Tumor necrosis factor antagonists: preliminary evidence for an emerging approach in the treatment of ocular inflammation

Decoding Behcet's Uveitis: an In-depth review of pathogenesis and therapeutic advances

Behcet's disease (BD) is a rare but globally distributed vasculitis that primarily affects populations in the Mediterranean and Asian regions. Behcet's uveitis (BU) is a common manifestation of BD, occurring in over two-thirds of the patients. BU is characterized by bilateral, chronic, recurrent, non-granulomatous uveitis in association with complications such as retinal ischemia and atrophy, optic atrophy, macular ischemia, macular edema, and further neovascular complications (vitreous hemorrhage, neovascular glaucoma). Although the etiology and pathogenesis of BU remain unclear, numerous studies reveal that genetic factors (such as HLA-B51), dysregulated immune responses of both the innate and adaptive immune systems, infections (such as streptococcus), and environmental factors (such as GDP) are all involved in its development. Innate immunity, including hyperactivity of neutrophils and γδT cells and elevated NK1/NK2 ratios, has been shown to play an essential role in this disease. Adaptive immune system disturbance, including homeostatic perturbations, Th1, Th17 overaction, and Treg cell dysfunction, is thought to be involved in BU pathogenesis. Treatment of BU requires a tailored approach based on the location, severity of inflammation, and systemic manifestations. The therapy aims to achieve rapid inflammation suppression, preservation of vision, and prevention of recurrence. Systemic corticosteroids combined with other immunosuppressive agents have been widely used to treat BU, and beneficial effects are observed in most patients. Recently, biologics have been shown to be effective in treating refractory BU cases. Novel therapeutic targets for treating BU include the LCK gene, Th17/Treg balance, JAK pathway inhibition, and cytokines such as IL-17 and RORγt. This article summarizes the recent studies on BU, especially in terms of pathogenesis, diagnostic criteria and classification, auxiliary examination, and treatment options. A better understanding of the significance of microbiome composition, genetic basis, and persistent immune mechanisms, as well as advancements in identifying new biomarkers and implementing objective quantitative detection of BU, may greatly contribute to improving the adequate management of BU patients.

The role of the cytokine TNF-α in choroidal neovascularization: a systematic review

TNF-α is a multifunctional cytokine produced by macrophages and T cells. This proinflammatory substance is considered to play a crucial role in the inflammatory process associated with age-related macular degeneration (AMD). The current review aimed to describe evidence for an association between TNF-α and AMD reported in various studies. The MEDLINE, Embase, PubMed and Global Health databases were systematically searched to identify studies that investigated the role of TNF-α in AMD. A total of 24 studies were deemed eligible for the review. To better understand and integrate the evidence, the studies were categorised into four major groups in relation to the role of TNF-α in AMD: (1) those examining biological signalling pathways through which TNF-α exerts its effect; (2) investigating levels of TNF-α; (3) exploring the genetics underlying the role of TNF-α; and (4) assessing anti-TNF-α agents as potential treatments for AMD. TNF-α is thought to directly contribute to choroidal neovascularization (CNV) enhancement and has been shown to exert its effect by augmenting the inflammatory response through other signalling pathways. Additionally, different genes have been found to be associated with activities linked to TNF-α in AMD. Overall, measurement of systemic and local levels of TNF-α has not yielded consistent findings, with variable conclusions for the role of anti-TNF-α agents in remission of AMD symptoms. The role of TNF-α in neovascular AMD is not clear, and not all anti-TNF-α agents are safe. The potential of this cytokine in atrophic AMD has not been examined. Future studies should address these unresolved questions.

An Update on Strategies to Deliver Protein and Peptide Drugs to the Eye

In the past few decades, advancements in protein engineering, biotechnology, and structural biochemistry have resulted in the discovery of various techniques that enhanced the production yield of proteins, targetability, circulating half-life, product purity, and functionality of proteins and peptides. As a result, the utilization of proteins and peptides has increased in the treatment of many conditions, including ocular diseases. Ocular delivery of large molecules poses several challenges due to their high molecular weight, hydrophilicity, unstable nature, and poor permeation through cellular and enzymatic barriers. The use of novel strategies for delivering protein and peptides such as glycoengineering, PEGylation, Fc-fusion, chitosan nanoparticles, and liposomes have improved the efficacy, safety, and stability, which consequently expanded the therapeutic potential of proteins. This review article highlights various proteins and peptides that are useful in ocular disorders, challenges in their delivery to the eye, and strategies to enhance ocular bioavailability using novel delivery approaches. In addition, a few futuristic approaches that will assist in the ocular delivery of proteins and peptides were also discussed.

Ocular Delivery of Therapeutic Proteins: A Review

Therapeutic proteins, including monoclonal antibodies, single chain variable fragment (ScFv), crystallizable fragment (Fc), and fragment antigen binding (Fab), have accounted for one-third of all drugs on the world market. In particular, these medicines have been widely used in ocular therapies in the treatment of various diseases, such as age-related macular degeneration, corneal neovascularization, diabetic retinopathy, and retinal vein occlusion. However, the formulation of these biomacromolecules is challenging due to their high molecular weight, complex structure, instability, short half-life, enzymatic degradation, and immunogenicity, which leads to the failure of therapies. Various efforts have been made to overcome the ocular barriers, providing effective delivery of therapeutic proteins, such as altering the protein structure or including it in new delivery systems. These strategies are not only cost-effective and beneficial to patients but have also been shown to allow for fewer drug side effects. In this review, we discuss several factors that affect the design of formulations and the delivery of therapeutic proteins to ocular tissues, such as the use of injectable micro/nanocarriers, hydrogels, implants, iontophoresis, cell-based therapy, and combination techniques. In addition, other approaches are briefly discussed, related to the structural modification of these proteins, improving their bioavailability in the posterior segments of the eye without affecting their stability. Future research should be conducted toward the development of more effective, stable, noninvasive, and cost-effective formulations for the ocular delivery of therapeutic proteins. In addition, more insights into preclinical to clinical translation are needed.

