Cytokines and Biologics in non-infectious autoimmune uveitis: bench to bedside

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.

Exploring the involvement of the alternative complement pathway in non-infectious uveitis pathogenesis

Purpose

Non-infectious uveitis is a complex disease characterized by intraocular inflammation of the uveal area and the leading cause of vision impairment and blindness in young people globally. However, what triggers inflammation and contributes to its recurrence remains unclear. The complement system has been linked to various immunological and inflammatory conditions. In the present study, we have systematically evaluated the role of the alternative complement pathway in the pathogenesis of non-infectious uveitis.

Methodology

Quantitative PCR was done in the peripheral leukocytes to study the expression of genes and regulatory miRNA in both anterior and posterior uveitis (n=28 in each category). Multiplex ELISA was performed to measure alternative pathway complement components, such as C3b, factor B, and CFH, and aqueous humor of infectious and non-infectious uveitis patients and non-inflammatory controls (n=10 each). Western blotting was done to validate the ELISA findings in a subset of patients and controls.

Results

Downregulation of C3 and CFH mRNA in the peripheral blood was shown by quantitative PCR in the group of anterior uveiits (AU), while the opposite result was found in the group of posterior uveitis (PU). ELISA levels of C3b and CFH proteins were significantly higher in aqueous humor of infectious and non-infectious uveitis (*p = 0.03 and **p = 0.0007 respectively) as compared to the control group. Western blotting further validated (VitH) the activation of the complement cascade in the aqueous (AH) and vitreous humor of patients with non-infectious uveitis, with an increased level of C3b (n=6) and CFH (n=4) in aqueous humor. C3b level was significantly increased while CFH was reduced relative to controls in the vitreous humor (VitH) of posterior uveitis patients compared to controls (n=27 in each category). A C3b to CFH ratio was computed to assess the regulation of complement activation and this index was several folds higher in both anterior and posterior uveitis (n=10 each). The expression of miRNA-hsa-miR-146a and miRNA-hsa-miR-155-5p that regulates CFH was downregulated and nicely correlated with the increased complement proteins in both anterior and posterior uveitis (n=10 each).

Conclusion

Our results demonstrate a clear role of CFH and the activation of the alternative complement pathway in the pathogenesis of non-infectious uveitis; however, its therapeutic potential warrants further investigations.

Pathogenesis and current therapies for non-infectious uveitis

Non-infectious uveitis (NIU) is a disorder with various etiologies and is characterized by eye inflammation, mainly affecting people of working age. An accurate diagnosis of NIU is crucial for appropriate therapy. The aim of therapy is to improve vision, relieve ocular inflammation, prevent relapse, and avoid treatment side effects. At present, corticosteroids are the mainstay of topical or systemic therapy. However, repeated injections are required for the treatment of chronic NIU. Recently, new drug delivery systems that may ensure intraocular delivery of therapeutic drug levels have been highlighted. Furthermore, with the development of immunosuppressants and biologics, specific therapies can be selected based on the needs of each patient. Immunosuppressants used in the treatment of NIU include calcineurin inhibitors and antimetabolites. However, systemic immunosuppressive therapy itself is associated with adverse effects due to the inhibition of immune function. In patients with refractory NIU or those who cannot tolerate corticosteroids and immunosuppressors, biologics have emerged as alternative treatments. Thus, to improve the prognosis of patients with NIU, NIU should be managed with different drugs according to the response to treatment and possible side effects.

Diagnosis and biomarkers for ocular tuberculosis: From the present into the future

