Preclinical screening for retinopathy of prematurity risk using IGF1 levels at 3 weeks post-partum

Associations between Bronchopulmonary Dysplasia, Insulin-like Growth Factor I and Nutrition

Insulin-like growth factor I (IGF-I) has been suggested as an important factor in the pathogenesis of bronchopulmonary dysplasia (BPD). In turn, nutrition has been associated with IGF-I levels and could be of importance in the pathogenesis of BPD. This study aimed to explore the association between nutrition, the IGF-I axis and the occurrence of BPD. Eighty-six preterm infants (44 male, mean gestational age: 29.0 weeks (standard deviation: 1.7 weeks)) were enrolled in an observational study. Serum IGF-I (µg/L) and insulin-like growth factor binding protein 3 (IGFBP-3; mg/L) were measured at birth and at 2, 4 and 6 weeks postnatal age. BPD was diagnosed at 36 weeks postmenstrual age. Twenty-nine infants were diagnosed with BPD. For every µg/L per week increase in IGF-I, the odds of BPD decreased (0.68, 95% CI 0.48-0.96, corrected for gestational age). The change in IGF-I in µg/L/week, gestational age in weeks and a week of predominant donor human milk feeding were associated with the occurrence of BPD in the multivariable analysis (respectively, OR 0.63 (0.43-0.92), OR 0.44 (0.26-0.76) and 7.6 (1.2-50.4)). IGFBP-3 was not associated with the occurrence of BPD in the multivariable analysis. In conclusion, a slow increase in IGF-I levels and a lower gestational age increase the odds of BPD. Donor human milk might increase the odds of BPD and should be further explored.

The incidence of retinopathy of prematurity in neonates in Germany in 2019; a nationwide epidemiological cohort study

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness in preterm infants. The incidence of ROP varies widely across countries, with rates as high as 30% in some regions. This study investigated the incidence, risk factors, treatment, and mortality of ROP patients in Germany. Data were extracted from the German Federal Statistical Office (Destatis) diagnosis-related group (DRG) and Institute for the Remuneration System in Hospitals (InEK) databases. Patients with a secondary diagnosis of ROP (ICD-10 code H35.1) in the first 28 days of life were included. Data were extracted for patients admitted between January 1, 2019 and December 31, 2019. The diagnoses and procedures were determined using the German version of the International Classification of Diseases (ICD-10-GM) and the German procedure coding system (OPS). The codes 5-154.xx, 5-155.xx, 8-020.xx, 5-156.9, 6-003.(c&d), 6-007.(2&8) were utilised to denote different ocular treatments. Patient Clinical Complexity Levels were extracted and used to compare ROP with non-ROP patients. A total of 1326 patients with ROP were identified. The incidence of ROP is estimated to be 17.04 per 10,000 live births. The incidence was highest in infants with birth weights less than 500 g and decreased with increasing birth weight. The most common risk factors for ROP were low birth weight, male sex, and prematurity. Of the infants with ROP, 7.2% required ocular treatment. The most common treatment was intraocular injections, followed by photocoagulation. No surgical treatment was required for any of the infants during the study period. The mortality rate for infants with ROP was 60.33 per 10,000. This is higher than the overall neonatal death rate of 24.2 per 10,000.

CONCLUSIONS

This study found that the incidence of ROP in Germany is similar to that in other developed countries. The study also found that the mortality rate for infants with ROP is higher than the overall neonatal death rate. These findings highlight the importance of early detection and treatment of ROP in preterm infants.

WHAT IS KNOWN

• ROP is a severe eye condition often affecting preterm infants. • Previous data are limited in scope and generalizability.

WHAT IS NEW

• Based on a national database, our study found ROP incidence to be 17.04 per 10,000 new births, higher in males (17.71) than in females (16.34). • 7.2% of ROP cases required ocular treatment, inversely correlated with birth weight. • High rates of multimorbidity such as neonatal jaundice (84.69%), respiratory distress syndrome (80.84%), and apnea (78.88%) were observed.

