Autoimmune and autoinflammatory mechanisms in uveitis

Unravelling T-cell dynamics and immune responses in initial and recurrent uveitis

This study aimed to identify novel serological targets and investigate immune responses in patients with non-infectious uveitis, focusing on differences between initial onset and recurrent episodes. Differential gene expression analysis, immunocyte typing and T-cell receptor (TCR) gene analysis were conducted on RNA-sequenced peripheral blood samples from healthy individuals (n = 6) and non-infectious uveitis patients (n = 12), divided into 6 patients each at initial onset and recurrent stages. Peripheral blood T-cell types were analysed using flow cytometry. Bioinformatics methods included tools for RNA sequencing data processing, CIBERSORT for immune cell type prediction and specialized software for TCR repertoire analysis. Findings indicated that individuals with recurrent uveitis demonstrated a stronger adaptive immune response and a more pronounced immune imbalance compared to those with initial onset. Memory T cells were predominant in recurrent episodes, suggesting their potential role as biomarkers for disease progression. Significant differences in TCR diversity and V(D)J gene usage were observed between the various uveitis groups and healthy controls. Importantly, 38 uveitis-specific TCR sequences showed substantial expansion in the uveitis patients compared to controls. An elevated expansion of these specific TCR sequences was associated with an increased risk of uveitis development. The study highlights the critical role of adaptive immune responses and specific immune cell types in the pathogenesis of recurrent uveitis. Identification of the uveitis-specific TCR repertoire set could provide deeper insights into the disease and facilitate the development of targeted therapies for uveitis patients.

Nailfold capillaroscopic assessment in pediatric patients with autoimmune uveitis: a case-control study

Uveitis is a major cause of visual impairment. Most uveitis cases have autoimmune etiology. Pediatric autoimmune uveitis may be associated with systemic diseases such as juvenile idiopathic arthritis or may arise as an isolated disorder. It may be accompanied by retinal vasculitis due to retinal microcirculation involvement. Nailfold capillaroscopy, a digital microscope, is a non-invasive tool for systemic microcirculation evaluation. We aimed to evaluate systemic microcirculation abnormalities in pediatric autoimmune uveitis. Twenty-five patients with pediatric autoimmune uveitis and 21 healthy children underwent detailed capillaroscopic evaluation. We assessed capillary density/mm, capillary morphology, capillary dimensions, and the presence or absence of microhemorrhages and avascular areas. The mean age of the study and control groups was 11.24 ± 3.03 and 9.9 ± 4.17 years, respectively. Most included patients had isolated uveitis and juvenile idiopathic arthritis (64% and 24%, respectively). The predominant uveitis subtype in the study was anterior uveitis (48%). A significant difference was found between cases and controls regarding mean capillary density (p-value = 0.0003) and the number of subjects having capillary density less than 7 (p-value = 0.002). Other capillaroscopic abnormalities did not show any significant difference between the studied groups. Mean capillary density did not correlate significantly with age, disease duration, or acute phase reactants. Children with autoimmune uveitis, whether isolated or as a part of systemic disease, may have systemic microcirculation involvement. Key Points • Idiopathic autoimmune uveitis is not always an isolated intraocular condition. • Systemic microcirculation involvement may occur in pediatric autoimmune uveitis, even in cases with isolated uveitis. • Nailfold capillaroscopy showed that capillary density in children with autoimmune uveitis is significantly reduced compared to healthy controls.

Microglial-mediated immune mechanisms in autoimmune uveitis: Elucidating pathogenic pathways and targeted therapeutics

This review offers a comprehensive examination of the role of microglia in the pathogenesis of autoimmune uveitis, an inflammatory eye disease with significant potential for vision impairment. Central to our discussion is the dual nature of microglial cells, which act as both protectors and potential perpetrators in the immune surveillance of the retina. We explore the mechanisms of microglial activation, highlighting the key signaling pathways involved, such as NF-κB, JAK/STAT, MAPK, and PI3K/Akt. The review also delves into the genetic and environmental factors influencing microglial behavior, underscoring their complex interaction in disease manifestation. Advanced imaging techniques and emerging biomarkers for microglial activation, pivotal in diagnosing and monitoring the disease, are critically assessed. Additionally, we discuss current and novel therapeutic strategies targeting microglial activity, emphasizing the shift towards more precise and personalized interventions. This article aims to provide a nuanced understanding of microglial dynamics in autoimmune uveitis, offering insights into potential avenues for effective treatment and management.

Prevalence and risk factors for complicated immuno-mediated uveitis: experience in a tertiary hospital

OBJECTIVE

To describe the characteristics of patients with uveitis and ocular complications in a tertiary hospital. As well as to determine the risk factors for the development of an ocular complication.

METHODS

Retrospective study of patients with uveitis evaluated in a Uveitis Unit of the Virgen de las Nieves Hospital from January 2018 to October 2022. A descriptive and analytical study was carried out using logistic regression to know the predictive factors of a poor ocular prognosis.

RESULTS

A total of 127 patients were studied, of which 63% were women and 83.5% were Caucasian. The median age was 51 years IQR (15-88) years. Following the SUN classification, uveitis was predominantly bilateral (55.1%) and anterior (52%), had a recurrent evolution in 51,2% and only 12,6% were granulomatous. Of the total uveitis, 74,2% of the sample turned out to have an immune-mediated profile, although a final diagnosis was only reached in 46,1% of the patients. A total of 17,3% patients suffer from loss of vision. Visual complications in decreasing order were: posterior synechiae (15,6%), cystic macular edema (14.8%), cataracts (13,1%), glaucoma (8,2%), epiretinal membranes (4,9%) and neovascular membranes (1,7%) and retinal detachment (4%). In the bivariate analysis, ethnicity other than Caucasian was significant, p = 0,024, and a number of outbreaks greater than 2, p = 0,045. The rest of the variables analyzed were not significant. In the multivariate analysis, they were significant outbreaks OR: 1,2 CI (1,051-1,426) and ethnicity OR: 0,11 CI (0,014-0,938).

CONCLUSIONS

The number of outbreaks and non-Caucasian race were related to a greater probability of presenting an ocular complication. An earlier and more specific diagnosis of the etiology, especially in these patients, would allow earlier treatment and improve their prognosis.

Ocular Inflammatory Events Following COVID-19 Vaccination in the Paediatric Population: A Multinational Case Series

BACKGROUND

Ocular inflammatory events following COVID-19 vaccination have been reported in the adult population.

METHODS

Multinational case series of patients under the age of 18 diagnosed with ocular inflammatory events within 28 days of COVID-19 vaccination.

RESULTS

Twenty individuals were included. The most common event was anterior uveitis (n = 8, 40.0%), followed by intermediate uveitis (7 patients, 35%), panuveitis (4 patients, 20%), and posterior uveitis (1 patient, 5%). The event was noticed in the first week after vaccination in 11 patients (55.0%). Twelve patients (60.0%) had a previous history of intraocular inflammatory event. Patients were managed with topical corticosteroids (n = 19, 95.0%), oral corticosteroids (n = 10, 50.0%), or increased dose of immunosuppressive treatment (n = 6, 30.0%). Thirteen patients (65.0%) had a complete resolution of the ocular event without complications. All patients had a final visual acuity unaffected or less than three lines of loss.

CONCLUSION

Ocular inflammatory events may happen in the paediatric population following COVID-19 vaccination. Most events were successfully treated, and all showed a good visual outcome.

Update on non-infectious uveitis treatment: anti-TNF-alpha and beyond

Non-infectious uveitis (NIU) encompasses a range of conditions marked by inflammation within various layers of the eye. NIU is a significant contributor to irreversible vision loss among the working-age population in developed countries. The aim of treating uveitis is to manage inflammation, prevent its recurrences and to restore or salvage vision. Presently, the standard treatment protocol for NIU involves initiating corticosteroids as the primary therapeutic agents, although more aggressive approaches and steroid sparing agent may be necessary in certain cases. These advanced treatments option include synthetic immunosuppressants like antimetabolites, calcineurin inhibitors and alkylating agents. For patients who exhibit an intolerance or resistance to corticosteroids and conventional immunosuppressive therapies, biologic agents have emerged as a promising alternative. Notably, among the biologic treatments evaluated, TNF-α inhibitors, anti-CD20 therapy and alkylating agents have shown considerable efficacy. In this review, we delve into the latest evidence surrounding the effectiveness of biologic therapy and introduce novel therapeutic strategies targeting immune components as potential avenues for advancing treatment of NIU.

