 (1.1-3.4) ng/ml, p = 0.017]. On day 28, premature infants showed higher values of psoriasin [preterm = 10.9 (5.6-14.2) vs. term = 6.3 (3.4-9.0) ng/ml, p < 0.001]. Notably, preterm infants with infectious or inflammatory context driven by histological proof of chorioamnionitis and early-onset or late-onset sepsis had higher concentrations of psoriasin as compared with non-affected preterm infants. After exclusion of infants with inflammatory hit, median concentrations of RNase 7 and psoriasin did not differ between preterm and full-term infants on days 0 and 28. Discussion: Psoriasin and RNase 7 concentrations increase over time on the skin of newborn infants and seem to play a role in the first defense against infection. This is of particularly interest as the role of AMPs on a maturing skin microbiome and its possible new prevention strategies is unclear and needs to be determined.

Indomethacin Prophylaxis Is Associated with Reduced Risk of Intraventricular Hemorrhage in Extremely Preterm Infants Born in the Context of Amniotic Infection Syndrome.

BACKGROUND: Amniotic infection syndrome (AIS) with perinatal inflammation may increase the susceptibility to intraventricular hemorrhage (IVH) in preterm infants. Given its anti-inflammatory and ductus arteriosus constricting capacities, we hypothesized that prophylactic administration of indomethacin reduces the incidence, severity, and consequences of IVH in the context of perinatal inflammation. METHODS: We evaluated data of infants born between 2009 and 2020 of 22 + 0-25+6 weeks of gestation from 68 German Neonatal Network centers. The effect of indomethacin prophylaxis on outcomes was analyzed in univariate analyses and multivariate regression models including a subgroup of infants with available data on 5-year follow-up. RESULTS: 4760 infants were included with a median gestational age of 24.6 SSW [interquartile range (IQR) 24.1w-25.2w] and a birth weight of 640 g [IQR 550-750 g]. 1767/4760 (37.1%) preterm infants were born in the context of AIS and 527/4760 (11.1%) received indomethacin prophylaxis. AIS infants receiving prophylactic indomethacin had lower rates of IVH (32.7% vs. 36.9%, p = 0.04), IVH III/IV (9.7% vs. 16.0%, p = 0.02) and the combined outcome of severe IVH or death (15.9% vs. 23.2%, p = 0.01) as compared to infants without prophylaxis. Multivariate logistic regression analyses confirmed our observations. In a subgroup analysis of 730 preterm infants at 5 years of age, we did not find any correlation between prophylactic indomethacin and intelligence quotient <70 or cerebral palsy. CONCLUSIONS: Our observational data demonstrate that prophylactic indomethacin is associated with a reduced risk of IVH in the highly vulnerable subgroup of preterm infants <26 weeks of gestation born from AIS.

Recurrent Late-Onset Sepsis in Extremely Low Birth Weight Infants Is Associated with Motor Deficits in Early School Age.

INTRODUCTION: Sepsis is regarded as a risk factor for brain injury in preterm infants. We herein hypothesize that extremely low birth weight infants (ELBWI, birth weight <1,000 g) having survived recurrent blood culture-proven late-onset sepsis (LOS) episodes are more likely to have an adverse long-term neurologic outcome. METHODS: In a large multicenter observational study of ELBWI ≤28 6/7 weeks, we evaluated the impact of recurrent LOS (blood culture-proven, after day 7 of life) on development at 5-6 years. Neurodevelopment, behavior, and motor qualities were tested by blinded investigators. Univariate and logistic regression analyses were performed. RESULTS: The cohort consisted of 1343 ELBWI including 1,080 infants without LOS, 186 infants with one LOS, and 77 with recurrent LOS, i.e., 55 infants with two and 22 infants with three LOS episodes. After Bonferroni-Holm correction, multiple logistic regression analysis revealed recurrent sepsis to be significantly associated with adverse motor development (critical MABC-2 testing: 3.3 [1.5-7.3], p = 0.003, pB = 0.012), whereas no significant impact of recurrent LOS was found on intelligence quotient and behavioral difficulties. Odds of having critical motor testing results for infants with recurrent LOS were 1.7 times (95% confidence interval 1.4-2.3) that of infants with one LOS. CONCLUSION: Recurrent sepsis in preterm infants is associated with adverse long-term motor development. However, infants with recurrent infections are also more likely to have preterm-related complications, and reasons for a worse neurodevelopmental outcome remain to be elucidated.

A Timely Administration of Antenatal Steroids Is Highly Protective Against Intraventricular Hemorrhage: An Observational Multicenter Cohort Study of Very Low Birth Weight Infants.

