Tear Biomarkers Research Articles

Organic photoelectrochemical transistor detection of tear lysozyme

A high-performance organic photoelectrochemical transistor (OPECT) is developed by synergizing a light-sensitive aptamer/CdS QDs/Ti wire gate photoanode with a PEDOT:PSS-based device towards detection of the tear biomarker lysozyme.

Electrostatic and Covalent Assemblies of Anionic Hydrogel-Coated Gold Nanoshells for Detection of Dry Eye Biomarkers in Human Tears.

Although dry eye is highly prevalent, many challenges exist in diagnosing the symptom and related diseases. For this reason, anionic hydrogel-coated gold nanoshells (AuNSs) were used in the development of a label-free biosensor for detection of high isoelectric point tear biomarkers associated with dry eye. A custom, aldehyde-functionalized oligo(ethylene glycol)acrylate (Al-OEGA) was included in the hydrogel coating to enhance protein recognition through the formation of dynamic covalent (DC) imine bonds with solvent-accessible lysine residues present on the surface of select tear proteins. Our results demonstrated that hydrogel-coated AuNSs, composed of monomers that form ionic and DC bonds with select tear proteins, greatly enhance protein recognition due to changes in the maximum localized surface plasmon resonance wavelength exhibited by AuNSs in noncompetitive and competitive environments. Validation of the developed biosensor in commercially available pooled human tears revealed the potential for clinical translation to establish a method for dry eye diagnosis.

Candidate Glaucoma Biomarkers: From Proteins to Metabolites, and the Pitfalls to Clinical Applications.

Simple SummaryGlaucoma is a devastating eye disease causing progressive vision loss and consequent irreversible blindness. The global prevalence of glaucoma is estimated at 80 million people, with a projected increase in the number of people affected to 112 million by 2040. The clinical diagnosis of glaucoma usually occurs late, by which time up to 40% of neurosensory cells may be lost. There is an overriding need for early diagnosis systems based on the analysis of glaucoma biomarkers. However, plenty of candidate biomarkers have been published to date in humans, without clear clinical translation. In this review, we have summarized the efforts carried out for the discovery of proteomics- and metabolomics-based glaucoma biomarkers in blood, aqueous humor, tears, and ocular tissues from human subjects. The huge amount of data without real clinical application merits a new integrative approach, allowing future diagnostic tests to be based on local and/or systemic biomarkers of glaucoma.Glaucoma is an insidious group of eye diseases causing degeneration of the optic nerve, progressive loss of vision, and irreversible blindness. The number of people affected by glaucoma is estimated at 80 million in 2021, with 3.5% prevalence in people aged 40–80. The main biomarker and risk factor for the onset and progression of glaucoma is the elevation of intraocular pressure. However, when glaucoma is diagnosed, the level of retinal ganglion cell death usually amounts to 30–40%; hence, the urgent need for its early diagnosis. Molecular biomarkers of glaucoma, from proteins to metabolites, may be helpful as indicators of pathogenic processes observed during the disease’s onset. The discovery of human glaucoma biomarkers is hampered by major limitations, including whether medications are influencing the expression of molecules in bodily fluids, or whether tests to validate glaucoma biomarker candidates should include human subjects with different types and stages of the disease, as well as patients with other ocular and neurodegenerative diseases. Moreover, the proper selection of the biofluid or tissue, as well as the analytical platform, should be mandatory. In this review, we have summarized current knowledge concerning proteomics- and metabolomics-based glaucoma biomarkers, with specificity to human eye tissue and fluid, as well the analytical approach and the main results obtained. The complex data published to date, which include at least 458 different molecules altered in human glaucoma, merit a new, integrative approach allowing for future diagnostic tests based on the absolute quantification of local and/or systemic biomarkers of glaucoma.