Optimization of Lipid Nanoparticles by Response Surface Methodology to Improve the Ocular Delivery of Diosmin: Characterization and In-Vitro Anti-Inflammatory Assessment

Diosmin is a flavonoid with a great variety of biological activities including antioxidant and anti-inflammatory ones. Its cytoprotective effect in retinal pigment epithelium cells under high glucose conditions makes it a potential support in the treatment of diabetic retinopathy. Despite its benefits, poor solubility in water reduces its potential for therapeutic use, making it the biggest biopharmaceutical challenge. The design of diosmin-loaded nanocarriers for topical ophthalmic application represents a novelty that has not been yet explored. For this purpose, the response surface methodology (RSM) was used to optimize nanostructured lipid carriers (NLCs), compatible for ocular administration, to encapsulate diosmin and improve its physicochemical issues. NLCs were prepared by a simple and scalable technique: a melt emulsification method followed by ultrasonication. The experimental design was composed of four independent variables (solid lipid concentration, liquid lipid concentration, surfactant concentration and type of solid lipid). The effect of the factors was assessed on NLC size and PDI (responses) by analysis of variance (ANOVA). The optimized formulation was selected according to the desirability function (0.993). Diosmin at two different concentrations (80 and 160 µM) was encapsulated into NLCs. Drug-loaded nanocarriers (D-NLCs) were subjected to a physicochemical and technological investigation revealing a mean particle size of 83.58 ± 0.77 nm and 82.21 ± 1.12 nm, respectively for the D-NLC formulation prepared with diosmin at the concentration of 80 µM or 160 µM, and a net negative surface charge (−18.5 ± 0.60 and −18.0 ± 1.18, respectively for the two batches). The formulations were analyzed in terms of pH (6.5), viscosity, and adjusted for osmolarity, making them more compatible with the ocular environment. Subsequently, stability studies were carried out to assess D-NLC behavior under different storage conditions up to 60 days, indicating a good stability of NLC samples at room temperature. In-vitro studies on ARPE-19 cells confirmed the cytocompatibility of NLCs with retinal epithelium. The effect of D-NLCs was also evaluated in-vitro on a model of retinal inflammation, demonstrating the cytoprotective effect of D-NLCs at various concentrations. RSM was found to be a reliable model to optimize NLCs for diosmin encapsulation.

The edematogenic effect of Micrurus lemniscatus venom is dependent on venom phospholipase A2 activity and modulated by non-neurogenic factors

Coral snakes mainly cause neurotoxic symptoms in human envenomation, but experimental studies have already demonstrated several pharmacological activities in addition to these effects. This investigation was carried out with the aim of evaluating (1) non-neurogenic mechanisms involved in the inflammatory response induced by Micrurus lemniscatus venom (MLV) in rat hind paws, (2) participation of PLA₂ in this response, and (3) neutralizing efficiency of commercial anti-elapid antivenom on edema. MLV promoted a rapid, significant increase in vascular permeability, influx of leukocytes, and disorganization of collagen bundles, as demonstrated by histological analysis. Several pretreatments were applied to establish the involvement of inflammatory mediators in MLV-induced edema (5 µg/paw). Treatment of animals with chlorpromazine reduced MLV-induced edema, indicating participation of TNF-α. However, the inefficiency of other pharmacological treatments suggests that eicosanoids, leukotrienes, and nitric oxide have no role in this type of edema formation. In contrast, PAF negatively modulates this venom-induced effect. MLV was recognized by anti-elapid serum, but this antivenom did not neutralize edema formation. Chemical modification of MLV with p-bromophenacyl bromide abrogated the phospholipase activity and markedly reduced edema, demonstrating PLA₂ participation in MLV-induced edema. In conclusion, the non-neurogenic inflammatory profile of MLV is characterized by TNF-α-mediated edema, participation of PLA₂ activity, and down-regulation by PAF. MLV induces an influx of leukocytes and destruction of collagen fibers at the site of its injection.

Long-Term Follow-up of Patients With Uveitis Treated With Adalimumab: Response Rates and Reasons for Discontinuation of Therapy

PURPOSE

To evaluate the effectiveness and reasons for discontinuation including the side effect profiles of adalimumab in a real-world setting.

DESIGN

Retrospective clinical cohort study.

METHODS

A medical chart review of clinical practice in 2 tertiary eye care services in Rotterdam, the Netherlands, was performed Data were collected from May 1, 2004, through September 1, 2020. Patients with noninfectious uveitis treated with adalimumab (n = 341; 633 affected eyes) were included. The primary outcome was the effectiveness of adalimumab, measured by the number of patients achieving inactive disease, remission, and relapse-free survival. The secondary outcomes were the reasons for discontinuation, including side effects, and the number of patients who developed antibodies.

RESULTS

In total, 341 patients were treated with adalimumab between May 2004 and September 2020. The uveitis recurrence-free survival interval was 3.4 years (range, 0-13 years). Adalimumab had an acceptable side effect profile. A total of 178 patients achieved inactive disease while continuing adalimumab, and 51 patients maintained remission after discontinuing adalimumab. Reasons for discontinuation of adalimumab were no response, relapse, or reasons unrelated to the effectiveness of treatment. Adalimumab antibodies were present in 40 of 115 patients (35%). Antibodies were associated with lower adalimumab levels, and antibodies were observed more often in patients on adalimumab monotherapy (P < .01).

CONCLUSIONS

Adalimumab is effective for patients with noninfectious uveitis, with an acceptable side effect profile. Although relapses can occur, the majority of the patients achieved inactive disease or remission after cessation of adalimumab, without other systemic immunosuppressive medication.

