A review and update on orphan drugs for the treatment of noninfectious uveitis

Lithospermum erythrorhizon Siebold & Zucc. extract reduces the severity of endotoxin-induced uveitis

BACKGROUND

Uveitis is an inflammatory eye condition that threatens vision, and effective anti-inflammatory treatments with minimal side effects are necessary to treat uveitis.

PURPOSE

This study aimed to investigate the effects of Lithospermum erythrorhizon Siebold & Zucc. against endotoxin-induced uveitis in rat and mouse models.

METHODS

Endotoxin-induced uveitis models of rats and mice were used to evaluate the effects of l. erythrorhizon treatment. Clinical inflammation scores and retinal thickness were assessed in the extract of l. erythrorhizon-treated rats. Histopathological examination revealed inflammatory cell infiltration into the ciliary body. Protein concentration, cellular infiltration, and prostaglandin-E2 levels were measured in the aqueous humor of the extract of l. erythrorhizon-treated rats. Protective effects of l. erythrorhizon on the anterior segment of the eye were examined in mice with endotoxin-induced uveitis. Additionally, we investigated the effect of l. erythrorhizon on the expression of pro-inflammatory cytokines [tumor necrosis factor alpha, interleukin-6, and interleukin-8] in lipopolysaccharide-stimulated THP1 human macrophages and examined the involvement of nuclear factor kappaB/activator protein 1 and interferon regulatory factor signaling pathways. Furthermore, three components of l. erythrorhizon were identified and assessed for their inhibitory effects on LPS-induced inflammation in RAW264.7 macrophage cells.

RESULTS

Treatment of the extract of l. erythrorhizon significantly reduced clinical inflammation scores and retinal thickening in rats with endotoxin-induced uveitis. Histopathological examination revealed decreased inflammatory cell infiltration into the ciliary body. The extract of l. erythrorhizon effectively reduced the protein concentration, cellular infiltration, and PG-E2 levels in the aqueous humor of rats with endotoxin-induced uveitis. In mice with endotoxin-induced uveitis, the extract of l. erythrorhizon demonstrated a protective effect on the anterior segment of the eye by reducing inflammation and retinal thickening. The extract of l. erythrorhizon suppressed the expression of pro-inflammatory cytokines (tumor necrosis factor alpha, interleukin-6, and interleukin-8) in lipopolysaccharide-induced inflammation in THP1 human macrophages, by modulating nuclear factor kappaB/activator protein 1 and interferon regulatory factor signaling pathways. Moreover, shikonin, acetylshikonin, and β, β-dimethylacryloylshikonin showed dose-dependent inhibition of nitric oxide, tumor necrosis factor alpha and interleukin-6 production in RAW264.7 macrophage cells.

CONCLUSION

The extract of l. erythrorhizon is a potential therapeutic agent for uveitis management. Administration of the extract of l. erythrorhizon led to reduced inflammation, retinal thickening, and inflammatory cell infiltration in rat and mouse models of uveitis. The compounds (shikonin, acetylshikonin, and β, β-dimethylacryloylshikonin) identified in this study played crucial roles in mediating the anti-inflammatory effects of l. erythrorhizon. These findings indicate that the extract of l. erythrorhizon and its constituent compounds are promising candidates for further research and development of novel treatment modalities for uveitis.

Uveitis: Study of 109 cases

PURPOSE

Analyse and describe the anatomical and etiological classification, clinical and epidemiological characteristics and most frequent symptoms of uveitis cases in our population.

PATIENTS AND METHOD

Descriptive, retrospective observational study of uveitis cases treated in the Ophthalmology Department of Virgen del Rocío University Hospital in 2021. The demographic and clinical characteristics were studied.

RESULTS

A total of 109cases of uveitis were studied, 46 men and 63 women, with a mean age of 45.43±16.11 years. The most frequent symptoms were pain (74.31%), hyperemia (73.39%) and blurred vision (65.14%). The most frequent anatomical classification was anterior (55.96%), followed by panuveitis (18.35%), posterior (12.84%) and intermediate uveitis (7.34%). Regarding etiology, most uveitis were idiopathic (42.99%), followed by non-infectious (38.32%) and finally infectious (18.69%).