Biopotency and surrogate assays to validate the immunomodulatory potency of extracellular vesicles derived from mesenchymal stem/stromal cells for the treatment of experimental autoimmune uveitis

Extracellular vesicles (EVs) derived from mesenchymal stem/stromal cells (MSCs) have been recognized as promising cytotherapeutics due to their demonstrated immunomodulatory effects in various preclinical models. The immunomodulatory capabilities of EVs stem from the proteins and genetic materials they carry from parent cells, but the cargo contents of EVs are significantly influenced by MSC tissues and donors, cellular age and culture conditions, resulting in functional variations. However, there are no surrogate assays available to validate the immunomodulatory potency of MSC-EVs before in vivo administration. In previous work, we discovered that microcarrier culture conditions enhance the immunomodulatory function of MSC-EVs, as well as the levels of immunosuppressive molecules such as TGF-β1 and let-7b in MSC-EVs. Building on these findings, we investigated whether TGF-β1 levels in MSC-EVs could serve as a surrogate biomarker for predicting their potency in vivo. Our studies revealed a strong correlation between TGF-β1 and let-7b levels in MSC-EVs, as well as their capacity to suppress IFN-γ secretion in stimulated splenocytes, establishing biopotency and surrogate assays for MSC-EVs. Subsequently, we validated MSC-EVs generated from monolayer cultures (ML-EVs) or microcarrier cultures (MC-EVs) using murine models of experimental autoimmune uveoretinitis (EAU) and additional in vitro assays reflecting the Mode of Action of MSC-EVs in vivo. Our findings demonstrated that MC-EVs carrying high levels of TGF-β1 exhibited greater efficacy than ML-EVs in halting disease progression in mice with EAU as well as inducing apoptosis and inhibiting the chemotaxis of retina-reactive T cells. Additionally, MSC-EVs suppressed the MAPK/ERK pathway in activated T cells, with treatment using TGF-β1 or let-7b showing similar effects on the MAPK/ERK pathway. Collectively, our data suggest that MSC-EVs directly inhibit the infiltration of retina-reactive T cells toward the eyes, thereby halting the disease progression in EAU mice, and their immunomodulatory potency in vivo can be predicted by their TGF-β1 levels.

Microglial mediators in autoimmune Uveitis: Bridging neuroprotection and neurotoxicity

Autoimmune uveitis, a severe inflammatory condition of the eye, poses significant challenges due to its complex pathophysiology and the critical balance between protective and detrimental immune responses. Central to this balance are microglia, the resident immune cells of the central nervous system, whose roles in autoimmune uveitis are multifaceted and dynamic. This review article delves into the dual nature of microglial functions, oscillating between neuroprotective and neurotoxic outcomes in the context of autoimmune uveitis. Initially, we explore the fundamental aspects of microglia, including their activation states and basic functions, setting the stage for a deeper understanding of their involvement in autoimmune uveitis. The review then navigates through the intricate mechanisms by which microglia contribute to disease onset and progression, highlighting both their protective actions in immune regulation and tissue repair, and their shift towards a pro-inflammatory, neurotoxic profile. Special emphasis is placed on the detailed pathways and cellular interactions underpinning these dual roles. Additionally, the review examines the potential of microglial markers as diagnostic and prognostic indicators, offering insights into their clinical relevance. The article culminates in discussing future research directions, and the ongoing challenges in translating these findings into effective clinical applications. By providing a comprehensive overview of microglial mechanisms in autoimmune uveitis, this review underscores the critical balance of microglial activities and its implications for disease management and therapy development.

scHyper: reconstructing cell-cell communication through hypergraph neural networks

Cell-cell communications is crucial for the regulation of cellular life and the establishment of cellular relationships. Most approaches of inferring intercellular communications from single-cell RNA sequencing (scRNA-seq) data lack a comprehensive global network view of multilayered communications. In this context, we propose scHyper, a new method that can infer intercellular communications from a global network perspective and identify the potential impact of all cells, ligand, and receptor expression on the communication score. scHyper designed a new way to represent tripartite relationships, by extracting a heterogeneous hypergraph that includes the source (ligand expression), the target (receptor expression), and the relevant ligand-receptor (L-R) pairs. scHyper is based on hypergraph representation learning, which measures the degree of match between the intrinsic attributes (static embeddings) of nodes and their observed behaviors (dynamic embeddings) in the context (hyperedges), quantifies the probability of forming hyperedges, and thus reconstructs the cell-cell communication score. Additionally, to effectively mine the key mechanisms of signal transmission, we collect a rich dataset of multisubunit complex L-R pairs and propose a nonparametric test to determine significant intercellular communications. Comparing with other tools indicates that scHyper exhibits superior performance and functionality. Experimental results on the human tumor microenvironment and immune cells demonstrate that scHyper offers reliable and unique capabilities for analyzing intercellular communication networks. Therefore, we introduced an effective strategy that can build high-order interaction patterns, surpassing the limitations of most methods that can only handle low-order interactions, thus more accurately interpreting the complexity of intercellular communications.

Interleukin-17A in diabetic retinopathy: The crosstalk of inflammation and angiogenesis

Diabetic retinopathy (DR) is a severe ocular complication of diabetes which can leads to irreversible vision loss in its late-stage. Chronic inflammation results from long-term hyperglycemia contributes to the pathogenesis and progression of DR. In recent years, the interleukin-17 (IL-17) family have attracted the interest of researchers. IL-17A is the most widely explored cytokine in IL-17 family, involved in various acute and chronic inflammatory diseases. Growing body of evidence indicate the role of IL-17A in the pathogenesis of DR. However, the pro-inflammatory and pro-angiogenic effect of IL-17A in DR have not hitherto been reviewed. Gaining an understanding of the pro-inflammatory role of IL-17A, and how IL-17A control/impact angiogenesis pathways in the eye will deepen our understanding of how IL-17A contributes to DR pathogenesis. Herein, we aimed to thoroughly review the pro-inflammatory role of IL-17A in DR, with focus in how IL-17A impact inflammation and angiogenesis crosstalk.

Targeting inflammasomes and pyroptosis in retinal diseases-molecular mechanisms and future perspectives

Retinal diseases encompass various conditions associated with sight-threatening immune responses and are leading causes of blindness worldwide. These diseases include age-related macular degeneration, diabetic retinopathy, glaucoma and uveitis. Emerging evidence underscores the vital role of the innate immune response in retinal diseases, beyond the previously emphasized T-cell-driven processes of the adaptive immune system. In particular, pyroptosis, a newly discovered programmed cell death process involving inflammasome formation, has been implicated in the loss of membrane integrity and the release of inflammatory cytokines. Several disease-relevant animal models have provided evidence that the formation of inflammasomes and the induction of pyroptosis in innate immune cells contribute to inflammation in various retinal diseases. In this review article, we summarize current knowledge about the innate immune system and pyroptosis in retinal diseases. We also provide insights into translational targeting approaches, including novel drugs countering pyroptosis, to improve the diagnosis and treatment of retinal diseases.

Defining mesenchymal stem/stromal cell-induced myeloid-derived suppressor cells using single-cell transcriptomics

Mesenchymal stem/stromal cells (MSCs) modulate the immune response through interactions with innate immune cells. We previously demonstrated that MSCs alleviate ocular autoimmune inflammation by directing bone marrow cell differentiation from pro-inflammatory CD11bhiLy6ChiLy6Glo cells into immunosuppressive CD11bmidLy6CmidLy6Glo cells. Herein, we analyzed MSC-induced CD11bmidLy6Cmid cells using single-cell RNA sequencing and compared them with CD11bhiLy6Chi cells. Our investigation revealed seven distinct immune cell types including myeloid-derived suppressor cells (MDSCs) in the CD11bmidLy6Cmid cells, while CD11bhiLy6Chi cells included mostly monocytes/macrophages with a small cluster of neutrophils. These MSC-induced MDSCs highly expressed Retnlg, Cxcl3, Cxcl2, Mmp8, Cd14, and Csf1r as well as Arg1. Comparative analyses of CSF-1RhiCD11bmidLy6Cmid and CSF-1RloCD11bmidLy6Cmid cells demonstrated that the former had a homogeneous monocyte morphology and produced elevated levels of interleukin-10. Functionally, these CSF-1RhiCD11bmidLy6Cmid cells, compared with the CSF-1RloCD11bmidLy6Cmid cells, inhibited CD4+ T cell proliferation and promoted CD4+CD25+Foxp3+ Treg expansion in culture and in a mouse model of experimental autoimmune uveoretinitis. Resistin-like molecule (RELM)-γ encoded by Retnlg, one of the highly upregulated genes in MSC-induced MDSCs, had no direct effects on T cell proliferation, Treg expansion, or splenocyte activation. Together, our study revealed a distinct transcriptional profile of MSC-induced MDSCs and identified CSF-1R as a key cell-surface marker for detection and therapeutic enrichment of MDSCs.

Interferons in vitreoretinal diseases; a review on their clinical application, and mechanism of action

PURPOSE

This review investigates the therapeutic benefits of interferons (IFNs) in vitreoretinal diseases, focusing on their regulatory roles in innate immunological reactions and angiogenesis. The study aims to categorize the clinical outcomes of IFN applications and proposes a molecular mechanism underlying their action.