Permeability, anti-inflammatory and anti-VEGF profiles of steroidal-loaded cationic nanoemulsions in retinal pigment epithelial cells under oxidative stress

Age-related macular degeneration (AMD) is defined as a degenerative, progressive and multifactorial disorder that affects the macula with a complex etiology. The retinal pigment epithelium is a monolayer of cells that has the function to separate the surface of the choroid from the neural retina that is involved in the signal transduction leading to vision. The blood-aqueous barrier and the blood retinal barrier limit the permeation of drugs into the retina and thereby reducing their efficacy. Triamcinolone acetonide (TA) is widely used as anti-inflammatory and immunomodulatory drug that promotes the inhibition of the inflammatory processes. The factors that stimulate or inhibit angiogenesis in AMD create a local balance that is responsible for the growth of sub-retinal neovascularization. In AMD, the main angiogenic stimulus is the vascular endothelial growth factor (VEGF). In this work, nanoemulsions with cationic surfactants (mono- and dicationic DABCO and quinuclidine) were produced to deliver TA, and were found to reduce the production of tumor necrosis factor alpha (TNF-α), which stimulates the choroidal neovascularization development by upregulating the VEGF production, and consequently decreased the VEGF levels. Our results support the potential use of mono- and dicationic DABCO and quinuclidine-based cationic nanoemulsions for the delivery of TA in the treatment of AMD.

British Association of Sexual Health and HIV national guideline on the management of sexually acquired reactive arthritis 2021

These guidelines update the 2008 UK guideline for the management of sexually acquired reactive arthritis. The guideline is aimed at those over the age of 16 years, presenting to healthcare professionals working in sexual health services. The recommendations are primarily aimed at services offering level 3 care in sexually transmitted infection management within the United Kingdom. However, the principles will apply to those presenting to level 1 and 2 services, and appropriate local referral pathways will need to be developed.

Histological Effects of Intravitreal Injection of Antifungal Agents in New Zealand White Rabbits: An Electron Microscopic and Immunohistochemical Study

Fungal endophthalmitis is a serious and vision-threatening infection which requires an immediate and effective treatment approach. Our research aims to elucidate the histological effects of the intravitreal injection of the maximum safe dosage of voriconazole and micafungin on retina. Six albino New Zealand White Rabbits were used. In experimental animals, a solution of voriconazole (Group V) or micafungin (Group M) was intravitreally injected in the right eye, while in control animals, balanced salt solution was intravitreally injected in the left eye (Group C). Euthanasia was performed ten days post injection and the retina was removed and prepared for histological examination with a light and electron microscope. Eosin-hematoxylin staining did not reveal any pathological changes in any of the samples examined. The immunohistochemical staining for Tumor Necrosis Factor alpha (TNF-a) marker was detected as negative in all samples, while Interleukin 6 (IL-6) marker was detected as mild only in the group injected with voriconazole. Electron microscopy revealed several ultrastructural alterations in retinal layers in both groups of experimental animals. Histological retinal lesions, revealed with electron microscopy in the present investigation, raises the question of the safe usage of these antifungal agents in the treatment of fungal intraocular infections in the future.

Long-term outcomes of systemic corticosteroid-sparing immunomodulatory therapy for Birdshot Retinochoroidopathy

PURPOSE

To report the visual prognosis, electroretinography (ERG) and perimetry outcomes of systemic corticosteroid-sparing immunomodulatory treatment (IMT) for birdshot retinochoroidopathy (BSRC).

METHODS

Retrospective non-comparative case series of 132 patients (264 eyes) with BSRC treated with IMT from Massachusetts Eye Research and Surgery Institution.

RESULTS

The average follow-up time was 60.1 months. After one year on IMT, 39.4% showed no clinically active inflammation. After 5 years of IMT, 78.0% had no signs of clinical inflammation. No significant differences were observed on best-corrected visual acuity (BCVA), ERG parameters, and perimetry parameters between baseline and subsequent visits on IMT.

CONCLUSION

Long-term systemic corticosteroid-sparing IMT was associated with a low rate of BSRC disease exacerbation. While differences were seen on testing parameters, they were not consistent trends and difference were attributed to variability of testing or fluctuation of inflammation that may be expected in the course of the disease.

Comparative analysis of pharmacokinetics of vancomycin hydrochloride in rabbits after ocular, intragastric, and intravenous administration by LC-MS/MS

The objective of this study was to compare the pharmacokinetics of vancomycin hydrochloride administered into rabbits through different routes and explore the feasibility of peptide drugs entering the systemic circulation through ocular administration. A convenient, accurate, and rapid liquid chromatography-trandem mass spectrometric (LC-MS/MS) method was established and used for the determination of vancomycin hydrochloride in rabbit plasma after intravenous administration (1.5 mg/kg), intragastric, and ocular administration (15 mg/kg). The pharmacokinetic parameters were analyzed using the DAS 2.0 software. We obtained a linear calibration curves vancomycin hydrochloride in plasma of rabbits over a concentration range of 0.05-10.0 μg/mL (R ² > 0.9995), the interassay accuracy was within 5%, precision of 1.66-3.38%, and recovery of >85%. No matrix effects were observed. The absolute bioavailability of vancomycin hydrochloride after intragastric and ocular administration was 1.0 and 7.3%, with the half-life values of 63.1 and 138.5 min, respectively. Therefore, the LC-MS/MS method established in this experiment was suitable for the determination of vancomycin hydrochloride. Vancomycin hydrochloride was rapidly absorbed into the blood circulation after ocular administration. Ocular administration was linked to higher bioavailability compared with intragastric administration, suggesting that the former will become a route for the delivery of peptide drugs.

Retinal vasculitis: A framework and proposal for a classification system

Retinal vasculitis, a poorly understood process involving inflammation or ischemia of the retinal vessel wall, may occur in association with a systemic process, although it can also be isolated to the retina. Because of the limited ability to perform histopathological studies on retinal vessels, there is no gold standard for diagnosis. Thus, there is utility in creating a classification system for retinal vasculitis and improving diagnostic strategies for this disease. We provide a framework for understanding retinal vasculitis based on size, location, and etiology. We hope that this information can be implemented in the clinical setting to provide some diagnostic strategies for this often confusing entity.

