Elevated tear fluid levels of MIP-1alpha in patients with cystic fibrosis

Corneal Refractive Surgery Considerations in Patients with Cystic Fibrosis and Cystic Fibrosis Transmembrane Conductance Regulator-Related Disorders

This article discusses common ocular manifestations of cystic fibrosis (CF) and cystic fibrosis transmembrane conductance regulator-related disorders (CFTR-RD). A structured approach for assessing and treating patients with CF/CFTR-RD seeking corneal refractive surgery is proposed, as well as a novel surgical risk scoring system. We also report two patients with various manifestations of CFTR dysfunction who presented for refractive surgery and the outcomes of the procedures. Surgeons seeking to perform refractive surgery on patients with CF/CFTR-RD should be aware of mild to severe clinical manifestations of CFTR dysfunction. Specific systemic and ocular manifestations of CF include chronic obstructive pulmonary disease (COPD), bronchiectasis, recurrent pulmonary infections, CF-related diabetes and liver disease, pancreatic insufficiency, conjunctival xerosis, night blindness, meibomian gland dysfunction (MGD), and blepharitis. Corneal manifestations include dry eye disease (DED), punctate keratitis (PK), filamentary keratitis (FK), xerophthalmia, and decreased endothelial cell density and central corneal thickness. Utilization of the appropriate review of systems (ROS) and screening tests will assist in determining if the patient is a suitable candidate for refractive surgery, as CF/CFTR-RD can impact the health of the cornea. Collaboration with other medical professionals who care for these patients is encouraged to ensure that their CF/CFTR-RD symptoms are best controlled via systemic and other treatment options. This will assist in reducing the severity of their ocular manifestations before and after surgery.

Biodetection Techniques for Quantification of Chemokines

Chemokines are a class of cytokine whose special properties, together with their involvement and relevant role in various diseases, make them a restricted group of biomarkers suitable for diagnosis and monitoring. Despite their importance, biodetection techniques dedicated to the selective determination of one or more chemokines are very scarce. For some years now, the critical diagnosis of inflammatory diseases by detecting both cytokine and chemokine biomarkers, has had a strong impact on the development of multiple detection platforms. However, it would be desirable to implement methodologies with a higher degree of selectivity for chemokines, in order to provide more precise information. In addition, better development of biosensor technology applied to this specific field would make it possible to address the main challenges of detection methods for several diseases with a high incidence in the population, avoiding high costs and low sensitivity. Taking this into account, this review aims to present the state of the art of chemokine biodetection techniques and emphasize the role of these systems in the prevention, monitoring and treatment of various diseases associated with chemokines as a starting point for future developments that are also analyzed throughout the article.

The potential of tear proteomics for diagnosis and management of orbital inflammatory disorders including Graves' ophthalmopathy

BACKGROUND

Orbital compartments harbor a variety of tissues that can be independently targeted in a plethora of disorders resulting in sight-threatening risks. Orbital inflammatory disorders (OID) including Graves' ophthalmopathy, sarcoidosis, IgG4 disease, granulomatosis with polyangiitis, and nonspecific orbital inflammation constitute an important cause of pain, diplopia and vision loss. Physical examination, laboratory tests, imaging, and even biopsy are not always adequate to classify orbital inflammation which is frequently deemed "nonspecific". Tear sampling and testing provide a potential "window" to the orbital disease process through a non-invasive technique that allows longitudinal sampling as the disease evolves. Using PubMed/Medline, we identified potentially relevant articles on tear proteomics published in the English language between 1988 and 2021. Of 303 citations obtained, 225 contained empirical data on tear proteins, including 33 publications on inflammatory conditions, 15 in glaucoma, 15 in thyroid eye disease, 1 in sarcoidosis (75) and 2 in uveitis (77,78). Review articles were used to identify an additional 56 relevant articles through citation search. In this review, we provide a short introduction to the potential use of tears as a diagnostic fluid and tool to investigate the mechanism of ocular diseases. A general review of previous tear proteomics studies is also provided, with a focus on Graves' ophthalmopathy (GO), and a discussion of unmet needs in the diagnosis and treatment of orbital inflammatory disease (OID). The review concludes by pointing out current limitations of mass spectrometric analysis of tear proteins and summarizes future needs in the field.

Bio-chemical markers of chronic, non-infectious disease in the human tear film

The tear film is a thin, moist layer covering the ocular surface and is laden with proteins, peptides, lipids, mucins, electrolytes and cellular debris which function to maintain the healthy status of the ocular surface. In many cases of ocular or systemic disease, the integrity of this layer is changed and/or the balance of its constituents is disturbed. Since tears are easy and quick to collect and can be stored for long periods, they have the potential to be a valuable source of information relevant to many disease states. The purpose of this review is to collate information on the known biomarkers of systemic disease that have been identified in tears. The range of conditions covered includes diabetes mellitus, diabetic retinopathy, diabetic peripheral neuropathy, multiple sclerosis, Parkinson's disease, Alzheimer's disease, migraine, systemic sclerosis, cystic fibrosis, thyroid disorders and cancer.