METHODS

A systematic review was conducted using MEDLINE/PubMed, Web of Science, EMBASE, and Google Scholar databases to identify randomized clinical trials, case series, and case-control studies related to IFNs' impact on vitreoretinal diseases (1990-2022). The data synthesis involved an in-depth analysis of the anti-inflammatory and anti-angiogenesis effects of IFNs across various studies.

RESULTS

Our findings indicate that IFNs exhibit efficacy in treating inflammation-associated vitreoretinal disorders. However, a lack of sufficient evidence exists regarding the suitability of IFNs in angiogenesis-associated vitreoretinal diseases like choroidal neovascularization and diabetic retinopathies. The synthesis of data suggests that IFNs may not be optimal for managing advanced stages of angiogenesis-associated disorders.

CONCLUSION

While IFNs emerge as promising therapeutic candidates for inflammation-related vitreoretinal diseases, caution is warranted in their application for angiogenesis-associated disorders, especially in advanced stages. Further research is needed to elucidate the nuanced molecular pathways of IFN action, guiding their targeted use in specific vitreoretinal conditions.

Relapse in ocular tuberculosis: relapse rate, risk factors and clinical management in a non-endemic country

AIMS

To assess the risk of uveitis relapse in ocular tuberculosis (OTB) following clinical inactivity, to analyse clinical factors associated with relapses and to describe the management strategies for relapses.

METHODS

A retrospective study was conducted on a 10-year patient registry of patients with OTB diagnosed at Erasmus MC in Rotterdam, The Netherlands. Time-to-relapse of uveitis was evaluated with Kaplan-Meier curve and risk factors for relapses were analysed.

RESULTS

93 OTB cases were identified, of which 75 patients achieved clinical inactivity following treatment. The median time to achieve uveitis inactivity was 3.97 months. During a median follow-up of 20.7 months (Q1-Q3: 5.2-81.2) after clinical inactivity, uveitis relapse occurred in 25 of these 75 patients (33.3%). Patients who were considered poor treatment responders for their initial uveitis episode had a significantly higher risk of relapse after achieving clinical inactivity than good responders (adjusted HR=3.84, 95% CI: 1.28 to 11.51). 13 of the 25 relapsed patients experienced multiple uveitis relapse episodes, accounting for 78 eye-relapse episodes during the entire observation period. Over half (46 out of 78, 59.0%) of these episodes were anterior uveitis. A significant number of uveitis relapse episodes (31 episodes, 39.7%) were effectively managed with topical corticosteroids.

CONCLUSIONS

Our results suggest that approximately one-third of patients with OTB will experience relapse after achieving clinical inactivity. The initial disease course and poor response to treatment predict the likelihood of relapse in the long-term follow-up. Topical corticosteroids were particularly effective in relapse presenting as anterior uveitis.

Design and Development of a Web-Based Prospective Nationwide Registry for Ocular Inflammatory Diseases: UVEITE.PT - The Portuguese Ocular Inflammation Registry

Uveitis is a heterogeneous collection of infrequent diseases, which poses significant challenges to cost-effective research in the field. Medical registries are being increasingly recognized as crucial tools to provide high-quality data, thus enabling prospective clinical research. This paper describes the design and technical structure development of an innovative countrywide electronic medical record for uveitis, Uveite.pt, and gives an overview of the cohort registered since its foundation, March 2020.Uveite.pt is an electronic medical record platform developed by the Portuguese Ocular Inflammation Group (POIG), a scientific committee of the Portuguese Ophthalmology Society. This is a nationwide customized web-based platform for uveitis patients useful for both clinical practice and real-world-based research, working as a central repository and reporting tool for uveitis. This paper describes the technical principles, the design and the development of a web-based interoperable registry for uveitis in Portugal and provides an overview of more than 400 patients registered in the first 18 months since inception.In infrequent diseases, the existence of registries enables to gather evidence and increase research possibilities to clinicians. The adoption of this platform enables standardization and improvement of clinical practice in uveitis. It is useful to apprehend the repercussion of medical and surgical treatments in uveitis and scleritis, supporting clinicians in the strict monitoring of drug adverse reactions and surgical outcomes.

Retinal microglia exacerbate uveitis by functioning as local antigen-presenting cells

Autoimmune uveitis is a major cause of blindness in the working-age population of developed countries. Experimental autoimmune uveitis (EAU) depends on activation of interphotoreceptor retinoid-binding protein (IRBP) specific CD4 + effector T cells that migrate systemically and infiltrate into the retina. Following systemic induction of retinal antigen-specific T cells, the development of EAU can be broken down into three phases: early phase when inflammatory cells begin to infiltrate the retina, amplification phase, and peak phase. Although studied extensively, the function of local antigen-presenting cells (APCs) within the retina remains unclear. Two potential types of APCs are present during uveitis, resident microglia and infiltrating CD11c + dendritic cells (DCs). MHC class II (MHC II) is expressed within the retina on both CD11c + DCs and microglia during the amplification phase of EAU. Therefore, we used microglia specific (P2RY12 and TMEM119) and CD11c + DC specific MHC II knockout mice to study the function of APCs within the retina using the conventional and adoptive transfer methods of inducing EAU. Microglia were essential during all phases of EAU development: the early phase when microglia were MHC Il negative, and amplification and peak phases when microglia were MHC II positive. Unexpectedly, retinal infiltrating MHC Il + CD11c + DCs were present within the retina but their antigen-presenting function was not required for all phases of uveitis. Our data indicate microglia are the critical APCs within the retina and an important therapeutic target that can prevent and/or diminish uveitis even in the presence of circulating IRBP-specific CD4 + effector T cells.

Kurarinone regulates Th17/Treg balance and ameliorates autoimmune uveitis via Rac1 inhibition

INTRODUCTION

Autoimmune uveitis (AU) is a severe intraocular autoimmune disorder with a chronic disease course and a high rate of blindness. Kurarinone (KU), a major component of the traditional Chinese medicine Sophorae Flavescentis Radix, possesses a wide spectrum of activities and has been used to treat several inflammation-related diseases.

OBJECTIVE

We aimed to investigate the effects of KU on AU and its modulatory mechanisms.

METHODS

We used an experimental autoimmune uveitis (EAU) animal model and characterized the comprehensive immune landscape of KU-treated EAU mice using single-cell RNA sequencing (scRNA-seq). The retina and lymph nodes were analyzed. The siRNAs and selective inhibitors were used to study the signaling pathway. The effect of KU on peripheral blood mononuclear cells (PBMCs) from uveitis patients was also examined.

RESULTS

We found that KU relieved chorioretinal lesions and immune cell infiltration in EAU model mice. Subsequent single-cell analysis revealed that KU downregulated the EAU-upregulated expression of inflammatory and autoimmune-related genes and suppressed pathways associated with immune cell differentiation, activation, and migration in a cell-specific manner. KU was implicated in restoring T helper 17 (Th17)/regulatory T (Treg) cell balance by alleviating inflammatory injury and elevating the expression of modulatory mediators in Tregs, while simultaneously ameliorating excessive inflammation by Th17 cells. Furthermore, Rac1 and the Id2/Pim1 axis potentiated the pathogenicity of Th17 cells during EAU, which was inhibited by KU treatment, contributing to the amelioration of EAU-induced inflammation and treatment of AU. In addition, KU suppressed inflammatory cytokine production in activated human PBMCs by inhibiting Rac1. Integration of the glucocorticoid-treated transcriptome suggests that KU has immunomodulatory effects on lymphocytes.

CONCLUSION

Our study constructed a high-resolution atlas of the immunoregulatory effects of KU treatment on EAU and identified its potential therapeutic mechanisms, which hold great promise in treating autoimmune disorders.

Repurposing of rituximab biosimilars to treat B cell mediated autoimmune diseases

Rituximab, the first monoclonal antibody approved for the treatment of lymphoma, eventually became one of the most popular and versatile drugs ever in terms of clinical application and revenue. Since its patent expiration, and consequently, the loss of exclusivity of the original biologic, its repurposing as an off-label drug has increased dramatically, propelled by the development and commercialization of its many biosimilars. Currently, rituximab is prescribed worldwide to treat a vast range of autoimmune diseases mediated by B cells. Here, we present a comprehensive overview of rituximab repurposing in 115 autoimmune diseases across 17 medical specialties, sourced from over 1530 publications. Our work highlights the extent of its off-label use and clinical benefits, underlining the success of rituximab repurposing for both common and orphan immune-related diseases. We discuss the scientific mechanism associated with its clinical efficacy and provide additional indications for which rituximab could be investigated. Our study presents rituximab as a flagship example of drug repurposing owing to its central role in targeting cluster of differentiate 20 positive (CD20) B cells in 115 autoimmune diseases.