CONCLUSIONS

In southern España, the characteristics of uveitis are similar to other studies in Western countries.

Microbiome in Immune-Mediated Uveitis

In the last decades, personalized medicine has been increasing its presence in different fields of medicine, including ophthalmology. A new factor that can help us direct medicine towards the challenge of personalized treatments is the microbiome. The gut microbiome plays an important role in controlling immune response, and dysbiosis has been associated with immune-mediated diseases such as non-infectious uveitis (NIU). In this review, we gather the published evidence, both in the pre-clinical and clinical studies, that support the possible role of intestinal dysbiosis in the pathogenesis of NIU, as well as the modulation of the gut microbiota as a new possible therapeutic target. We describe the different mechanisms that have been proposed to involve dysbiosis in the causality of NIU, as well as the potential pharmacological tools that could be used to modify the microbiome (dietary supplementation, antibiotics, fecal microbiota transplantation, immunomodulators, or biologic drugs) and, consequently, in the control of the NIU. Furthermore, there is increasing scientific evidence suggesting that the treatment with anti-TNF not only restores the composition of the gut microbiota but also that the study of the composition of the gut microbiome will help predict the response of each patient to anti-TNF treatment.

A Review of Systemic Biologics and Local Immunosuppressive Medications in Uveitis

Uveitis is one of the most common causes of vision loss and blindness worldwide. Local and/or systemic immunosuppression is often required to treat ocular inflammation in noninfectious uveitis. An understanding of safety and efficacy of these medications is required to individualize treatment to each patient to ensure compliance and achieve the best outcome. In this article, we reviewed the effectiveness of systemic biologic response modifiers and local treatments commonly used in the management of patients with noninfectious uveitis.

Annexin A1 Mimetic Peptide and Piperlongumine: Anti-Inflammatory Profiles in Endotoxin-Induced Uveitis

Uveitis is one of the main causes of blindness worldwide, and therapeutic alternatives are worthy of study. We investigated the effects of piperlongumine (PL) and/or annexin A1 (AnxA1) mimetic peptide Ac2-26 on endotoxin-induced uveitis (EIU). Rats were inoculated with lipopolysaccharide (LPS) and intraperitoneally treated with Ac2-26 (200 µg), PL (200 and 400 µg), or Ac2-26 + PL after 15 min. Then, 24 h after LPS inoculation, leukocytes in aqueous humor, mononuclear cells, AnxA1, formyl peptide receptor (fpr)1, fpr2, and cyclooxygenase (COX)-2 were evaluated in the ocular tissues, along with inflammatory mediators in the blood and macerated supernatant. Decreased leukocyte influx, levels of inflammatory mediators, and COX-2 expression confirmed the anti-inflammatory actions of the peptide and pointed to the protective effects of PL at higher dosage. However, when PL and Ac2-26 were administered in combination, the inflammatory potential was lost. AnxA1 expression was elevated among groups treated with PL or Ac2-26 + PL but reduced after treatment with Ac2-26. Fpr2 expression was increased only in untreated EIU and Ac2-26 groups. The interaction between Ac2-26 and PL negatively affected the anti-inflammatory action of Ac2-26 or PL. We emphasize that the anti-inflammatory effects of PL can be used as a therapeutic strategy to protect against uveitis.

Azithromycin modulates Teff/Treg balance in retinal inflammation via the mTOR signaling pathway

Uveitis is one of the most common blindness-causing ocular disorders. Due to its complicated pathogenesis, the treatment of uveitis has been widely recognized as a challenge for ophthalmologists. Recently, the anti-inflammatory properties of the antibiotic Azithromycin (AZM) have been reported. However, the therapeutic effects of Azithromycin in experimental autoimmune uveitis (EAU), a representative model of human AU, have not been elucidated till date. We conducted this study to examine the therapeutic effects and potential mechanisms of Azithromycin in EAU. We observed that Azithromycin significantly attenuated retinal inflammation in EAU mice at day 14 after immunization along with a significantly decreased inflammatory cell infiltration and cytokine production in the retina. Furthermore, we observed that Azithromycin increased the number of regulatory T cells (Treg) and decreased the number of effector T cells (Teff) in both the draining lymph nodes and spleen of EAU mice. Additionally, Azithromycin suppressed the proliferation and activation of CD4 + T cells, and induced the apoptosis of CD4 + CD44 + memory T and CD4 + CXCR3 + Th1 cells. Mechanistically, we proved that Azithromycin could regulate Teff/Treg balance by inhibiting the phosphorylation of S6 ribosomal protein, a downstream target of mammalian target of rapamycin (mTOR). Together, our findings revealed that Azithromycin alleviated EAU by regulating the Teff/Treg balance through the mTOR signaling pathway, suggesting that Azithromycin could be a promising therapeutic candidate for AU.

