The Future Is Now: Biologics for Non-Infectious Pediatric Anterior Uveitis

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.

Juvenile idiopathic arthritis-associated uveitis in the era of biological therapy: how the disease changed in more than 20 years of observation in a tertiary referral center in Rome (Italy)

Objectives

To describe the ophthalmological characteristics in a Juvenile idiopathic arthritis (JIA) cohort and to evaluate how therapeutic advances have changed the course of the uveitis.

Methods

Analysis of a retrospective cohort study of consecutive JIA pediatric patients including JIA-associated uveitis (JIA-U) and comparison with a previous study in the same uveitis center assessed before the wide-spread of biological therapy.

Results

The total of 49 JIA patients were analyzed, of whom 18 JIA-U, compared with a JIA-U past cohort of 66 patients. Systemic corticosteroids were used significantly less in the current JIA-U group (p = 0.008) than in the past one. JIA-U present cohort was on therapy more frequently with conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) than the past group (p = 0.039), mostly treated with methotrexate (93.3%). Furthermore, a larger use of biologic disease-modifying anti-rheumatic drugs (bDMARDs) was described in the current JIA-U group (p = 0.005) also associated with csDMARDs (p = 0.003). Adalimumab was used more (72.7%) in the present JIA-U cohort compared to a larger treatment with infliximab (61.5%) in the past (p = 0.005). Higher number of uveitis recurrences was observed in the previous cohort compared to the current one (p = 0.005). Fewer complications were described in this study than in the previous: posterior synechiae (p = 0.007), cataract (p < 0.001), band keratopathy (p < 0.001), and elevated intraocular pressure (IOP) (p = 0.047).

Conclusion

Current therapies reduced the uveitis recurrences and ocular complications including cataract due also to the lower use of corticosteroids. The new close collaboration with the pediatric rheumatologic center in the same University has contributed to the care improvement and decrease of uveitis complications.

COVID-19 and the Use of Immunomodulatory Agents in Ophthalmology

Immunomodulatory agents are often used in the systemic treatment of non-infectious uveitis. These drugs consist of corticosteroids, conventional immunosuppressives, and biological agents. As it is known that they suppress the immune system, the most important concern associated with immunomodulatory therapy (IMT) is the increased risk of infection. The World Health Organization declared COVID-19 a pandemic on 11 March 2020. Although severe acute respiratory distress syndrome secondary to SARS-CoV-2 infection may develop in all people, patients who receive IMT may be at higher risk in terms of both the transmission of the infection and more severe disease course. Therefore, guidelines on the management of patients receiving IMT due to uveitis during the pandemic are needed. In this review, we examined the immunomodulatory drugs used in the treatment of uveitis in terms of infectious complications and the data of patients who received IMT during the COVID-19 pandemic and discussed recommendations for the use of these drugs. According to the latest information, patients who receive IMT may continue their treatment as long as there are no disruptions in regular complete blood count (especially white blood cell count >4,000/μL) and liver and kidney function tests. Patients diagnosed with COVID-19 should be managed with a multidisciplinary approach.

Kallistatin Attenuates Experimental Autoimmune Uveitis by Inhibiting Activation of T Cells

Experimental autoimmune uveoretinitis (EAU) is a mouse model of human autoimmune uveitis. EAU spontaneously resolves and is marked by ocular autoantigen-specific regulatory immunity in the spleen. Kallikrein binding protein (KBP) or kallistatin is a serine proteinase inhibitor that inhibits angiogenesis and inflammation, but its role in autoimmune uveitis has not been explored. We report that T cells activation is inhibited and EAU is attenuated in human KBP (HKBP) mice with no significant difference in the Treg population that we previously identified both before and after recovery from EAU. Moreover, following EAU immunization HKBP mice have potent ocular autoantigen specific regulatory immunity that is functionally suppressive.