Discovery of a novel pyroptosis inhibitor acting though modulating glutathionylation to suppress NLRP3-related signal pathway

Pyroptosis is a proinflammatory type of regulated cell death and has been involved in many pathological processes. Inhibition of pyroptosis is thought to be a promising strategy for the treatment of related diseases. Here, we performed a phenotypic screening against NLRP3-dependent pyroptosis and obtained the novel compound N77 after structure optimization. N77 showed a half-maximal effective concentration (EC50) of 0.070 ± 0.008 μM against cell pyroptosis induced by nigericin, and exhibited a remarkable ability to prevent NLRP3-dependent inflammasome activation and the release of IL-1β. Chemical proteomics revealed the biological target of N77 to be glutathione-S-transferase Mu 1 (GSTM1); our mechanism of action studies indicated that GSTM1 might act as a negative regulator of NLRP3 inflammasome activation by modulating the glutathionylation of caspase-1. In vivo, N77 substantially alleviated the inflammatory reaction in a pyroptosis-related acute keratitis model. Overall, we identified a novel pyroptosis inhibitor and revealed a new regulatory mechanism of pyroptosis. Our findings suggest an alternative potential therapeutic strategy for pyroptosis-related diseases.

Unilateral acute idiopathic maculopathy related to hand-foot-mouth disease: Case report and literature review

Unilateral acute idiopathic maculopathy (UAIM) is a rare disease that may cause unilateral vision loss in young adults after a flu-like illness. Occasionally, it is associated with hand-foot-mouth disease (HFMD) and is often underdiagnosed. Herein, we report a case with characteristics of UAIM associated with HFMD with acute enteroviral infection. On the basis of the clinical findings using multimodality diagnostic imaging, including fundus image, optical coherence tomography, fluorescence angiography, and serological test for pan-enterovirus RNA polymerase chain reaction, we detailed the clinical course and postulated the pathogenesis of UAIM with choroiditis associated with HFMD. This study could remind every doctor of the potential visual loss caused by UAIM in HFMD, and referring patients to the ophthalmologic survey is important to eliminate potential visual impairment.

Cytokines in Immune-mediated "Non-infectious" Uveitis

Uveitis is a significant cause of ocular morbidity and accounts for approximately 5 - 10% of visual impairments worldwide, particularly among the working-age population. Infections are the cause of ~ 50% cases of uveitis, but it has been suggested that infection might also be implicated in the pathogenesis of immune-mediated "non-infectious" uveitis. There is growing evidence that cytokines (i.e., interleukins, interferons, etc.) are key mediators of immune-mediated "non-infectious" uveitis. For example, activation of the interleukin-23/interleukin-17 signalling pathway is involved in immune-mediated "non-infectious" uveitis. Studies in animal models have been important in investigating the role of cytokines in uveitis. Recent studies of clinical samples from patients with uveitis have allowed the measurement of a considerable array of cytokines even from very small sample volumes (e.g., aqueous and vitreous humour). The identification of complex patterns of cytokines may contribute to a better understanding of their potential pathogenetic role in uveitis as well as to an improved diagnostic and therapeutic approach to treat these potentially blinding pathologies. This review provides further insights into the putative pathobiological role of cytokines in immune-mediated "non-infectious" uveitis.

T memory stem cell characteristics in autoimmune diseases and their promising therapeutic values

Memory T cells are conventionally subdivided into T central memory (T_CM) and T effector memory (T_EM) cells. However, a new subset of memory T cells named T memory stem cell (T_SCM) cells has been recognized that possesses capabilities of both T_CM and T_EM cells including lymphoid homing and performing effector roles through secretion of cytokines such as interleukin-2 (IL-2) and interferon-gamma (IFN-γ). The T_SCM subset has some biological properties including stemness, antigen independency, high proliferative potential, signaling pathway and lipid metabolism. On the other hand, memory T cells are considered one of the principal culprits in the pathogenesis of autoimmune diseases. T_SCM cells are responsible for developing long-term defensive immunity against different foreign antigens, alongside tumor-associated antigens, which mainly derive from self-antigens. Hence, antigen-specific T_SCM cells can produce antitumor responses that are potentially able to trigger autoimmune activities. Therefore, we reviewed recent evidence on T_SCM cell functions in autoimmune disorders including type 1 diabetes, systemic lupus erythematosus, rheumatoid arthritis, acquired aplastic anemia, immune thrombocytopenia, and autoimmune uveitis. We also introduced T_SCM cell lineage as an innovative prognostic biomarker and a promising therapeutic target in autoimmune settings.

Progesterone attenuates Th17-cell pathogenicity in autoimmune uveitis via Id2/Pim1 axis

BACKGROUND

Autoimmune uveitis (AU) is the most common ophthalmic autoimmune disease (AD) and is characterized by a complex etiology, high morbidity, and high rate of blindness. AU remission has been observed in pregnant female patients. However, the effects of progesterone (PRG), a critical hormone for reproduction, on the treatment of AU and the regulatory mechanisms remain unclear.

METHODS

To this end, we established experimental autoimmune uveitis (EAU) animal models and constructed a high-dimensional immune atlas of EAU-model mice undergoing PRG treatment to explore the underlying therapeutic mechanisms of PRG using single-cell RNA sequencing.

RESULTS

We found that PRG ameliorated retinal lesions and inflammatory infiltration in EAU-model mice. Further single-cell analysis indicated that PRG reversed the EAU-induced expression of inflammatory genes (AP-1 family, S100a family, and Cxcr4) and pathological processes related to inflammatory cell migration, activation, and differentiation. Notably, PRG was found to regulate the Th17/Treg imbalance by increasing the reduced regulatory functional mediators of Tregs and diminishing the overactivation of pathological Th17 cells. Moreover, the Id2/Pim1 axis, IL-23/Th17/GM-CSF signaling, and enhanced Th17 pathogenicity during EAU were reversed by PRG treatment, resulting in the alleviation of EAU inflammation and treatment of AD.

CONCLUSIONS

Our study provides a comprehensive single-cell map of the immunomodulatory effects of PRG therapy on EAU and elaborates on the possible therapeutic mechanisms, providing novel insights into its application for treating autoimmune diseases.

Single-cell analysis of immune cells on gingiva-derived mesenchymal stem cells in experimental autoimmune uveitis

Gingiva-derived mesenchymal stem cells (GMSCs) have shown astonishing efficacy in the treatment of various autoimmune diseases. However, the mechanisms underlying these immunosuppressive properties remain poorly understood. Here, we generated a lymph node single-cell transcriptomic atlas of GMSC-treated experimental autoimmune uveitis mice. GMSC exerted profound rescue effects on T cells, B cells, dendritic cells, and monocytes. GMSCs rescued the proportion of T helper 17 (Th17) cells and increased the proportion of regulatory T cells. In addition to globally altered transcriptional factors (Fosb and Jund), we observed cell type-dependent gene regulation (e.g., Il17a and Rac1 in Th17 cells), highlighting the GMSCs' cell type-dependent immunomodulatory capacity. GMSCs strongly influenced the phenotypes of Th17 cells, suppressing the formation of the highly inflammatory CCR6-CCR2+ phenotype and enhancing the production of interleukin (IL) -10 in the CCR6+CCR2+ phenotype. Integration of the glucocorticoid-treated transcriptome suggests a more specific immunosuppressive effect of GMSCs on lymphocytes.

Prednisone acetate modulates Th1/Th2 and Th17/Treg cell homeostasis in experimental autoimmune uveitis via orchestrating the Notch signaling pathway

Uveitis is an immune eye disease that can seriously impair vision. Glucocorticoids (GC_S) have been extensively used to treat uveitis, though the mechanisms have not been fully elucidated. In this study, we investigated the regulatory effects of prednisone acetate (PA) on the Th1/Th2 and Th17/Treg balance in experimental autoimmune uveitis (EAU) through modulating the Notch signaling pathway. Briefly, Lewis rats were randomly divided into the normal control (NC), EAU, and EAU + PA groups. Rats in EAU and EAU + PA groups were induced EAU, while those in the EAU + PA group were treated with PA. Clinical and histopathological scores were employed to assess the progression of EAU. The expression levels of Notch signaling-related molecules (Notch1, Notch2, Dll3, Dll4, and Rbpj) and Th-associated cytokines (IFN-γ, IL-4, IL-10, and IL-17) were assessed via quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA). In addition, the frequencies of Th1, Th2, Th17 and Treg cells were detected by flow cytometry. These experimental results indicated that activation of the Notch signaling pathway occurred in EAU rats and resulted in a severe imbalance of the Th17/Treg and Th1/Th2 ratios. PA treatment significantly alleviated ocular inflammation, inhibited activation of the Notch signaling pathway, and declined Th1, and Th17 cell differentiation, thereby restoring the Th1/Th2 and Th17/Treg balance. Collectively, PA can positively enhance the systemic immune response and improve the intraocular microenvironmental homeostasis by inhibiting activation of the Notch signaling pathway and by restoring Th1/Th2 and Th17/Treg balance, thus achieving the goal of treating uveitis.

Antigen-Specific Intraocular Cytokine Responses Distinguish Ocular Tuberculosis From Undifferentiated Uveitis in Tuberculosis-Immunoreactive Patients

PURPOSE

To compare antigen-specific intraocular immune responses between different clinical phenotypes of tuberculin skin test (TST)-positive and TST-negative uveitis.