CLEAR - Contact lens technologies of the future

Contact lenses in the future will likely have functions other than correction of refractive error. Lenses designed to control the development of myopia are already commercially available. Contact lenses as drug delivery devices and powered through advancements in nanotechnology will open up further opportunities for unique uses of contact lenses. This review examines the use, or potential use, of contact lenses aside from their role to correct refractive error. Contact lenses can be used to detect systemic and ocular surface diseases, treat and manage various ocular conditions and as devices that can correct presbyopia, control the development of myopia or be used for augmented vision. There is also discussion of new developments in contact lens packaging and storage cases. The use of contact lenses as devices to detect systemic disease has mostly focussed on detecting changes to glucose levels in tears for monitoring diabetic control. Glucose can be detected using changes in colour, fluorescence or generation of electric signals by embedded sensors such as boronic acid, concanavalin A or glucose oxidase. Contact lenses that have gained regulatory approval can measure changes in intraocular pressure to monitor glaucoma by measuring small changes in corneal shape. Challenges include integrating sensors into contact lenses and detecting the signals generated. Various techniques are used to optimise uptake and release of the drugs to the ocular surface to treat diseases such as dry eye, glaucoma, infection and allergy. Contact lenses that either mechanically or electronically change their shape are being investigated for the management of presbyopia. Contact lenses that slow the development of myopia are based upon incorporating concentric rings of plus power, peripheral optical zone(s) with add power or non-monotonic variations in power. Various forms of these lenses have shown a reduction in myopia in clinical trials and are available in various markets.

Neutrophil extracellular traps are present in the airways of ENaC-overexpressing mice with cystic fibrosis-like lung disease

Background

Neutrophils are key components of the exacerbated inflammation and tissue damage in cystic fibrosis (CF) airways. Neutrophil extracellular traps (NETs) trap and kill extracellular pathogens. While NETs are abundant in the airways of CF patients and have been hypothesized to contribute to lung damage in CF, the in vivo role of NETs remains controversial, partially due to lack of appropriate animal models. The goal of this study was to detect NETs and to further characterize neutrophil-mediated inflammation in the airways of mice overexpressing the epithelial sodium channel (βENaC-Tg mice on C57BL/6 background) in their lung with CF-like airway disease, in the absence of any apparent bacterial infections.

Methods

Histology scoring of lung tissues, flow cytometry, multiplex ELISA, immunohistochemistry and immunofluorescence were used to characterize NETs and the airway environment in uninfected, βENaC-Tg mice at 6 and 8 weeks of age, the most chronic time points so far studied in this model.

Results

Excessive neutrophilic infiltration characterized the lungs of uninfected, βENaC-Tg mice at 6 and 8 weeks of age. The bronchoalveolar lavage fluid (BALF) of βENaC-Tg mice contains increased levels of CF-associated cytokines and chemokines: KC, MIP-1α/β, MCP-1, G-CSF, IL-5, and IL-6. The BALF of βENaC-Tg mice contain MPO-DNA complexes, indicative of the presence of NETs. Immunofluorescence and flow cytometry of BALF neutrophils and lung tissues demonstrated increased histone citrullination, a NET-specific marker, in βENaC-Tg mice.

Conclusions

NETs are detected in the airways of βENaC-Tg mice, in the absence of bacterial infections. These data demonstrate the usefulness of the βENaC-Tg mouse to serve as a model for studying the role of NETs in chronic CF airway inflammation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00397-w.

Contact Lens Technology: From Fundamentals to Applications

Contact lenses are ocular prosthetic devices used by over 150 million people worldwide. Primary applications of contact lenses include vision correction, therapeutics, and cosmetics. Contact lens materials have significantly evolved over time to minimize adverse effects associated with contact lens wearing, to maintain a regular corneal metabolism, and to preserve tear film stability. This article encompasses contact lens technology, including materials, chemical and physical properties, manufacturing processes, microbial contamination, and ocular complications. The function and the composition of the tear fluid are discussed to assess its potential as a diagnostic media. The regulatory standards of contact lens devices with regard to biocompatibility and contact lens market are presented. Future prospects in contact lens technology are evaluated, with particular interest given to theranostic applications for in situ continuous monitoring the ocular physiology.

