Inflammation and retinopathy of prematurity

SOCS3 regulates pathological retinal angiogenesis through modulating SPP1 expression in microglia and macrophages

Pathological ocular angiogenesis has long been associated with myeloid cell activation. However, the precise cellular and molecular mechanisms governing the intricate crosstalk between the immune system and vascular changes during ocular neovascularization formation remain elusive. In this study, we demonstrated that the absence of the suppressor of cytokine signaling 3 (SOCS3) in myeloid cells led to a substantial accumulation of microglia and macrophage subsets during the neovascularization process. Our single-cell RNA sequencing data analysis revealed a remarkable increase in the expression of the secreted phosphoprotein 1 (Spp1) gene within these microglia and macrophages, identifying subsets of Spp1-expressing microglia and macrophages during neovascularization formation in angiogenesis mouse models. Notably, the number of Spp1-expressing microglia and macrophages exhibited further elevation during neovascularization in mice lacking myeloid SOCS3. Moreover, our investigation unveiled the Spp1 gene as a direct transcriptional target gene of signal transducer and activator of transcription 3. Importantly, pharmaceutical activation of SOCS3 or blocking of SPP1 resulted in a significant reduction in pathological neovascularization. In conclusion, our study highlights the pivotal role of the SOCS3/STAT3/SPP1 axis in the regulation of pathological retinal angiogenesis.

Neonatal sepsis as a cause of retinopathy of prematurity: An etiological explanation

Retinopathy of prematurity (ROP) is a complex neonatal disorder with multiple contributing factors. In this paper we have mounted the evidence in support of the proposal that neonatal sepsis meets all requirements for being a cause of ROP (not a condition, mechanism, or even innocent bystander) by means of initiating the early stages of the pathomechanism of ROP occurrence, systemic inflammation. We use the model of etiological explanation, which distinguishes between two overlapping processes in ROP causation. It can be shown that sepsis can initiate the early stages of the pathomechanism via systemic inflammation (causation process) and that systemic inflammation can contribute to growth factor aberrations and the retinal characteristics of ROP (disease process). The combined contribution of these factors with immaturity at birth (as intrinsic risk modifier) and prenatal inflammation (as extrinsic facilitator) seems to provide a cogent functional framework of ROP occurrence. Finally, we apply the Bradford Hill heuristics to the available evidence. Taken together, the above suggests that neonatal sepsis is a causal inducer of ROP.

Early detection and correlation of tear fluid inflammatory factors that influence angiogenesis in premature infants with and without retinopathy of prematurity

Purpose

To measure the levels of inflammatory factors in tear fluid of pre-term infants with and without retinopathy of prematurity (ROP).

Methods

The cross-sectional pilot study included 29 pre-term infants undergoing routine ROP screening. Pre-term infants were grouped as those without ROP (no ROP; n = 14) and with ROP (ROP; n = 15). Sterile Schirmer's strips were used to collect the tear fluid from pre-term infants. Inflammatory factors such as interleukin (IL)-6, IL-8, MCP1 (Monocyte Chemoattractant Protein 1; CCL2), RANTES (Regulated on Activation, Normal T Cell Expressed and Secreted; CCL5), and soluble L-selectin (sL-selectin) were measured by cytometric bead array using a flow cytometer.

Results

Birth weight (BW) and gestation age (GA) were significantly (P < 0.05) lower in pre-term infants with ROP compared with those without ROP. Higher levels of RANTES (P < 0.05) and IL-8 (P = 0.09) were observed in the tear fluid of pre-term infants with ROP compared with those without ROP. Lower levels of tear fluid IL-6 (P = 0.14) and sL-selectin (P = 0.18) were measured in pre-term infants with ROP compared with those without ROP. IL-8 and RANTES were significantly (P < 0.05) higher in the tear fluid of pre-term infants with stage 3 ROP compared with those without ROP. Tear fluid RANTES level was observed to be inversely associated with GA and BW of pre-term infants with ROP and not in those without ROP. Furthermore, the area under the curve and odds ratio analysis demonstrated the relevance of RANTES/BW (AUC = 0.798; OR-7.2) and RANTES/MCP1 (AUC = 0.824; OR-6.8) ratios in ROP.

Conclusions

Distinct changes were observed in the levels of tear inflammatory factors in ROP infants. The status of RANTES in ROP suggests its possible role in pathobiology and warrants further mechanistic studies to harness it in ROP screening and management.

Comorbidities Affecting Children with Autism Spectrum Disorder: A Retrospective Chart Review

Autism spectrum disorder (ASD) is a developmental disorder characterized by deficits in social interaction/communication, restricted interests, and repetitive behaviors. Recent discussions have emerged worldwide regarding the heterogeneity around presentation/etiology and comorbidities. This study aimed to determine the frequency and characteristics of comorbidities among children diagnosed with ASD in Manitoba and to evaluate differences in presentation between those with and without medical comorbidities. We conducted a retrospective chart review of >1900 electronic charts at the only publicly funded referral site for children ≤6 years requiring evaluation for ASD in Manitoba. All children aged 0-6 years diagnosed with ASD at this site between May 2016 and September 2021 were identified. χ2 and t-tests were used to compare groups. Of the total of 1858 children identified, 1452 (78.1%) were boys, 251 (13.5%) were prematurely born, and 539 (29.0%) had ≥1 medical comorbidity. Global developmental delay (GDD) was diagnosed in 428 (23.0%). The age of referral and diagnosis did not differ between groups. Comorbidities were more common among premature children (16.0% vs. 12.5%, p: 0.005) and children with comorbid GDD (34.9% vs. 18.2%, p < 0.001). Neurological comorbidities were most common (37.1%). No sex difference in the overall presence of comorbidities was found (boys = 77.1% vs. 78.5%, p: 0.518); however, girls had a higher incidence of neurological comorbidities, e.g., cerebral palsy, seizures, hypotonia (14.8% vs. 9.64%, p: 0.009), as well as genetic comorbidities (4.92% vs. 2.75%, p: 0.04). The high rates of associated neurological conditions, GDD, and prematurity add heterogeneity to this group leading to potential difficulties with prognosis and service allocation. Primary vs. secondary ASD can be a way of separating individuals based on relevant medical comorbidities.

A novel marker for predicting type 1 retinopathy of prematurity: C-reactive protein/albumin ratio

PURPOSE

We aimed to investigate whether the C-reactive protein (CRP) to albumin ratio (CAR) an inflammatory predictor can be used as a marker for the development of ROP.