DESIGN

Single center, retrospective cross-sectional study.

METHODS

Patients requiring diagnostic or therapeutic vitrectomy for the management of intraocular inflammation were divided into 3 groups based on Standardization of Uveitis Nomenclature (SUN) classification criteria for tubercular uveitis. Group 1 included patients with ocular tuberculosis (OTB; n = 23) who were TST-positive patients, met the SUN criteria, and/or had a polymerase chain reaction (PCR)-positive test for TB. Group 2 included patients with uveitis of unknown origin (UNK; n = 24) who were undifferentiated TST-positive patients who had not met SUN criteria. Group 3 included non-TB uveitis patients (n = 24) who were TST-negative either with or without a well-defined non-TB diagnosis. Total vitreous cells were activated with Mycobacterium tuberculosis-specific Early Secreted Antigenic Target-6 (ESAT-6) or the retinal autoantigen, interphotoreceptor retinoid-binding protein peptide (pIRBP 1-20), stained for intracellular interferon gamma (IFNγ), tumor necrosis factor-alfa (TNFα), and interleukin 17 (IL-17), and analyzed by flow cytometry. Antigen-specific single and dual (polyfunctional) cytokine responses to ESAT-6 and IRBP were compared between the 3 groups.

RESULTS

All cytokine responses to ESAT-6 were higher in the UNK group compared with the non-TB control subjects, while all except IL-17 were comparable between the OTB and non-TB groups. Polyfunctional responses-IFNγ/IL-17 (P = .002), TNFα/IL-17 (P = .02), and TNFα/IFNγ (P = .01)-were significantly greater for UNK than the OTB group. Polyfunctional cells also produced more cytokine per cell than respective monofunctional cells. IRBP cytokine responses were comparable between different groups and were not affected by the clinical phenotype or duration of disease.

CONCLUSION

The intraocular polyfunctional cytokine response is stronger in undifferentiated TST-positive uveitis than in OTB patients, likely representing an exaggerated anti-TB immune response rather than active infection.

Non-biologic, steroid-sparing therapies for non-infectious intermediate, posterior, and panuveitis in adults

BACKGROUND

Non-infectious intermediate, posterior, and panuveitis (NIIPPU) represent a heterogenous collection of autoimmune and inflammatory disorders isolated to or concentrated in the posterior structures of the eye. Because NIIPPU is typically a chronic condition, people with NIIPPU frequently require treatment with steroid-sparing immunosuppressive therapy. Methotrexate, mycophenolate, cyclosporine, azathioprine, and tacrolimus are non-biologic, disease-modifying antirheumatic drugs (DMARDs) which have been used to treat people with NIIPPU.

OBJECTIVES

To compare the effectiveness and safety of selected DMARDs (methotrexate, mycophenolate mofetil, tacrolimus, cyclosporine, and azathioprine) in the treatment of NIIPPU in adults.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register), MEDLINE, Embase, the Latin American and Caribbean Health Sciences database, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform, most recently on 16 April 2021.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing selected DMARDs (methotrexate, mycophenolate, tacrolimus, cyclosporine, and azathioprine) with placebo, standard of care (topical steroids, with or without oral steroids), or with each other.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 11 RCTs with a total of 601 participants in this review. DMARDs versus control Two studies compared an experimental DMARD (cyclosporine A or enteric-coated mycophenolate [EC-MPS]) plus oral steroid with steroid monotherapy. We did not pool these results into a meta-analysis because the dose of cyclosporine used was much higher than that used in current clinical practice. The evidence is very uncertain about whether EC-MPS plus low-dose oral steroid results in a higher proportion of participants achieving control of inflammation over steroid monotherapy (risk ratio [RR] 2.81, 95% confidence interval [CI] 1.10 to 7.17; 1 study, 41 participants; very low-certainty evidence). The change in best-corrected visual acuity (BCVA) was reported separately for right and left eyes. The evidence for improvement (lower logarithm of the minimum angle of resolution (logMAR) indicates better vision) between the groups is very uncertain (mean difference [MD] -0.03 and -0.10, 95% CI -0.96 to 0.90 and -0.27 to 0.07 for right and left, respectively; 1 study, 82 eyes; very low-certainty evidence). No data were available for the following outcomes: proportion of participants achieving a 2-line improvement in visual acuity, with confirmed macular edema, or achieving steroid-sparing control. The evidence for the proportion of participants requiring cessation of medication in the DMARD versus control group is very uncertain (RR 2.61, 95% CI 0.11 to 60.51; 1 study, 41 participants; very low-certainty evidence). Methotrexate versus mycophenolate We were able to combine two studies into a meta-analysis comparing methotrexate versus mycophenolate mofetil. Methotrexate probably results in a slight increase in the proportion of participants achieving control of inflammation, including steroid-sparing control, compared to mycophenolate at six months (RR 1.23, 95% CI 1.01 to 1.50; 2 studies, 261 participants; moderate-certainty evidence). Change in BCVA was reported per eye and the treatments likely result in little to no difference in change in vision (MD 0.01 logMAR higher [worse] for methotrexate versus mycophenolate; 2 studies, 490 eyes; moderate-certainty evidence). No data were available for the proportion of participants achieving a 2-line improvement in visual acuity. The evidence is very uncertain regarding the proportion of participants with confirmed macular edema between methotrexate versus mycophenolate (RR 0.49, 95% CI 0.19 to 1.30; 2 studies, 35 eyes; very low-certainty). Methotrexate versus mycophenolate may result in little to no difference in the proportion of participants requiring cessation of medication (RR 0.99, 95% CI 0.43 to 2.27; 2 studies, 296 participants; low-certainty evidence). Steroids with or without azathioprine versus cyclosporine A Four studies compared steroids with or without azathioprine (oral steroids, intravenous [IV] steroids, or azathioprine) to cyclosporine A. We excluded two studies from the meta-analysis because the participants were treated with 8 mg to 15 mg/kg/day of cyclosporine A, a significantly higher dose than is utilized today because of concerns for nephrotoxicity. The remaining two studies were conducted in all Vogt-Koyanagi-Harada disease (VKH) populations and compared cyclosporine A to azathioprine or IV pulse-dose steroids. The evidence is very uncertain for whether the steroids with or without azathioprine or cyclosporine A influenced the proportion of participants achieving control of inflammation (RR 0.84, 95% CI 0.70 to 1.02; 2 studies, 112 participants; very low-certainty evidence), achieving steroid-sparing control (RR 0.64, 95% CI 0.33 to 1.25; 1 study, 21 participants; very low-certainty evidence), or requiring cessation of medication (RR 0.85, 95% 0.21 to 3.45; 2 studies, 91 participants; very low-certainty evidence). The evidence is uncertain for improvement in BCVA (MD 0.04 logMAR lower [better] with the steroids with or without azathioprine versus cyclosporine A; 2 studies, 91 eyes; very low-certainty evidence). There were no data available (with current cyclosporine A dosing) for the proportion of participants achieving a 2-line improvement in visual acuity or with confirmed macular edema. Studies not included in synthesis We were unable to include three studies in any of the comparisons (in addition to the aforementioned studies excluded based on historic doses of cyclosporine A). One was a dose-response study comparing cyclosporine A to cyclosporine G, a formulation which was never licensed and is not clinically available. We excluded another study from meta-analysis because it compared cyclosporine A and tacrolimus, considered to be of the same class (calcineurin inhibitors). We were unable to combine the third study, which examined tacrolimus monotherapy versus tacrolimus plus oral steroid, with any group.

AUTHORS' CONCLUSIONS

There is a paucity of data regarding which DMARD is most effective or safe in NIIPPU. Studies in general were small, heterogenous in terms of their design and outcome measures, and often did not compare different classes of DMARD with each other. Methotrexate is probably slightly more efficacious than mycophenolate in achieving control of inflammation, including steroid-sparing control (moderate-certainty evidence), although there was insufficient evidence to prefer one medication over the other in the VKH subgroup (very low-certainty evidence). Methotrexate may result in little to no difference in safety outcomes compared to mycophenolate.

The role of the adaptive immune system and T cell dysfunction in neurodegenerative diseases

The adaptive immune system and associated inflammation are vital in surveillance and host protection against internal and external threats, but can secondarily damage host tissues. The central nervous system is immune-privileged and largely protected from the circulating inflammatory pathways. However, T cell involvement and the disruption of the blood-brain barriers have been linked to several neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, and multiple sclerosis. Under normal physiological conditions, regulatory T cells (Treg cells) dampen the inflammatory response of effector T cells. In the pathological states of many neurodegenerative disorders, the ability of Treg cells to mitigate inflammation is reduced, and a pro-inflammatory environment persists. This perspective review provides current knowledge on the roles of T cell subsets (e.g., effector T cells, Treg cells) in neurodegenerative and ocular diseases, including uveitis, diabetic retinopathy, age-related macular degeneration, and glaucoma. Many neurodegenerative and ocular diseases have been linked to immune dysregulation, but the cellular events and molecular mechanisms involved in such processes remain largely unknown. Moreover, the role of T cells in ocular pathologies remains poorly defined and limited literature is available in this area of research. Adoptive transfer of Treg cells appears to be a vital immunological approach to control ocular pathologies. Similarities in T cell dysfunction seen among non-ocular neurodegenerative diseases suggest that this area of research has a great potential to develop better therapeutic agents for ocular diseases and warrants further studies. Overall, this perspective review article provides significant information on the roles of T cells in numerous ocular and non-ocular neurodegenerative diseases.