Tear metabolomics highlights new potential biomarkers for differentiating between Sjögren's syndrome and other causes of dry eye

PurposeThe lacrimal exocrinopathy of primary Sjögren's syndrome (pSS) is one of the main causes of severe dry eye syndrome and a burden for patients. Early recognition and treatment could prevent irreversible damage to lacrimal glands. The aim of this study was to find biomarkers in tears, using metabolomics and data mining approaches, in patients with newly-diagnosed pSS compared to other causes of dry eye syndrome. MethodsA prospective cohort of 40 pSS and 40 non-pSS Sicca patients with dryness was explored through a standardized targeted metabolomic approach using liquid chromatography coupled with mass spectrometry. A metabolomic signature predictive of the pSS status was sought out using linear (logistic regression with elastic-net regularization) and non-linear (random forests) machine learning architectures, after splitting the studied population into training, validation and test sets. ResultsAmong the 104 metabolites accurately measured in tears, we identified a discriminant signature composed of nine metabolites (two amino acids: serine, aspartate; one biogenic amine: dopamine; six lipids: Lysophosphatidylcholine C16:1, C18:1, C18:2, sphingomyelin C16:0 and C22:3, and the phoshatidylcholine diacyl PCaa C42:4), with robust performances (ROC-AUC = 0.83) for predicting the pSS status. Adjustment for age, sex and anti-SSA antibodies did not disrupt the link between the metabolomic signature and the pSS status. The non-lipidic components also remained specific for pSS regardless of the dryness severity. ConclusionOur results reveal a metabolomic signature for tears that distinguishes pSS from other dry eye syndromes and further highlight nine key metabolites of potential interest for early diagnosis and therapeutics of pSS.

An ultrasensitive reusable aptasensor for noninvasive diabetic retinopathy diagnosis target on tear biomarker

A sensitive, non-invasive and specific tear biomarker sensor for diabetic retinopathy (DR) could be of great significance in clinical practice. Vascular endothelial growth factor (VEGF) was targeted as a tear biomarker for DR. In principle, we used hybridization chain reaction (HCR) and CeO2 nanoparticles as a cascade signal amplification strategy to construct a reusable aptasensor in search of VEGF. The report probes H1 and H2 modified with medium CeO2 nanoparticles were added in and HCR reaction. The first analysis method for a quantitative detection of VEGF was obtained using CeO2 nanoparticles to catalyze H2O2 to generate electrical signals. The fabricated biosensor exhibited an ultrasensitive detection of VEGF down to 0.27 fg mL−1, response range from 1 fg mL−1 to 0.1 ng mL−1. Subsequently the aptasensor carried out a second repeated assembly to obtain a second signal by strand displacement reaction (SDR). The ratio of the former and latter signals was used to carry out a second analysis method for quantifying VEGF. The second analysis method had detection limits as low as 7.39 fg mL-1, ranging from 10 fg mL−1 to 0.1 ng mL−1. The aptasensor could maintain above 99 % signal in five days and shows the acceptable reproducibility. For a practical tear biomarker detection, the analysis of the tears was carried out simultaneously using ELISA and the aptasensor which showed excellent precision. This non-invasive screening method provides a potential tool for the early diagnosis and monitoring of DR and may improve screening success among high-risk patients with diabetes.

The acute phase response protein SERPINA3 is increased in tear fluid from the unaffected eyes of patients with unilateral acute anterior uveitis

BackgroundTo identify candidate tear fluid biomarkers in patients with unilateral acute anterior uveitis (AAU) that can aid in the differentiation between these patients and patients with bacterial keratitis or healthy controls.MethodsThirteen patients (40.1 ± 16.2 years of age) with unilateral AAU, seven patients with unilateral bacterial keratitis (40.2 ± 15.3 years of age), and 14 healthy subjects (41.1 ± 11.6 years of age) were included. The tear proteome of affected eyes was compared with that of the unaffected eye or healthy controls. Proteins were identified by liquid chromatography tandem mass spectrometry and enzyme-linked immunosorbent assay.ResultsRelative protein ratios were detected and calculated for 272 unique proteins. Compared with healthy controls and the unaffected eye, the top upregulated proteins in AAU eyes were submaxillary gland androgen regulated protein 3B (SMR3B) and SMR3A. Similarly, the top upregulated proteins in bacterial keratitis were S100 calcium-binding protein A9 and orosomucoid 2. The acute phase response protein Serpin Family A Member 3 (SERPINA3) was increased in the healthy eye of AAU patients (P = 0.019) compared with healthy controls. Laser flare measurements in affected eyes of AAU patients showed positive logarithmic correlation with SERPINA3 in tear samples of the unaffected eye (P = 0.022). The use of SERPINA3 as a tear biomarker yielded a sensitivity of 85% and a specificity of 71% in detecting patients with AAU in the study population.ConclusionsThe acute phase response protein SERPINA3 was increased in tear samples of unaffected eyes of patients with unilateral AAU compared with healthy controls. This study highlights SERPINA3 as a potential biomarker for AAU. Future research should explore the dynamic properties of SERPINA3 in the tear fluid of active and quiescent uveitis eyes.