Real-Time Imaging of Immune Modulation by Cannabinoids Using Intravital Fluorescence Microscopy

Introduction: The endocannabinoid system (ECS) is an endogenous regulatory system involved in a wide range of physiologic and disease processes. Study of ECS regulation provides novel drug targets for disease treatment. Intravital microscopy (IVM), a microscopy-based imaging method that allows the observation of cells and cell-cell interactions within various tissues and organs in vivo, has been utilized to study tissues and cells in their physiologic microenvironment. This article reviews the current state of the IVM techniques used in ECS-related inflammation research. Methodological Aspects of IVM: IVM with focus on conventional fluorescent microscope has been introduced in investigation of microcirculatory function and the behavior of individual circulating cells in an in vivo environment. Experimental setting, tissue protection under physiologic condition, and microscopical observation are described. Application of IVM in Experimental Inflammatory Disorders: Using IVM to investigate the effects of immune modulation by cannabinoids is extensively reviewed. The inflammatory disorders include sepsis, arthritis, diabetes, interstitial cystitis, and inflammatory conditions in the central nervous system and eyes. Conclusion: IVM is a critical tool in cannabinoid and immunology research. It has been applied to investigate the role of the ECS in physiologic and disease processes. This review demonstrates that the IVM technique provides a unique means in understanding ECS regulation on immune responses in diseases under their physical conditions, which could not be achieved by other methods.

Multidisciplinary management of auto-immune ocular diseases in adult patients by ophthalmologists and rheumatologists

Purpose

Management of chronic vision threatening auto‐immune ocular diseases (AIOD, e.g. uveitis, scleritis) can be challenging. Guidelines recommend a multidisciplinary approach (MDA) with ophthalmologists and rheumatologists, to enhance the recognition of systemic diseases and guide the use of immunosuppressives. However, the indications and results of such an approach have not yet been studied.

Methods

A monocentre, retrospective chart review of all patients treated in a MDA between ophthalmologists and rheumatologists, in a Dutch tertiary center. The collaboration was twofold: a combined multidisciplinary team meeting every 2 weeks, and an ophthalmology‐dedicated rheumatology outpatient clinic. Primary endpoints of this descriptive study were as follows: indications for MDA, new diagnoses of systemic auto‐immune diseases and changes in systemic immunosuppression and prednisone dosages.

Results

In total, 157 adults (mean age 46 years, 57% female, median disease duration 19 months) were included, mainly with uveitis (74%) and scleritis (12%). Multidisciplinary approach (MDA)‐indications included diagnostic workup (32%), treatment support (44%), diagnostic‐and‐treatment support (10%) and side effects (8%). A systemic disease was newly diagnosed in eight and already present in 34 patients. At baseline, 54 patients used oral prednisone at >7.5 mg/day. Non‐corticoid immunosuppressives, mostly methotrexate, were started in 41% of the patients. During follow‐up, systemic prednisone was lowered to ≤7.5 mg/day in 68% of the patients.

Conclusion

This evaluation of an MDA‐programme in the management of AIOD demonstrated its added value. Mainly, it addressed the high demand for support in managing systemic immunosuppression, resulting in significant corticosteroid tapering. In addition, it resulted in the recognition of underlying systemic diseases.