Physical and Psychosocial Health in Pediatric Uveitis Patients

BACKGROUND

To investigate the possible associations between childhood noninfectious uveitis and cardio-respiratory fitness, physical activity, health related quality of life and fatigue.

METHODS

Cross-sectional analysis of 23 patients with noninfectious uveitis, aged 8-18 years. BMI, exercise capacity, muscle strength and physical activity were measured. Health-related quality of life and fatigue were assessed. The results were compared to standardized values for age matched healthy children.

RESULTS

Twenty-three patients were included. Children with uveitis had a higher bodyweight and body mass index. Children with uveitis had lower cardio-respiratory fitness and they were less physically active, but they experienced a normal quality of life and normal fatigue. Parents of children with uveitis reported a lower quality of life and more fatigue for their children than parents of healthy children.

CONCLUSION

Our study indicates that children with noninfectious uveitis are at risk of developing lower physical and psychosocial health.

FTO-mediated m6A modification alleviates autoimmune uveitis by regulating microglia phenotypes via the GPC4/TLR4/NF-κB signaling axis

Uveitis, a vision-threatening inflammatory disease worldwide, is closely related to resident microglia. Retinal microglia are the main immune effector cells with strong plasticity, but their role in uveitis remains unclear. N6-methyladenosine (m⁶A) modification has been proven to be involved in the immune response. Therefore, we in this work aimed to identify the potentially crucial m⁶A regulators of microglia in uveitis. Through the single-cell sequencing (scRNA-seq) analysis and experimental verification, we found a significant decrease in the expression of fat mass and obesity-associated protein (FTO) in retinal microglia of uveitis mice and human microglia clone 3 (HMC3) cells with inflammation. Additionally, FTO knockdown was found to aggravate the secretion of inflammatory factors and the mobility/chemotaxis of microglia. Mechanistically, the RNA-seq data and rescue experiments showed that glypican 4 (GPC4) was the target of FTO, which regulated microglial inflammation mediated by the TLR4/NF-κB pathway. Moreover, RNA stability assays indicated that GPC4 upregulation was mainly regulated by the downregulation of the m⁶A "reader" YTH domain family protein 3 (YTHDF3). Finally, the FTO inhibitor FB23-2 further exacerbated experimental autoimmune uveitis (EAU) inflammation by promoting the GPC4/TLR4/NF-κB signaling axis, and this could be attenuated by the TLR4 inhibitor TAK-242. Collectively, a decreased FTO could facilitate microglial inflammation in EAU, suggesting that the restoration or activation of FTO function may be a potential therapeutic strategy for uveitis.

Low-dose melittin is safe for intravitreal administration and ameliorates inflammation in an experimental model of uveitis

Uveitis is a group of sight-threatening ocular inflammatory disorders, whose mainstay of therapy is associated with severe adverse events, prompting the investigation of alternative treatments. The peptide melittin (MEL) is the major component of Apis mellifera bee venom and presents anti-inflammatory and antiangiogenic activities, with possible application in ophthalmology. This work aims to investigate the potential of intravitreal MEL in the treatment of ocular diseases involving inflammatory processes, especially uveitis. Safety of MEL was assessed in retinal cells, chick embryo chorioallantoic membranes, and rats. MEL at concentrations safe for intravitreal administration showed an antiangiogenic activity in the chorioallantoic membrane model comparable to bevacizumab, used as positive control. A protective anti-inflammatory effect in retinal cells stimulated with lipopolysaccharide (LPS) was also observed, without toxic effects. Finally, rats with bacille Calmette-Guerin- (BCG) induced uveitis treated with intravitreal MEL showed attenuated disease progression and improvement of clinical, morphological, and functional parameters, in addition to decreased levels of proinflammatory mediators in the posterior segment of the eye. These effects were comparable to the response observed with corticosteroid treatment. Therefore, MEL presents adequate safety profile for intraocular administration and has therapeutic potential as an anti-inflammatory and antiangiogenic agent for ocular diseases.

•

Melittin at low concentration is safe for intravitreal administration.

•

The antiangiogenic effect of melittin on the chorioallantoic membrane model is comparable to bevacizumab.

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Melittin protects retinal cells from inflammatory response induced by lipopolysaccharide.

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Melittin improves clinical, functional and morphological signs of inflammation in rats with BCG-induced uveitis.

Assessment of Anterior Uveitis Through Anterior-Segment Optical Coherence Tomography and Artificial Intelligence-Based Image Analyses

Purpose

The purpose of this study was to develop an automated artificial intelligence (AI) based method to quantify inflammation in the anterior chamber (AC) using anterior-segment optical coherence tomography (AS-OCT) and to explore the correlation between AI assisted AS-OCT based inflammation analyses and clinical grading of anterior uveitis by Standardization of Uveitis Nomenclature (SUN).

Methods

A prospective double blinded study of AS-OCT images of 32 eyes of 19 patients acquired by Tomey CASIA-II. OCT images were analyzed with proprietary AI-based software. Anatomic boundaries of the AC were segmented automatically by the AI software and Spearman's rank correlation between parameters related to AC cellular inflammation were calculated.

Results

No significant (p = 0.6602) differences were found between the analyzed AC areas between samples of the different SUN grading, suggesting accurate and unbiased border detection/AC segmentation. Segmented AC areas were processed by the AI software and particles within the borders of AC were automatically counted by the software. Statistical analysis found significant (p < 0.001) correlation between clinical SUN grading and AI software detected particle count (Spearman ρ = 0.7077) and particle density (Spearman ρ = 0.7035). Significant (p < 0.001) correlation (Pearson's r = 0.9948) between manually and AI detected particles was found. No significant (p = 0.8080) difference was found between the sizes of the AI detected particles for all studies.

Conclusions

AI-based image analysis of AS-OCT slides show significant and independent correlation with clinical SUN assessment.

Translational Relevance

Automated AI-based AS-OCT image analysis suggests a noninvasive and quantitative assessment of AC inflammation with clear potential application in early detection and management of anterior uveitis.

Proteome Analysis of Urinary Biomarkers in a Bovine IRBP-Induced Uveitis Rat Model via Data-Independent Acquisition and Parallel Reaction Monitoring Proteomics

Uveitis, a group of intraocular inflammatory diseases, is one of the major causes of severe visual impairment among the working-age population. This study aimed to screen potential urinary biomarkers for uveitis based on proteome analysis. An experimental autoimmune uveitis (EAU) rat model induced by bovine interphotoreceptor retinoid-binding protein (IRBP) was used to mimic uveitis. In discovery phase, a total of 704 urinary proteins were identified via data-independent acquisition (DIA) proteomic technique, of which 76 were significantly changed (34, 36, and 37 on days 5, 8, and 12, respectively, after bovine IRBP immunization). Gene Ontology annotation of the differential proteins indicates that acute-phase response, innate immune response, neutrophil aggregation, and chronic inflammatory response were significantly enriched. Protein-protein interaction network indicates that these differential urinary proteins were biologically connected in EAU, as a group. In validation phase, 17 proteins having human orthologs were verified as the potential markers associated with uveitis by parallel reaction monitoring (PRM) targeted quantitative analysis. Twelve differential proteins changed even when there were no clinical manifestations or histopathological ocular damage. These 12 proteins are potential biomarkers for early diagnosis of uveitis to prevent the development of visual impairment. Five differential proteins changed at three time-points and showed progressive changes as the uveitis progressed, and another five differential proteins changed only on day 12 when EAU severity peaked. These 10 proteins may serve as potential biomarkers for prognostic evaluation of uveitis. Our findings revealed that the urinary proteome could sensitively reflect dynamic pathophysiological changes in EAU, and represent the first step towards the application of urinary protein biomarkers for uveitis.