Identification of novel inhibitors for TNFα, TNFR1 and TNFα-TNFR1 complex using pharmacophore-based approaches

BACKGROUND

Tumor necrosis factor α (TNFα) is a multifunctional cytokine with a potent pro-inflammatory effect. It is a validated therapeutic target molecule for several disorders related to autoimmunity and inflammation. TNFα-TNF receptor-1 (TNFR1) signaling contributes to the pathological processes of these disorders. The current study is focused on finding novel small molecules that can directly bind to TNFα and/or TNFR1, preventing the interaction between TNFα or TNFR1, and regulating downstream signaling pathways.

METHODS

Cheminformatics pipeline (pharmacophore modeling, virtual screening, molecular docking and in silico ADMET analysis) was used to screen for novel TNFα and TNFR1 inhibitors in the Zinc database. The pharmacophore-based models were generated to screen for the best drug like compounds in the Zinc database.

RESULTS

The 39, 37 and 45 best hit molecules were mapped with the core pharmacophore features of TNFα, TNFR1, and the TNFα-TNFR1 complex respectively. They were further evaluated by molecular docking, protein-ligand interactions and in silico ADMET studies. The molecular docking analysis revealed the binding energies of TNFα, TNFR1 and the TNFα-TNFR1 complex, the basis of which was used to select the top five best binding energy compounds. Furthermore, in silico ADMET studies clearly revealed that all 15 compounds (ZINC09609430, ZINC49467549, ZINC13113075, ZINC39907639, ZINC25251930, ZINC02968981, ZINC09544246, ZINC58047088, ZINC72021182, ZINC08704414, ZINC05462670, ZINC35681945, ZINC23553920, ZINC05328058, and ZINC17206695) satisfied the Lipinski rule of five and had no toxicity.

CONCLUSIONS

The new selective TNFα, TNFR1 and TNFα-TNFR1 complex inhibitors can serve as anti-inflammatory agents and are promising candidates for further research.

Expert opinion on the use of biological therapy in non-infectious uveitis

INTRODUCTION

Conventional immunosuppressive drugs, anti-TNF alpha treatments and biotherapies are increasingly being used in non-infectious uveitis.

AREAS COVERED

The present work was led by a multidisciplinary panel of experts, including internal medicine specialists, rheumatologists and ophthalmologists, and proposes an extensive review on the use of biological agents in non-infectious uveitis.

EXPERT OPINION

In case of dependency to steroids or sight-threatening disease, conventional immunosuppressive drugs (methotrexate, azathioprine and mycophenolate mofetil) and/or biological therapies such as anti-TNF alpha treatments (adalimumab, infliximab) can be used to achieve and maintain disease quiescence. Interferon is an efficient immunomodulatory drug that can be proposed as second-line therapy in specific indications (eg. refractory macular edema, sight-threatening Behçet's uveitis). Other biologics, especially tocilizumab, are showing promising results. Local treatments (steroids, sirolimus etc.) can be used as adjuvant therapies in case of unilateral relapse. Therapeutic response must always be evaluated by clinical examination and appropriate ancillary investigations.

Improvement of neurological and ocular symptoms of Behçet's disease after the introduction of infliximab

Behçet's disease is a chronic inflammatory condition of unknown origin characterized by multiple organ involvement. The most common symptoms of Behçet's disease are recurrent oral and/or genital ulcerations in combination with symptoms affecting eyes, skin, central and peripheral nervous system, blood vessels and gastrointestinal tract. We present a 43-year-old female patient with the history of recurrent episodes of genital and oral ulcerations, elevated acute phase reactants and skin lesions. The diagnosis of Behçet's disease has been delayed (for more than 10 years) and reached only after she developed neurological and ocular symptoms. Treatment with glucocorticoids and azathioprine was partially successful. High doses of glucocorticoids were needed to control the disease and cyclosporine A was nephrotoxic. Remission was reached after the introduction of infliximab (plus methotrexate) and glucocorticoids were stopped. In the recent years, infliximab has been accepted as a standard therapy for refractory cases of Behçet's disease (neurological, ocular or gastrointestinal). Our patient presented with refractory ocular and neurological symptoms and infliximab was effective for both manifestations. Long-term side-effects of glucocorticoids and other immunosuppressants can be avoided with TNF-α blockade. We emphasize the importance of a timely and accurate diagnosis and significance of excluding more common diseases in a work-up algorithm.

Psoriatic Eye Manifestations

The relationship between the eye and psoriasis has been recognized for decades, but the precise eye manifestations in patients with psoriasis and psoriatic arthritis are only recently coming to light. Psoriatic eye findings may include conjunctivitis, dry eye, episcleritis, and uveitis, all of which may precede articular changes. Uveitis, seen in 7% to 25% of psoriatic arthritis patients, may be recognized by the presence of conjunctival injection, photophobia, pain, lid swelling, or otherwise unexplained visual changes. Early recognition is paramount because its natural course may lead to vision loss. Immunopathogenesis has shown evidence for T-helper cell (Th) type 1 (Th1) and Th17 involvement in the pathogenesis of uveitis according to the murine experimental autoimmune uveitis model. Corticosteroids are the primary treatment modality; however, increasing emphasis has been placed on immunomodulators and biologics for more intractable cases. Referral to an ophthalmologist is essential for definitive diagnosis and treatment.

[Therapeutic strategy for the treatment of non-infectious uveitis proposed by an expert panel]

Conventional immunosuppressive drugs, anti-TNF alpha and other biotherapies used in clinical practice are capable of controlling non-infectious anterior uveitis, posterior uveitis and panuveitis. The present work has been led by a multidisciplinary panel of experts, internists, rheumatologists and ophthalmologists and is based on a review of the literature. In case of corticodependency or sight-threatening disease, conventional immunosuppressive drugs (methotrexate, azathioprine and mycophenolate mofetil) and/or anti-TNF alpha (adalimumab, infliximab) are used to achieve and maintain remission. Interferon is an efficient immunomodulatory treatment, as a second-line therapy, for some therapeutic indications (refractory macular edema, Behçet's vascularitis). Other biologics, especially tocilizumab, are showing promising results. Local treatments (corticosteroids, sirolimus etc.) are adjuvant therapies in case of unilateral inflammatory relapse. Therapeutic response must be evaluated precisely by clinical examination and repeated complementary investigations (laser flare photometry, multimodal imaging, perimetry, electroretinography measures).