Systemic Cytokines in Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a vasoproliferative vitreoretinal disorder, is the leading cause of childhood blindness worldwide. Although angiogenic pathways have been the main focus, cytokine-mediated inflammation is also involved in ROP etiology. Herein, we illustrate the characteristics and actions of all cytokines involved in ROP pathogenesis. The two-phase (vaso-obliteration followed by vasoproliferation) theory outlines the evaluation of cytokines in a time-dependent manner. Levels of cytokines may even differ between the blood and the vitreous. Data from animal models of oxygen-induced retinopathy are also valuable. Although conventional cryotherapy and laser photocoagulation are well established and anti-vascular endothelial growth factor agents are available, less destructive novel therapeutics that can precisely target the signaling pathways are required. Linking the cytokines involved in ROP to other maternal and neonatal diseases and conditions provides insights into the management of ROP. Suppressing disordered retinal angiogenesis via the modulation of hypoxia-inducible factor, supplementation of insulin-like growth factor (IGF)-1/IGF-binding protein 3 complex, erythropoietin, and its derivatives, polyunsaturated fatty acids, and inhibition of secretogranin III have attracted the attention of researchers. Recently, gut microbiota modulation, non-coding RNAs, and gene therapies have shown promise in regulating ROP. These emerging therapeutics can be used to treat preterm infants with ROP.

Retinopathy prematurity: a systematic review and meta-analysis study based on neonatal and maternal risk factors

BACKGROUND

Retinopathy of prematurity is the abnormal development of retinal arteries in preterm neonates less than 32 weeks and weighing 1500 g, and less, which can lead to visual impairment during life and blindness. This study aims to investigate the relationship between some clinical characteristics of neonates and mothers with Retinopathy of prematurity in the world via a systematic review and meta-analysis.

MATERIALS AND METHODS

The present study is a systematic review and meta-analysis on the relationship between maternal and neonatal clinical variables with Retinopathy of prematurity in the world from the beginning of 2000 to the end of 2020. Accordingly, all English articles published on the topic were searched in scientific databases of Web of Science, PubMed, Google Scholar, Science Direct, and Scopus. The articles were searched independently by two researchers. Statistical analysis of data was performed using fixed and random effects model statistical tests in the meta-analysis, Cochran, meta-regression, I² index, Funnel plot, and Begg's by STATA software program, version 14.

RESULT

A total of 191 studies with a sample size of 140,921 persons were including in the meta-analysis. Accordingly, Preterm delivery ≤28 weeks (OR:6.3, 95% CI:4.9-8.1), Birth Weight ≤1000 g (OR:5.8, 95% CI:4.8-6.8), Birth Weight ≤1500 g (OR:4.8, 95% CI:3.8-6.1), PROM (OR:1.2, 95% CI:1.0-1.4), induced fertility (OR:1.9, 95% CI:1.1-3.0) and Chorioamnionitis (OR:1.5, 95% CI:1.0-2.2) There was a statistically significant association with retinopathy.

CONCLUSION

Based on the results of the present meta-analysis, the risk of retinopathy of prematurity in neonates born at 28 weeks and less, LBW (weight 1500 g and less), neonatal hypotension, chorioamnionitis, and induced fertility increases.

Protective Effects and Molecular Signaling of n-3 Fatty Acids on Oxidative Stress and Inflammation in Retinal Diseases

Oxidative stress and inflammation play crucial roles in the development and progression of retinal diseases. Retinal damage by various etiologies can result in retinopathy of prematurity (ROP), diabetic retinopathy (DR), and age-related macular degeneration (AMD). n-3 fatty acids are essential fatty acids and are necessary for homeostasis. They are important retinal membrane components and are involved in energy storage. n-3 fatty acids also have antioxidant and anti-inflammatory properties, and their suppressive effects against ROP, DR, and AMD have been previously evaluated. α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and their metabolites have been shown to alleviate retinal oxidative stress and inflammation involving various biological signaling pathways. In this review, we summarize the current understanding of the n-3 fatty acids effects on the mechanisms of these retinal diseases and how they exert their therapeutic effects, focusing on ALA, EPA, DHA, and their metabolites. This knowledge may provide new remedial strategies for n-3 fatty acids in the prevention and treatment of retinal diseases associated with oxidative stress and inflammation.