Cytokines, chemokines and growth factors profile in human aqueous humor in idiopathic uveitis

To investigate which cytokines, chemokines and growth factors are involved in the immunopathogenesis of idiopathic uveitis, and whether cytokine profiles are associated with. Serum and aqueous humor (AH) samples of 75 patients with idiopathic uveitis were analyzed by multiplex immunoassay. Infectious controls consisted of 16 patients with ocular toxoplasmosis all confirmed by intraocular fluid analyses. Noninfectious controls consisted of 7 patients with Behçet disease related uveitis and 15 patients with sarcoidosis related uveitis. The control group consisted of AH and serum samples from 47 noninflammatory control patients with age-related cataract. In each sample, 27 immune mediators ± IL-21 and IL-23 were measured. In idiopathic uveitis, 13 of the 29 mediators, including most proinflammatory and vascular mediators such as IL-6, IL-8, IL-12, G-CSF, GM-CSF, MCP-1, IP-10, TNF-α and VEGF, were significantly elevated in the aqueous humor when compared to all controls. Moreover, IL-17, IP-10, and IL-21, were significantly elevated in the serum when compared to all controls. We clustered 4 subgroups of idiopathic uveitis using a statistical analysis of hierarchical unsupervised classification, characterized by the order of magnitude of concentrations of intraocular cytokines. The pathogenesis of idiopathic uveitis is characterized by the presence of predominantly proinflammatory cytokines and chemokines and vascular endothelial growth factor with high expression levels as compared to other causes of uveitis. There are indications for obvious Th-1/ IL21-Th17 pathways but also IL9-Th9 and increased IFN-γ-inducing cytokine (IL12) and IFN-γ-inducible CXC chemokine (IP-10). The combined data suggest that immune mediator expression is different among idiopathic uveitis. This study suggests various clusters among the idiopathic uveitis group rather than one specific uveitis entity.

Depletion of Retinal Dopaminergic Activity in a Mouse Model of Rod Dysfunction Exacerbates Experimental Autoimmune Uveoretinitis: A Role for the Gateway Reflex

The gateway reflex is a mechanism by which neural inputs regulate chemokine expression at endothelial cell barriers, thereby establishing gateways for the invasion of autoreactive T cells into barrier-protected tissues. In this study, we hypothesized that rod photoreceptor dysfunction causes remodeling of retinal neural activity, which influences the blood–retinal barrier and the development of retinal inflammation. We evaluated this hypothesis using Gnat1^rd17 mice, a model of night blindness with late-onset rod-cone dystrophy, and experimental autoimmune uveoretinitis (EAU). Retinal remodeling and its effect on EAU development were investigated by transcriptome profiling, target identification, and functional validation. We showed that Gnat1^rd17 mice primarily underwent alterations in their retinal dopaminergic system, triggering the development of an exacerbated EAU, which was counteracted by dopamine replacement with L-DOPA administered either systemically or locally. Remarkably, dopamine acted on retinal endothelial cells to inhibit NF-κB and STAT3 activity and the expression of downstream target genes such as chemokines involved in T cell recruitment. These results suggest that rod-mediated dopamine release functions in a gateway reflex manner in the homeostatic control of immune cell entry into the retina, and the loss of retinal dopaminergic activity in conditions associated with rod dysfunction increases the susceptibility to autoimmune uveitis.

Pyroptosis: A New Insight Into Eye Disease Therapy

Pyroptosis is a lytic form of programmed cell death mediated by gasdermins (GSDMs) with pore-forming activity in response to certain exogenous and endogenous stimuli. The inflammasomes are intracellular multiprotein complexes consisting of pattern recognition receptors, an adaptor protein ASC (apoptosis speck-like protein), and caspase-1 and cause autocatalytic activation of caspase-1, which cleaves gasdermin D (GSDMD), inducing pyroptosis accompanied by cytokine release. In recent years, the pathogenic roles of inflammasomes and pyroptosis in multiple eye diseases, including keratitis, dry eyes, cataracts, glaucoma, uveitis, age-related macular degeneration, and diabetic retinopathy, have been continuously confirmed. Inhibiting inflammasome activation and abnormal pyroptosis in eyes generally attenuates inflammation and benefits prognosis. Therefore, insight into the pathogenesis underlying pyroptosis and inflammasome development in various types of eye diseases may provide new therapeutic strategies for ocular disorders. Inhibitors of pyroptosis, such as NLRP3, caspase-1, and GSDMD inhibitors, have been proven to be effective in many eye diseases. The purpose of this article is to illuminate the mechanism underlying inflammasome activation and pyroptosis and emphasize its crucial role in various ocular disorders. In addition, we review the application of pyroptosis modulators in eye diseases.

Epigenetic Modifications and Therapy in Uveitis

Uveitis is a sight-threatening intraocular inflammation, and the exact pathogenesis of uveitis is not yet clear. Recent studies, including multiple genome-wide association studies (GWASs), have identified genetic variations associated with the onset and progression of different types of uveitis, such as Vogt–Koyanagi–Harada (VKH) disease and Behcet’s disease (BD). However, epigenetic regulation has been shown to play key roles in the immunoregulation of uveitis, and epigenetic therapies are promising treatments for intraocular inflammation. In this review, we summarize recent advances in identifying epigenetic programs that cooperate with the physiology of intraocular immune responses and the pathology of intraocular inflammation. These attempts to understand the epigenetic mechanisms of uveitis may provide hope for the future development of epigenetic therapies for these devastating intraocular inflammatory conditions.

The assessment of the concentration of candidate cytokines in response to conjunctival-exposure of atmospheric low-temperature plasma in an animal model

BACKGROUND

Atmospheric Low-Temperature Plasma (ALTP) can be used as an effective tool in conjunctival cyst ablation, but little is known about how conjunctival ALTP-exposure affects the concentration of inflammatory mediators and also the duration of inflammatory responses.

METHODS

We used 8 female adult Lewis rats that were followed up in 4 groups. The right eye of each rat was selected for the test, whereas the left eye was considered as a control. The ALTP was generated and used to target 3 spots of the conjunctiva. The digital camera examinations were performed to follow-up the clinical outcomes after ALTP exposure. Tear and serum samples were isolated-at 2 days, 1 week, 1 month, and 6 months after treatment-from each rat and the concentration of candidate pro-inflammatory (i.e. IL-1α, IL-2, IL-6, IFN-γ, and TNF-α) and anti-inflammatory cytokines (i.e. IL-4 and IL-10) were measured using flow cytometry.

RESULTS

The external and digital camera examinations showed no ocular surface complications in all ALTP-exposed rats after 1 week. The analyses revealed that the ALTP transiently increases the concentration of pro-inflammatory cytokines-IL-1α and IL-2 in tear samples in 1 week and 2 days after exposure, respectively; no differences were observed regarding other pro- and anti-inflammatory cytokines in the tear or serum samples.

CONCLUSIONS

ALTP can probably be used as a minimally-invasive therapeutic method that triggers no permanent or continual inflammatory responses. The results of this study might help the patients to shorten the consumption of immunosuppressive drugs, e.g. corticosteroids, that are prescribed to mitigate the inflammation after ALTP-surgery.

Changes in Choroidal Vascularity Index (CVI) in Intermediate Uveitis

Purpose

To investigate the longitudinal changes in choroidal vascularity index (CVI) in eyes with active and quiescent intermediate uveitis using enhanced depth imaging optical coherence tomography (EDI-OCT).

Methods

EDI-OCT images of eyes with active and quiescent intermediate uveitis were retrospectively reviewed and binarized using ImageJ software. Choroidal parameters including CVI, total choroidal area (TCA), luminal area (LA), stromal area (SA), and subfoveal choroidal thickness (SCT) were measured and compared between baseline and follow-up visits among eyes with active and quiescent intermediate uveitis.

Results

Thirty-eight eyes from 21 patients with active intermediate uveitis and 30 eyes from 17 patients with quiescent intermediate uveitis were included. CVI in eyes with active intermediate uveitis significantly increased from baseline (66.50% ± 3.40%) with resolution of inflammation on follow-up (68.82% ± 3.90%; P < 0.001). In eyes with quiescent intermediate uveitis at baseline eyes, CVI did not significantly change after follow-up (66.34% ± 3.19% to 66.25% ± 3.13%; P = 0.850).

Conclusions

CVI significantly increased when active inflammation in intermediate uveitis resolved while CVI remained unchanged at follow-up in quiescent intermediate uveitis.

Translational Relevance

CVI may be a useful noninvasive tool to monitor treatment response in intermediate uveitis. Our findings also highlight the involvement of choroidal vasculature in uveitic eyes without any clinical evidence of choroiditis.

Microbiota and Ocular Diseases

Recent advances have identified significant associations between the composition and function of the gut microbiota and various disorders in organ systems other than the digestive tract. Utilizing next-generation sequencing and multiomics approaches, the microbial community that possibly impacts ocular disease has been identified. This review provides an overview of the literature on approaches to microbiota analysis and the roles of commensal microbes in ophthalmic diseases, including autoimmune uveitis, age-related macular degeneration, glaucoma, and other ocular disorders. In addition, this review discusses the hypothesis of the "gut-eye axis" and evaluates the therapeutic potential of targeting commensal microbiota to alleviate ocular inflammation.