Soluble CD83 Regulates Dendritic Cell-T Cell Immunological Synapse Formation by Disrupting Rab1a-Mediated F-Actin Rearrangement

Dendritic cell-T cell (DC-T) contacts play an important role in T cell activation, clone generation, and development. Regulating the cytoskeletal protein rearrangement of DCs can modulate DC-T contact and affect T cell activation. However, inhibitory factors on cytoskeletal regulation in DCs remain poorly known. We showed that a soluble form of CD83 (sCD83) inhibited T cell activation by decreasing DC-T contact and synapse formation between DC and T cells. This negative effect of sCD83 on DCs was mediated by disruption of F-actin rearrangements, leading to alter expression and localization of major histocompatibility complex class II (MHC-II) and immunological synapse formation between DC and T cells. Furthermore, sCD83 was found to decrease GTP-binding activity of Rab1a, which further decreased colocalization and expression of LRRK2 and F-actin rearrangements in DCs, leading to the loss of MHC-II at DC-T synapses and reduced DC-T synapse formation. Further, sCD83-treated DCs alleviated symptoms of experimental autoimmune uveitis in mice and decreased the number of T cells in the eyes and lymph nodes of these animals. Our findings demonstrate a novel signaling pathway of sCD83 on regulating DC-T contact, which may be harnessed to develop new immunosuppressive therapeutics for autoimmune disease.

Effect of a Fluocinolone Acetonide Insert on Recurrence Rates in Noninfectious Intermediate, Posterior, or Panuveitis: Three-Year Results

PURPOSE

To examine the 36-month efficacy and safety of a 0.2 μg/day fluocinolone acetonide insert (FAi) to treat noninfectious uveitis of the posterior segment (NIU-PS).

DESIGN

Phase 3, prospective, double-masked, multicenter study (clinicaltrials.gov, NCT01694186).

PARTICIPANTS

Adults (≥18 years old) with a diagnosis of NIU-PS in ≥1 eye for ≥1 year and ≥2 recurrences of uveitis requiring systemic corticosteroid, immunosuppressive treatment, or intraocular corticosteroids.

METHODS

Participants were randomized 2:1 to FAi or sham (injection plus standard of care) treatment.

MAIN OUTCOME MEASURES

The primary outcome was the difference between the proportion of FAi-treated and sham-treated patients who had a uveitis recurrence. Secondary outcomes included time to first recurrence, number of recurrences, best-corrected visual acuity (BCVA) change from baseline, resolution of macular edema, and number of adjunctive treatments.

RESULTS

One hundred twenty-nine participants (n = 87 FAi-treated; n = 42 sham-treated) were enrolled. Over 36 months of treatment, cumulative uveitis recurrences were significantly reduced with FAi compared with sham (65.5% vs. 97.6%, respectively; P < 0.001); time to first recurrence was commensurately longer (median 657.0 and 70.5 days, respectively; P < 0.001). The number of recurrences per eye was significantly lower in the FAi-treated compared with the sham-treated group (mean 1.7 vs. 5.3, respectively, P < 0.001). At 36 months, more FAi-treated eyes had a ≥15-letter increase in BCVA from baseline and fewer FAi-treated eyes had investigator-determined macular edema at month 36 compared with sham-treated eyes (33.3% vs. 14.7% and 13.0% vs. 27.3% for BCVA and macular edema, respectively). Fewer FAi compared with sham-treated participants required adjunctive treatments (57.5% vs. 97.6%, respectively). Intraocular pressure (IOP) was similar for both study groups at month 36 (mean ± standard deviation 14.5±5.1 and 14.8±5.3, respectively), and approximately half as many eyes in the FAi-treated group when compared with the sham-treated group underwent IOP-lowering surgery (5.7% vs. 11.9%). Cataract surgery was required more frequently over 36 months in the FAi-treated compared with the sham-treated group (73.8% vs. 23.8% of eyes, respectively).

CONCLUSIONS

Fluocinolone acetonide insert-treated eyes had significantly reduced uveitis recurrence rates throughout the study duration, significantly increased recurrence-free durations, fewer recurrence episodes among those with recurrences, less adjunctive therapy, and an acceptable side-effect profile compared with sham-treated eyes.