Tuberculosis is an airborne disease caused by Mycobacterium tuberculosis (Mtb) and can manifest both pulmonary and extrapulmonary disease, including ocular tuberculosis (OTB). Accurate diagnosis and swift optimal treatment initiation for OTB is faced by many challenges combined with the lack of standardized treatment regimens this results in uncertain OTB outcomes. The purpose of this study is to summarize existing diagnostic approaches and recently discovered biomarkers that may contribute to establishing OTB diagnosis, choice of anti-tubercular therapy (ATT) regimen, and treatment monitoring. The keywords ocular tuberculosis, tuberculosis, Mycobacterium, biomarkers, molecular diagnosis, multi-omics, proteomics, genomics, transcriptomics, metabolomics, T-lymphocytes profiling were searched on PubMed and MEDLINE databases. Articles and books published with at least one of the keywords were included and screened for relevance. There was no time limit for study inclusion. More emphasis was placed on recent publications that contributed new information about the pathogenesis, diagnosis, or treatment of OTB. We excluded abstracts and articles that were not written in the English language. References cited within the identified articles were used to further supplement the search. We found 10 studies evaluating the sensitivity and specificity of interferon-gamma release assay (IGRA), and 6 studies evaluating that of tuberculin skin test (TST) in OTB patients. IGRA (Sp = 71-100%, Se = 36-100%) achieves overall better sensitivity and specificity than TST (Sp = 51.1-85.7%; Se = 70.9-98.5%). For nuclear acid amplification tests (NAAT), we found 7 studies on uniplex polymerase chain reaction (PCR) with different Mtb targets, 7 studies on DNA-based multiplex PCR, 1 study on mRNA-based multiplex PCR, 4 studies on loop-mediated isothermal amplification (LAMP) assay with different Mtb targets, 3 studies on GeneXpert assay, 1 study on GeneXpert Ultra assay and 1 study for MTBDRplus assay for OTB. Specificity is overall improved but sensitivity is highly variable for NAATs (excluding uniplex PCR, Sp = 50-100%; Se = 10.5-98%) as compared to IGRA. We also found 3 transcriptomic studies, 6 proteomic studies, 2 studies on stimulation assays, 1 study on intraocular protein analysis and 1 study on T-lymphocyte profiling in OTB patients. All except 1 study evaluated novel, previously undiscovered biomarkers. Only 1 study has been externally validated by a large independent cohort. Future theranostic marker discovery by a multi-omics approach is essential to deepen pathophysiological understanding of OTB. Combined these might result in swift, optimal and personalized treatment regimens to modulate the heterogeneous mechanisms of OTB. Eventually, these studies could improve the current cumbersome diagnosis and management of OTB.

Could different aqueous humor and plasma cytokine profiles help differentiate between ocular sarcoidosis and ocular tuberculosis?

OBJECTIVE AND DESIGN

A cross-sectional single-center study was conducted to assess cytokine levels in aqueous humor (AH) and plasma of three different uveitis entities: definite ocular sarcoidosis (OS), definite OS associated with QuantiFERON®-TB Gold test positivity (Q + OS) and presumed tubercular uveitis (TBU).

SUBJECTS

Thirty-two patients (15 OS, 5 Q + OS, 12 TBU) were included.

METHODS

Quantification of selected cytokines was performed on blood and AH samples collected before starting any treatment. Statistical analysis was conducted using the Kruskal-Wallis test, the Mann-Whitney or Fisher test and the Principal Component Analysis (PCA).

RESULTS

IL-6, IL-8 and IP-10 levels were higher in AH samples than in peripheral blood. In AH samples, BLC, IL-8 and IP-10 were significantly higher in definite OS than in presumptive TBU. There were no statistically significant differences in terms of cytokine levels between Q + OS and presumptive TBU. PCA showed a similar cytokine pattern in the latter two groups (IFNγ, IL-15, IL-2, IP-10, MIG), while the prevalent expression of BLC, IL-10 and MIP-3 α was seen in definite OS.

CONCLUSIONS

The different AH and plasma cytokine profiles observed in OS compared to Q + OS and TBU may help to differentiate OS from TBU in overlapping clinical phenotypes of granulomatous uveitis (Q + OS).

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.

Clinical effectiveness and safety of baricitinib for the treatment of juvenile idiopathic arthritis-associated uveitis or chronic anterior antinuclear antibody-positive uveitis: study protocol for an open-label, adalimumab active-controlled phase 3 clinical trial (JUVE-BRIGHT)

Background

Juvenile idiopathic arthritis (JIA) is the most common pediatric rheumatic disease and the most common systemic disorder associated with uveitis in childhood. Uveitis is more common in JIA patients who are antinuclear antibody (ANA)-positive, have an early-onset disease, and have oligoarticular arthritis. JIA-associated uveitis (JIA-uveitis) is typically anterior, chronic, bilateral, nongranulomatous, and asymptomatic. Visual outcomes in JIA-uveitis have improved with current screening and treatment options; however, many patients fail to respond or do not achieve long-lasting remission. Baricitinib, an oral selective Janus kinase (JAK)1 and 2 inhibitor, may impact key cytokines implicated in the pathogenesis of JIA-uveitis or ANA-positive uveitis, representing a potential novel treatment option for disease management.