A Pilot Proteomic Study of Normal Human Tears: Leptin as a Potential Biomarker of Metabolic Disorders

The concentrations of insulin, leptin, active ghrelin, C-peptide and gastric inhibitory polypeptide (GIP) and their inter-day variations were examined in normal human tears. In addition, correlations between the concentrations of these metabolic proteins and ocular surface parameters were determined. Subjects with healthy ocular surfaces attended three visits, with 7-day intervals. Tear evaporation rate (TER) and non-invasive tear break-up time (NITBUT) were assessed, and a total of 2 µL tears were collected from all subjects. Tear fluid concentrations of insulin, leptin, active ghrelin, C-peptide and GIP were measured by multiplex bead analysis. Insulin was the most highly expressed metabolic protein, followed by leptin, C-peptide, active ghrelin and GIP. Of these, only active ghrelin had a significant inter-day variation (p < 0.05). There was no inter-day variation in the mean concentrations of the other metabolic proteins. Leptin had a strong intra-class reproducibility. No correlation was detected between tear metabolic protein concentrations and ocular surface parameters. This pilot study shows, for the first time, that active ghrelin and GIP are detectable in healthy tears. The strong intra-class reproducibility for leptin shows that it could be used as a potential tear fluid biomarker and, possibly, in determining the effects of metabolic disorders on the ocular surface.

Update on ocular graft-versus-host disease.

Ocular graft-versus-host disease (oGVHD) occurs as a complication following hematopoietic stem cell transplantation and is associated with significant ocular morbidity resulting in a marked reduction in the quality of life. With no current consensus on treatment protocols, management becomes challenging as recurrent oGVHD often refractory to conventional treatment. Most authors now diagnose and grade the disease based on criteria provided by the National Institutes of Health Consensus Conference (NIH CC) or the International Chronic oGVHD (ICCGVHD) consensus group. This article will provide an insight into the diagnostic criteria of oGVHD, its classification, and clinical severity grading scales. The inflammatory process in oGVHD can involve the entire ocular surface including the eyelids, meibomian gland, corneal, conjunctiva, and lacrimal system. The varied clinical presentations and treatment strategies employed to manage them have been discussed in the present study. The recent advances in ocular surface imaging in oGVHD patients such as the use of meibography and in vivo confocal microscopy may help in early diagnosis and prognostication of the disease. Researching tear proteomics and identification of novel potential tear biomarkers in oGVHD patients is an exciting field as they may help in objectively diagnosing the disease and monitoring the response to treatment.

TGFβ1, MMPs and cytokines profiles in ocular surface: Possible tear biomarkers for pseudoexfoliation.

Pseudoexfoliation (PXF) is a unique form of glaucoma characterized by accumulation of exfoliative material in the eyes. Changes in tear profile in disease stages may give us insights into molecular mechanisms involved in causing glaucoma in the eye. All patients were categorized into three main categories; pseudoexfoliation (PXF), pseudoexfoliation glaucoma (PXG) and cataract, which served as control. Cytokines, transforming growth factor β1 (TGFβ1), matrix metalloproteases (MMPs) and fibronectin (FN1) were assessed with multiplex bead assay, enzyme-linked immunosorbent assay (ELISA), gelatin zymography, and immunohistochemistry (IHC) respectively in different ocular tissues such as tears, tenon's capsule, aqueous humor (AH) and serum samples of patients with PXF stages. We found that TGFβ1, MMP-9 and FN1 protein expression were upregulated in tears, tenon's capsule and AH samples in PXG compared to PXF, though the MMP-9 protein activity was downregulated in PXG compared with control or PXF. We have also found that in PXG tears sample the fold change of TGF-α (Transforming Growth Factor-α), MDC (Macrophage Derived Chemokine), IL-8 (Interleukin-8), VEGF (Vascular Endothelial Growth Factor) were significantly downregulated and the levels of GM-CSF (Granulocyte Macrophage Colony Stimulating Factor), IP-10 (Interferon- γ produced protein-10) were significant upregulated. While in AH; IL-6 (Interleukin-6), IL-8, VEGF, IFN-a2 (Interferon- α2), GRO (Growth regulated alpha protein) levels were found lower and IL1a (Interleukin-1α) level was higher in PXG compared to PXF. And in serum; IFN-a2, Eotaxin, GM-CSF, Fractalkine, IL-10 (Interleukin-10), IL1Ra (Interleukin-1 receptor antagonist), IL-7 (Interleukin-7), IL-8, MIP1β (Macrophage Inflammatory Protein-1β), MCP-1 (Monocyte Chemoattractant Protein-1) levels were significantly upregulated and PDGF-AA (Platelet Derived Growth Factor-AA) level was downregulated in the patients with PXG compared to PXF. Altered expression of these molecules in tears may therefore be used as a signal for onset of glaucoma or for identifying eyes at risk of developing glaucoma in PXF.