Ocular delivery of proteins and peptides: Challenges and novel formulation approaches

The impact of proteins and peptides on the treatment of various conditions including ocular diseases over the past few decades has been advanced by substantial breakthroughs in structural biochemistry, genetic engineering, formulation and delivery approaches. Formulation and delivery of proteins and peptides, such as monoclonal antibodies, aptamers, recombinant proteins and peptides to ocular tissues poses significant challenges owing to their large size, poor permeation and susceptibility to degradation. A wide range of advanced drug delivery systems including polymeric controlled release systems, cell-based delivery and nanowafers are being exploited to overcome the challenges of frequent administration to ocular tissues. The next generation systems integrated with new delivery technologies are anticipated to generate improved efficacy and safety through the expansion of the therapeutic target space. This review will highlight recent advances in formulation and delivery strategies of protein and peptide based biopharmaceuticals. We will also describe the current state of proteins and peptides based ocular therapy and future therapeutic opportunities.

Infliximab exerts a dose-dependent effect on retinal safety in the albino rabbit

PURPOSE

To assess the retinal toxicity of an intravitreal injection of infliximab, a monoclonal antibody to tumor necrosis factor α, in a rabbit model.

MATERIALS AND METHODS

Two groups of adult albino rabbits (n = 5) received intravitreal injections of infliximab (0.1 ml) in the study eye and balanced salt solution (BSS, 0.1 ml) in the control eye at baseline. Group 1 was administered with 1.5 mg/0.1 ml, and group 2 was injected with 7.5 mg/0.1 ml of infliximab solution. Electroretinography (ERG) was performed at baseline and at 1, 7, 30, and 45 days after the injection. Visual evoked potentials (VEPs) were recorded at 7 and 45 days after the injection. After the last electrophysiological assessment, the rabbits were euthanized and retinal histopathology and immunhistochemistry for glial fibrillary acidic protein (GFAP) were performed.

RESULTS

ERG responses demonstrated no significant deficit in retinal function in eyes injected with infliximab. Mean dark-adapted a-wave and b-wave maximal amplitude and semi-saturation constant values at baseline and throughout the 45 days of follow-up after the injection indicated no remarkable difference in outer retinal function between the control and experimental eyes. VEP responses were similar at each time point (7 and 45 days). No difference was seen in retinal histopathology and immunocytochemistry sections in eyes receiving the 1.5 mg/0.1 ml dose compared to the control eyes. However, increased GFAP labeling in retinal Müller cells was detected in rabbit eyes treated with the 7.5 mg/0.1 ml dose.

CONCLUSIONS

Intravitreal injection of 1.5 mg/0.1 ml infliximab dose has no toxic effect on the integrity (functional or structural) of the retina in rabbits. A higher dose of 7.5 mg/0.1 ml may be slightly toxic as suggested by positive Müller cell GFAP expression. Additional studies of retinal toxicity at higher doses and after multiple injections are needed to establish the retinal safety of intravitreal infliximab therapy in humans.

A Pilot Study on Ocular Safety and Efficacy of Infliximab as an Antifibrotic Agent After Experimental Glaucoma Filtration Surgery

Introduction

Tumor necrosis factor-α (TNF-α) is a multifunctional, proinflammatory cytokine that mediates pleiotropic biological functions, especially inflammation and immunoregulation. We hypothesized that blocking TNF-α with a monoclonal antibody would decrease inflammation and subconjunctival scarring in an animal model of experimental filtration surgery.

Methods

In a randomized, prospective, masked-observer study, 30 New Zealand albino rabbits underwent glaucoma filtration surgery. The animals were allocated to receive either intraoperative application of infliximab (group A) or mitomycin C (MMC) at a concentration of 0.2 mg/ml (group B) or balanced salt solution (BSS, control) (group C). Different infliximab doses, namely 1.0, 2.0, 3.0, 4.0, 5.0 mg in 0.1 ml, were applied. Bleb survival and characteristics were evaluated over a 30-day period. The animals were killed on postoperative day 15 or 30. Histology of the operated eyes was performed to evaluate and grade the amount of scarring in each group. Cellular density was evaluated in each case.

Results

Infliximab did not appear to improve outcomes in this model of glaucoma filtration surgery. Bleb survival was significantly higher in the MMC group compared to the other groups (p < 0.001 for both comparisons). Vascularity was also significantly lower in the MMC group compared to the other groups (p = 0.018 for both comparisons). There was a significant decrease in cellular density in the MMC group compared to the control (p = 0.0352) and the infliximab group (p < 001).

Conclusion

Our results have shown that trabeculectomies in the infliximab group failed faster and displayed more scarring, compared to the control and MMC groups. This outcome suggests that the infliximab doses used in this pilot study resulted in a subconjunctival TNF-α concentration, which acted as a stimulator to fibroblasts.

Uveitic macular edema

Macular edema (ME) may complicate anterior, intermediate, and posterior uveitis, which may be because of various infectious, neoplastic or autoimmune etiologies. BRB breakdown is involved in the pathogenesis of Uveitic ME (UME). Optical coherence tomography has become a standard tool to confirm the diagnosis of macular thickening, due to its non-invasive, reproducible, and sensitive features. Retinal fluorescein and indocyanine green angiography is helpful to study the macula and screen for associated vasculitis, detect ischemic areas and preretinal, prepapillary or choroidal neovascular complications, and it may provide information about the etiology and be needed to assess the therapeutic response. UME due to an infection or neoplastic infiltration may require a specific treatment. If it remains persistent or occurs in other etiologies, immunomodulatory treatments may be needed. Intravitreal, subconjunctival, or subtenon corticosteroids are widely used. Their local use is contraindicated in glaucoma patients and limited by their short-lasting action. In case of bilateral sight-threatening chronic posterior uveitis, systemic treatments are usually needed, and corticosteroids are used as the standard first-line therapy. In order to reduce the daily steroid dose, immunosuppressive or immunomodulatory agents may be added, some of them being now available intravitreally. Ongoing prospective studies are assessing biotherapies and immunomodulators to determine their safety and efficacy in this indication.