Methods

The multicenter, phase 3 trial will be conducted using an open-label Bayesian design. The study will enroll at least 20 and up to 40 patients aged 2 to <18 years with active JIA-uveitis or chronic ANA-positive uveitis without systemic features. At least 20 patients who have had an inadequate response or intolerance to methotrexate (MTX-IR), but not biologic disease-modifying antirheumatic drugs (bDMARDs), will be randomized (1:1) to open-label baricitinib or adalimumab. Approximately 20 additional patients who are MTX-IR or bDMARD inadequate responders will receive baricitinib treatment. Patients will be treated with once daily oral baricitinib at a fixed dose by age group (4 mg for patients aged ≥6 to <18 years and 2 mg for patients <6 years) or adalimumab (20 mg for patients weighing <30 kg and 40 mg for patients ≥30 kg) as a subcutaneous injection every 2 weeks. Treatment with stable background conventional synthetic DMARDs, low-dose corticosteroids, and/or nonsteroidal anti-inflammatory drugs is allowed. The primary endpoint is the proportion of patients with response at week 24. Patients may continue treatment for up to 5 years.

Discussion

This is the first pediatric clinical trial to assess the clinical effectiveness and safety of a JAK inhibitor in JIA-uveitis or chronic ANA-positive uveitis. A novel Bayesian design is used to assess the efficacy of baricitinib, including an adalimumab reference arm, in this small patient population with unmet medical need.

Trial registration

EudraCT 2019-000119-10. Registered on January 4, 2019; NCT04088409. Registered on September 12, 2019

Interleukins and cytokine biomarkers in uveitis

Interleukins and cytokines are involved in the pathogenesis of uveitis of heterogeneous origin. Understanding the basics of the ocular immune privilege is a fulcrum to discern their specific role in diverse uveitis to potentially translate as therapeutic targets. This review attempts to cover these elements in uveitis of infectious, noninfectious and masquerade origin. Insights of the molecular targets in novel therapy along with the vision of future research are intriguing.

Protein Biomarkers in Uveitis

The diseases affecting the retina or uvea (iris, ciliary body, or choroid) generate changes in the biochemical or protein composition of ocular fluids/tissues due to disruption of blood-retinal barrier. Ocular infections and inflammations are sight-threatening diseases associated with various infectious and non-infectious etiologies. Several etiological entities cause uveitis, a complex intraocular inflammatory disease. These causes of uveitis differ in different populations due to geographical, racial, and socioeconomic variations. While clinical appearance is sufficiently diagnostic in many diseases, some of the uveitic entities manifest nonspecific or atypical clinical presentation. Identification of biomarkers in such diseases is an important aid in their diagnostic armamentarium. Different diseases and their different severity states release varying concentrations of proteins, which can serve as biomarkers. Proteomics is a high throughput technology and a powerful screening tool for serum biomarkers in various diseases that identifies proteins by mass spectrometry and helps to improve the understanding of pathogenesis of a disease. Proteins determine the biological state of a cell. Once identified as biomarkers, they serve as future diagnostic and pharmaceutical targets. With a potential to redirect the diagnosis of idiopathic uveitis, ocular proteomics provide a new insight into the pathophysiology and therapeutics of various ocular inflammatory diseases. Tears, aqueous and vitreous humor represent potential repositories for proteomic biomarkers discovery in uveitis. With an extensive proteomics work done on animal models of uveitis, various types of human uveitis are being subjected to proteome analysis for biomarker discovery in different ocular fluids (vitreous, aqueous, or tears).