New therapies in development for the management of non-infectious uveitis: A review

Uveitis is a spectrum of inflammatory disorders characterized by ocular inflammation and is one of the leading causes of preventable visual loss. The main aim of the treatment of uveitis is to control the inflammation, prevent recurrences of the disease and preserve vision while minimizing the adverse effects associated with the therapeutic agents. Initial management of uveitis relies heavily on the use of corticosteroids. However, monotherapy with high-dose corticosteroids is associated with side effects and cannot be maintained long term. Therefore, steroid-sparing agents are needed to decrease the burden of steroid therapy. Currently, the therapeutic approach for non-infectious uveitis (NIU) consists of a step-ladder strategy with the first-line option being corticosteroids in various formulations followed by the use of first-, second- and third-line agents in cases with suboptimal steroid response. Unfortunately, the agents currently at our disposal have limitations such as having a narrow therapeutic window along with their own individual potential side-effect profiles. Therefore, research has been targeted to identify newer drugs as well as new uses for older drugs that target specific pathways in the inflammatory response. Such efforts are made in order to provide targeted and safer therapy with reduced side effects and greater efficacy. Several specially designed molecular antibodies are currently in various phases of investigations that can potentially halt the inflammation in patients with NIU. In the review, we have provided a comprehensive overview of the current and upcoming therapeutic options for patients with NIU.

Importance of pediatric rheumatologists and transitional care for juvenile idiopathic arthritis-associated uveitis: a retrospective series of 9 cases

BACKGROUND

Juvenile idiopathic arthritis-associated uveitis (JIA-U) is a serious condition associated with the risk of blindness. However, pediatric rheumatologists rarely encounter cases of blindness, because most patients reach adulthood during the course of follow-up before blindness occurs. Here, we report the progress of 9 patients with JIA-U, including 2 patients who became blind after the transition period. We aimed to highlight the importance of the role of pediatric rheumatologists and transitional care in preventing blindness associated with JIA-U.

CASE PRESENTATION

We conducted a retrospective analysis of the case records of 9 JIA-U patients (1 male, 8 female; median age 16.8 years, range 5.5-19.8 years). All patients presented with oligo-juvenile idiopathic arthritis (oligo-JIA) (one presented with extended oligo-JIA); the median age of uveitis onset was 5.0 years (range 3.0-13.0 years), and the onset of uveitis preceded the onset of arthritis in 2 patients. The median disease duration was 12.5 years (range 3.5-24.7 years); 4 patients had anti-nuclear antibody (ANA) positivity (≧1:160) (all with a homogeneous and speckled-pattern subtype). All patients were negative for rheumatoid factor. Eight patients received methotrexate, 7 patients received one or more biologic drugs (etanercept, infliximab, adalimumab, and golimumab), and 6 patients required ophthalmic surgery at an early age (≦ 18 years). Two patients developed blindness after the transition period. Medical examination by pediatric rheumatologists and use of biologics had been delayed in both patients. One patient developed depression after transition and interrupted her own treatment.

CONCLUSIONS

The reason for blindness in the 2 patients was thought to be the delay in the commencement of treatment and failure to provide transitional care. Inflammation is difficult to control in JIA-U even with appropriate treatment. Pediatric rheumatologists must be informed about the risk of JIA-U blindness, especially after transition. To ensure a good prognosis, the specialized treatment with the involvement of pediatric rheumatologists is necessary early on, and consideration for transitional medicine is essential. Therefore, this report reaffirms the importance of planned transitional care that has been advocated for globally.

Safety of systemic therapy for noninfectious uveitis

Introduction: The treatment strategies for noninfectious uveitis (NIU) aim to achieve disease remission, prevention of recurrences, and preserving vision, while minimizing the side effects associated with the therapies used.Areas covered: The index review aims to provide a detailed overview of the adverse events and safety parameters associated with the systemic therapies for the management of the NIU.Expert opinion: Despite being the cornerstone of management of acute cases of NIU, long-term corticosteroid use is associated with multi-system side effects, requiring the use of steroid-sparing agents. Adalimumab was recently approved by the FDA for the management of NIU based on the results of VISUAL studies. Similarly, newer drugs targeting various aspects of the inflammatory cascade are being developed. However, until we completely understand the molecular pathways of the inflammatory diseases, the therapeutic profile of these newer agents needs to be broad enough to suppress inflammatory cascade and narrow enough to spare normal cellular processes. Another strategy that has shown some potential in decreasing the systemic side effects is to provide local drug delivery. Therefore, the future of management of NIU is very bright with many novel therapeutic agents and strategies of drug delivery on the horizon.