Aim: The aim of the study is to evaluate the influence of the timing of antenatal steroids (ANSs) on neonatal outcome of very low birth weight infants (VLBWI) born before 30 weeks of gestation in the German Neonatal Network. Methods: The German Neonatal Network is a large population-based cohort study enrolling VLBWIs since 2009. We included 672 neonates, who were born between January 1, 2009 and December 31, 2019 in our analysis in 10 selected centers. Infants were divided into four subgroups based on the interval between the first steroid administration and preterm birth: (I) two doses of betamethasone, ANS-birth interval: >24 h to 7 days, n = 187, (II) only one dose of betamethasone, ANS-birth interval 0-24 h, n = 70, (III) two doses of betamethasone, ANS-birth interval >7 days, n = 177, and (IV) no antenatal steroids, n = 238. Descriptive statistics and logistic regression analyses were performed for the main neonatal outcome parameters. Group IV (no ANS) was used as a reference. Results: An ANS-birth interval of 24 h to 7 days after the first dose was associated with a reduced risk for intraventricular hemorrhage (OR 0.17; 95% CI 0.09-0.31, p < 0.001) and mechanical ventilation (OR 0.37; 95% CI 0.23-0.61, p < 0.001), whereas the group of infants that only received a single dose of steroids reflected a subgroup at high risk for adverse neonatal outcomes; an ANS-birth interval of >7 days was still associated with a lower risk for intraventricular hemorrhage (OR 0.43; 95% CI 0.25-0.72, p = 0.002) and the need for mechanical ventilation (OR 0.43; 95% CI 0.27-0.71, p = 0.001). Conclusion: Our observational data indicate that an ANS-birth interval of 24 h to 7 days is strongly associated with a reduced risk of intraventricular hemorrhage in VLBWIs. Further research is needed to improve the prediction of preterm birth in order to achieve a timely administration of antenatal steroids that may improve neonatal outcomes such as intraventricular hemorrhage.

Sleep problems in infancy and early school age in very preterm infants.

BACKGROUND: Sleep plays an important role for psychological and physical health, especially in infants at high risk for long-term neurodevelopmental impairment such as preterm infants. OBJECTIVE: Our study aimed at determining risk factors for long-term sleep impairment in very-preterm (VPT; <32 weeks of gestation) infants. METHODS: Sleep problems were analyzed in an observational study in infants of the German Neonatal Network born between January 1st 2009 and December 31st 2014. Parental questionnaires of n = 2928 VPT children were evaluated regarding the child's sleep behavior at five years of age. Univariate and logistic regression analyses were used to identify risk factors for delayed sleep onset and hyperactivity/inattention (Strength and Difficulties Questionnaire). In a second cohort of n = 342 VPT infants, sleep habits were evaluated at toddlers age via the Infant Sleep Questionnaire. RESULTS: In our cohorts, 424/2928 (14.5 %) preterm children were diagnosed with delayed sleep onset at early school age while 57/342 (16.7 %) had sleep impairment in early infancy. Gestational age was not independently associated with sleep problems (i.e., early school age: OR 0.97, 95 % CI 0.9-1.1, p = 0.15). Notably, in both our cohorts, neonatal exposure to analgesics and sedatives was associated with a higher risk for sleep problems, i.e., early school age: exposure to sedatives: OR 1.31, 95%CI 1.02-1.7, p = 0.03. Sleep problems and drug exposure were both associated with hyperactivity/inattention. CONCLUSION: Sleep problems of VPT children are unrelated to gestational age which suggests rather individual risk factors. The significant neonatal exposure to analgesics and sedatives may contribute to long-term sleep impairment.

Association of Administration of Surfactant Using Less Invasive Methods With Outcomes in Extremely Preterm Infants Less Than 27 Weeks of Gestation.