A 2.5-nW Radio Platform With an Internal Wake-Up Receiver for Smart Contact Lens Using a Single Loop Antenna

The human eye has been considered to be a promising platform for real-time diagnosis of various biomarkers in tears. The smart contact lens (SCL), as a device which directly accesses surface of human eye, is a miniaturized autonomous system integrating all the required functions on the surface of a thin film. This article presents the first implementation of a set of radio including a wake-up receiver required for SCL. The system performs RF transmission upon wake-up call using a single loop antenna. The receiver path has a baseline-tracking offset control loop to successfully detect wakeup signal in the standby state under noisy environment. The operating frequencies for uplink and downlink are 346 and 433 MHz, respectively. A magnetic-coupled wireless charging of an OFF-chip battery is also provided through the same loop antenna. The designed IC is fabricated using 0.18- μm CMOS process, consuming a power of 2.5 nW in wakeup-ready standby state. The IC is also verified with a loop antenna and a thin-film battery integrated on a substrate of SCL.

Tear fluid biomarkers in major depressive disorder: Potential of spectral methods in biomarker discovery

Spectroscopic methods represent a group of analytical methods that demonstrate high potential in providing clinically relevant diagnostic information, such as biochemical, functional or structural changes of macromolecular complexes that might occur due to pathological processes or therapeutic intervention. Although application of these methods in the field of psychiatric research is still relatively recent, the preliminary results show that they have the capacity to detect subtle neurobiological abnormalities in major depressive disorder (MDD). Methods of mass spectrometry (MALDI-TOF MS), zymography, synchronous fluorescence spectroscopy (SFS), circular dichroism (CD) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM) were used to analyze the human tear fluid of subjects with MDD. Using MALDI-TOF MS, two diagnostically significant peaks (3747 and 16 411 m/z) were identified with an AUC value of 0.89 and 0.92 in tear fluid of subjects with MDD vs controls, respectively. We also identified various forms of matrix metalloproteinase 9 in subjects with MDD using zymography and synchronous fluorescence spectra (SFS) showed a significant increase in fluorescence intensity at 280 nm. CD spectra were redshifted in tear fluid of subjects with MDD vs healthy controls. FTIR spectroscopy showed changes in the positions of peaks for amide A, I, II in tear fluid of subjects with MDD vs controls. Moreover, atomic force microscopy (AFM) showed different pattern in the crystal structures of tear fluid components in subjects with MDD. SFS, CD, FTIR spectroscopy, AFM and MALDI-TOF MS confirmed, that the human tear fluid proteome could be helpful in discriminating between the group of subjects with MDD and healthy controls. These preliminary findings suggest that spectral methods could represent a useful tool in clinical psychiatry, especially in establishing differential diagnosis, monitoring illness progression and the effect of psychiatric treatment.

Critical role of mass spectrometry proteomics in tear biomarker discovery for multifactorial ocular diseases (Review).

The tear film is a layer of body fluid that maintains the homeostasis of the ocular surface. The superior accessibility of tears and the presence of a high concentration of functional proteins make tears a potential medium for the discovery of non-invasive biomarkers in ocular diseases. Recent advances in mass spectrometry (MS) have enabled determination of an in-depth proteome profile, improved sensitivity, faster acquisition speed, proven variety of acquisition methods, and identification of disease biomarkers previously lacking in the field of ophthalmology. The use of MS allows efficient discovery of tear proteins, generation of reproducible results, and, more importantly, determines changes of protein quantity and post-translation modifications in microliter samples. The present review compared techniques for tear collection, sample preparation, and acquisition applied for the discovery of tear protein markers in normal subjects and multifactorial conditions, including dry eye syndrome, diabetic retinopathy, thyroid eye disease and primary open-angle glaucoma, which require an early diagnosis for treatment. It also summarized the contribution of MS to early discovery by means of disease-related protein markers in tear fluid and the potential for transformation of the tear MS-based proteome to antibody-based assay for future clinical application.