Tissue-specific production of MicroRNA-155 inhibits melanocortin 5 receptor-dependent suppressor macrophages to promote experimental autoimmune uveitis

Tissue-specific immune regulation is an important component of the immune response relevant to many areas of immunology. The focus of this study is on tissue-specific mechanisms that contribute to autoimmune uveitis. Precise gene regulation is necessary for the proper expression of an inflammatory or regulatory response. This precision gene regulation can be accomplished by microRNA at the level of the mRNA transcript. miR-155, in particular, has a complicated role in the immune response with positive and negative inflammatory effects. In this work, we identify a decrease in miR-155 in suppressor macrophages and further examine how tissue-specific production of miR-155 impacts experimental autoimmune uveitis. Importantly, we show that eliminating miR-155 expression by the target tissue before initiation reduces disease severity, but elimination of miR-155 after the onset of inflammation does not alter the course of disease. Additionally, expression of miR-155 by the target tissue before initiation is necessary for the induction of regulatory immunity that protects from further autoimmune disease, but not after the onset of inflammation. In summary, we find a MC5r-dependent decrease in miR-155 in postexperimental autoimmune uveitis APC, miR-155 production by the target tissue is necessary for the initiation of autoimmune uveitis, and may have a role in establishing protective regulatory immunity.

[Clinical and epidemiological profile of pediatric uveitis, course of inflammatory uveitis treated with anti-TNF alpha]

INTRODUCTION

Uveitis is the leading cause of acquired childhood blindness with a prevalence of 30 cases per 100,000 inhabitants. There are multiple causes ; nevertheless, there is no standardized etiological assessment. The goal of our study is to define an epidemiological and clinical profile of uveitis diagnosed in a university hospital and their course when treated with anti-tumor necrosis factor (TNF) α.

PATIENTS AND METHODS

All cases of uveitis under 18 years old, from 1994 to 2016, were included. Post-traumatic, post-surgical, pseudo-uveitis and retinopathy of prematurity were excluded. Demographic data, patient history, initial ophthalmological status, etiologic assessment data and treatments already underway were collected.

RESULTS

Ninety cases of pediatric uveitis were included, among which were 16.7 % infectious uveitis, 38.9 % inflammatory uveitis and 44.4 % idiopathic uveitis. Etiologic investigations were considered incomplete in 45 % of idiopathic uveitis cases. Treatment with anti-TNFα was selected for 15.5 % of patients. In total, 33 % of patients treated with etanercept required other anti-TNFα drugs due to a lack of control of inflammation. Infliximab and adalimumab successfully managed to control inflammation in 28.6 % of cases each.

DISCUSSION

Diagnostic criteria based adult systemic disease are sometimes inappropriate for children. The advent of anti-TNFα appears to improve the visual prognosis of inflammatory uveitis resistant to conventional immunosuppressant therapy, but we still need to perfect protocols for their use.

CONCLUSION

There are neither standardized etiological assessment nor clear diagnostic and therapeutic protocols for children. TNFα inhibitors are more effective in controlling inflammation in severe pediatric uveitis.

The Syndrome of Tubulointerstitial Nephritis With Uveitis (TINU)

The syndrome of tubulointerstitial nephritis and uveitis (TINU) is a multisystemic autoimmune disorder that may occur in response to various environmental triggers, including drugs and microbial pathogens. Evidence exists of HLA antigen-related genetic predisposition to developing TINU. The resulting inflammation affects chiefly the ocular uvea and renal tubules, although other organs may be involved. TINU is uncommon; only about 200 cases are on record since its original description 40 years ago, although it is possible that new ones are no longer being reported. Although its incidence is highest in children and adolescents, all ages may be affected. Renal and ocular inflammation may be clinically severe and persistent, but the prognosis for the majority of patients with TINU is favorable. Owing to its low prevalence, no standard therapeutic protocols have been established, but most reported cases have been treated with corticosteroids or other immunomodulatory agents. TINU has many features in common with sarcoidosis, the main clinical entity from which it must be distinguished. This article begins with an illustrative case vignette, followed by an overview of the syndrome and current theories regarding its pathogenesis.