Importance: The inclusion of less invasive surfactant administration (LISA) in the care of preterm infants has been found to be beneficial for respiratory outcomes. Recently, the OPTIMIST trial found higher mortality rates in the subgroup of infants born at 25 to 26 weeks' gestational age (GA) who received surfactant treatment while spontaneously breathing. Objective: To analyze outcomes among LISA-exposed, highly vulnerable babies born at less than 27 weeks' GA within the large-scale observational cohort of the German Neonatal Network. Design, Setting, and Participants: In this cohort study of data from 68 tertiary level neonatal intensive care units in Germany of infants born between 22 weeks 0 days to 26 weeks 6 days of gestation between April 1, 2009, and December 31, 2020, short-term outcomes among infants receiving LISA vs infants not receiving LISA were compared. Exposure: Use of LISA within the first 72 hours of life. Main Outcomes and Measures: The main outcomes were rates of LISA use, use of mechanical ventilation within the first 72 hours (considered failure of LISA), and association of LISA with outcomes, including death from all causes, bronchopulmonary dysplasia (BPD), death and BPD combined, pneumothorax, retinopathy of prematurity, intracerebral hemorrhage, and periventricular leukomalacia. To address potential confounding factors, multivariate logistic regression models were used. Results: A total of 6542 infants (3030 [46.3%] female and 3512 [53.7%] male; mean [SD] GA, 25.3 (1.1) weeks; mean [SD] birth weight, 715 [180] g) were analyzed; 2534 infants (38.7%) received LISA, which was most frequently given quasi-prophylactically during delivery room management. Among the infants who received LISA, 1357 (53.6%) did not require mechanical ventilation in the first 72 hours compared with 331 infants (8.3%) of 4008 who did not receive LISA. In a multivariate logistic regression model that adjusted for GA, small-for-GA status, sex, multiple birth, inborn status, antenatal steroid use, and maximum fraction of inspired oxygen in the first 12 hours of life, LISA was associated with reduced risks of all-cause death (odds ratio [OR], 0.74; 95% CI, 0.61-0.90; P = .002), BPD (OR, 0.69; 95% CI, 0.62-0.78; P < .001), and BPD or death (OR, 0.64; 95% CI, 0.57-0.72; P < .001) compared with infants without LISA exposure. Conclusions and Relevance: The results of this long-term multicenter cohort study suggest that LISA may be associated with reduced risks of adverse outcomes in extremely preterm infants.

Haematological and biochemical reference intervals for infants and children in Gabon.

OBJECTIVES: To establish reference intervals for major haematological and biochemical parameters in Gabonese infants and children. METHODS: The reference sample population consisted of 226 healthy infants (4-9 weeks of age) and 185 healthy children (18-60 months of age). Basic red cell parameters as well as total and differential white blood cell counts were performed. Clinical chemistry parameters consisted of glutamate-pyruvic transaminase and creatinine, and total bilirubin was measured in children. Statistical analysis was based on the guidelines of the Clinical and Laboratory Standards Institute. Nonparametric methods were used to determine 95% reference limits and their 90% confidence intervals. RESULTS: Compared to European populations, values for several red cell parameters (haemoglobin, haematocrit, red blood cell count, mean corpuscular volume) were lower and platelet counts were higher. Eosinophils were higher in the older age group, most likely caused by intestinal helminths. CONCLUSIONS: The study confirms the importance of establishing reference limits for local populations. The reference ranges could be used as a benchmark for similar populations in Central Africa.

Infants Younger Than 90 Days Admitted for Late-Onset Sepsis Display a Reduced Abundance of Regulatory T Cells.

Objective: To provide epidemiological data of infants < 90 days of age with suspected late-onset sepsis (LOS) and evaluate distinct immunological specificities. We hypothesized that previously healthy infants < 3 months of age with sepsis have a yet undefined immunological predisposition; e.g. differences in lymphocyte subsets including regulatory T cells. Methods: We performed an exploratory, single center study between January 1st, 2019 and June 1st, 2021. Routine diagnostics included conventional culture (blood, cerebrospinal fluid, urine), PCR and inflammatory markers in infants < 90 days of age with suspected sepsis. We additionally analyzed lymphocyte subsets and CD4+ CD25+ forkhead box protein (FoxP3)+ Tregs at admission for sepsis workup as compared to age-matched controls. Results: A convenience sample cohort of n= 51 infants with sepsis workup was enrolled. Invasive bacterial infection (IBI) was diagnosed in 25 (49.0%) patients including two infants with a rhinovirus co-infection and viral infection in 14 (27.5%) neonates. No infectious cause was found in 12 cases. Infants with suspected LOS displayed a decreased abundance of CD4+ FoxP3+ T cells as compared to controls, which was most pronounced in the subgroup of infants with IBI. We also noticed elevated HLA-DR-positive CD3+ cells in infants with LOS and a higher CD4/CD8-ratio in infants with viral infection as compared to healthy controls. Infants with viral infections had a higher number of natural killer cells as compared to infants with IBI. Conclusion: Our exploratory data support the concept of a potential immaturity state and failed immune tolerance development for young infants with LOS. Future large-scale studies are needed to elucidate pre-sepsis conditions and to target the microbiome-immunity interplay as a potential risk pattern.