METHODS

Gestational age, birth weight, gender, neonatal, and maternal risk factors were recorded. The patients were divided into two groups: those who did not develop ROP (ROP -) and those who developed ROP (ROP +). The ROP + group was further separated into two groups: those who required treatment (ROP + T) and those who were not treated (ROP + NT). The following parameters were noted in the first postnatal week and at the end of the first postnatal month: CRP, albumin, CAR, white blood cell (WBC), neutrophil, lymphocyte, neutrophil-to-lymphocyte ratio (NLR), distribution red cell width (RDW), platelet (Plt), and RDW/platelet ratio.

RESULTS

We evaluated 131 premature infants who met the inclusion criteria. There was no difference between the main groups in hemogram parameters and CAR at the postnatal first week. WBC count (p = 0.011), neutrophil count (p = 0.002), and NLR were high (p = 0.004) in the ROP + group at the end of the postnatal 1st month. The CAR level at the end of the first month was higher in the ROP + group (p = 0.027). CAR was similar between the ROP + T and ROP + NT groups (p = 0.112) in the postnatal first week but higher in the treatment-required group at the end of the first month (p < 0.01).

CONCLUSION

High CAR and high NLR at the end of the postnatal first month can be used to predict the development of severe ROP.

Telemedicine in retinopathy of prematurity: Crossing borders in pediatric vision health. TELEROP study

GENERAL OBJECTIVE

To evaluate the accuracy and validity of images with smartphone compared to the RetCam® system for the diagnosis of retinopathy of prematurity (ROP).

METHODOLOGY

Observational, longitudinal and masked study carried out at the Dr. Elías Santana hospital. Infants with birth weight ≤1500 g, gestational age ≤30 weeks and/or patients exposed to risk factors or complications linked to ROP were included. These subjects were screened using images with smartphone or RetCam®, both compared to conventional fundoscopy. The ICROP classification was used for staging. The main results analyzed were sensitivity, specificity, positive predictive values and kappa index.

RESULTS

915 images (n = 121) were obtained, distributed in smartphone group (50.4%) and RetCam® group (49.6%) between August 2020 and March 2021. Subjects with ROP had lower gestational age (30.2 sem ± 2.8), birth weight (1361 g ± 398), and greater exposure to oxygen therapy (12.8 days ± 11.3). The RetCam® group presented sensitivity = 80%, specificity = 78%, positive predictive value = 90% and kappa index = 0.70. The smartphone group presented sensitivity = 88%, specificity = 90%, positive predictive value = 93.75% and kappa index = 0.81.

CONCLUSIONS

Both diagnostic methods were accurate to identify ROP. The smartphone group obtained superior results with excellent resolution, representing a cost-effective method to create a global impact on reducing preventable blindness in the pediatric population.

Incidence and risk factors for retinopathy of prematurity in premature, extremely low birth weight and extremely low gestational age infants

BACKGROUND

The aim of the study was to determine the incidence and risk factors of retinopathy of prematurity (ROP) in premature, extremely low birth weight (BW, ELBW) and extremely low gestational age (GA, ELGA) infants.

METHODS

The medical records of preterm infants who were screened for ROP between January 2012 and December 2020 were retrospectively reviewed. Only one eye of each infant with higher grade ROP was included in the study. BW; GA; medical characteristics; the presence, severity, and need for treatment of ROP were recorded. Infants were divided into groups according to BW (≤1000 g, 1001-1750 g, > 1750 g) and GA (≤25w, 26-28w, 29-31w, 32-34w, ≥35w) and data were analyzed.

RESULTS

Data of 2186 infants were evaluated. The overall incidences of any stage ROP and ROP requiring treatment were 43.5 and 8.0%, respectively. These rates were 81.1 and 23.9% in ELBW (≤1000 g) infants and were 92.9 and 64.3% in ELGA (≤25w) infants, respectively. The rates of ROP, the median duration of oxygen therapy and systemic diseases increased significantly as BW and GA decreased. The median duration of oxygen therapy and the rates of sepsis, pulmonary dysplasia (BPD), and intraventricular hemorrhage (IVH) were statistically higher in infants with ROP compared to those without ROP (p < 0.001). Multivariate regression analysis demonstrated that low BW and GA; prolonged duration of oxygen therapy; presence of PDA and necrotizing enterocolitis (NEC) were important risk factors for ROP.

CONCLUSIONS

ELBW and ELGA infants develop higher rates of ROP and severe ROP. Prolonged duration of oxygen therapy, the presence of concomitant neonatal sepsis, BPD, IVH, PDA, and NEC further increases the risk of ROP.

Retinopathy of prematurity: contribution of inflammatory and genetic factors

Retinopathy of prematurity (ROP) is a retinal vasoproliferative disorder that represents an important cause of childhood visual impairment and blindness. Although oxidative stress has long been implicated in ROP etiology, other prenatal and perinatal factors are also involved. This review focuses on current research involving inflammation and genetic factors in the pathogenesis of ROP. Increasing evidence suggests that perinatal inflammation or infection contributes to ROP pathogenesis. Cytokines and chemokines with a fundamental role in inflammatory responses and that significantly contributing to angiogenesis are analyzed. Microglia cells, the retinal-resident macrophages, are crucial for retinal homeostasis, however, under sustained pathological stimuli release exaggerated amounts of inflammatory mediators and can promote pathological neovascularization. Current modulation of angiogenic cytokines, such as treatment with antibodies to vascular endothelial growth factor (anti-VEGF), has shown efficacy in the treatment of ocular neovascularization; however, some patients are refractory to anti-VEGF agents, suggesting that other angiogenic or anti-angiogenic cytokines need to be identified. Much evidence suggests that genetic factors contribute to the phenotypic variability of ROP. Several studies have implicated the involvement of candidate genes from different signaling pathways in the development of ROP. However, a genetic component with a major impact on ROP has not yet been discovered. Most studies have limitations and did not replicate results. Future research involving bioinformatics, genomics, and proteomics may contribute to finding more genes associated with ROP and may allow discovering better solutions in the management and treatment of ROP.

Visuopathy of prematurity: is retinopathy just the tip of the iceberg?

Research on retinopathy of prematurity (ROP) focuses mainly on the abnormal vascularization patterns that are directly visible for ophthalmologists. However, recent findings indicate that children born prematurely also exhibit changes in the retinal cellular architecture and along the dorsal visual stream, such as structural changes between and within cortical areas. Moreover, perinatal sustained systemic inflammation (SSI) is associated with an increased risk for ROP and the visual deficits that follow. In this paper, we propose that ROP might just be the tip of an iceberg we call visuopathy of prematurity (VOP). The VOP paradigm comprises abnormal vascularization of the retina, alterations in retinal cellular architecture, choroidal degeneration, and abnormalities in the visual pathway, including cortical areas. Furthermore, VOP itself might influence the developmental trajectories of cerebral structures and functions deemed responsible for visual processing, thereby explaining visual deficits among children born preterm.

