The postnatal presence of human chorionic gonadotropin in preterm infants and its potential inverse association with retinopathy of prematurity

Is There a Relationship Between First-Trimester Aneuploidy Screening Serum Biomarker Values and Nuchal Translucency Measurements and the Development of Retinopathy of Prematurity (ROP) in Premature Infants?

Purpose The purpose of this study is the evaluation of serum biomarker and nuchal translucency (NT) values measured during first-trimester aneuploidy screening in terms of the development of retinopathy of prematurity (ROP) in premature infants and investigation of whether the development of ROP is associated with these parameters. Methods In this retrospective cohort study, 3,750 premature infants who underwent ROP screening from 2016 to 2021 were identified from the hospital medical record system. Among 2,130 premature babies screened for first-trimester aneuploidy, 166 babies whose mothers had single pregnancies were screened by the same method and showed the same clinical course in both eyes were included in the study. The infants were divided into two groups according to the presence of ROP, and those with ROP were further evaluated in two groups according to the presence of proliferation. The groups were compared in terms of the serum values of human chorionic gonadotropin and pregnancy-associated plasma protein A, among aneuploidy screening biomarkers, and NT measurements. Results There was no significant difference in the evaluated serum biomarker values and NT measurements between the ROP and non-ROP groups or between the proliferative ROP, non-proliferative ROP, and non-ROP groups. Conclusion Our results showed that first-trimester aneuploidy screening serum biomarker values and NT measurements were not associated with the development of ROP in premature infants.

Novel Potential Biomarkers for Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is the main risk factor for vision-threatening disease in premature infants with low birth weight. An accumulating number of independent studies have focused on ROP pathogenesis and have demonstrated that laser photocoagulation therapy and/or anti-VEGF treatment are effective. However, early diagnosis of ROP is still critical. At present, the main method of ROP screening is based on binocular indirect ophthalmoscopy. However, the judgment of whether ROP occurs and whether treatment is necessary depends largely on ophthalmologists with a great deal of experience. Therefore, it is essential to develop a simple, accurate and effective diagnostic method. This review describes recent findings on novel biomarkers for the prediction, diagnosis and prognosis of ROP patients. The novel biomarkers were separated into the following categories: metabolites, cytokines and growth factors, non-coding RNAs, iconography, gut microbiota, oxidative stress biomarkers, and others. Biomarkers with high sensitivity and specificity are urgently needed for the clinical applications of ROP. In addition, using non-invasive or minimally invasive methods to obtain samples is also important. Our review provides an overview of potential biomarkers of ROP.

Breast Milk for Term and Preterm Infants-Own Mother's Milk or Donor Milk?

Hormones are important biological regulators, controlling development and physiological processes throughout life. We investigated pituitary hormones such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL) and total protein levels during the first 6 months of lactation. Breast milk samples were collected every fourth week of lactation from mothers who gave birth to preterm (n = 14) or term (n = 16) infants. Donor milk is suggested when own mother’s milk is not available; therefore, we collected breast milk samples before and after Holder pasteurization (HoP) from the Breast Milk Collection Center of Pécs, Hungary. Three infant formulas prepared in the Neonatal Intensive Care Unit of the University of Pécs were tested at three different time points. Our aim was to examine the hormone content of own mother’s milk and donor milk. There were no significant changes over time in the concentrations of any hormone. Preterm milk had higher PRL (28.2 ± 2.5 vs. 19.3 ± 2.3 ng/mL) and LH (36.3 ± 8.8 vs. 15.9 ± 4.1 mIU/L) concentrations than term milk during the first 6 months of lactation. Total protein and FSH concentrations did not differ between preterm and term breast milk. Holder pasteurization decreased the PRL concentration (30.4 ± 1.8 vs. 14.4 ± 0.6 ng/mL) and did not affect gonadotropin levels of donor milk. Infant formulas have higher total protein content than breast milk but do not contain detectable levels of pituitary hormones. Differences were detected in the content of pituitary hormones produced for preterm and term infants. Divergence between feeding options offers opportunities for improvement of nutritional guidelines for both hospital and home feeding practices.