Five Year Follow Up of Extremely Low Gestational Age Infants after Timely or Delayed Administration of Routine Vaccinations.

This study is aimed at detecting the rate of untimely immunization in a large cohort of extremely low gestational age neonates (ELGANs) of the German Neonatal Network (GNN) and at addressing risk factors for delayed vaccination and associated long-term consequences. We performed an observational study of the GNN between 1st January 2010 and 31st December 2019. The immunization status for the hexavalent and pneumococcal immunization was evaluated in n = 8401 preterm infants <29 weeks of gestation. Univariate analysis and logistic/linear regression models were used to identify risk factors for vaccination delay and outcomes at a 5-year follow-up. In our cohort n = 824 (9.8%) ELGANs did not receive a timely first immunization with the hexavalent and pneumococcal vaccine. Risk factors for delayed vaccination were SGA status (18.1% vs. 13.5%; OR 1.3; 95% CI: 1.1-1.7), impaired growth and surrogates for complicated clinical courses (i.e., need for inotropes, necrotizing enterocolitis). At 5 years of age, timely immunized children had a lower risk of bronchitis (episodes within last year: 27.3% vs. 37.7%; OR 0.60, 95% CI: 0.42-0.86) but spirometry measures were unaffected. In conclusion, a significant proportion of ELGANs are untimely immunized, specifically those with increased vulnerability, even though they might particularly benefit from the immune-promoting effects of a timely vaccination.

Genetic predisposition for vitamin D deficiency is not associated with adverse outcome of very low birth weight infants: A cohort study from the German Neonatal Network.

OBJECTIVE: Postnatal vitamin D supplementation is standard of care in neonates and preterm infants. Despite routine supplementation of vitamin D, a wide range of complications related to vitamin D deficiency has been described in the literature. Since standard vitamin D supplementation might be not sufficient in preterm infants with a genetic predisposition for vitamin D deficiency, we investigated the outcome of preterm infants with regard to their genetic estimated vitamin D levels. METHODS: Preterm infants with a birth weight below 1500 grams were included in the German Neonatal Network at the time of their birth and tested at the age of five. The vitamin D level was genetically calculated based on three single nucleotide polymorphisms (SNPs: rs12794714, rs7944926 and rs2282679) which alter vitamin D synthesis pathways. Specific alleles of these polymorphisms are validated markers for low plasma vitamin D levels. Outcome data were based on baseline data at the time of birth, typical complications of prematurity, body measurements at the age of five and occurrence of bone fractures. T-test and Fisher's exact test were used for statistical comparison. RESULTS: According to their genetic predisposition, 1,924 preterm infants were divided into groups of low (gsVitD < 20. Percentile), intermediate and high vitamin D level estimates. Low genetic vitamin D level estimates could not be shown to be associated with any adverse outcome measures examined. The analyses covered data on aforementioned determinants. CONCLUSION: Low genetic vitamin D level estimates could not be shown to be associated with previously described adverse outcome in preterm infants.

Neonatal Outcome After Preeclampsia and HELLP Syndrome: A Population-Based Cohort Study in Germany.

Aim: To analyze short term outcomes of very low birth weight infants (VLBWI) born preterm after maternal preeclampsia and HELLP syndrome within the German Neonatal Network. Methods: The German Neonatal Network is a large population-based cohort study enrolling VLBWI since 2009. Two thousand six hundred and fifty two infants below 32 weeks of gestation born after maternal preeclampsia or HELLP syndrome and 13,383 infants born prematurely for other causes between 2009 and 2018 were included in our analysis. Descriptive statistics and multinomial regression models including preeclampsia and HELLP syndrome were performed for short-term outcome measures such as intracerebral hemorrhage, necrotizing enterocolitis requiring surgery, bronchopulmonary dysplasia, retinopathy of prematurity, periventricular leukomalacia, persistent ductus arteriosus requiring surgery, blood culture positive sepsis and death. Results: After adjustment for confounding variables, preterm birth due to preeclampsia or HELLP syndrome was associated with a reduced risk for intracerebral hemorrhage (OR 0.73, 95% CI 0.60-0.89), necrotizing enterocolitis requiring surgery (OR 0.35 95% CI 0.15-0.82), periventricular leukomalacia (OR 0.61 95% CI 0.40-0.92), and death (OR 0.72 95% CI 0.55-0.96) as compared to other causes of preterm birth. Conclusions: The indication for preterm birth has an impact on neonatal outcome in preterm infants born below 32 weeks. This notion should be included when counseling the families.