The prenatal phase of retinopathy of prematurity

AIM

To explore the current literature on prenatal inflammation-associated risk factors for retinopathy of prematurity (ROP).

METHODS

Subjective summary of selected experimental and epidemiological publications that support the authors' central hypothesis that the aetiology of ROP begins before birth.

RESULTS

Based on current evidence we suggest that, contrary to current aetiological models, the process of ROP development begins with a prephase in utero. This beginning is likely initiated by inflammatory responses that are associated with intrauterine infection.

CONCLUSION

We propose a novel aetio-pathogenetic model of ROP and suggest that the effects of postnatal exposure to inflammatory stressors (resulting from infection or hyperoxia or both) as well as those of other pre- and postnatal contributors to the complex pathogenesis of ROP might be modified by the prenatal phase of the disease.

ANKFY1 is essential for retinal endothelial cell proliferation and migration via VEGFR2/Akt/eNOS pathway

Dysregulation of endothelial cell proliferation and migration are hallmarks of angiogenic diseases. Among them, excessive ocular angiogenesis is a major cause of blindness. Vascular endothelial growth factor (VEGF)-VEGF receptor 2 (VEGFR2) signaling plays crucial roles in angiogenesis, endothelial cell proliferation and migration. Here, we showed that ankyrin repeat and FYVE domain containing 1 (ANKFY1), a Rab5-GTP-interacting protein, is required for retinal endothelial cell proliferation and migration. ANKFY1 knockdown significantly suppressed cell growth of human retinal microvascular endothelial cells (HRMECs) in the presence or absence of VEGF. HRMEC migration was also inhibited by depletion of ANKFY1. Western blot analysis showed that ANKFY1 knockdown reduced cell surface VEGFR2 level. In contrast, qRT-PCR analysis indicated that ANKFY1 knockdown had no effect on VEGFR2 mRNA levels. We also found that the attenuation of the protein kinase B/endothelial nitric oxide synthase (Akt/eNOS) pathway in ANKFY1 knockdown HRMECs. In conclusion, our findings revealed novel functions of ANKFY1 in cell growth and migration of retinal endothelial cells.

Serious neonatal morbidities are associated with differences in DNA methylation among very preterm infants

Background

Infants born very preterm are more likely to experience neonatal morbidities compared to their term peers. Variations in DNA methylation (DNAm) associated with these morbidities may yield novel information about the processes impacted by these morbidities.

Methods

This study included 532 infants born < 30 weeks gestation, participating in the Neonatal Neurobehavior and Outcomes in Very Preterm Infants study. We used a neonatal morbidity risk score, which was an additive index of the number of morbidities experienced during the NICU stay, including bronchopulmonary dysplasia (BPD), severe brain injury, serious neonatal infections, and severe retinopathy of prematurity. DNA was collected from buccal cells at discharge from the NICU, and DNAm was measured using the Illumina MethylationEPIC. We tested for differential methylation in association with the neonatal morbidity risk score then tested for differentially methylated regions (DMRs) and overrepresentation of biological pathways.

Results

We identified ten differentially methylated CpGs (α Bonferroni-adjusted for 706,278 tests) that were associated with increasing neonatal morbidity risk scores at three intergenic regions and at HPS4, SRRD, FGFR1OP, TNS3, TMEM266, LRRC3B, ZNF780A, and TENM2. These mostly followed dose–response patterns, for 8 CpGs increasing DNAm associated with increased numbers of morbidities, while for 2 CpGs the risk score was associated with decreasing DNAm. BPD was the most substantial contributor to differential methylation. We also identified seven potential DMRs and over-representation of genes involved in Wnt signaling; however, these results were not significant after Bonferroni adjustment for multiple testing.

Conclusions

Neonatal DNAm, within genes involved in fibroblast growth factor activities, cellular invasion and migration, and neuronal signaling and development, are sensitive to the neonatal health complications of prematurity. We hypothesize that these epigenetic features may be representative of an integrated marker of neonatal health and development and are promising candidates to integrate with clinical information for studying developmental impairments in childhood.

Maternal smoking as an independent risk factor for the development of severe retinopathy of prematurity in very preterm infants

BACKGROUND/OBJECTIVES

Retinopathy of prematurity (ROP) is a severe neonatal complication potentially leading to visual impairment and blindness. Known risk factors include preterm birth, low birth weight and respiratory support. Limited and contradictory data exist on the risk of maternal smoking during pregnancy on the development of ROP. This study aims to investigate smoking as an independent risk factor for the development of severe ROP (≥stage 3).

SUBJECTS/METHODS

This is a single centre retrospective case-control study of prospectively collected clinical data of infants born before 32 weeks of gestation between 2001 and 2012 at a tertiary care university hospital. The association between maternal smoking during pregnancy and the development of severe ROP was analyzed by multivariate logistic regression.

RESULTS

In total, n = 751 infants born < 32 weeks of gestation were included in this study. In total, 52.9% (n = 397) were diagnosed with ROP and 10.8% (n = 81) developed ROP ≥ stage 3. In total, 8.4% (n = 63) mothers presented with a history of smoking during pregnancy, which was associated to a higher rate of ROP (OR 2.59, 95% CI 1.10-6.12). Low gestational age, low birth weight and prolonged respiratory support were confirmed as independent risk factors for the development of severe ROP.

CONCLUSIONS

To date, this is the largest study evaluating the effect of maternal smoking on the development of ROP. Maternal smoking during pregnancy is identified as an independent risk factor for the development of severe ROP in preterm infants born < 32 weeks of gestation.

Effects of fish oil-containing lipid emulsions on retinopathy of prematurity in very low birth weight infants

BACKGROUND

The aim of the study was to assess the impact of different types of parenteral emulsions on retinopathy of prematurity (ROP) in very low birth weight (VLBW, birth body weight < 1500 g) infants by comparing fish oil-containing and soy-based parenteral emulsions.

METHODS

Data of preterm infants with body weights below 1500 gm at birth and receiving total parenteral nutrition (TPN) for a minimum of 7 days during the period between January 2009 and November 2017 were analyzed in this retrospective study. We compared clinical outcomes in two epochs using different lipid emulsions: epoch 1 (soybean-based lipid emulsions, January 2009-February 2014) versus epoch 2 (fish oil-containing lipid emulsions, January 2015-November 2017). The primary outcomes measured were the incidence of ROP and the number of ROP cases requiring bevacizumab therapy.