LONG-TERM EFFICACY OF SYSTEMIC INFLIXIMAB IN RECALCITRANT RETINAL VASCULITIS

PURPOSE

To evaluate the efficacy of systemic infliximab for the induction of remission in patients with retinal vasculitis, inadequately responsive to other immunomodulatory therapy, based on fluorescein angiography grading for retinal vasculitis evaluation.

METHODS

We analyzed 60 patients with retinal vasculitis, from the Massachusetts Eye Research and Surgery Institution in Cambridge, MA. Response to therapy was based on analysis of serial fluorescein angiography and fundus photography, including a baseline angiogram before initiation of infliximab.

RESULTS

Sixty patients received infliximab therapy between July 2007 and July 2012 at Massachusetts Eye Research and Surgery Institution for a diagnosis of retinal vasculitis. All had previously showed a poor clinical response to other immunomodulatory regimens, or ceased therapy due to intolerable side effects. The initial dose of infliximab was 5 mg/kg in all patients and remained at this dose for the extent of treatment in 57 (95%) patients. At 6 months, 45 of 51 (88.23%) patients were maintaining remission with therapy, 5 (9.8%) were in partial remission, and 1 patient had failed. At 12 months, 39 of 39 (100%) patients were maintaining remission with therapy.

CONCLUSION

Infliximab is effective for the treatment of recalcitrant noninfectious retinal vasculitis, refractory to conventional immunomodulatory therapy.

Anti-TNF therapeutics for the treatment of sarcoidosis

Sarcoidosis is a systemic disease with an incidence of 1 to 40 per 100 000 persons per year. It predominantly affects people in the age of 20 to 40 years old. Disease course varies from mild self-limiting to chronic debilitating and life-threatening disease. Since the cause of sarcoidosis is unknown, curative therapy is not available. Immunosuppressive drugs may, however, control the symptoms of the disease. The hallmark of sarcoidosis is the formation of granulomas that are most commonly found in lungs and lymph nodes. As TNF plays an important role in both formation and maintenance of these granulomas, as well as in the immune response, anti-TNF biologicals such as infliximab and adalimumab are considered a last resort therapeutic option. Clinical effectiveness, however, varies considerably and data showing which patients would benefit most from this expensive therapy are scarce. This review summarizes current knowledge on anti-TNF therapeutics in sarcoidosis, and describes insights on prediction of response, outcome measures and antibody development.

Contribution of microglia-mediated neuroinflammation to retinal degenerative diseases

Retinal degenerative diseases are major causes of vision loss and blindness worldwide and are characterized by chronic and progressive neuronal loss. One common feature of retinal degenerative diseases and brain neurodegenerative diseases is chronic neuroinflammation. There is growing evidence that retinal microglia, as in the brain, become activated in the course of retinal degenerative diseases, having a pivotal role in the initiation and propagation of the neurodegenerative process. A better understanding of the events elicited and mediated by retinal microglia will contribute to the clarification of disease etiology and might open new avenues for potential therapeutic interventions. This review aims at giving an overview of the roles of microglia-mediated neuroinflammation in major retinal degenerative diseases like glaucoma, age-related macular degeneration, and diabetic retinopathy.

Retinal pigment epithelial cells display specific transcriptional responses upon TNF-α stimulation

BACKGROUND/AIMS

Tumour necrosis factor-α (TNF-α) is a key mediator of ocular inflammation and its interaction with the retinal pigment epithelium (RPE) may be a driving force in vitreoretinal disorders such as age-related macular degeneration, proliferative vitreoretinopathy (PVR) and diabetic retinopathy. Under inflammatory conditions, the ability of RPE cells to maintain the blood-retinal barrier and immune privilege may be lost and proliferation of RPE cells is facilitated. To gain insight into the effects of TNF-α on RPE cells, a gene expression study was performed.

METHODS

ARPE-19 and HT-29 cells were stimulated with 50 ng/mL TNF-α for 6 h. Gene expression patterns were compared between stimulated and control cells using whole genome gene expression arrays. Data were analysed using Partek and OmniViz and validated using quantitative RT-PCR. Functional annotation analysis was performed using Ingenuity and DAVID.

RESULTS

A total of 97 genes were uniquely modulated by TNF-α in ARPE-19 cells compared with HT-29 cells (86 upregulated and 11 downregulated). Most commonly affected biological processes were apoptosis, cell motility and cell signalling. The highest upregulated gene was EFNA1. Among the downregulated genes were transcription factors implicated in ocular development (SIX3, PAX6) and modulation of p53-mediated apoptosis (CITED2).

CONCLUSIONS

This study provides insight into the unique responses of RPE cells to TNF-α stimulation and suggests a role for genes involved in apoptosis and retinal epithelial development. These findings contribute to our understanding of the behaviour of RPE cells under inflammatory conditions and the crucial role of RPE cells in vitreoretinal diseases.

[Uveitic macular edema]

Macular edema may complicate anterior, intermediate, and posterior uveitis, which may be due to various infectious, tumoral, or autoimmune etiologies. Breakdown of the internal or external blood-retinal barrier is involved in the pathogenesis of inflammatory macular edema. Optical coherence tomography has become standard in confirming the diagnosis of macular thickening, due to its non-invasive, reproducible and sensitivity characteristics. Fluorescein and indocyanine green angiography allows for, in addition to study of the macula, screening for associated vasculitis, detection of ischemic areas, easy diagnosis of preretinal, prepaillary or choroidal neovascular complications, and it can provide etiological information and may be required to evaluate the therapeutic response. Treatment of inflammatory macular edema requires specific treatment in cases of infectious or tumoral etiologies. If it remains persistent, or occurs in other etiologies, anti-inflammatory treatments are needed. Steroid treatment, available in intravitreal, subconjunctival and sub-Tenon's routes, are widely used. Limitations of local use include induced cataract and glaucoma, and their short-lasting action. Such products may reveal retinal infection. Thus, bilateral chronic sight-threatening posterior uveitis often requires systemic treatment, and steroids represent the classic first-line therapy. In order to reduce the daily steroid dose, immunosuppressant or immunomodulatory drugs may be added. Certain of these compounds are now available intravitreally.