Preterm birth and sustained inflammation: consequences for the neonate.

Almost half of all preterm births are caused or triggered by an inflammatory process at the feto-maternal interface resulting in preterm labor or rupture of membranes with or without chorioamnionitis ("first inflammatory hit"). Preterm babies have highly vulnerable body surfaces and immature organ systems. They are postnatally confronted with a drastically altered antigen exposure including hospital-specific microbes, artificial devices, drugs, nutritional antigens, and hypoxia or hyperoxia ("second inflammatory hit"). This is of particular importance to extremely preterm infants born before 28 weeks, as they have not experienced important "third-trimester" adaptation processes to tolerate maternal and self-antigens. Instead of a balanced adaptation to extrauterine life, the delicate co-regulation between immune defense mechanisms and immunosuppression (tolerance) to allow microbiome establishment is therefore often disturbed. Hence, preterm infants are predisposed to sepsis but also to several injurious conditions that can contribute to the onset or perpetuation of sustained inflammation (SI). This is a continuing challenge to clinicians involved in the care of preterm infants, as SI is regarded as a crucial mediator for mortality and the development of morbidities in preterm infants. This review will outline the (i) role of inflammation for short-term consequences of preterm birth and (ii) the effect of SI on organ development and long-term outcome.

Surgical necrotizing enterocolitis but not spontaneous intestinal perforation is associated with adverse neurological outcome at school age.

Gastrointestinal complications during the neonatal period, i.e. necrotizing enterocolitis (NEC) and spontaneous intestinal perforation (SIP), are associated with adverse short-term outcome in very-low-birthweight infants (VLBWI, <1500 g birth weight). However, little is known about the neurological outcome of survivors at school age. We analysed data of 2241 infants followed-up at the age of 6 years. To determine the effect of NEC and SIP on cognitive outcome in consideration of other important confounding factors, we used multivariable logistic regression models. In addition, infants with surgical diagnosis of NEC (n = 43) or SIP (n = 41) were compared to NEC (n = 43) or SIP (n = 41) negative controls using Mahalanobis distance matching. Infants with a history for NEC had a three times increased risk (RR 3.0 [1.8-4.2], p < 0.001) to develop IQ scores <85 while history of surgical SIP did not increase the relative risk for lower IQs at school age (RR 1.0 [0.4-2.1], p = 1.000). In a matched-cohort analysis, we confirmed that infants with surgical NEC had lower mean IQ results than unaffected controls (±SD) (85±17 vs. 94±14, p = 0.023) while no differences were found for history of SIP. Our results reflect that the different aetiology and inflammatory extent of NEC and SIP may lead to disparate neurodevelopment trajectories. Hence, our data suggest a potential role of early gut-brain axis distortion in infants with NEC which needs to be further explored.

Sepsis related mortality of extremely low gestational age newborns after the introduction of colonization screening for multi-drug resistant organisms.

BACKGROUND: In 2013 German infection surveillance guidelines recommended weekly colonization screening for multidrug-resistant (MDRO) or highly epidemic organisms for neonatal intensive care units (NICUs) and extended hygiene measures based on screening results. It remains a matter of debate whether screening is worth the effort. We therefore aimed to evaluate sepsis related outcomes before and after the guideline update. METHODS: The German Neonatal Network (GNN) is a prospective cohort study including data from extremely preterm infants between 22 + 0 and 28 + 6 gestational weeks born in 62 German level III NICUs. RESULTS: Infants treated after guideline update (n = 8.903) had a lower mortality (12.5% vs. 13.8%, p = 0.036), reduced rates for clinical sepsis (31.4 vs. 42.8%, p <  0.001) and culture-proven sepsis (14.4% vs. 16.5%, p = 0.003) as compared to infants treated before update (n = 3.920). In a multivariate logistic regression analysis, nine pathogens of culture-proven sepsis were associated with sepsis-related death, e.g. Pseudomonas aeruginosa [OR 59 (19-180), p <  0.001)]. However, the guideline update had no significant effect on pathogen-specific case fatality, total sepsis-related mortality and culture-proven sepsis rates with MDRO. While the exposure of GNN infants to cefotaxime declined over time (31.1 vs. 40.1%, p <  0.001), the treatment rate with meropenem was increased (31.6 vs. 26.3%, p <  0.001). CONCLUSIONS: The introduction of weekly screening and extended hygiene measures is associated with reduced sepsis rates, but has no effects on sepsis-related mortality and sepsis with screening-relevant pathogens. The high exposure rate to meropenem should be a target of antibiotic stewardship programs.