The potential effect of human chorionic gonadotropin on vasoproliferative disorders of the immature retina

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.

Recent advances in understanding gonadotropin signaling

Gonadotropins are glycoprotein sex hormones regulating development and reproduction and bind to specific G protein–coupled receptors expressed in the gonads. Their effects on multiple signaling cascades and intracellular events have recently been characterized using novel technological and scientific tools. The impact of allosteric modulators on gonadotropin signaling, the role of sugars linked to the hormone backbone, the detection of endosomal compartments supporting signaling modules, and the dissection of different effects mediated by these molecules are areas that have advanced significantly in the last decade. The classic view providing the exclusive activation of the cAMP/protein kinase A (PKA) and the steroidogenic pathway by these hormones has been expanded with the addition of novel signaling cascades as determined by high-resolution imaging techniques. These new findings provided new potential therapeutic applications. Despite these improvements, unanswered issues of gonadotropin physiology, such as the intrinsic pro-apoptotic potential to these hormones, the existence of receptors assembled as heteromers, and their expression in extragonadal tissues, remain to be studied. Elucidating these issues is a challenge for future research.

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.

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

BACKGROUND

Human chorionic gonadotropin (hCG) and luteinizing hormone (LH) are pro-angiogenic gonadotropic hormones, which classically target the reproductive organs. However, hCG, LH, and their shared CG/LH receptor are also present in the human eye. The possibility that a deficiency of these hormones may be involved in the pathogenesis of retinopathy of prematurity (ROP) during its early non-proliferative phase has not been explored.

METHODS

We conducted a cross-sectional study of Michigan-born preterm infants utilizing dried blood spots. We analyzed hCG and LH blood levels at 1 week and 4 weeks of age from 113 study participants (60 without ROP; 53 with non-proliferative ROP). We utilized electrochemiluminescence assays on the Mesoscale Discovery platform.

RESULTS

Similar levels of hCG are found in preterm infants at both 1 week and 4 weeks after birth. Preterm infants with non-proliferative ROP, after adjusting for sex and gestational age, have 2.42 [95% CI: 1.08-5.40] times the odds of having low hCG at fourth week of age.

CONCLUSIONS

We found that hCG is present postnatally in preterm infants and that a deficiency of hCG at 4 weeks of age is potentially associated with non-proliferative ROP. This provides novel evidence to suggest that hCG may participate in human retinal angiogenesis.