Contact-Lens Biosensors

Rapid diagnosis and screening of diseases have become increasingly important in predictive and preventive medicine as they improve patient treatment strategies and reduce cost as well as burden on our healthcare system. In this regard, wearable devices are emerging as effective and reliable point-of-care diagnostics that can allow users to monitor their health at home. These wrist-worn, head-mounted, smart-textile, or smart-patches devices can offer valuable information on the conditions of patients as a non-invasive form of monitoring. However, they are significantly limited in monitoring physiological signals and biomechanics, and, mostly, rely on the physical attributes. Recently, developed wearable devices utilize body fluids, such as sweat, saliva, or skin interstitial fluid, and electrochemical interactions to allow continuous physiological condition and disease monitoring for users. Among them, tear fluid has been widely utilized in the investigation of ocular diseases, diabetes, and even cancers, because of its easy accessibility, lower complexity, and minimal invasiveness. By determining the concentration change of analytes within the tear fluid, it would be possible to identify disease progression and allow patient-oriented therapies. Considering the emerging trend of tear-based biosensing technology, this review article aims to focus on an overview of the tear fluid as a detection medium for certain diseases, such as ocular disorders, diabetes, and cancer. In addition, the rise and application of minimally invasive detection and monitoring via integrated contact lens biosensors will also be addressed, in regards to their practicality and current developmental progress.

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown.

Quiescent and Active Tear Protein Profiles to Predict Vernal Keratoconjunctivitis Reactivation

Objective. Vernal keratoconjunctivitis (VKC) is a chronic recurrent bilateral inflammation of the conjunctiva associated with atopy. Several inflammatory and tissue remodeling factors contribute to VKC disease. The aim is to provide a chip-based protein analysis in tears from patients suffering from quiescent or active VKC. Methods. This study cohort included 16 consecutive patients with VKC and 10 controls. Participants were subjected to clinical assessment of ocular surface and tear sampling. Total protein quantification, total protein sketch, and protein array (sixty protein candidates) were evaluated. Results. An overall increased Fluorescent Intensity expression was observed in VKC arrays. Particularly, IL1β, IL15, IL21, Eotaxin2, TACE, MIP1α, MIP3α, NCAM1, ICAM2, βNGF, NT4, BDNF, βFGF, SCF, MMP1, and MMP2 were increased in quiescent VKC. Of those candidates, only IL1β, IL15, IL21, βNGF, SCF, MMP2, Eotaxin2, TACE, MIP1α, MIP3α, NCAM1, and ICAM2 were increased in both active and quiescent VKC. Finally, NT4, βFGF, and MMP1 were highly increased in active VKC. Conclusion. A distinct “protein tear-print” characterizes VKC activity, confirming some previously reported factors and highlighting some new candidates common to quiescent and active states. Those candidates expressed in quiescent VKC might be considered as predictive indicators of VKC reactivation and/or exacerbation out-of-season.

Practical issues concerning tear protein assays in dry eye

Dry eye is a common clinical condition diagnosed by cumulative evidence of symptoms and signs. Many new treatments in dry eye are either expensive, invasive, have potential for side effects, or are not easily accessible. In severe dry eye, the ideal modality of treatment to begin with is often not clear as specific molecular disturbances are not evident from just examination of clinical manifestations. Assessing the effects of ongoing treatment is not straight forward since there is lack of agreement between clinical signs and symptoms. There is a need to have more objective methods of selecting treatment for dry eye and monitoring the effect of treatment. Recently, there are many new technologies applied to the discovery of tear biomarkers, for e.g., mass spectrometry based proteomics techniques and multiplex assays such as the bead-based sandwich indirect immunofluorescent assays. Tear proteins assays have even been made available as point-of-care devices. This review focuses on the evidence for the involvements of tear proteins in dry eye, possible changes in tear concentrations with therapy and the strength of evidence regarding dry eye pathology. Much remains to be done in terms of developing office-based assays and ascertaining their reliability, but current evidence suggests that tear proteins have a role in the clinical practice of dry eye.

Neonatal hyperoxia alters the host response to influenza A virus infection in adult mice through multiple pathways

Exposing preterm infants or newborn mice to high concentrations of oxygen disrupts lung development and alters the response to respiratory viral infections later in life. Superoxide dismutase (SOD) has been separately shown to mitigate hyperoxia-mediated changes in lung development and attenuate virus-mediated lung inflammation. However, its potential to protect adult mice exposed to hyperoxia as neonates against viral infection is not known. Here, transgenic mice overexpressing extracellular (EC)-SOD in alveolar type II epithelial cells are used to test whether SOD can alleviate the deviant pulmonary response to influenza virus infection in adult mice exposed to hyperoxia as neonates. Fibrotic lung disease, observed following infection in wild-type (WT) mice exposed to hyperoxia as neonates, was prevented by overexpression of EC-SOD. However, leukocyte recruitment remained excessive, and levels of monocyte chemoattractant protein (MCP)-1 remained modestly elevated following infection in EC-SOD Tg mice exposed to hyperoxia as neonates. Because MCP-1 is often associated with pulmonary inflammation and fibrosis, the host response to infection was concurrently evaluated in adult Mcp-1 WT and Mcp-1 knockout mice exposed to neonatal hyperoxia. In contrast to EC-SOD, excessive leukocyte recruitment, but not lung fibrosis, was dependent upon MCP-1. Our findings demonstrate that neonatal hyperoxia alters the inflammatory and fibrotic responses to influenza A virus infection through different pathways. Therefore, these data suggest that multiple therapeutic strategies may be needed to provide complete protection against diseases attributed to prematurity and early life exposure to oxygen.