Ocular surface indicators and biomarkers in chronic ocular graft-versus-host disease: a prospective cohort study

This longitudinal cohort study compared ocular surface indicators in forty allogeneic hematopoietic stem cell transplant (HSCT) subjects with twenty healthy controls at baseline and identified changes in ocular graft-versus-host disease (oGVHD). Outcome measures included: Ocular Surface Disease Index (OSDI), tear osmolarity, Schirmer’s test, Oxford corneal staining score, tear break-up time (TBUT), and tear and serum biomarkers (IFN-γ, IL-10, MMP-9, IL-12, IL-13, IL-17α, IL-1β, IL-2, IL-4, IL-6, IL-8, CXCL10, MCP-1, MIP-1α, RANTES, TNF-α). At baseline the HSCT group had higher median Oxford corneal staining score (1.7 vs. 0.0; P < 0.0001), higher tear TNF-α (20.0 vs. 11.2 pg/mL; P < 0.0001), lower tear RANTES (70.4 vs. 190.2 pg/mL; P < 0.0001), higher serum IL-8 (10.2 vs. 4.5 pg/mL; P = 0.0008), and higher serum TNF-α (8.7 vs. 4.2 pg/mL; P < 0.0001). The incidence of oGVHD was 62% and associated changes included increased Oxford corneal staining score (4.6 vs. 1.8, P = 0.0001), decreased Schirmer’s test (3.0 vs. 10.0; P < 0.0001), and decreased TBUT (4.7 vs. 9.0 s; P = 0.0004). Baseline differences in ocular surface indicators suggest a tendency toward ocular dryness in individuals with hematologic disorders preparing for HSCT. Individuals who developed oGVHD showed changes in corneal staining score, Schirmer’s test, and TBUT.

Tear Proteomics Study of Dry Eye Disease: Which Eye Do You Adopt as the Representative Eye for the Study?

Most studies about dry eye disease (DED) chose unilateral eye for investigation and drew conclusions based on monocular results, whereas most studies involving tear proteomics were based on the results of pooling tears from a group of DED patients. Patients with DED were consecutively enrolled for binocular clinical tests, tear biochemical markers of DED, and tear proteome. We found that bilateral eyes of DED patients may have similar but different ocular surface performance and tear proteome. Most ocular surface homeostatic markers and tear biomarkers were not significantly different in the bilateral eyes of DED subjects, and most clinical parameters and tear biomarkers were correlated significantly between bilateral eyes. However, discrepant binocular presentation in the markers of ocular surface homeostasis and the associations with tear proteins suggested that one eye’s performance cannot represent that of the other eye or both eyes. Therefore, in studies for elucidating tear film homeostasis of DED, we may lose some important messages hidden in the fellow eye if we collected clinical and proteomic data only from a unilateral eye. For mechanistic studies, it is recommended that researchers collect tear samples from the eye with more severe DED under sensitive criteria for identifying the more severe eye and evaluating the tear biochemical and proteomic markers with binocular concordance drawn in prior binocular studies.

Tear Lipid Metabolites As Potential Diagnostic Biomarkers for Ocular Chronic Graft-Versus-Host Disease