Current evidence and outcomes for retinopathy of prematurity prevention: insight into novel maternal and placental contributions

Retinopathy of prematurity (ROP) is a blinding morbidity of preterm infants, which represents a significant clinical problem, accounting for up to 40% of all childhood blindness. ROP displays a range of severity, though even mild disease may result in life-long visual impairment. This is complicated by the fact that our current treatments have significant ocular and potentially systemic effects. Therefore, disease prevention is desperately needed to mitigate the life-long deleterious effects of ROP for preterm infants. Although ROP demonstrates a delayed onset of retinal disease following preterm birth, representing a potential window for prevention, we have been unable to sufficiently alter the natural disease course and meaningfully prevent ROP. Prevention therapeutics requires knowledge of early ROP molecular changes and risk, occurring prior to clinical retinal disease. While we still have an incomplete understanding of these disease mechanisms, emerging data integrating contributions of maternal/placental pathobiology with ROP are poised to inform novel approaches to prevention. Herein, we review the molecular basis for current prevention strategies and the clinical outcomes of these interventions. We also discuss how insights into early ROP pathophysiology may be gained by a better understanding of maternal and placental factors playing a role in preterm birth.

Validation of an IGF1 Screening Method for Retinopathy of Pre-maturity

Retinopathy of pre-maturity (ROP) is a retinal disease that causes arrest of vascularization of the retina and can result in retinal detachment and blindness. Current screening protocols may not be sufficiently accurate to identify all at-risk patients. The aim of this study is to validate a method for improved identification of newborns at risk of ROP. We conducted a prospective clinical trial of pre-term newborns <32 weeks of gestation and/or <1,500 g birth weight during a 6-year period in a tertiary care hospital. We applied our new method based on measurement of insulin-like growth factor 1 (IGF1) levels at 3 weeks of age and the presence of sepsis during the first 3 weeks of life. Our screening protocol allowed exclusion of 121 (79.1%) patients for whom American Academy of Pediatrics (AAP) guidelines recommended screening, had a negative predictive value of 100%, and correctly identified all patients with ROP. Following retrospective assessment of our data based on these findings, we propose further restriction of the current AAP indications for screening to <1,100 g and <28 weeks of gestation in order to improve diagnostic efficacy while ensuring optimal use of restriction of human and material resources.

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.

N-terminal B-type natriuretic peptide urinary concentrations and retinopathy of prematurity

BackgroundTo validate the findings of a single-center pilot study showing elevated urinary N-terminal B-type natriuretic peptide (NTproBNP) concentrations in preterm infants subsequently developing severe retinopathy of prematurity (ROP) in a multicenter setting across eight European and Middle East countries.MethodsProspective observational study in 967 preterm infants <30 weeks' gestational age assessing the capacity of urinary NTproBNP on days of life (DOLs) 14 and 28 to predict ROP requiring treatment.ResultsUrinary NTproBNP concentrations were markedly elevated in infants who developed ROP requiring treatment (n=94) compared with survivors without ROP treatment (n=837), at both time points (median (interquartile range) DOL14: 8,950 (1,925-23,783) vs. 3,083 (1,193-17,393) vs. 816 (290-3,078) pg/ml, P<0.001) and DOL28 (2,203 (611-4,063) vs. 1,671 (254-11,340) vs. 408 (162-1,126) pg/ml, P<0.001). C-statistic of NTproBNP for treated ROP or death was 0.731 (95% confidence interval 0.654-0.774) for DOL14 and 0.683 (0.622-0.745) for DOL28 (P<0.001). Threshold scores were calculated, potentially enabling around 20% of infants with low NTproBNP scores never to be screened with ophthalmoscopy.ConclusionThere is a strong association between early urinary NTproBNP and subsequent ROP development, which can be used to further refine subgroups of patients with high or low risk of severe ROP.

