Novel Potential Biomarkers for Retinopathy of Prematurity

Neonatal gut microbiota profile and the association with retinopathy of prematurity in preterm infants

BACKGROUND

To explore the role of gut microbiota in preterm infants at high risk of developing retinopathy of prematurity (ROP).

METHODS

Preterm infants with gestational age (GA) < 32 weeks and/or birth weight (BW) < 1500 g born between 2020 and 2021 were prospectively enrolled. Their faecal samples were collected and analysed at different postnatal ages of life using 16S rRNA gene sequencing on the Miseq platform. The main outcome measures were the microbial diversity, taxonomy, relative abundance, bacterial predicted functional analysis, and their associations with different ROP groups. Subgroup analyses were performed by matching their GA and BW across different ROP groups.

RESULTS

A total of 268 stool samples were collected from 110 preterm infants, including 13 with type 1 ROP, 44 with type 2 or mild ROP, and 53 without ROP. Type 1 ROP showed no significant difference in microbial diversity up to 8 postnatal weeks (p = 0.057), while type 2 and no ROP groups displayed increased diversity (p = 0.0015 and p = 0.049, respectively). Bifidobacterium genera was notably less abundant in type 1 ROP group at first postnatal week (p = 0.022) and remained low in subsequent weeks. Predicted functional analysis revealed enriched pathways in membrane transport, carbohydrate metabolism, amino acid metabolism, and replication and repair.

CONCLUSIONS

Reduced gut microbial diversity may be associated with ROP development in high-risk preterm infants. Further research is needed to comprehend how early-life Bifidobacterium reduction affects metabolism and how targeting microbiome may help for ROP prevention and management.

Predicting Retinopathy of Prematurity Risk Using Plasma Levels of Insulin-like Growth Factor 1 (IGF1), Tumor Necrosis Factor-Alpha (TNF-Alpha), and Neonatal Parameters

BACKGROUND/OBJECTIVES

Retinopathy of Prematurity (ROP) remains a leading cause of vision impairment in premature infants, especially those with Respiratory Distress Syndrome (RDS) necessitating respiratory support. This study aimed to identify correlations between plasma levels of Insulin-like Growth Factor 1 (IGF1) and Tumor Necrosis Factor-alpha (TNF-alpha), and the risk of developing ROP. Additionally, it explored the association of ROP severity grades with plasma levels of glucose, lactate dehydrogenase (LDH), creatin phosphokinase (CPK), and other biomarkers, aiming to uncover predictive markers for ROP risk and severity in this population.

METHODS

This prospective study included premature neonates admitted with RDS requiring respiratory support, conducted over 18 months at the Neonatal Intensive Care Unit of the Louis Turcanu Emergency Clinical Hospital for Children, Timisoara. Plasma levels of IGF1 and TNF-alpha were measured on days 1 and 14 post-birth, alongside the initial assessment of glucose, LDH, and CPK levels.

RESULTS

Significant correlations were observed between lower gestational age and elevated LDH levels on day 7-10 (rho = -0.341, p = 0.0123) and between TNF-alpha levels at 2 weeks and ROP severity (rho = 0.512, p = 0.0004). Elevated IGF1 levels were protective against ROP, with Beta coefficients of 0.37 (p = 0.0032) for the first collection and 0.32 (p = 0.0028) for the second, suggesting their potential as biomarkers for ROP risk assessment. Higher levels of TNF-alpha at 2 weeks were associated with an increased risk of ROP (Beta = -0.45, p = 0.0014), whereas higher IGF1 levels offered protective effects against ROP, with Beta coefficients of 0.37 (p = 0.0032) for the first collection and 0.32 (p = 0.0028) for the second. Elevated LDH levels on day 7-10 post-birth were linked to an increased risk of ROP (Beta = 0.29, p = 0.0214).

CONCLUSIONS

These findings highlight the potential of IGF1 and TNF-alpha as predictive biomarkers for ROP, offering avenues for early intervention and improved management strategies in this high-risk group.