Associations between VEGF isoforms and impending retinopathy of prematurity

BACKGROUND/OBJECTIVE

Vascular Endothelial Growth Factor (VEGF) is the main driver of angiogenesis during neurodevelopment (i.e., brain and retina). VEGF165 and VEGF121 are the two most prevalent human VEGF isoforms. Although retinopathy of prematurity (ROP), a neuroretinal disorder, is associated with VEGF dysregulation, little is known about the interaction of VEGF isoforms on neuroretinal angiogenesis. We hypothesized that: (a) A specific VEGF165/VEGF121 correlation, at a given time point, is associated with normal retinal development (no ROP) and (b) An altered correlation, of such, is associated with aberrant retinal development (ROP). Utilizing pre-collected dried blood spots (DBS) from <1-week-old preterm infants, we aimed to determine whether correlations between VEGF165 and VEGF121 precede the diagnosis of early stage, non-proliferative ROP (NP-ROP).

METHODOLOGY

We conducted a case/control study, utilizing DBS from 65 preterm infants. We measured DBS levels of VEGF165 on the Mesoscale Discovery Platform and VEGF121 via Cloud Clone Elisa Assay.

RESULTS

In infants with NP-ROP, VEGF165 is significantly higher in males (than females). In infants without ROP, there is a significant correlation between VEGF165 and VEGF121 in females (but not males). In infants with NP-ROP, the opposite is so; there is a significant correlation between VEGF165 and VEGF121 in males (but not females).

CONCLUSIONS

This pilot study, utilizing de-identified data, suggests the potential importance of examining interactions between VEGF isoforms, at <1 week after birth, to better understand ROP development. Our study also suggests that retinal angiogenesis may not be a sex-neutral process. A prospective study is needed to confirm our novel findings.

Feasibility of neonatal haemoglobin A1C as a biomarker for retinopathy of prematurity

INTRODUCTION

Retinopathy of prematurity (ROP) is a potentially serious eye disorder affecting very preterm infants. Non-proliferative ROP (NP-ROP), also known as Early Stage ROP, is characterized by deficient retinal angiogenesis. Proliferative ROP (P-ROP), also known as Late Stage ROP, is characterized by pathologic angiogenesis. The use of neonatal haemoglobin A1C as a biomarker for ROP has not yet been evaluated.

MATERIALS AND METHODS

We modified the Haemoglobin A1C assay for use with neonatal dried blood spots (DBS) and then assessed A1C levels via Elisa immunoassay on DBS from 43 preterm infants (with gestational ages 26-28 weeks). We measured A1C on DBS collected at <1 week and 4 weeks of chronological age.

RESULTS

Compared to matched counterparts without ROP, there is significantly lower HbA1c in infants who develop NP-ROP, this occurs at Week 4 (p=0.004), but is not seen at Week 1; there is significantly higher HbA1c in infants with P-ROP, this occurs both at Week 1 (p<0.05) and Week 4 (p=0.005).

CONCLUSIONS

The A1C test, modified for use with DBS, is a feasible biomarker for ROP; low A1C is a potential biomarker for non-proliferative ROP and high A1C is for proliferative ROP.

The association between high levels of luteinizing hormone and proliferative retinopathy of prematurity in female preterm infants

BACKGROUND

Luteinizing hormone (LH) and human chorionic gonadotropin (hCG), generally considered reproductive hormones, have potent proangiogenic properties. Both of these hormones and their joint receptor (CG/LH receptor) are found in the human eye. We hypothesized that an excess of these hormones is associated with proliferative retinopathy of prematurity (P-ROP).

METHODS

Dried blood spots (DBS) were used to perform a cross-sectional study of infants (gestational age of <26 weeks) with and without P-ROP, born in Michigan between August 1, 2012, and March 15, 2015. The DBS were collected at 1 week and 4 weeks of age from 45 preterm infants (27 no-ROP and 18 P-ROP). The DBS were linked to hospital records and then deidentified. ICD-9 codes were used to identify P-ROP cases. Hormones levels were measured via electrochemiluminescence assays on the Meso Scale Discovery platform. Associations between hormone levels at 1 and 4 weeks of age and the presence or absence of P-ROP were assessed.

RESULTS

In female infants, we noted a trend toward higher LH levels in ROP cases at week 1 (P = 0.11) and significantly higher LH levels in cases at week 4 (P = 0.03). In male infants, no ROP-related differences in LH levels were found at either time point. For hCG levels, no associations with P-ROP were found in either sex at either time point.

CONCLUSIONS

The association of high LH with P-ROP in female but not male infants raises the possibility that there are sex-specific hormonal determinants of aberrant retinal angiogenesis.