RESULTS

A total of 396 infants were enrolled in this study (203 in epoch 1 and 193 in epoch 2). A lower incidence of any stage ROP (24.1 vs. 11.4%, p < 0.001) and lower requirement of bevacizumab therapy (12.8 vs. 5.2%, p = 0.001) were observed in epoch 2. Gestational age, glutamic-pyruvic transaminase, total bilirubin, and alkaline phosphatase levels, and type of lipid emulsion in TPN were associated with higher ROP incidence. Multivariate logistic regression analysis revealed that parenteral nutrition in the form of lipid emulsions containing fish oil was associated with a lower risk of development of ROP [Odds Ratio: 0.178, 95% confidence interval (CI): 0.095-0.330, p < 0.001].

CONCLUSIONS

Compared with soybean-based lipid solutions, the use of fish oil-containing lipid solutions may be associated with a lower incidence of ROP and decreased need for bevacizumab treatment in preterm infants.

Cho S, Britton W, S. Kern T, Antonetti DA, Hellström A, E.H. Smith L. Targeting Neurovascular Interaction in Retinal Disorders

The tightly structured neural retina has a unique vascular network comprised of three interconnected plexuses in the inner retina (and choroid for outer retina), which provide oxygen and nutrients to neurons to maintain normal function. Clinical and experimental evidence suggests that neuronal metabolic needs control both normal retinal vascular development and pathological aberrant vascular growth. Particularly, photoreceptors, with the highest density of mitochondria in the body, regulate retinal vascular development by modulating angiogenic and inflammatory factors. Photoreceptor metabolic dysfunction, oxidative stress, and inflammation may cause adaptive but ultimately pathological retinal vascular responses, leading to blindness. Here we focus on the factors involved in neurovascular interactions, which are potential therapeutic targets to decrease energy demand and/or to increase energy production for neovascular retinal disorders.

Mechanisms and Treatment of Light-Induced Retinal Degeneration-Associated Inflammation: Insights from Biochemical Profiling of the Aqueous Humor

Ocular inflammation contributes to the pathogenesis of blind-causing retinal degenerative diseases, such as age-related macular degeneration (AMD) or photic maculopathy. Here, we report on inflammatory mechanisms that are associated with retinal degeneration induced by bright visible light, which were revealed while using a rabbit model. Histologically and electrophysiologically noticeable degeneration of the retina is preceded and accompanied by oxidative stress and inflammation, as evidenced by granulocyte infiltration and edema in this tissue, as well as the upregulation of total protein, pro-inflammatory cytokines, and oxidative stress markers in aqueous humor (AH). Consistently, quantitative lipidomic studies of AH elucidated increase in the concentration of arachidonic (AA) and docosahexaenoic (DHA) acids and lyso-platelet activating factor (lyso-PAF), together with pronounced oxidative and inflammatory alterations in content of lipid mediators oxylipins. These alterations include long-term elevation of prostaglandins, which are synthesized from AA via cyclooxygenase-dependent pathways, as well as a short burst of linoleic acid derivatives that can be produced by both enzymatic and non-enzymatic free radical-dependent mechanisms. The upregulation of all oxylipins is inhibited by the premedication of the eyes while using mitochondria-targeted antioxidant SkQ1, whereas the accumulation of prostaglandins and lyso-PAF can be specifically suppressed by topical treatment with cyclooxygenase inhibitor Nepafenac. Interestingly, the most prominent antioxidant and anti-inflammatory benefits and overall retinal protective effects are achieved by simultaneous administrating of both drugs indicating their synergistic action. Taken together, these findings provide a rationale for using a combination of mitochondria-targeted antioxidant and cyclooxygenase inhibitor for the treatment of inflammatory components of retinal degenerative diseases.

Neutrophil-to-lymphocyte ratio in ocular diseases: a systematic review

AIM

To summarize the results of studies investigating neutrophil-to-lymphocyte ratio (NLR) and to identify the role of NLR in ocular diseases.

METHODS

With the aim of identifying the studies related to NLR, a search was conducted on http://www.ncbi.nlm.nih.gov/pubmed by utilizing the key words "neutrophil lymphocyte ratio, ocular diseases, and eye diseases" up to February 2018. All of the original articles were assessed according to date of publications, countries, clinics and topics. Studies about ocular inflammatory diseases were evaluated according to their qualifications, review methods and results.

RESULTS

A total of 4473 publications, including original research articles and reviews were screened. The number of publications was shown a regular logarithmic increase over the years. The majority of studies were performed by clinics in Turkey and many of these publications were performed by oncology and cardiology clinics. A total of 75 publications were identified to be about ocular diseases.

CONCLUSION

Elevated NLR as a cheap, reproducible, and readily available marker could be used as a diagnostic and/or prognostic marker in ocular diseases.

Outcomes after implementing restrictive blood transfusion criteria in extremely premature infants

OBJECTIVE

To assess mortality and morbidities in very low birthweight (VLBW) infants before and after changing to a restrictive blood transfusion guideline (RTG).

STUDY DESIGN

This is a large retrospective study comparing outcomes of a liberal transfusion guideline (LTG) and RTG in VLBW infants admitted to a large single neonatal intensive care unit. Blood and platelet transfusion details, mortality, and diagnoses of frequently diagnosed morbidities were collected for each infant.

RESULTS

Mortality was similar between RTG and LTG groups (6.8% vs. 6.3%, p = 0.755). Rates of periventricular leukomalacia (PVL), retinopathy of prematurity (ROP), sepsis and the diagnosis of necrotizing enterocolitis (NEC) within 48 h of a PRBC transfusion were significantly lower with RTG (p < 0.05). Chronic lung disease was similar between groups.

CONCLUSION

RTG are safe compared to LTG, and are associated with lower rates of PVL, ROP, transfusion-associated cases of NEC and sepsis.

Retinal Vasculature in Development and Diseases

The retina is one of the most metabolically active tissues in the body, consuming high levels of oxygen and nutrients. A well-organized ocular vascular system adapts to meet the metabolic requirements of the retina to ensure visual function. Pathological conditions affect growth of the blood vessels in the eye. Understanding the neuronal biological processes that govern retinal vascular development is of interest for translational researchers and clinicians to develop preventive and interventional therapeutics for vascular eye diseases that address early drivers of abnormal vascular growth. This review summarizes the current knowledge of the cellular and molecular processes governing both physiological and pathological retinal vascular development, which is dependent on the interaction among retinal cell populations, including neurons, glia, immune cells, and vascular endothelial cells. We also review animal models currently used for studying retinal vascular development.