Tear fluid cytokine analysis: a non-invasive approach for assessing retinopathy of prematurity severity

PURPOSE

To determine whether there is a significant association between inflammatory cytokines in the tear fluid and the severity of Retinopathy of Prematurity (ROP).

STUDY DESIGN

Retrospective cohort study.

METHODS

The cytokine levels in tear fluids were determined in 34 eyes with ROP and 18 eyes without ROP. There were 15 eyes with severe ROP requiring treatment and 19 eyes with mild ROP not requiring treatment. For severe ROP eyes, tear fluids were collected before treatment.

RESULTS

Significantly higher levels of CCL2 and vascular endothelial growth factor (VEGF) were detected in eyes with severe ROP compared to eyes with mild ROP and no ROP. When assessed for cytokine levels that discriminate each disease group, CCL2 showed a significant odds ratio of 1.76 for severity change (/quintile, P = 0.032, after adjusting for birth weight). Correlation analysis showed that birth weight correlated with IL-1α levels, and decreased weight gain increased IFN-γ levels. We next determined tear fluid cytokines which discriminate severe ROP using receiver operating characteristics' analysis. We found that combination of higher CCL2 levels, higher VEGF levels, and lower IFN-γ levels in the tear fluid had a stronger predictive value for severe ROP (area under curve, 0.85).

CONCLUSION

The levels of CCL2, VEGF, and IFN-γ in tear fluid may serve as useful biomarkers for assessing the severity of ROP.

Tear Proteomics in Infants at Risk of Retinopathy of Prematurity: A Feasibility Study

Purpose

This feasibility study investigated the practicability of collecting and analyzing tear proteins from preterm infants at risk of retinopathy of prematurity (ROP). We sought to identify any tear proteins which might be implicated in the pathophysiology of ROP as well as prognostic markers.

Methods

Schirmer's test was used to obtain tear samples from premature babies, scheduled for ROP screening, after parental informed consent. Mass spectrometry was used for proteomic analysis.

Results

Samples were collected from 12 infants, which were all adequate for protein analysis. Gestational age ranged from 25 + 6 to 31 + 1 weeks. Postnatal age at sampling ranged from 19 to 66 days. One infant developed self-limiting ROP. Seven hundred one proteins were identified; 261 proteins identified in the majority of tear samples, including several common tear proteins, were used for analyses. Increased risk of ROP as determined by the postnatal growth ROP (G-ROP) criteria was associated with an increase in lactate dehydrogenase B chain in tears. Older infants demonstrated increased concentration of immunoglobulin complexes within their tear samples and two sets of twins in the cohort showed exceptionally similar proteomes, supporting validity of the analysis.

Conclusions

Tear sampling by Schirmer test strips and subsequent proteomic analysis by mass spectrometry in preterm infants is feasible. A larger study is required to investigate the potential use of tear proteomics in identification of ROP.

Translational Relevance

Tear sampling and subsequent mass spectrometry in preterm infants is feasible. Investigation of the premature tear proteome may increase our understanding of retinal development and provide noninvasive biomarkers for identification of treatment-warranted ROP.

Differences in Oxygen-Induced Retinopathy Susceptibility Between Two Sprague Dawley Rat Vendors: A Comparison of Retinal Transcriptomes

PURPOSE

To determine the retinal transcriptomic differences underlying the oxygen-induced retinopathy phenotypes between Sprague Dawley rat pups from two commonly used commercial vendors. This will allow us to discover genes and pathways that may be related to differences in disease severity in similarly aged premature babies and suggest possible new treatment approaches.

METHODS

We analyzed retinal vascular morphometry and transcriptomes from Sprague Dawley rat pups from Charles River Laboratories and Envigo (previously Harlan). Room air control and oxygen-induced retinopathy groups were compared. Oxygen-induced retinopathy was induced with the rat 50/10 model.