Eye on the Enigmatic Link: Dysbiotic Oral Pathogens in Ocular Diseases; The Flip Side

Mouth and associated structures were regarded as separate entities from the rest of the body. However, there is a paradigm shift in this conception and oral health is now considered as a fundamental part of overall well-being. In recent years, the subject of oral-foci of infection has attained a resurgence in terms of systemic morbidities while limited observations denote the implication of chronic oral inflammation in the pathogenesis of eye diseases. Hitherto, there is a paucity for mechanistic insights underlying the reported link between periodontal disease (PD) and ocular comorbidities. In light of prevailing scientific evidence, this review article will focus on the understudied theme, that is, the impact of oral dysbiosis in the induction and/or progression of inflammatory eye diseases like diabetic retinopathy, scleritis, uveitis, glaucoma, age-related macular degeneration (AMD). Furthermore, the plausible mechanisms by which periodontal microbiota may trigger immune dysfunction in the Oro-optic-network and promote the development of PD-associated AMD have been discussed.

Comparative Analysis of Multiplex Platforms for Detecting Vitreous Biomarkers in Diabetic Retinopathy

Purpose

To evaluate the feasibility of using the Proximity Extension Assay (PEA) platform to detect biomarkers in vitreous and to compare the findings with results obtained with an electrochemiluminescent (ECL) sandwich immunoassay.

Methods

Vitreous samples from patients with proliferative diabetic retinopathy (PDR) and non-diabetic controls were tested using two different proteomics platforms. Forty-one assays were completed with the ECL platform and 459 with the PEA platform. Spearman's rank correlation coefficient (r_s) was used to determine the direction and strength of the relationship between protein levels detected by both platforms.

Results

Three hundred sixty-six PEA assays detected the tested protein in at least 25% of samples, and the difference in protein abundance between PDR and controls was statistically significant for 262 assays. Seventeen ECL assays yielded a detection rate ≥ 25%, and the difference in protein concentration between PDR and controls was statistically significant for 13 proteins. There was a subset of proteins that were detected by both platforms, and for those the Spearman's correlation coefficient was higher than 0.8.

Conclusions

PEA is suitable for the analysis of vitreous samples, showing a strong correlation with the ECL platform. The detection rate of PEA panels was higher than the panels tested with ECL. The levels of several proinflammatory and angiogenic cytokines were significantly higher in PDR vitreous compared to controls.

Translational Relevance

This study provides new information on the yields of small-volume assays that can detect proteins of interest in ocular specimens, and it identifies patterns of cytokine dysregulation in PDR.

Cytokine Profiling in Aqueous Humor Samples From Patients With Non-Infectious Uveitis Associated With Systemic Inflammatory Diseases

Non-infectious uveitis are intraocular inflammatory conditions caused by dysregulated activation of the immune response without any detectable infectious agents. The aim of this study was to explore potential markers and therapeutic targets for two distinct types of non-infectious uveitis associated with Behçet's disease (BD) and Vogt Koyanagi Harada (VKH) disease. Concentrations of 27 cytokines were investigated in aqueous humor (AH) samples from patients with active uveitis vs. healthy controls (HC) (n = 10 patients with BD-associated uveitis; n = 10 patients with VKH-associated uveitis; n = 10 HC) using the Bio-Plex Pro^TM human cytokine group I panel. Additionally, leukocytes in AH samples were counted with hemocytometers and characterized by flow cytometry. Eleven cytokines were differentially expressed between patients with uveitis and HC with a median concentration greater than 10 pg/ml. IL-6, IP-10, G-CSF, and IFNγ showed higher concentrations in AH samples from both BD and VKH patients while IL-2, IL-8, IL-13, TNFα, eotaxin, IL-1ra showed statistically significant higher concentrations only in AH samples from BD patients. GM-CSF was the sole cytokine with an opposite profile showing decreased levels in AH samples from BD patients. IL-1ra and IL-6 were detected at higher frequencies in AH samples from BD and VKH patients compared with those from HC while IFNγ and TNFα were not detected in HC. The concentrations of IL-6, IL-8, IP-10, G-CSF, IFNγ, TNFα, eotaxin, IL-1ra positively correlated with the concentrations of leukocytes in AH, suggesting that such cytokines can be produced by immune cells and/or attract and/or promote proliferation and survival of immune cells in these types of uveitis. The correlation matrix of cytokine concentrations in AH samples revealed that IFNγ, TNFα, eotaxin, IL-6, G-CSF highly correlated each other. The ratios of cytokine concentrations between AH and plasma intra-individuals showed that IL-2, IL-6, IP-10, GM-CSF were increased intraocularly. In conclusion, AH sampling followed by multiplex analysis of cytokines should be fostered in non-infectious uveitis to identify cytokines dysregulated intraocularly in each individual laying the groundwork for precision medicine.