An iTRAQ-Based Quantitative Proteomic Analysis of Plasma Proteins in Preterm Newborns With Retinopathy of Prematurity

Purpose

Retinopathy of prematurity (ROP) is a vision-threatening complication of a premature birth, in which the etiology still remains unclear. Importantly, the molecular processes that govern these effects can be investigated in a perturbed plasma proteome composition. Thus, plasma proteomics may add new insights into a better understanding of the pathogenesis of this disease.

Methods

The cord and peripheral blood of neonates (≤30 weeks gestational age) was drawn at birth and at the 36th postmenstrual week (PMA), respectively. Blood samples were retrospectively subdivided into ROP(+) and ROP(-) groups, according to the development of ROP.

Results

The quantitative analysis of plasma proteome at both time points revealed 30 protein abundance changes between ROP(+) and ROP(-) groups. After standardization to gestational age, children who developed ROP were characterized by an increased C3 complement component and fibrinogen level at both analyzed time points.

Conclusions

Higher levels of the complement C3 component and fibrinogen, present in the cord blood and persistent to 36 PMA, may indicate a chronic low-grade systemic inflammation and hypercoagulable state that may play a role in the development of ROP.

Sildenafil and Retinopathy of Prematurity in Preterm Infants with Bronchopulmonary Dysplasia

OBJECTIVE

To assess whether sildenafil is associated with worsening retinopathy of prematurity (ROP) in very low birth weight (VLBW) infants (≤1500 g) with bronchopulmonary dysplasia (BPD).

STUDY DESIGN

This retrospective case-control study included VLBW infants admitted to the neonatal intensive care unit between January 1, 2006, and December 31, 2012. Each infant treated with sildenafil was assigned 3 unexposed controls matched for gestational age, birth weight, and BPD diagnosis. Severe ROP was defined as stage ≥3 ROP. Worsening ROP was defined as increased stage of ROP within 8 weeks + 4 days after initiation of sildenafil or matched postmenstrual age.

RESULTS

Twenty-three exposed infants and 69 matched controls met the inclusion criteria for the study (mean birth weight, 715 ± 210 g; mean gestational age, 25 ± 1 weeks). The mean postmenstrual age at sildenafil treatment was 42 ± 8 weeks. Exposed infants had more days of respiratory support (mean, 208 ± 101 days vs 102 ± 33 days; P < .001). Exposed infants had a higher prevalence of severe ROP (26% [6 of 23] vs 7% [5 of 69]; OR, 6.4; 95% CI, 1.2-32.9; P = .026). Five exposed infants and 2 unexposed infants had severe ROP before starting sildenafil and were excluded from the analysis for worsening ROP. The rate of worsening ROP did not differ significantly between exposed infants and unexposed infants ((41% [7 of 17] vs 24% [12 of 51]; OR, 8.4; 95% CI, 0.9-78.6; P = .061).

CONCLUSION

Although sildenafil treatment was not statistically significantly associated with worsening of ROP, the raw difference in ROP rate is concerning. Larger studies are warranted to confirm this finding.

Retinopathy of prematurity: a review of risk factors and their clinical significance

Retinopathy of prematurity (ROP) is a retinal vasoproliferative disease that affects premature infants. Despite improvements in neonatal care and management guidelines, ROP remains a leading cause of childhood blindness worldwide. Current screening guidelines are primarily based on two risk factors: birth weight and gestational age; however, many investigators have suggested other risk factors, including maternal factors, prenatal and perinatal factors, demographics, medical interventions, comorbidities of prematurity, nutrition, and genetic factors. We review the existing literature addressing various possible ROP risk factors. Although there have been contradictory reports, and the risk may vary between different populations, understanding ROP risk factors is essential to develop predictive models, to gain insights into pathophysiology of retinal vascular diseases and diseases of prematurity, and to determine future directions in management of and research in ROP.

Abnormal Complement Activation and Inflammation in the Pathogenesis of Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a neurovascular complication in preterm babies, leading to severe visual impairment, but the underlying mechanisms are yet unclear. The present study aimed at unraveling the molecular mechanisms underlying the pathogenesis of ROP. A comprehensive screening of candidate genes in preterms with ROP (n = 189) and no-ROP (n = 167) was undertaken to identify variants conferring disease susceptibility. Allele and genotype frequencies, linkage disequilibrium and haplotypes were analyzed to identify the ROP-associated variants. Variants in CFH (p = 2.94 × 10⁻⁷), CFB (p = 1.71 × 10⁻⁵), FBLN5 (p = 9.2 × 10⁻⁴), CETP (p = 2.99 × 10⁻⁵), and CXCR4 (p = 1.32 × 10⁻⁸) genes exhibited significant associations with ROP. Further, a quantitative assessment of 27 candidate proteins and cytokines in the vitreous and tear samples of babies with severe ROP (n = 30) and congenital cataract (n = 30) was undertaken by multiplex bead arrays and further validated by western blotting and zymography. Significant elevation and activation of MMP9 (p = 0.038), CFH (p = 2.24 × 10⁻⁵), C3 (p = 0.05), C4 (p = 0.001), IL-1ra (p = 0.0019), vascular endothelial growth factor (VEGF) (p = 0.0027), and G-CSF (p = 0.0099) proteins were observed in the vitreous of ROP babies suggesting an increased inflammation under hypoxic condition. Along with inflammatory markers, activated macrophage/microglia were also detected in the vitreous of ROP babies that secreted complement component C3, VEGF, IL-1ra, and MMP-9 under hypoxic stress in a cell culture model. Increased expression of the inflammatory markers like the IL-1ra (p = 0.014), MMP2 (p = 0.0085), and MMP-9 (p = 0.03) in the tears of babies at different stages of ROP further demonstrated their potential role in disease progression. Based on these findings, we conclude that increased complement activation in the retina/vitreous in turn activated microglia leading to increased inflammation. A quantitative assessment of inflammatory markers in tears could help in early prediction of ROP progression and facilitate effective management of the disease, thereby preventing visual impairment.

Pre-eclampsia and the risk of retinopathy of prematurity in preterm infants with birth weight <1500 g and/or <31 weeks' gestation

Objective

To evaluate the relationship between pre-eclampsia and development of retinopathy of prematurity (ROP) in infants with birth weight of <1500 g and/or gestation <31 weeks.

Methods

A retrospective cohort study comprising infants born to mothers with pre-eclampsia between January 2007 and June 2010 at a single tertiary care centre. Their ROP outcome was compared with infants born to the next two normotensive mothers with a ±1 week gestational age difference. Pearson χ² test was used for categorical variables and Mann-Whitney U test was used for continuous variables. Multivariable regression was used to estimate the OR of ROP with prenatal pre-eclampsia exposure and adjust for confounders.