RESULTS

Pups from Charles River Laboratories developed a more severe oxygen-induced retinopathy phenotype, with 3.6-fold larger percent avascular area at P15 and twofold larger % neovascular area at P20 than pups from Envigo. Changes in retinal transcriptomes of rat pups from both vendors were substantial at baseline and in response to oxygen-induced retinopathy. Baseline differences centered on activated pathways of neuronal development in Charles River Laboratories pups. In response to oxygen-induced retinopathy, during the neovascular phase, retinas from Charles River Laboratories pups exhibited activation of pathways regulating necrosis, neuroinflammation, and interferon signaling, supporting the observed increase of neovascularization. Conversely, retinas from Envigo pups showed decreased necrosis and increased focal adhesion kinase signaling, supporting more normal vascular development. Comparing oxygen-induced retinopathy transcriptomes at P15 to those at P20, canonical pathways such as phosphate and tensin homolog, interferon, and coordinated lysosomal expression and regulation element signaling were identified, highlighting potential novel mechanistic targets for future research.

CONCLUSION

Transcriptomic profiles differ substantially between rat pup retinas from Charles River Laboratories and Envigo at baseline and in response to oxygen-induced retinopathy, providing insight into vascular morphologic differences. Comparing transcriptomes identified new pathways for further research in oxygen-induced retinopathy pathogenesis and increased scientific rigor of this model.

Evaluation of optical coherence tomography biomarkers to differentiate favourable and unfavourable responders to intravitreal anti-vascular endothelial growth factor treatment in retinopathy of prematurity

OBJECTIVE

Evaluation of optical coherence tomography biomarkers in predicting treatment response to intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) Bevacizumab, in aggressive retinopathy of prematurity (A-ROP).

METHODS

Non-contact ultra-widefield (NC-UWF) fundus imaging with integrated UWF guided swept source Optical coherence tomography (SS-OCT) was performed prospectively in preterm babies before and after intravitreal anti-VEGF (Bevacizumab) monotherapy. OCT biomarkers were analysed in eyes that reached complete vascularization versus others.

RESULTS

Eyes with retinal vessels reaching near ora serrata were labelled as regressed ROP and vascularised retina (Group1). Eyes with reactivation of ROP needing laser or vitreoretinal surgery or eyes with peripheral avascular retina (PAR) at 16th week post-injection were considered as Group 2. Pre-injection baseline OCT showed a hyperreflectivity of inner retinal layers in 12 out of 46 eyes in Group 1 versus 30 out of 34 eyes in Group 2 (p value 0.002). None of the eyes in Group 1 showed choroidal thinning at posterior pole as compared to 14 out of 34 eyes in Group 2 (p value 0.001). Intraretinal hypo reflective Cystic changes at fovea were seen in 16 out of 46 eyes in Group 1 and 2 out of 34 eyes in Group 2 (p value 0.012).

CONCLUSION

Pre-injection swept source OCT biomarkers could predict the treatment outcomes of anti-VEGF (Bevacizumab) monotherapy in A-ROP eyes. Hyperreflectivity of inner retinal layers and choroidal thinning had poorer and unpredictable response to anti-VEGF injection whereas, cystic changes at fovea predicted favourable response.

Image-free recognition of moderate ROP from mild with machine learning algorithm on plasma Raman spectrum