Identification of Potential Biomarkers in Peripheral Blood Supernatants of South African Patients with Syphilitic and Herpetic Uveitis

Purpose: To identify potential diagnostic biomarkers for herpetic and syphilitic uveitis.Methods: Blood samples were collected from 92 uveitis patients. Concentrations of 47 biomarkers were evaluated in unstimulated Quantiferon supernatants using the Luminex platform.Results: Results showed 11 patients (12%) had herpetic uveitis, 11 (12%) syphilis, 40 (43.5%) other infectious causes, 16 (17.4%) established noninfectious causes and 14 (15.2%) were idiopathic. Biomarker analysis revealed three proteins (Apo-A1, Apo-CIII, CRP) that differed between syphilis and other causes. A three-marker biosignature (CCL4/MIP-1β, Apo-CIII and CRP) separated syphilis from other groups with AUC = 0.83 (95% CI: 0.68-0.98). Apo-CIII and CRP differed between herpetic cases and other groups (p < .05). A three-analyte biosignature (Apo-A1, SAP and CRP) separated the herpetic group from other groups with AUC = 0.79 (95% CI: 0.65-0.93).Conclusion: We have identified candidate biomarkers with potential to differentiate between herpetic, syphilitic and other causes of uveitis. These results warrant further investigation in larger future studies.

Intraocular Biopsy and ImmunoMolecular Pathology for "Unmasking" Intraocular Inflammatory Diseases

Intraocular inflammation can hide a variety of eye pathologies. In 33% of cases, to obtain a correct diagnosis, investigation of the intraocular sample is necessary. The combined analyses of the intraocular biopsy, using immuno-pathology and molecular biology, point to resolve the diagnostic dilemmas in those cases where history, clinical tests, and ophthalmic and systemic examinations are inconclusive. In such situations, the teamwork between the ophthalmologist and the molecular pathologist is critically important to discriminate between autoimmune diseases, infections, and intraocular tumors, including lymphoma and metastases, especially in those clinical settings known as masquerade syndromes. This comprehensive review focuses on the diagnostic use of intraocular biopsy and highlights its potential to enhance research in the field. It describes the different surgical techniques of obtaining the biopsy, risks, and complication rates. The review is organized according to the anatomical site of the sample: I. anterior chamber containing aqueous humor, II. iris and ciliary body, III. vitreous, and IV. choroid and retina. We have excluded the literature concerning biopsy for choroidal melanoma and retinoblastoma, as this is a specialized area more relevant to ocular oncology.

The associations between interleukin 10 polymorphisms and susceptibility to autoimmune uveitis - a meta-analysis

Autoimmune uveitis is an ocular inflammatory disease that is associated with genetic factors. Interleukin 10 (IL-10) is an immune-regulatory cytokine of autoimmune diseases. IL-10 is considered a candidate gene for uveitis. We evaluate the association of IL-10 with susceptibility to autoimmune uveitis. The results from seven studies were pooled in the meta-analysis, covering a total of 2893 cases of uveitis and 4873 controls. Published literature from MEDLINE and Embase was retrieved. Meta-analyses were conducted on the associations between autoimmune uveitis and the -1082 A/G and -819 C/T polymorphisms of the IL-10 gene. The meta-analysis revealed no association between uveitis and the IL-10 -1082 A allele (OR = 0.91, 95% CI = 0.64-1.30, p = 0.62). The recessive, dominant, and homozygous models of the IL-10 -1082 A/G allele also suggested no association between autoimmune uveitis and each genotype. The meta-analysis revealed significant association between uveitis and the -892 C allele (OR = 0.81, 95% CI = 0.67-0.98, p = 0.03). In addition, significant association was found in homozygous models (OR = 0.58, 95% CI = 0.36-0.92, p = 0.02). However, the dominant and recessive models of the IL-10 -819 C/T polymorphisms showed no association between uveitis and each genotype. This meta-analysis showed that the -1082 A/G polymorphisms of IL-10 were not associated with autoimmune uveitis, but the -819 C/T polymorphisms were significantly associated with uveitis.