Spectral domain-optical coherence tomographic findings in patients with ankylosing spondylitis under anti-tumor necrosis factor-alpha therapy

OBJECTIVE

To evaluate the effect of tumor necrosis factor-alpha (TNF-α) blockade on the thickness of the peripapillary retinal nerve fiber layer (RNFL), the ganglion cell-inner plexiform layers (GCIPL), and the macula in ankylosing spondylitis (AS) patients under anti-TNF-α therapy.

MATERIALS AND METHODS

Twenty-one patients with AS received etanercept, or adalimumab, or infliximab for at least 6 months. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels, and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores were measured before and 6 months after the beginning of the treatment. Peripapillary RNFL, four regional fields (superior, inferior, nasal, and temporal), GCIPL, and macular thicknesses of the patients were analyzed by optical coherence tomography before the treatment, at 3 months and 6 months after the beginning of the treatment.

RESULTS

The mean BASDAI, ESR, and CRP values were 5.2 ± 1.5, 31.6 ± 21.7, and 15.7 ± 13.9, respectively, at the beginning of the treatment and 2.3 ± 1.7, 21.3 ± 15.1, and 10.1 ± 10.3, respectively, 6 months after the beginning of treatment. There were significant differences among the mean BASDAI, ESR, and CRP values at the beginning of treatment and 6 months later (p < 0.001, p = 0.007, and p = 0.009, respectively). There were no significant differences among peripapillary RNFL (p = 0.24), four regional fields (p = 0.98, p = 0.23, p = 0.09, p = 0.47), GCIPL (p = 0.25), or macular (p = 0.33) thicknesses of the patients during anti-TNF-α treatment. In addition, the mean intraocular pressure levels throughout the follow-up did not show significant variation on repeated-measures ANOVA (p = 0.77).

CONCLUSIONS

TNF-α blockade does not seem to influence RNFL, GCIPL, or macular thickness of patients with AS in the short term.

Update on intravitreal anti-tumor necrosis factor alpha therapies for ocular disorders

Tumor necrosis factor alpha (TNF-?) is an important pro-inflammatory cytokine associated with a variety of ocular diseases. The currently available TNF-? inhibitors are etanercept, infliximab, adalimumab, golimumab, and certolizumab. Experimental and clinical studies on the intravitreal use of these agents have been reported with etanercept, infliximab, and adalimumab: etanercept has shown limited efficacy in scarce reports; infliximab has been associated with local safety concerns but appears to benefit certain cases; adalimumab has shown no efficacy in cases of age-related macular degeneration (AMD) or diabetic macular edema (DME), but the combination with bevacizumab may be effective in refractory cases of macular diseases. Further preclinical and clinical studies are warranted in order to be able to obtain a more robust conclusion on the use of intravitreal TNF-? inhibitors.

Cytokines are both villains and potential therapeutic targets in thyroid-associated ophthalmopathy: From bench to bedside

The pathophysiology underlying Graves' disease and its ocular manifestation, thyroid associated ophthalmopathy (TAO) is incompletely understood. Characterization of the mononuclear cells driving the disease and the cytokines they produce has led to significant advances in our understanding of TAO. This in turn has resulted in the identification of potentially attractive drug targets. For instance, development of inhibitors of specific cytokine pathways for use in other autoimmune diseases now presents an opportunity for their application in TAO. In this paper, we review the rationale for considering anti-cytokine therapy in TAO, evidence linking specific cytokines such as interleukin-6, tumor necrosis factor-α, and interleukin-17 pathways to TAO, and explore the potential for targeting of these pathways as therapy.

Local therapies for inflammatory eye disease in translation: past, present and future

Despite their side-effects and the advent of systemic immunosuppressives and biologics, the use of corticosteroids remains in the management of patients with uveitis, particularly when inflammation is associated with systemic disease or when bilateral ocular disease is present. The use of topical corticosteroids as local therapy for anterior uveitis is well-established, but periocular injections of corticosteroid can also be used to control mild or moderate intraocular inflammation. More recently, intraocular corticosteroids such as triamcinolone and steroid-loaded vitreal inserts and implants have been found to be effective, including in refractory cases. Additional benefits are noted when ocular inflammation is unilateral or asymmetric, when local therapy may preclude the need to increase the systemic medication.

Implants in particular have gained prominence with evidence of efficacy including both dexamethasone and fluocinolone loaded devices. However, an appealing avenue of research lies in the development of non-corticosteroid drugs in order to avoid the side-effects that limit the appeal of injected corticosteroids. Several existing drugs are being assessed, including anti-VEGF compounds such as ranibizumab and bevacizumab, anti-tumour necrosis factor alpha antibodies such as infliximab, as well as older cytotoxic medications such as methotrexate and cyclosporine, with varying degrees of success. Intravitreal sirolimus is currently undergoing phase 3 trials in uveitis and other inflammatory pathways have also been proposed as suitable therapeutic targets. Furthermore, the advent of biotechnology is seeing advances in generation of new therapeutic molecules such as high affinity binding peptides or modified high affinity or bivalent single chain Fab fragments, offering higher specificity and possibility of topical delivery.

Off-label uses of anti-TNF therapy in three frequent disorders: Behçet's disease, sarcoidosis, and noninfectious uveitis

Tumoral necrosis factor α plays a central role in both the inflammatory response and that of the immune system. Thus, its blockade with the so-called anti-TNF agents (infliximab, etanercept, adalimumab, certolizumab pegol, and golimumab) has turned into the most important tool in the management of a variety of disorders, such as rheumatoid arthritis, spondyloarthropatties, inflammatory bowel disease, and psoriasis. Nonetheless, theoretically, some other autoimmune disorders may benefit from these agents. Our aim is to review these off-label uses of anti-TNF blockers in three common conditions: Behçet's disease, sarcoidosis, and noninfectious uveitis. Due to the insufficient number of adequate clinical trials and consequently to their lower prevalence compared to other immune disorders, this review is mainly based on case reports and case series.