The retinopathy of prematurity (ROP) can cause serious clinical consequences and, fortunately, it is remediable while the time window for treatment is relatively narrow. Therefore, it is urgent to screen all premature infants and diagnose ROP degree timely, which has become a large workload for pediatric ophthalmologists. We developed a retinal image-free procedure using small amount of blood samples based on the plasma Raman spectrum with the machine learning model to automatically classify ROP cases before medical intervention was performed. Statistical differences in infrared Raman spectra of plasma samples were found among the control, mild (ZIIIS1), moderate (ZIIIS2 & ZIIS1), and advanced (ZIIS2) ROP groups. With the different wave points of Raman spectra as the inputs, the outputs of our support vector machine showed that the area under the curves in the receiver operating characteristic (AUC) were 0.763 for the pair comparisons of the control with the mild groups, 0.821 between moderate and advanced groups (ZIIS2), while more than 90% in comparisons of the other four pairs: control vs. moderate (0.981), control vs. advanced (0.963), mild vs. moderate (0.936), and mild vs. advanced (0.953), respectively. Our study could advance principally the ROP diagnosis in two dimensions: the moderate ROPs have been classified remarkably from the mild ones, which leaves more time for the medical treatments, and the procedure of Raman spectrum with a machine learning model based on blood samples can be conveniently promoted to those hospitals lacking of the pediatric ophthalmologists with experience in reading retinal images.

Association of serum levels of inflammatory cytokines with retinopathy of prematurity in preterm infants

Introduction

Retinopathy of prematurity (ROP) is a retinal vascular developmental disease associated with risks factors such as supplementary oxygen use or low birth weight/early gestational age. Multiple studies have reported associations between ROP and systemic inflammation. In this study, we investigated serum cytokines associated with ROP development and severity and assessed their applicability as potential biomarkers of ROP.

Methods

This prospective study was conducted at an institutional referral center between 2019 and 2021. To measure the serum levels of 40 inflammatory cytokines in eligible premature patients, we collected their serum samples during the enrollment of patients or the intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents and after 2 and 4 weeks.

Results

Fifty patients were enrolled. In patients with type 1 ROP who received anti-VEGF agents (n = 22), the levels of serum intercellular adhesion molecule-1 decreased significantly (p < 0.05) at 4 weeks compared with the baseline level, whereas those of serum granulocyte-macrophage colony-stimulating factor increased significantly (p < 0.05). In patients with ROP who did not require any treatment (n = 14), no significant change was noted in the level of any of the 40 inflammatory cytokines. In control infants without ROP (n = 14), the serum levels of tumor necrosis factor-α, interleukin (IL)-15, and IL-12p40 increased significantly (p < 0.05) at 4 weeks. The changes in the levels of serum inflammatory cytokines did not vary significantly among the aforementioned three groups. A generalized estimating equation indicated that zone 1 ROP, stage 3 ROP, older postmenstrual age, respiratory distress syndrome, necrotizing enterocolitis, and sepsis were associated with the changes in serum cytokine levels.

Conclusions

Although significant changes (compared with baseline) were observed in the serum levels of certain inflammatory cytokines in patients with type 1 ROP and infants without ROP, no significant difference in cytokine level fluctuations were noted among the three groups. Changes in serum inflammatory cytokine levels may not predict ROP development or severity. Additional comprehensive studies are warranted to establish their definitive role and significance in ROP, emphasizing the need for continued research in this area.

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.

Complete blood count parameters as biomarkers of retinopathy of prematurity: a Portuguese multicenter study

PURPOSE

To evaluate complete blood count (CBC) parameters in the first week of life as predictive biomarkers for the development of retinopathy of prematurity (ROP).

METHODS

Multicenter, prospective, observational study of a cohort of preterm infants born with gestational age (GA) < 32 weeks or birth weight < 1500 g in eight Portuguese neonatal intensive care units. All demographic, clinical, and laboratory data from the first week of life were collected. Univariate logistic regression was used to assess risk factors for ROP and then multivariate regression was performed.

RESULTS

A total of 455 infants were included in the study. The median GA was 29.6 weeks, and the median birth weight was 1295 g. One hundred and seventy-two infants (37.8%) developed ROP. Median values of erythrocytes (p < 0.001), hemoglobin (p < 0.001), hematocrit (p < 0.001), mean corpuscular hemoglobin concentration (p < 0.001), lymphocytes (p = 0.035), and platelets (p = 0.003) of the group of infants diagnosed with ROP any stage were lower than those without ROP. Mean corpuscular volume (MCV) (p = 0.044), red blood cell distribution width (RDW) (p < 0.001), erythroblasts (p < 0.001), neutrophils (p = 0.030), neutrophils-lymphocytes ratio (p = 0.028), and basophils (p = 0.003) were higher in the ROP group. Higher values of MCV, erythroblasts, and basophils remained significantly associated with ROP after multivariate regression.