Adenovirus-mediated down-regulation of miR-21-5p alleviates experimental autoimmune uveoretinitis in mice

MiR-21-5p has been found to be up-regulated in the retina of experimental autoimmune uveoretinitis (EAU) mice and correlated with the pathogenesis of EAU. The objective of the present study is to explore the role of miR-21-5p in EAU. C57 mice were immunized with residue1-20 (IRBP_1-20) in complete Freund's adjuvant supplemented with Mycobacterium tuberculosis H37Ra to induce EAU, and miR-21-5p was knocked down via subretinal injection of anti-miR-21-5p adenovirus. The pathological score, TUNEL positive cells and the expression of pro-inflammatory factors in the retina were reduced, and the expression of IL-10 was increased by down-regulation of miR-21-5p. Up-regulation of miR-21-5p significantly decreased the mRNA and protein levels of IL-10 in ARPE-19 cells. The binding activity of miR-21-5p on the 3'UTR of IL-10 mRNA was confirmed by luciferase reporter assay. Moreover, the miR-21-5p level in splenic lymphocytes of EAU mice was increased at the 7th day after immunization and reached its peak at the 14th day, that was in accordance with the changing trend with the Th17 cell frequency in the spleen. Besides, lentivirus-mediated down-regulation of miR-21-5p reduced the Th17 cell frequency and increased the Treg cell fraction of IRBP_1-20-stimulated lymphocytes in vitro. Taken together, in situ down-regulation of miR-21-5p attenuates EAU by inhibiting inflammatory responses and reducing retinal cell apoptosis. miR-21-5p may also participate in the progress of EAU by affecting Th17/Treg balance via the regulation of IL-10. Therefore, we demonstrate that miR-21-5p can serve as a therapeutic target in the management of uveitis and other autoimmune diseases.

Exploring the role of programmed cell death protein 1 and its ligand 1 in eye diseases

Programmed death receptor-1 (PD-1) and its ligand, PD-L1, as negative co-stimulatory molecules, are indispensable for regulating both physiological and pathological immune responses. The PD-1/PD-L1-mediated signaling pathway has been studied extensively in cancer research and has become a hotspot for biopharmaceuticals and immunotherapy. Furthermore, monoclonal antibodies to PD-1 have just been approved by the US Food and Drug Administration to treat certain types of malignancies. Recent research has unveiled a close association between the PD-1/PD-L1 system and eye diseases. This review describes the expression and physiological functions of PD-1 and its ligand in ocular tissues and summarizes the pathogenic, regulatory, and therapeutic roles of PD-1/PD-L1 system in eye diseases, including uveal melanoma, autoimmune uveitis, autoimmune dry eye, sympathetic ophthalmia, Graves' ophthalmopathy, diabetic retinopathy, herpes simplex keratitis, and trachoma, with the intent of highlighting the potential of PD-1/PD-L1 as novel therapeutic targets or biomarkers for these ocular diseases.

[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.

Management of chronic ocular sarcoidosis: challenges and solutions

Background

Sarcoidosis constitutes one of the leading causes of ocular inflammation. Chronic ocular sarcoidosis can affect any segment of the eye and its adnexa, producing a wide range of clinical manifestations and severity. If left untreated, permanent visual impairment or even blindness may ensue. Treatment approaches vary from topical therapy to systemic agents that induce immunosuppression to different levels according to disease severity.

Objective

To review the published literature on the management options for chronic ocular sarcoidosis and provide a comprehensive list of available treatment strategies, including the newer biologics.

Summary

Ocular disease remains a challenging aspect of sarcoidosis and may even be the presenting sign of the disease. Prompt and effective therapy may reverse visual damage and prevent permanent loss of vision. Because of the complexity of the disease, a multidisciplinary approach is often required, with a view to addressing both the ocular and other systemic manifestations of sarcoidosis. Recent data suggest that achieving overall optimal systemic control is of paramount importance in controlling eye inflammation as well. Cytotoxic immunosuppressive agents for refractory chronic ocular disease, as well as biologic anti-TNFα therapies, have advanced the management of chronic disease and should be considered corticosteroid-sparing strategies before the onset of significant steroid-induced morbidity.