Anti-TNFα therapy early improves hemodynamics in local intestinal and extraintestinal circulations in active Crohn's disease

BACKGROUND AND AIMS

Active Crohn's disease affects intestine but may alter other locations as eyes vasculature. Previous studies provide evidence of elevated blood flow velocities (BFv) and volume (BFV) in superior mesenteric artery (SMA). We prospectively studied hemodynamics in feeding arteries of bowel and eyes before and 2 weeks after treatment induction with anti-TNFα.

METHODS

Fifteen patients (5 females, 10 males, 35.4 ± 9.0 years, mean ± SD) with active Crohn's disease for 7.5 ± 7.7 years were enrolled. Ultrasound imaging was performed before and 2 weeks after treatment in SMA and retrobulbar arteries: central retinal (CRA), temporal posterior ciliary (TPCA) and ophthalmic (OA) arteries. Serum markers of inflammation (CRP and fibrinogen), arterial blood pressures (ABP) and skin flow-mediated dilation (sFMD) were measured and patients were compared to 10 control age- and sex-matched subjects.

RESULTS

Before treatment, CRP and fibrinogen plasma concentrations, SMA BFV (339 ± 100 mL/min) were higher in patients than in controls by 8.5-fold (p<0.001), 1.4-fold (p<0.01) and 1.5-fold, respectively (p<0.01). BFv in CRA (3.5 ± 0.7 cm/s) and TPCA (4.4 ± 1.0 cm/s), sFMD (371 ± 469%) were significantly lower than in controls by 83%, 73% and 52% respectively (p<0.05). Two weeks after treatment, CRP and fibrinogen decreased, SMA BFV was normalized (230 ± 39L/min, p<0.01), BFv in CRA, TPCA and OA increased respectively to 4.0 ± 1.1 (p<0.05), 5.2 ± 1.4 (p<0.001), 8.9 ± 3 cm/s (p<0.05). ABP and sFMD remained unchanged.

CONCLUSIONS

In active Crohn's disease, a first anti-TNFα administration rapidly normalized concomitantly plasma inflammatory markers and blood-flows in the mesenteric and retrobulbar arteries without affecting blood pressure and endothelial function.

Safety and Efficacy of Infliximab and Adalimumab for Refractory Uveitis in Juvenile Idiopathic Arthritis: 1-year Followup Data from the Italian Registry

Objective.

To evaluate safety and efficacy of adalimumab (ADA) and infliximab (IFX) for the treatment of juvenile idiopathic arthritis-related anterior uveitis (JIA-AU).

Methods.

Starting January 2007, patients with JIA-AU treated with IFX and ADA were managed by a standard protocol and data were entered into the National Italian Registry (NIR). At baseline, all patients were refractory to standard immunosuppressive treatment and/or were corticosteroid-dependent. Data recorded every 3 months included uveitis course, number/type of ocular complications, drug-related adverse events (AE), treatment change or withdrawal, and laboratory measures. Data of patients treated for at least 1 year were retrieved from the NIR and analyzed using descriptive statistics. Treatment efficacy was based on change in uveitis course and in number of ocular complications.

Results.

Up to December 2009, data for 108 patients with JIA-AU treated with anti-tumor necrosis factor-α agents were recorded in the NIR and data from 91, with at least 12 months’ followup, were included in the study. Forty-eight patients were treated with IFX, 43 with ADA. Forty-seven patients (55.3%) achieved remission of AU, 28 (32.9%) had recurrent AU, and 10 (11.8%) maintained a chronic course. A higher remission rate was observed with ADA (67.4% vs 42.8% with IFX; p = 0.025). Ocular complications decreased from 0.47 to 0.32 per subject. Five patients experienced resolution of structural complications. No patient reported serious AE; 8 (8.8%) experienced 11 minor AE (9 with IFX, 2 with ADA).

Conclusion.

IFX and ADA appear to be effective and safe for treatment of refractory JIA-related uveitis, with a better performance of ADA in the medium-term period.

Intravitreal infliximab for sight-threatening relapsing uveitis in Behçet disease: a pilot study in 15 patients

PURPOSE

To assess the safety and to conduct a preliminary assessment of efficacy of intravitreal infliximab, an anti-tumor necrosis factor antibody, for sight-threatening relapsing uveitis in Behçet disease.

DESIGN

Prospective, noncomparative, interventional pilot study.

METHODS

A single intravitreal injection of infliximab (1 mg/0.05 mL) was given to 15 patients with relapsing posterior uveitis at the onset of a unilateral attack. Best-corrected visual acuity, anterior chamber cells, vitreous haze, and posterior eye segment inflammation were assessed at baseline and at 1, 7, 14, and 30 days after treatment.

RESULTS

Ocular or extra-ocular side effects were not observed. Baseline best-corrected visual acuity (mean logarithm of minimal angle of resolution, 0.74; range, 0.15 to 1.7) improved significantly by day 7 and continued to improve through day 30 after infliximab (mean, 0.30; P < .0001). Profound decreases in anterior chamber cells and vitreous haze (both P < .0001), as well as beneficial effects in retinal vasculitis (P = .0001) and retinitis (P = .001) were evident through day 30. Cystoid macular edema persisted in 9 of 11 eyes affected, but central macular thickness decreased from a baseline mean of 434 to 309 mm at the end of follow-up (P < .0001). Lack of systemic treatment at baseline in 4 patients or background immunosuppressive medications, which remained unchanged during follow-up, did not influence significantly these responses; additional treatment was not required.

CONCLUSIONS

These findings suggest that intraocularly produced or acting tumor necrosis factor, or both, is crucial in Behçet disease-associated relapsing uveitis and that intravitreal infliximab should be considered when systemic administration is not feasible or contraindicated. Further studies may identify patients for whom intravitreal infliximab is preferable to systemic treatment.