CONCLUSION

In our cohort, the increase in erythroblasts, MCV, and basophils in the first week of life was significantly and independently associated with the development of ROP. These CBC parameters may be early predictive biomarkers for ROP.

Identifying novel candidate compounds for therapeutic strategies in retinopathy of prematurity via computational drug-gene association analysis

Purpose

Retinopathy of prematurity (ROP) is the leading cause of preventable childhood blindness worldwide. Although interventions such as anti-VEGF and laser have high success rates in treating severe ROP, current treatment and preventative strategies still have their limitations. Thus, we aim to identify drugs and chemicals for ROP with comprehensive safety profiles and tolerability using a computational bioinformatics approach.

Methods

We generated a list of genes associated with ROP to date by querying PubMed Gene which draws from animal models, human studies, and genomic studies in the NCBI database. Gene enrichment analysis was performed on the ROP gene list with the ToppGene program which draws from multiple drug-gene interaction databases to predict compounds with significant associations to the ROP gene list. Compounds with significant toxicities or without known clinical indications were filtered out from the final drug list.

Results

The NCBI query identified 47 ROP genes with pharmacologic annotations present in ToppGene. Enrichment analysis revealed multiple drugs and chemical compounds related to the ROP gene list. The top ten most significant compounds associated with ROP include ascorbic acid, simvastatin, acetylcysteine, niacin, castor oil, penicillamine, curcumin, losartan, capsaicin, and metformin. Antioxidants, NSAIDs, antihypertensives, and anti-diabetics are the most common top drug classes derived from this analysis, and many of these compounds have potential to be readily repurposed for ROP as new prevention and treatment strategies.

Conclusion

This bioinformatics analysis creates an unbiased approach for drug discovery by identifying compounds associated to the known genes and pathways of ROP. While predictions from bioinformatic studies require preclinical/clinical studies to validate their results, this technique could certainly guide future investigations for pathologies like ROP.

Identification and clinical significance of tsRNAs and miRNAs in PBMCs of treatment-requiring retinopathy of prematurity

The aim of the study is to reveal the expression profiling and clinical significance of peripheral blood mononuclear cell (PBMC) tRNA-derived small RNAs (tsRNAs) and microRNAs (miRNAs) of premature infants with treatment-requiring retinopathy of prematurity (ROP). Significantly altered tsRNAs and miRNAs were screened using small RNA sequencing. RT-qPCR was used to verify the altered RNAs identified by small RNA transcriptomics. The target genes, their enriched functions, and possibly involved signaling pathways were identified by bioinformatics analyses. According to the small RNA sequencing, 125 tsRNAs and 205 miRNAs were significantly altered in PBMCs obtained from infants with treatment-requiring ROP compared with the premature controls without retinopathy. We preliminarily validated the significant alterations of 6 tsRNAs and 9 miRNAs. The target genes for those tsRNAs were enriched for cellular macromolecule metabolic process, intracellular anatomical structure, transcription regulatory region nucleic acid binding, and Th17 cell differentiation; those of the altered miRNAs were enriched for the developmental process, cell junction, DNA-binding transcription activator activity, and FoxO signaling pathway. By verification with the extended sample size, we identified tsRNAs and miRNAs that could be potential biomarkers with clinical values. The study recognized the alterations and clinical significance of changed tsRNA/miRNA profiles in PBMCs from premature infants with ROP. These significantly altered tsRNAs and miRNAs might be useful as potential diagnostic biomarkers and molecular targets for treatment-requiring ROP.