Results

Of the 97 infants in the pre-eclampsia group, 27 (27%) developed ROP and of the 185 infants in the normotensive group, 50 (27%) developed ROP. On multivariable regression modelling, pre-eclampsia was not a risk factor for the development of ROP (OR 1.4, 95% CI 0.46 to 4.1). Gestational age, intrauterine growth restriction and blood transfusion were significant risk factors for the development of ROP.

Conclusions

In our cohort, pre-eclampsia was not a significant risk factor for the development of ROP. Intrauterine growth restricted infants of pre-eclamptic and normotensive mothers were at higher risk of ROP.

Galectin-3 binding protein in human preterm infant umbilical cord plasma

BACKGROUND

Galectin-3 binding protein (Gal3BP) is a glycoprotein isolated in colostrum that may be an immunologically active component with effects on the neonatal immune system. This compound has been found in the blood of term newborn infants, but has not been studied in preterm infants.

OBJECTIVE

Compare umbilical cord plasma Gal3BP concentration between preterm and term infants.

STUDY DESIGN

Observational study of mother-infant pairs consented at UCSD Medical Center comparing umbilical cord plasma Gal3BP concentration in preterm and term infants. Umbilical cord plasma was collected at birth and stored at -80°C before Gal3BP analysis by ELISA. This study was powered to evaluate differences in preterm and term infant Gal3BP concentration. The secondary aim was to determine the effect of maternal and infant clinical factors on Gal3BP concentration.

RESULTS

A total of 64 preterm and 30 term umbilical cord plasma samples were analyzed. By univariate analysis, Gal3BP concentration was elevated in the setting of prematurity, maternal diabetes, antenatal steroid exposure, and increasing maternal parity (p <  0.05); and decreased in chorioamnionitis (p = 0.03). Using a multiple linear regression model prematurity, chorioamnionitis and maternal diabetes remained significant.

CONCLUSIONS

Umbilical cord plasma Gal3BP concentration is elevated in prematurity. This may reflect inflammatory states in infant and mother, but further study is warranted.

Serum neutrophil-to-lymphocyte ratio in retinopathy of prematurity

PURPOSE

To evaluate the relationship between serum neutrophil-to-lymphocyte ratio (NLR) and development of retinopathy of prematurity (ROP).

METHODS

Infants with a gestational age of ≤32 week were screened for ROP. Complete blood cell, high-sensitivity C-reactive protein, and interleukin 6 levels of subjects were measured within the first 24 hours of life. The NLR was calculated by dividing neutrophil count by lymphocyte count. The association between other risk factors and the development of ROP were analyzed using univariate analysis and multivariate logistic regression analysis.

RESULTS

A total of 100 infants were included: 80 with ROP and 20 without ROP. The NLR values differed significantly between the ROP group (median, 0.67; interquartile range, 0.38-1.09) and non-ROP group (median, 0.32; interquartile range, 0.22-0.79; P = 0.02). The lymphocyte count in the ROP group (4.01 ± 1.89) compared to that of the non-ROP group (5.69 ± 2.16) was significantly lower (P = 0.001). In multivariate analysis, lymphocyte count remained an independent predictor of ROP (OR = 0.599; 95% CI, 0.430-0.836; P = 0.003).

CONCLUSIONS

The NLR seems not to be an independent predictor of development of ROP. Lymphocyte count is inversely associated with ROP.

An activated unfolded protein response promotes retinal degeneration and triggers an inflammatory response in the mouse retina

Recent studies on the endoplasmic reticulum stress have shown that the unfolded protein response (UPR) is involved in the pathogenesis of inherited retinal degeneration caused by mutant rhodopsin. However, the main question of whether UPR activation actually triggers retinal degeneration remains to be addressed. Thus, in this study, we created a mouse model for retinal degeneration caused by a persistently activated UPR to assess the physiological and morphological parameters associated with this disease state and to highlight a potential mechanism by which the UPR can promote retinal degeneration. We performed an intraocular injection in C57BL6 mice with a known unfolded protein response (UPR) inducer, tunicamycin (Tn) and examined animals by electroretinography (ERG), spectral domain optical coherence tomography (SD-OCT) and histological analyses. We detected a significant loss of photoreceptor function (over 60%) and retinal structure (35%) 30 days post treatment. Analysis of retinal protein extracts demonstrated a significant upregulation of inflammatory markers including interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and IBA1. Similarly, we detected a strong inflammatory response in mice expressing either Ter349Glu or T17M rhodopsin (RHO). These mutant rhodopsin species induce severe retinal degeneration and T17M rhodopsin elicits UPR activation when expressed in mice. RNA and protein analysis revealed a significant upregulation of pro- and anti-inflammatory markers such as IL-1β, IL-6, p65 nuclear factor kappa B (NF-kB) and MCP-1, as well as activation of F4/80 and IBA1 microglial markers in both the retinas expressing mutant rhodopsins. We then assessed if the Tn-induced inflammatory marker IL-1β was capable of inducing retinal degeneration by injecting C57BL6 mice with a recombinant IL-1β. We observed ~19% reduction in ERG a-wave amplitudes and a 29% loss of photoreceptor cells compared with control retinas, suggesting a potential link between pro-inflammatory cytokines and retinal pathophysiological effects. Our work demonstrates that in the context of an established animal model for ocular disease, the persistent activation of the UPR could be responsible for promoting retinal degeneration via the UPR-induced pro-inflammatory cytokine IL-1β.

Neuropilin-1 mediates myeloid cell chemoattraction and influences retinal neuroimmune crosstalk

Immunological activity in the CNS is largely dependent on an innate immune response and is heightened in diseases, such as diabetic retinopathy, multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer's disease. The molecular dynamics governing immune cell recruitment to sites of injury and disease in the CNS during sterile inflammation remain poorly defined. Here, we identified a subset of mononuclear phagocytes (MPs) that responds to local chemotactic cues that are conserved among central neurons, vessels, and immune cells. Patients suffering from late-stage proliferative diabetic retinopathy (PDR) had elevated vitreous semaphorin 3A (SEMA3A). Using a murine model, we found that SEMA3A acts as a potent attractant for neuropilin-1-positive (NRP-1-positive) MPs. These proangiogenic MPs were selectively recruited to sites of pathological neovascularization in response to locally produced SEMA3A as well as VEGF. NRP-1-positive MPs were essential for disease progression, as NRP-1-deficient MPs failed to enter the retina in a murine model of oxygen-induced retinopathy (OIR), a proxy for PDR. OIR mice with NRP-1-deficient MPs exhibited decreased vascular degeneration and diminished pathological preretinal neovascularization. Intravitreal administration of a NRP-1-derived trap effectively mimicked the therapeutic benefits observed in mice lacking NRP-1-expressing MPs. Our findings indicate that NRP-1 is an obligate receptor for MP chemotaxis, bridging neural ischemia to an innate immune response in neovascular retinal disease.