A predictive score for retinopathy of prematurity by using clinical risk factors and serum insulin-like growth factor-1 levels

AIM

To detect the impact of insulin-like growth factor-1 (IGF-1) and other risk factors for the early prediction of retinopathy of prematurity (ROP) and to establish a scoring system for ROP prediction by using clinical criteria and serum IGF-1 levels.

METHODS

The study was conducted with 127 preterm infants. IGF-1 levels in the 1^st day of life, 1^st, 2^nd, 3^rd and 4^th week of life was analyzed. The score was established after logistic regression analysis, considering the impact of each variable on the occurrences of any stage ROP. A validation cohort containing 107 preterm infants was included in the study and the predictive ability of ROP score was calculated.

RESULTS

Birth weights (BW), gestational weeks (GW) and the prevalence of breast milk consumption were lower, respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD) and necrotizing enterocolitis (NEC) were more frequent, the duration of mechanical ventilation and oxygen supplementation was longer in patients with ROP (P<0.05). Initial serum IGF-1 levels tended to be lower in newborns who developed ROP. Logistic regression analysis revealed that low BW (<1250 g), presence of intraventricular hemorrhage (IVH) and formula feeding increased the risk of ROP. Afterwards, the scoring system was validated on 107 infants. The negative predictive values of a score less than 4 were 84.3%, 74.7% and 79.8% while positive predictive values were 76.3%, 65.5% and 71.6% respectively.

CONCLUSION

In addition to BW <1250 g and IVH, formula consumption was detected as a risk factor for the development of ROP. Breastfeeding is important for prevention of ROP in preterm infants.

Neuroprotective Effects of Intranasal IGF-1 against Neonatal Lipopolysaccharide-Induced Neurobehavioral Deficits and Neuronal Inflammation in the Substantia Nigra and Locus Coeruleus of Juvenile Rats

Neonatal lipopolysaccharide (LPS) exposure-induced brain inflammation resulted in motor dysfunction and brain dopaminergic neuronal injury, and increased the risks of neurodegenerative disorders in adult rats. Our previous studies showed that intranasal administration of insulin-like growth factor-1 (IGF-1) protects against LPS-induced white matter injury in the developing rat brain. To further examine whether IGF-1 protects against LPS-induced brain neuronal injury and neurobehavioral dysfunction, recombinant human IGF-1 (rhIGF-1) at a dose of 50 µg/pup was administered intranasally 1 h following intracerebral injection of LPS (1 mg/kg) in postnatal day 5 (P5) Sprague-Dawley rat pups. Neurobehavioral tests were carried out from P7 to P21, and brain neuronal injury was examined at P21. Our results showed that LPS exposure resulted in disturbances of motor behaviors in juvenile rats. Moreover, LPS exposure caused injury to central catecholaminergic neurons, as indicated by a reduction of tyrosine hydroxylase (TH) immunoreactivity in the substantia nigra (SN), ventral tegmental area (VTA) and olfactory bulb (OB), and brain noradrenergic neurons, as indicated by a reduction of TH immunoreactivity in the locus coeruleus (LC) of the P21 rat brain. The LPS-induced reduction of TH+ cells was observed at a greater degree in the SN and LC of the P21 rat brain. Intranasal rhIGF-1 treatment attenuated LPS-induced central catecholaminergic neuronal injury and motor behavioral disturbances, including locomotion, beam walking test and gait analysis. Intranasal rhIGF-1 administration also attenuated LPS-induced elevation of IL-1β levels and numbers of activated microglia, and cyclooxygenase-2+ cells, which were double labeled with TH+ cells in the SN, VTA, OB and LC of the P21 rat brain. These results suggest that IGF-1 may provide protection against neonatal LPS exposure-induced central catecholaminergic neuronal injury and motor behavioral disturbances, and that the protective effects are associated with the inhibition of microglia activation and the reduction of neuronal oxidative stress by the suppression of the neuronal cyclooxygenase-2 expression.

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.