Combined Ahmed valve and phacoemulsification with intraocular lens implantation under infliximab in refractory uveitic glaucoma

PURPOSE

To evaluate the outcome of combined Ahmed glaucoma valve (AGV) and phacoemulsification with posterior chamber intraocular lens implantation under infliximab in refractory uveitic glaucoma (UG).

METHODS

In this prospective interventional case series, 26 eyes of 26 patients with refractory UG underwent surgery under intravenous infliximab. The success rate was defined as intraocular pressure (IOP) 5 to 21 mm Hg with or without antiglaucoma medications (AGM), without additional glaucoma surgical intervention.

RESULTS

The mean IOP (37.8 ± 11.86 to 12.2 ± 2.8 mm Hg; p<0.0001) and mean number of AGM (3.4 ± 1.2 to 0.4 ± 0.1; p<0.001) were significantly reduced after surgery at 2 years. Kaplan-Meier survival analysis showed a cumulative probability of success for IOP control of 92% at 2 years of follow-up.

CONCLUSIONS

Combined AGV and phacoemulsification is an effective treatment for controlling refractory UG with complicated cataract under infliximab.

Noninfectious uveitis: strategies to optimize treatment compliance and adherence

Noninfectious uveitis includes a heterogenous group of sight-threatening ocular and systemic disorders. Significant progress has been made in the treatment of noninfectious uveitis in recent years, particularly with regard to the effective use of corticosteroids and non-corticosteroid immunosuppressive drugs, including biologic agents. All of these therapeutic approaches are limited, however, by any given patient’s ability to comply with and adhere to their prescribed treatment. In fact, compliance and adherence are among the most important patient-related determinants of treatment success. We discuss strategies to optimize compliance and adherence.

Immunopharmacotherapy of non-infectious uveitis: where do we stand?

With ever-evolving concept of personalised medicine backed up with specific biomarkers for ocular inflammatory disease, there is a sudden surge of using biologics in non-infectious recalcitrant posterior uveitis. Have we understood these biologic agents enough to embark on this long enduring journey with the patient to optimise control of intraocular inflammation? On the other hand, there is still a strong inhibition of using these novel agents in management of uveitis even at tertiary referral centres. Immunopharmacotherapy of non-infectious uveitis poses a significant conundrum for both physicians and patients as it is like a two-edged sword effective to control inflammation but at the same time potentially toxic, suspected of causing long-term adverse effects. Systemic immunosuppressive therapy is used in a substantial number of most vision-threatening ocular inflammatory diseases. There is lack of randomised control trials establishing the safety of this therapy and our current practice pattern is based on retrospective studies and personal experience in using this treatment modality. This overview will highlight on the current dilemma faced by the clinicians in opting for steroid-sparing immunosuppressive therapy.

Immunopathogenesis of ocular Behçet's disease

Behçet's disease (BD) is a chronic recurrent systemic inflammatory disorder of unknown etiology characterized by oral and genital ulcerations, skin lesions, and uveitis. The ocular involvement of BD, or Behçet's uveitis (BU), is characterized by panuveitis or posterior uveitis with occlusive retinal vasculitis and tends to be more recurrent and sight threatening than other endogenous autoimmune uveitides, despite aggressive immunosuppression. Although pathogenesis of BD is unclear, researches have revealed that immunological aberrations may be the cornerstone of BD development. General hypothesis of BD pathogenesis is that inflammatory response is initiated by infectious agents or autoantigens in patients with predisposing genetic factors and perpetuated by both innate and acquired immunity. In addition, a network of immune mediators plays a substantial role in the inflammatory cascade. Recently, we found that the immunopathogenesis of BU is distinct from other autoimmune uveitides regarding intraocular effector cell profiles, maturation markers of dendritic cells, and the cytokine/chemokine environment. In addition, accumulating evidence indicates the involvement of Th17 cells in BD and BU. Recent studies on genetics and biologics therapies in refractory BU also support the immunological association with the pathogenesis of BU. In this review, we provide an overview of novel findings regarding the immunopathogenesis of BU.