The incidence and risk factors of severe retinopathy of prematurity in extremely low birth weight infants in Turkey

Background

The aim of this study was to identify the incidence of severe retinopathy of prematurity (ROP) requiring laser treatment and the overall incidence of ROP in extremely low birth weight (ELBW) infants, and to evaluate the associated risk factors for developing severe ROP in ELBW infants in Turkey.

Material/Methods

This retrospective, case-control, tertiary care-hospital based study included 235 ELBW infants screened for ROP. The incidence of the onset of ROP and severe ROP requiring laser treatment were assessed. The relationship between various clinical risk factors, and the development of severe ROP and onset of ROP were analyzed using univariate analysis and multivariate logistic regression analysis.

Results

The overall incidence of any stage ROP and severe ROP requiring laser treatment in ELBW infants was 75.5% and 38.7%, respectively. Severe ROP requiring laser treatment in ELBW infants was significantly associated with various independent risk factors, including blood transfusion (P=0.002), gestational age at birth (P<0.001), gestational weight at birth (P=0.001), culture-proven sepsis (P=0.047).

Conclusions

The severity of ROP may increase as weight at birth and gestational age at birth decrease, and in those with culture-proven sepsis as well as in those that receive blood transfusion. Clinicians should be aware of the presence of these risk factors when treating ELBW premature infants. Early detection and prevention of sepsis and reducing the number of blood transfusions may decrease the incidence of severe ROP requiring laser treatment.

Retinopathy of prematurity and brain damage in the very preterm newborn

PURPOSE

To explain why very preterm newborns who develop retinopathy of prematurity (ROP) appear to be at increased risk of abnormalities of both brain structure and function.

METHODS

A total of 1,085 children born at <28 weeks' gestation had clinically indicated retinal examinations and had a developmental assessment at 2 years corrected age. Relationships between ROP categories and brain abnormalities were explored using logistic regression models with adjustment for potential confounders.

RESULTS

The 173 children who had severe ROP, defined as prethreshold ROP (n = 146) or worse (n = 27) were somewhat more likely than their peers without ROP to have brain ultrasound lesions or cerebral palsy. They were approximately twice as likely to have very low Bayley Scales scores. After adjusting for risk factors common to both ROP and brain disorders, infants who developed severe ROP were at increased risk of low Bayley Scales only. Among children with prethreshold ROP, exposure to anesthesia was not associated with low Bayley Scales.

CONCLUSIONS

Some but not all of the association of ROP with brain disorders can be explained by common risk factors. Most of the increased risks of very low Bayley Scales associated with ROP are probably not a consequence of exposure to anesthetic agents.

Incidence and main risk factors for severe retinopathy of prematurity in infants weighing less than 1000 grams in Brazil

OBJECTIVES

This study evaluated the incidence and risk factors for severe retinopathy of prematurity (ROP) in babies <1000 g at Porto Alegre, Brazil.

METHODS

Prospective cohort study including premature children with birth weight ≤1000 g was conducted. Main outcome was the occurrence of severe ROP needing treatment.

RESULTS

A total of 157 infants were included. Severe ROP occurred in 20 infants (12.7%). Nineteen patients were treated by laser photocoagulation. Main risk factors for severe ROP were gestational age (P = 0.029), infant's weight measured at sixth week of life (P < 0.001) and number of days of oxygen therapy under mechanical ventilation (P < 0.001). After logistic regression, infant's weight at sixth week of life and number of days in mechanical ventilation were associated to severe ROP.

CONCLUSIONS

We reported the incidence of 12.7% of severe ROP among babies born ≤ 1000 g in our institution. Laser photocoagulation was effective to stabilize the disease among 19 treated patients.

Retinopathy of prematurity

The immature retinas of preterm neonates are susceptible to insults that disrupt neurovascular growth, leading to retinopathy of prematurity. Suppression of growth factors due to hyperoxia and loss of the maternal-fetal interaction result in an arrest of retinal vascularisation (phase 1). Subsequently, the increasingly metabolically active, yet poorly vascularised, retina becomes hypoxic, stimulating growth factor-induced vasoproliferation (phase 2), which can cause retinal detachment. In very premature infants, controlled oxygen administration reduces but does not eliminate retinopathy of prematurity. Identification and control of factors that contribute to development of retinopathy of prematurity is essential to prevent progression to severe sight-threatening disease and to limit comorbidities with which the disease shares modifiable risk factors. Strategies to prevent retinopathy of prematurity will depend on optimisation of oxygen saturation, nutrition, and normalisation of concentrations of essential factors such as insulin-like growth factor 1 and ω-3 polyunsaturated fatty acids, as well as curbing of the effects of infection and inflammation to promote normal growth and limit suppression of neurovascular development.

The association between respiratory tract Ureaplasma urealyticum colonization and severe retinopathy of prematurity in preterm infants ≤1250 g

AIM

To evaluate the association between respiratory tract Ureaplasma urealyticum (Uu) colonization and development of retinopathy of prematurity (ROP) requiring treatment.

METHODS

The infants with birthweight (BW) ≤1250 g born in a third-level neonatal intensive care unit between March 2009 and May 2010 were prospectively identified. Nasopharyngeal swabs for Uu colonization were taken in postnatal first 3 days. Culture-positive patients were reevaluated on the twelfth day by nasopharyngeal swabs for Uu. The primary outcome was to define whether there was an association between respiratory tract Uu colonization and severe ROP requiring treatment. Independent sample's t-test or Mann-Whitney U-test was used to compare continuous variables and Chi-square test or Fisher's exact test for categorical variables. Multivariate (backward) logistic regression analysis was performed to simultaneously measure the influence of the independent variables with ROP as the dependent variable.

RESULTS

A total of 25 (12.1%) infants developed severe ROP requiring treatment among 206 infants who underwent ROP screening. Mean BW and gestational age of total cohort were 1013±159 g and 27.9±1.6 weeks, respectively. Multivariate analysis demonstrated that BW (OR: 0.64 (95% Cl 0.47-0.88); P=0.006), duration of mechanical ventilation (OR: 1.17 (95% Cl 1.06-1.28); P=0.001), premature rupture of membrane >18 h (OR: 3.83 (95% Cl 1.2-12.2); P=0.02), and Uu positivity in both cultures (OR: 5.02 (95% Cl 1.8-13.9); P=0.002) were independent risk factors for the development of severe ROP requiring treatment.