Chronic graft-versus-host disease (cGVHD) remains a common threat after allogeneic hematopoietic cell transplantation (allo-HSCT), and ocular manifestations occur in up to 60% to 90% of cGVHD patients. We sought to reveal major metabolic dysregulation and to determine tear metabolites as potential biomarkers for ocular cGVHD. Twenty-three ocular cGVHD and 16 control tear samples were collected for this study. Differential metabolites were identified using a liquid chromatography-mass spectrometry system. Spearman's test was used to analyze the correlation between metabolites and ophthalmic indexes (National Institutes of Health [NIH] eye score, fluorescein tear film break-up time [T-BUT], corneal fluorescein staining [CFS], and Schirmer's test). Receiver operating characteristic (ROC) curve was analyzed to evaluate the prediction potential of identified metabolites for ocular cGVHD. Differential metabolites were mainly observed in lipid metabolites, and we highlighted the lipid dysregulation in glycerophospholipid metabolism, sphingolipid metabolism, and biosynthesis of unsaturated fatty acids. In glycerophospholipid metabolism, phosphatidylcholine (34:1) (PC [34:1]) exhibited the strongest correlation with NIH eye score (r=0.80), T-BUT (r=0.79), CFS (r=0.77), and Schirmer's test (r=0.69). In sphingolipid metabolism, sphingomyelin (SM) was the most consistent with T-BUT (r=0.74) and CFS (r=0.71), whereas lactosylceramide (LacCer) was the most consistent with NIH eye score (r=0.76) and Schirmer's test (r=0.64). In biosynthesis of unsaturated fatty acids, docosahexaenoic acid (DHA) had the highest correlation with NIH eye score (r=0.73), T-BUT (r=0.60), CFS (r=0.67) and Schirmer's test (r=0.67) (P < .0001 for all). ROC analysis revealed that area under the curve (AUC) values for PC (34:1) (AUC=0.967), LacCer (AUC=0.946), SM (AUC=0.932), and DHA (AUC=0.929) were significantly correlated with cGVHD (P < .0001 for all). Our study identified PC (34:1), SM, LacCer, and DHA as promising tear biomarkers to indicate metabolic dysregulation and ophthalmic manifestations in ocular cGVHD.

Ocular Surface Biomarkers.

Sjögren syndrome (SS) is a chronic inflammatory autoimmune disease of the lacrimal and salivary glands. Salivary gland biopsy is still one of the most valuable and acceptable diagnostic tests for SS, which however, is an invasive test. Therefore, noninvasive diagnostic biomarkers with high specificity and sensitivity are required for the diagnosis and assessment of SS. Because ophthalmological testing constitutes to an important part for the diagnosis of SS. Tears harbor biomarkers with a high potential to be used for differential diagnosis and assessment of treatment in many systemic disorders, including SS. This review aims to summarize recent advances in the identification of tear biomarkers of SS, trying to identify reliable, sensitive, and specific biomarkers that can be used to guide treatment decisions.

Update on noninfectious uveitis in children and its treatment.

To give an overview of recently published articles covering risk factors, novel biomarkers and treatment for noninfectious uveitis in children. In the last few years, several genetic markers, serum biomarkers, aqueous humor markers, tear biomarkers and clinical factors have been identified, which are associated with childhood noninfectious uveitis. We describe the most important reports in this field that may help to tailor the screening and monitoring of this population in the future and might become the target of novel therapies. The advances in the biologic therapy of paediatric uveitis, thanks to evidence provided by the SYCAMORE, ADJUVITE and APTITUDE trials, offer new possibilities for the treatment of patients who fail methotrexate with adalimumab and tocilizumab. We discuss the importance of comprehensive outcome measures as proposed by the Multinational Interdisciplinary Working Group for Uveitis in Childhood (MIWGUC). Paediatric noninfectious uveitis is a sight-threatening condition and the identification of risk factors and novel biomarkers is critical for tailored management. Biologic therapies are revolutionizing the outcomes of patients resistant to conventional therapy. Increasing our knowledge of disease pathogenesis is crucial to improve targeting of screening to those at highest risk and stratification of treatments.

Profiling tear proteomes of patients with unilateral relapsed Behcet's disease-associated uveitis using data-independent acquisition proteomics.

PurposeTo explore whether unilateral relapse of Bechet’s disease-associated uveitis (BDU) causes differences in the tear proteome between the diseased and the contralateral quiescent eye and potential tear biomarkers for uveitis recurrence and disease monitoring.MethodTo minimize interindividual variations, bilateral tear samples were collected from the same patient (n = 15) with unilateral relapse of BDU. A data-independent acquisition (DIA) strategy was used to identify proteins that differed between active and quiescent eyes.ResultsA total of 1,797 confident proteins were identified in the tear samples, of which 381 (21.2%) were also highly expressed in various tissues and organs. Fifty-one (2.8%) proteins differed in terms of expression between tears in active and quiescent eyes, 9 (17.6%) of which were functionally related to immunity or inflammation. Alpha-1-acid glycoprotein 1 (fold change = 3.2, p = 0.007) was increased and Annexin A1 (fold change = −1.7, p < 0.001) was decreased in the tears of the active BDU eye compared to the contralateral quiescent eye.ConclusionsA substantial amount of confident proteins were detected in the tears of BDU patients, including proteins that were deferentially expressed in the uveitis-relapsed eyes and the contralateral quiescent eyes. Some of these identified tear proteins play important roles in immune and inflammatory processes. Tear proteome might be a good source of biomarkers for uveitis.