Hematologic Risk Factors for the Development of Retinopathy of Prematurity—A Retrospective Study

(1) Background: Retinopathy of prematurity (ROP) can cause severe visual impairment or even blindness. We aimed to assess the hematological risk factors that are associated with different stages of ROP in a cohort of preterm newborns, and to compare the clinical characteristics and therapeutic interventions between groups. (2) Methods: This retrospective study included 149 preterm newborns from a tertiary maternity hospital in Romania between January 2018 and December 2018, who were segregated into: Group 1 (with ROP, n = 59 patients), and Group 2 (without ROP, n = 90 patients). The patients that were affected by ROP were subsequently divided into the following subgroups: Subgroup 1 (Stage 1, n = 21), Subgroup 2 (Stage 2, n = 35), and Subgroup 3 (Stage 3, n = 25). The associations were analyzed using multivariate logistic regression and sensitivity analysis. (3) Results: Platelet mass indexes (PMI) that were determined in the first, seventh, and tenth days of life were significantly associated with Stage 1 ROP. PMI determined in the first day of life was also significantly associated with Stage 2 ROP. The sensitivity and specificity of these parameters were modest, ranging from 44 to 57%, and 59 to 63%. (4) Conclusions: PMI has a modest ability to predict the development of ROP.

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.

Latest Trends in Retinopathy of Prematurity: Research on Risk Factors, Diagnostic Methods and Therapies

Retinopathy of prematurity (ROP) is a vasoproliferative disorder with an imminent risk of blindness, in cases where early diagnosis and treatment are not performed. The doctors' constant motivation to give these fragile beings a chance at life with optimal visual acuity has never stopped, since Terry first described this condition. Thus, throughout time, several specific advancements have been made in the management of ROP. Apart from the most known risk factors, this narrative review brings to light the latest research about new potential risk factors, such as: proteinuria, insulin-like growth factor 1 (IGF-1) and blood transfusions. Digital imaging has revolutionized the management of retinal pathologies, and it is more and more used in identifying and staging ROP, particularly in the disadvantaged regions by the means of telescreening. Moreover, optical coherence tomography (OCT) and automated diagnostic tools based on deep learning offer new perspectives on the ROP diagnosis. The new therapeutical trend based on the use of anti-VEGF agents is increasingly used in the treatment of ROP patients, and recent research sustains the theory according to which these agents do not interfere with the neurodevelopment of premature babies.

Potential biomarkers for retinopathy of prematurity identified by circular RNA profiling in peripheral blood mononuclear cells

Purpose

This study aims to reveal the altered expression profiles of circular RNAs (circRNAs) in the peripheral blood mononuclear cells (PBMCs) of patients with retinopathy of prematurity (ROP), and to identify potential biomarkers for ROP diagnosis.

Methods

Differentially expressed circRNAs in PBMCs of five infants with ROP and five controls were identified using microarray analysis. Twelve altered circRNAs were validated using reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR). Bioinformatic analyses were conducted to predict the circRNA/miRNA interactions, competing endogenous RNA (ceRNA) network, related biological functions, and signaling pathways. Four selected circRNAs in PBMCs were verified using RT-qPCR in another cohort, including 24 infants with ROP and 23 premature controls, and receiver operating characteristic (ROC) curves were used to estimate their potential as diagnostic biomarkers of ROP.

Results

A total of 54 and 143 circRNAs were significantly up- and down-regulated, respectively, in the PBMCs of patients with ROP compared with controls. Twelve of the significantly altered circRNAs were preliminarily validated by RT-qPCR, which confirmed the reliability of the microarray analysis. The circRNA/miRNA interactions and ceRNA network were displayed according to the altered circRNAs. Three circRNAs (hsa_circRNA_061346, hsa_circRNA_092369, and hsa_circRNA_103554) were identified as potential diagnostic biomarkers for ROP with certain clinical values.

Conclusions

CircRNAs were significantly altered in PBMCs of treatment-requiring ROP patients. CircRNAs may be used as potential biomarkers and possible therapeutic targets for ROP.