CCL4/MIP-1beta levels in tear fluid and serum of patients with cystic fibrosis

Cystic fibrosis (CF) is an autosomal recessive genetic disorder. The disease affects all secretory epithelia including the eye and belongs to the group of ocular surface epithelial diseases, termed keratoconjunctivitis sicca that develop in dry eye. In the pathogenesis of dry eye, inflammation plays a crucial role. The aim of this study was to assess the potential role of MIP-1beta in the pathogenesis of dry eye syndrome in patients with CF. We assayed MIP-1beta levels in tear fluid and serum of 28 patients with CF and 27 controls by ELISA. The ophthalmic examinations including the tests for dry eye were used to study the ocular surface. The tear levels of MIP-1beta in the CF patients were significantly higher than those in the controls. Dry eye syndrome was observed in 10 (36%) CF patients. The tear fluid levels of MIP-1beta were significantly raised in CF patients with dry eye syndrome compared with CF patients without dry eye symptoms. Our results suggest a crucial role of CCL4/MIP-1beta in the development of dry eye syndrome in CF patients and immunopathogenesis of ocular surface changes in this disease. Clarification of the role of CCL4/MIP-1beta in the pathogenesis of ocular findings in CF patients will be useful in establishing immunotherapeutic strategies for this disease.

[Dry eye syndrome and neurotrophic keratitis in childhood. Causes and therapy]

PURPOSE

The purpose of this review is to enhance the physician's awareness of dry eye syndrome and neurotrophic keratitis in children, to describe the most frequently associated conditions and to discuss the diagnostic and therapeutic options available.

METHODS

A literature review of the pathogenesis of dry eye syndrome and neurotrophic keratitis in children was carried out, clinical cases from our pediatric ophthalmology office are presented as well as therapeutic strategies.

RESULTS

Diseases of the cornea and ocular surface such as dry eye syndrome, neurotrophic keratitis and corneal ulcers are infrequent in children compared to adults. However, they do occur and should be diagnosed and treated as soon as possible in order to prevent long-term complications and amblyopia.

CONCLUSIONS

Inflammatory diseases of the ocular surface can be easily overlooked in children due to the often unknown spectrum of differential diagnoses and the frequently reduced cooperation during examination of young children. Correct and early diagnosis is essential for prevention of long-term complications, e.g. corneal ulceration and scarring.

Antibody protein array analysis of the tear film cytokines

PURPOSE

Many bioactive proteins including cytokines are reported to increase in dry eye disease although the specific profile and concentration of inflammatory mediators varies considerably from study to study. In part, this variability results from inherent difficulties in quantifying low abundance proteins in a limited sample volume using relatively low sensitivity dot ELISA methods. Additional complexity comes with the use of pooled samples collected using a variety of techniques and intrinsic variation in the diurnal pattern of individual tear proteins. The current study describes a recent advance in the area of proteomics that has allowed the identification of dozens of low abundance proteins in human tear samples.

METHODS

Commercially available stationary phase antibody protein arrays were adapted to improve suitability for use in small volume biological fluid analysis with particular emphasis on tear film proteomics. Arrays were adapted to allow simultaneous screening for a panel of inflammatory cytokines in low volume tear samples collected from individual eyes.

RESULTS

A preliminary study comparing tear array results in a small population of Sjögren's syndrome patients was conducted. The multiplex microplate array assays of cytokines in tear fluid present an unanticipated challenge due to the unique nature of tear fluid. The presence of factors that exhibit an affinity for plastic, capture antibodies and IgG and create a complex series of matrix effects profoundly impacting the reliability of dot ELISA, including with elevated levels of background reactivity and reduction in capacity to bind targeted protein.

CONCLUSIONS

Preliminary results using tears collected from patients with Sjögren's syndrome reveal methodological advantages of protein array technology and support the concept that autoimmune-mediated dry eye disease has an inflammatory component. They also emphasize the inherent difficulties one can face when interpreting the results of micro-well arrays that result from blooming effects, matrix effects, image saturation and cross-talk between capture and probe antibodies that can greatly reduce signal-to-noise and limit the ability to obtain meaningful results.