887-P: Development of the Noninvasive Diabetes Monitoring Method

Aims/Background: To prevent diabetic complications, strict glucose control and frequent monitoring of blood glucose levels with invasive methods are necessary. We considered monitoring of diabetes-related biomarkers in tears may be the possible methods for diabetes monitoring methods. Many studies about tear glucose levels have been reported and tear glucose levels correlate with blood glucose levels. This time, we focused on glycoalbumin (GA) levels, which reflect an average of blood glucose levels over the preceding 2 weeks, and studied the correlation between GA levels in blood and tears. Methods: We recruited 100 diabetic subjects and collected blood and tear samples. GA levels in blood were measured by an enzymatic method, and GA levels in tears were measured by Liquid Chromatography/Mass Spectrometry (LC-MS/MS). Results: The GA levels in tears of 99 out of 100 samples were appropriately measured by LC-MS/MS. GA levels in blood and tears were significantly correlated (P &amp;lt; 0.001). Multiple regression analysis revealed that this correlation was maintained even after adjustment for age, gender, nephropathy stage, and obesity (P &amp;lt; 0.001). Conclusions: GA in tears was the first measured diabetes-related biomarker. GA levels in tears were strongly correlated with those in blood, considering various factors. As GA value is a ratio, GA levels in tears were not thought to be influenced by dilution or concentration of tears and showed strong correlation with those in blood. From the above, GA in tears could be a diabetes-related biomarker that can be measured noninvasively. In the future, we plan to optimize measurement conditions, develop measurement equipment and verify the effectiveness and usefulness of this diabetes monitoring method. Disclosure M. Aihara: None. N. Kubota: None. T. Kadowaki: Research Support; Self; Astellas Pharma Inc., Daiichi Sankyo, Mitsubishi Tanabe Pharma Corporation, MSD Corporation, Novartis Pharma K.K., Novo Nordisk Pharma Ltd., Ono Pharmaceutical Co., Ltd., Sanofi, Sumitomo Dainippon Pharma Co., Ltd., Takeda Pharmaceutical Company Limited. Speaker’s Bureau; Self; Abbott, Astellas Pharma Inc., AstraZeneca K.K., Boehringer Ingelheim Pharmaceuticals, Inc., Cosmic Corporation, Daiichi Sankyo, Eli Lilly Japan K.K., FUJIFILM, Kowa Company, Ltd., Kyowa Hakko Kirin Co., Ltd., Medscape Education, Medtronic, Mitsubishi Tanabe Pharma Corporation, MSD Corporation, NIPRO Medical Corporation, Novartis Pharma K.K., Novo Nordisk Pharma Ltd., Ono Pharmaceutical Co., Ltd., Sanofi, Sanwa Kagaku Kenkyusho, Sumitomo Dainippon Pharma Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited, Terumo Medical Corporation. Other Relationship; Self; Asahi Mutual Life Insurance.

S100 Proteins, Cytokines, and Chemokines as Tear Biomarkers in Children with Juvenile Idiopathic Arthritis-associated Uveitis

ABSTRACT Purpose: Biomarkers for juvenile idiopathic arthritis-associated uveitis (JIA-U) are needed. We aimed to measure inflammatory biomarkers in tears as a noninvasive method to identify biomarkers of uveitis activity. Methods: Tears were collected from children with JIA-U (n = 20) and pediatric controls (n = 20) using Schirmer strips. S100A8, A9, A12, IL-18, IL-8, IP-10, MCP-1, RANTES, and sICAM-1 were measured by ELISA and Luminex assays. Levels of biomarkers were compared between children with JIA-U and controls, and active and inactive JIA-U. Results: IL-8, sICAM-1, and S100A12 levels were similar between JIA-U and controls, but differed by activity. Active JIA-U had significantly increased S100A12 compared to inactive JIA-U (mean 27,722.5 pg/ML (SE 1.3) vs. 5,937.2 (1.3), p = .002), IL-8 (73.5 [1.2] vs. 36.2 [1.2], p = .009), and sICAM-1 (15,822.7 [1.2) vs. 8,778.0 [1.6], p = .024). Conclusion: We detected inflammatory biomarkers noninvasively in tears of children with JIA-U. IL-8, sICAM-1, and S100A12 are potential biomarkers for uveitis activity.