CONCLUSIONS

Respiratory tract colonization with Uu was independently associated with severe ROP requiring treatment.

Maternal preeclampsia is associated with an increased risk of retinopathy of prematurity

OBJECTIVE

To determine the effect of maternal preeclampsia on development and severity of retinopathy of prematurity (ROP) in preterm infants.

METHODS

This prospective study consisted of two groups: the study group, which is composed of preterm infants (≤32 weeks) born to a mother with preeclampsia, and the comparison group, which is composed of preterm infants (≤32 gestational age) born to normotensive mothers. We used the International Classification of Retinopathy of Prematurity Revisited for classifying ROP. The first eye examination was performed at postnatal age of 4 weeks.

RESULTS

A total of 385 infants were included in the study. ROP was diagnosed in 109 infants (28%). The incidence of ROP in infants born to preeclamptic mothers (40.5%) was significantly higher compared with those born to normotensive mothers (22.4%) (P<0.05). The number of infants with stage 1, 2, and 3 ROP was significantly higher in infants born to preeclamptic mothers compared with the control group (P<0.05). In multiple logistic regression model, preeclampsia was found to predict ROP (odds ratio 1.78, 95% confidence interval 0.66-1.90).

CONCLUSION

Maternal preeclampsia was found to be associated with increased ROP development risk in premature infants. ROP was also more severe in infants born to pre-eclamptic mothers. The role of maternal preeclampsia in the occurrence and severity of ROP remains to be elucidated.

Placenta microbiology and histology and the risk for severe retinopathy of prematurity

PURPOSE

To test the hypothesis that the presence of bacteria and/or histologic inflammation in the placenta of infants born preterm is associated with an increased risk for severe retinopathy of prematurity (ROP).

METHODS

This was a prospective cohort study. Exploratory and multivariable data analyses were used, including logistic regression models with interaction terms. Main outcomes were four definitions of severe ROP: stage 3 or higher, any ROP in zone I, prethreshold/threshold, and plus disease.

RESULTS

Individually, placenta bacteria and histologic inflammation were not associated with severe ROP in univariable analyses among 1064 infants with gestational age <28 weeks or among 715 infants with gestational age <27 weeks (we excluded infants with a gestational age of 27 weeks because of the very small number of ROP cases). However, the co-occurrence of bacteria and inflammation was associated with an increased risk for ROP in zone I (odds ratio, 3.1; 95% confidence interval, 1.02-9.5). Among 339 infants with any placental bacteria, the co-occurrence of (1) inflammation and a gestational age of 23 to 24 weeks and (2) inflammation and hyperoxia were associated with prominent increases in risk for all definitions of severe ROP.

CONCLUSIONS

While antenatal exposure to infection or inflammation alone does not appear to convey risk information for severe ROP, their co-occurrence does. This finding supports the hypothesis that a fetal inflammatory response to antenatal infection might be part of the etiology of severe ROP.

Fish-oil fat emulsion supplementation may reduce the risk of severe retinopathy in VLBW infants

OBJECTIVE

The retina contains rods and cones that have membranes highly enriched with docosahexaenoic acid (DHA). Infants born prematurely are at risk of DHA insufficiency, because they may not have benefited from a full third trimester of the mother's lipid stores. Moreover, within the first 2 to 3 weeks of life, the main sources of lipids for premature infants are fat emulsions, which do not contain DHA.

PATIENTS AND METHODS

This observational study was designed to compare the safety and efficacy outcomes of an intravenous fat emulsion that consists of fish-oil emulsion (contains DHA) with soybean and olive oil, administered from the first day of life to 40 infants who weighed <1250 g; results were obtained from a historical cohort of 44 preterm neonates who were given an emulsion of soybean and olive oil. The primary study outcomes were the occurrence of retinopathy and need for laser therapy and cholestasis. Infants in the 2 groups were comparable with regard to demographic and clinical characteristics and were subjected to the same conventional therapy.

RESULTS

There was a significantly lower risk of laser therapy for infants who received an emulsion of soybean, olive oil, and fish oil (P = .023). No significant differences were found in acuity and latency of visual evoked potentials between infants in the 2 groups. There was no infant with cholestasis among those who received fish-oil emulsion, and there were 5 subjects with cholestasis in the historical group (P = .056).

CONCLUSION

Fish-oil-based fat emulsion administered from the first day of life may be effective in the prophylaxis of severe retinopathy.

The clustering of disorders in infants born before the 28th week of gestation

AIM

To see whether disorders prevalent in infants born extremely preterm cluster.

DESIGN

Observational cohort study.

SETTING

  University-affiliated newborn intensive care nurseries.

SUBJECTS

  One thousand two hundred and twenty-three infants born before the 28th week of gestation who survived until 36 weeks postmenstrual age when the diagnosis of bronchopulmonary dysplasia (BPD) could be made.

INTERVENTIONS

  None.

MAIN OUTCOME MEASURES

  Cerebral white matter damage (an echolucent lesion, or moderate or severe ventriculomegaly on a protocol cranial ultrasound scan), BPD, retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC) and early and late bacteremia.

RESULTS

After adjustment for gestational age, children who had severe NEC (Bell stage IIIb) were at increased risk of cerebral white matter damage, severe ROP (stage 3+), and severe BPD (defined as both oxygen and ventilator dependent). Children who had early bacteremia were at increased risk of late bacteremia and severe ROP. Those who had severe ROP were at increased risk of severe BPD and both early and late bacteremia.

CONCLUSIONS

  Necrotizing enterocolitis is the disorder common to most of the clusters, but we do not know if its onset occurred before the others. Organ-damage-promoting substances, however, have been found in the circulation of newborn animals with bowel inflammation, supporting the view that NEC contributes to the damage of other organs.

Inflammation-related proteins in the blood of extremely low gestational age newborns. The contribution of inflammation to the appearance of developmental regulation

BACKGROUND

We wanted to assess to what extent concentrations of circulating proteins appear to be developmentally regulated, and to what extent such regulation is influenced by intra-uterine inflammation.

METHODS

We measured 22 proteins in blood obtained on postnatal days 1, 7, and 14 from 818 children born before the 28th week of gestation for whom we also had information about placenta morphology.

RESULTS

Within the narrow gestational age range of this sample, some protein concentrations increase in blood with increasing gestational age. More commonly, the concentrations of inflammation-related proteins decrease with increasing gestational age. We observed this inverse pattern both in children whose placenta was and was not inflamed. CONCLUSIONS/INFERENCES: Regardless of whether or not the placenta is inflamed, the concentrations of inflammation-related proteins in early blood specimens appear to be developmentally regulated with the most common pattern being a decrease with increasing gestational age.