An Update on Treatment of Pediatric Chronic Non-Infectious Uveitis

There are no standardized treatment protocols for pediatric non-infectious uveitis. Topical corticosteroids are the typical first-line agent, although systemic corticosteroids are used in intermediate, posterior and panuveitic uveitis. Corticosteroids are not considered to be long-term therapy due to potential ocular and systemic side effects. In children with severe and/or refractory uveitis, timely management with higher dose disease-modifying antirheumatic drugs (DMARDs) and biologic agents is important. Increased doses earlier in the disease course may lead to improved disease control and better visual outcomes. In general, methotrexate is the usual first-line steroid-sparing agent and given as a subcutaneous weekly injection at >0.5 mg/kg/dose or 10-15 mg/m2 due to better bioavailability. Other DMARDs, for instance mycophenolate, azathioprine, and cyclosporine are less common treatments for pediatric uveitis. Anti-tumor necrosis factor-alpha agents, primarily infliximab and adalimumab are used as second line agents in children refractory to methotrexate, or as first-line treatment in those with severe complicated disease at presentation. Infliximab may be given at a minimum of 7.5 mg/kg/dose every 4 weeks after loading doses, up to 20 mg/kg/dose. Adalimumab may be given up to 20 or 40 mg weekly. In children who fail anti-tumor necrosis factor-alpha agents, develop anti-tumor necrosis factor-alpha antibodies, experience adverse effects, or have difficulty with tolerance, there is less data available regarding subsequent treatment. Promising results have been noted with tocilizumab infusions every 2-4 weeks, abatacept monthly infusions and rituximab.

Prevalence of Anti-infliximab Antibodies and Their Associated Co-factors in Children with Refractory Arthritis and/or Uveitis: A Retrospective Longitudinal Cohort Study

Objective.

Infliximab (IFX) is a monoclonal tumor necrosis factor-α–inhibiting antibody used in children with refractory arthritis and uveitis. Immunogenicity is associated with a lack of clinical response and infusion reactions in adults; data on immunogenicity in children treated with IFX for rheumatic diseases are scarce. We aimed to describe the prevalence of anti-IFX antibodies and determine co-factors associated with anti-IFX antibodies in children with inflammatory rheumatic and ocular diseases.

Methods.

Consecutive children treated between August 2009 and August 2012 with IFX at our department were included. Blood samples were collected every 6 months before IFX infusion and tested for anti-IFX antibodies by radioimmunoassay. Patients’ charts were retrospectively reviewed for clinical features and analyzed for associations with anti-IFX antibodies.

Results.

Anti-IFX antibodies occurred in 14/62 children (23%) and 32/253 blood samples (12.6%) after a mean treatment time of 1084 days (range 73–3498). Infusion reactions occurred in 10/62 (16%) children during the treatment period. With continuation of IFX, anti-IFX antibodies disappeared in 7/14 children. In the bivariate analysis, the occurrence of anti-IFX antibodies was associated with younger age at IFX treatment start (mean age 7.01 vs 9.88 yrs, p = 0.003) and infusion reactions (OR 15.0), while uveitis as treatment indication was protective against development of anti-IFX antibodies (OR 0.17), likely because of higher IFX doses. In the multivariate logistic regression, all 3 covariates remained highly significant.

Conclusion.

Anti-IFX antibodies occurred commonly at any time during IFX treatment. Anti-IFX antibodies were associated with younger age at IFX start, infusion reactions, and arthritis as treatment indication.

Profile of adalimumab and its potential in the treatment of uveitis

Uveitis refers to the presence of intraocular inflammation, and as a strict definition compromises the iris and ciliary body anteriorly and the choroid posteriorly (the uvea). Untreated, uveitis can lead to visual loss or blindness. The etiology of uveitis can include both infectious and noninfectious (usually immune-mediated) causes, the latter of which are often mediated predominantly by Th1 CD4⁺ T-cells that secrete proinflammatory cytokines. Tumor necrosis factor-alpha (TNF-α) is a proinflammatory cytokine involved in the pathogenesis of uveitis, which at high concentrations can cause excess inflammation and tissue damage. Adalimumab is a recombinant human IgG1 monoclonal antibody specific for human TNF-α. Historically, corticosteroids and methotrexate were used to treat uveitis; however, newer biologic agents such as adalimumab have revolutionized therapy for noninfectious uveitis. Adalimumab has shown efficacy in treating refractory uveitis in multiple settings, including idiopathic disease, juvenile idiopathic arthritis, sarcoidosis, Behçets disease, and uveitis secondary to spondyloarthropathies, among several other noninfectious uveitis conditions. In this paper, we will review the profile of adalimumab, the role of TNF-α in uveitis, discuss safety data, and summarize key articles evaluating the efficacy of adalimumab in treating uveitis secondary to the most commonly associated autoimmune diseases.