Overexpressing Kallistatin Aggravates Experimental Autoimmune Uveitis Through Promoting Th17 Differentiation

Kallistatin or kallikrein-binding protein (KBP) has been reported to regulate angiogenesis, inflammation and tumor progression. Autoimmune uveitis is a common, sight-threatening inflammatory intraocular disease. However, the roles of kallistatin in autoimmunity and autoreactive T cells are poorly investigated. Compared to non-uveitis controls, we found that plasma levels of kallistatin were significantly upregulated in patients with Vogt-Koyanagi-Harada (VKH) disease, one of the non-infectious uveitis. Using an experimental autoimmune uveitis (EAU) model induced by human interphotoreceptor retinoid-binding protein peptide 651-670 (hIRBP_651-670), we examined the effects of kallistatin on the pathogenesis of autoimmune diseases. Compared to wild type (WT) mice, kallistatin transgenic (KS) mice developed severe uveitis with dominant Th17 infiltrates in the eye. In addition, the proliferative antigen-specific T cells isolated from KS EAU mice produced increased levels of IL-17A, but not IFN-γ or IL-10 cytokines. Moreover, splenic CD4⁺ T cells from naïve KS mice expressed higher levels of Il17a mRNA compared to WT naïve mice. Under Th17 polarization conditions, KS mice exhibited enhanced differentiation of naïve CD4⁺ T cells into Th17 cells compared to WT controls. Together, our results indicate that kallistatin promotes Th17 differentiation and is a key regulator of aggravating autoinflammation in EAU. Targeting kallistatin might be a potential to treat autoimmune disease.

Anti-Inflammatory Effect of Tacrolimus/Hydroxypropyl-β-Cyclodextrin Eye Drops in an Endotoxin-Induced Uveitis Model

Background: Uveitis is an infrequent disease which constitutes a major cause of ocular morbidity. Correct management is essential, being corticosteroids its cornerstone. In case of contraindication to corticosteroids or treatment failure, the use of topical tacrolimus (TAC) could be an alternative which has already demonstrated safety and effectiveness in other ocular pathologies. However, TAC eye drops are not marketed, thus their elaboration must be carried out in Hospital Pharmacy Departments (HPDs). Methods: 32 Sprague-Dawley rats were divided into 4 groups of 8 rats each: (a) untreated healthy rats (Healthy); (b) untreated Endotoxin-Induced Uveitis model-rats (EIU); (c) EIU-rats treated with standard treatment of dexamethasone ophthalmic drops (DXM) and (d) EIU-rats treated with TAC-hydroxypropyl-β-cyclodextrin eye drops previously developed by our group (TAC-HPβCD). The mRNA expression levels of IL-6, IL-8, MIP-1α and TNF-α, quantitative analysis of leucocytes in aqueous humor and histological evaluation were performed. Results: TAC-HPβCD eye drops demonstrated to reduce ocular inflammation, expression of IL-6, TNF-α, MIP-1α and leukocyte infiltration in aqueous humor. Conclusions: TAC-HPβCD eye drops showed beneficial effect in EIU model in rats, positioning as an alternative for uveitis treatment in case of corticosteroids resistance or intolerance.

Managing Psoriatic Arthritis With Inflammatory Bowel Disease and/or Uveitis

Psoriatic arthritis (PsA) is a chronic inflammatory disease that presents with psoriasis (PsO), peripheral and axial arthropathy. The heterogeneity of disease presentation leads to the term "psoriatic disease (PsD)" which is thought to better encompass the range of clinical manifestations. PsA is associated with several comorbidities such as cardiovascular diseases, metabolic syndrome and other extra-articular manifestations including uveitis, and inflammatory bowel disease (IBD). While novel therapeutics are being developed following advances in our understanding of the pathogenesis of the disease, the diverse combinations of PsA with its various comorbidities still pose a clinical challenge in managing patients with PsA. This article reviews our current understanding of the pathogenesis of PsA and how various pathways in the pathogenesis lead to the two comorbid extra-articular manifestations - uveitis and IBD. We also review current evidence of treatment strategies in managing patients with PsA with comorbidities of uveitis and/or IBD.

Beneficial effect of dimethyl fumarate on experimental autoimmune uveitis is dependent of pro-inflammatory markers immunomodulation

Autoimmune uveitis is an inflammatory disease of the eye and is one of the major causes of blindness worldwide. Experimental autoimmune uveoretinitis (EAU) constitutes an animal disease model of human endogenous uveitis. In our study, we investigated the immunomodulatory effect of dimethyl fumarate (DMF) using bovine retinal extract-induced uveitis in a Female Wistar rats. To evaluate the in vivo efficacy, Female Wistar rats were divided into seven experimental groups: control group (n = 5), consisting of non-immunized animals; Uveoretinitis (n = 5), and DMF/Uveoretinitis groups (n = 15), which received a subcutaneous injection of bovine retinal extract emulsified in complete Freund's adjuvant; MC group (n = 5), treated by daily intragastric administration of methylcellulose 0.08% in tap water; DMF group, consisting of control positive group, rats received daily oral gavage administration of 500 μL of dimethyl fumarate at 100 mg/Kg dissolved in 0.08% methylcellulose in tap water (n = 5). On day 14 post immunization, the rats were then euthanized and associated indications were investigated to evaluate the therapeutic efficacy. Nitric oxide (NO) and TNF-α were assessed in plasma. Meanwhile, eyes were collected for histological and immunohistochemical studies. The retinal expression of iNOS, CD68, CD20, CD25, CD4, and CD8 was examined. Interestingly, DMF enhanced a significant reduction of NO and TNF-α production in the treated group. This effect was strongly related to the histological structure of eyes improvement. In the same context, a significant decrease of iNOS, CD68, and CD20 expression and CD25 increase expression were reported in retinal tissue of DMF/Uveoretinitis group in comparison to the immunized group. Collectively, our results indicate that DMF treatment has a beneficial effect in experimental autoimmune uveoretinitis and could constitute a good candidate for monitoring an ocular inflammatory diseases.

Attenuation of Experimental Autoimmune Uveitis in Lewis Rats by Betaine

Experimental autoimmune uveitis (EAU) is an animal model of human autoimmune uveitis that is characterized by the infiltration of autoimmune T cells with concurrent increases in pro-inflammatory cytokines and reactive oxygen species. This study aimed to assess whether betaine regulates the progression of EAU in Lewis rats. EAU was induced via immunization with the interphotoreceptor retinoid-binding protein (IRBP) and oral administration of either a vehicle or betaine (100 mg/kg) for 9 consecutive days. Spleens, blood, and retinas were sampled from the experimental rats at the time of sacrifice and used for the T cell proliferation assay, serological analysis, real-time polymerase chain reaction, and immunohistochemistry. The T cell proliferation assay revealed that betaine had little effect on the proliferation of splenic T cells against the IRBP antigen in an in vitro assay on day 9 post-immunization. The serological analysis showed that the level of serum superoxide dismutase increased in the betaine-treated group compared with that in the vehicle-treated group. The anti-inflammatory effect of betaine was confirmed by the downregulation of pro-inflammation-related molecules, including vascular cell adhesion molecule 1 and interleukin-1β in the retinas of rats with EAU. The histopathological findings agreed with those of ionized calcium-binding adaptor molecule 1 immunohistochemistry, further verifying that inflammation in the retina and ciliary bodies was significantly suppressed in the betaine-treated group compared with the vehicle-treated group. Results of the present study suggest that betaine is involved in mitigating EAU through anti-oxidation and anti-inflammatory activities.

Blocking the inflammasome: A novel approach to treat uveitis

Uveitis is a complex ocular inflammatory disease often accompanied by bacterial or viral infections (infectious uveitis) or underlying autoimmune diseases (non-infectious uveitis). Treatment of the underlying infection along with corticosteroid-mediated suppression of acute inflammation usually resolves infectious uveitis. However, to develop more effective therapies for non-infectious uveitis and to better address acute inflammation in infectious disease, an improved understanding of the underlying inflammatory pathways is needed. In this review, we discuss the disease aetiology, preclinical in vitro and in vivo uveitis models, the role of inflammatory pathways, as well as current and future therapies. In particular, we highlight the involvement of the inflammasome in the development of non-infectious uveitis and how it could be a future target for effective treatment of the disease.

Development of Aldose Reductase Inhibitors for the Treatment of Inflammatory Disorders and Cancer: Current Drug Design Strategies and Future Directions

Aldose Reductase (AR) is an enzyme that converts glucose to sorbitol during the polyol pathway of glucose metabolism. AR has been shown to be involved in the development of secondary diabetic complications due to its involvement in causing osmotic as well as oxidative stress. Various AR inhibitors have been tested for their use to treat secondary diabetic complications, such as retinopathy, neuropathy, and nephropathy in clinical studies. Recent studies also suggest the potential role of AR in mediating various inflammatory complications. Therefore, the studies on the development and potential use of AR inhibitors to treat inflammatory complications and cancer besides diabetes are currently on the rise. Further, genetic mutagenesis studies, computer modeling, and molecular dynamics studies have helped design novel and potent AR inhibitors. This review discussed the potential new therapeutic use of AR inhibitors in targeting inflammatory disorders and cancer besides diabetic complications. Further, we summarized studies on how AR inhibitors have been designed and developed for therapeutic purposes in the last few decades.