I-alowCD11bhigh DC Regulates the Immune Response in the Eyes of Experimental Autoimmune Uveitis

Regulatory dendritic cells (DC_reg) have been reported to be a negative regulator in the immune response. These cells are widely distributed in the liver, spleen, and lung. However, the status and function of DC_reg in the eyes and disease are still not very clear. Herein, we found that the number of I-a^lowCD11b^high DC increased in the eye and spleen at the recovery stage of experimental autoimmune uveitis (EAU), which is a mouse model for autoimmune uveitis. These cells expressed lower levels of CD80, CD86, and CD54 than the mature DCs and expressed interleukin 10 (IL-10), indoleamine 2,3-dioxygenase (IDO), and transforming growth factor beta (TGF-β) as well. Moreover, these DC_reg can regulate the development of EAU by promoting CD4⁺CD25⁺Foxp3⁺ regulatory T cells. The increased interferon-gamma (IFN-γ) in the aqueous humor of EAU participates in inducing DC_reg to alleviate the symptom of EAU. Furthermore, DC_reg was found to exist in the eyes of normal mice. Aqueous humor, containing a certain concentration of IL-10, TGF-β, prostaglandin E2 (PGE2), IDO, and nitric oxide (NO), induced the tolerance of DC_reg in normal eyes. It can be concluded that DC_reg exists in the eyes and plays a protective role in inflamed eyes. These DC_reg induced by IFN-γ might be used as a strategy to develop therapy for EAU management.

[Pharmacological treatment strategies and surgical options for uveitis]

BACKGROUND

Modern treatment of uveitis aims at a complete control of inflammatory activity, preservation of visual function and the prevention of secondary organ damage as a consequence of the underlying inflammatory disease and its treatment.

OBJECTIVE

This article gives an update about the strategies of pharmacological and surgical options for uveitis.

MATERIAL AND METHODS

The outcomes reported here are based on a PubMed search using the terms <"uveitis" AND "therapy"> and <"uveitis" AND "surgery" OR "surgical treatment">. All prospective studies and case series with more than 20 cases as well as review articles from the last 5 years along with cited cross-references were evaluated.

RESULTS

Local and systemic corticosteroids form the foundation of treatment after exclusion of an infectious etiology. If uveitis activity is not controlled within 6 weeks or if the daily corticosteroid dosage is unacceptably high, a treatment escalation using immunomodulatory drugs is required. If a complete control of inflammatory activity is not achieved, in a third phase treatment is supplemented by antibody-based treatment or cytokines, so-called biologics, with the aim of complete long-term freedom from disease without local or systemic steroid treatment. This target is achieved in 65-80% and guarantees long-term functional stability and anatomical integrity. Early treatment escalation in cases of persisting or recurrent activity as a rule prevents new secondary organ damage. Surgical options are utilized for diagnostic purposes, the administration of intravitreal drugs and for treatment of secondary complications.

CONCLUSION

Just like the majority of immunological diseases, uveitis is a chronic disease requiring long-term and possibly lifelong treatment and remission (absence of inflammation without treatment) is achieved in only <20%. Surgical interventions can be performed with a good prognosis, if the optic nerve head and macula are not involved. They have a substantially lower complication rate when freedom from symptoms exists preoperatively for at least 3 months.

Outcomes of treatment with sirolimus for non-infectious uveitis: a meta-analysis and systematic review

Background

Uveitis is a group of intraocular inflammatory diseases whose primary treatment involves immunosuppression. Although corticosteroids (CSs) remain the mainstay therapy, sirolimus is among the recently studied immunomodulatory drugs for treating noninfectious uveitis (NIU).

Objective

The aim of this review was to assess and summarize the updated evidence on the outcomes of treatment with sirolimus for NIU.

Materials and methods

Two reviewers conducted a systematic search on November 5, 2018, of electronic databases (EMBASE, MEDLINE, and The Cochrane Library) and clinical trial registers having no restrictions on language or publication date. The primary outcome was uveitis activity as measured by vitreous haze (VH), while the secondary outcomes included central macular thickness (CMT), best-corrected visual acuity (BCVA), CS-sparing effect, IOP elevation, and other adverse events. A meta-analysis was conducted on selected studies with appropriate clinical and methodological homogeneity.

Results

Seven studies were included and reviewed. Four randomized clinical trials were eligible for meta-analysis: SAVE 2013, One-year outcomes of the SAVE study, SAVE 2 2016, SAKURA 2016. The pooled proportions of inflammation control (VH improvement) were 38% (95% CI 16.19%-62.66%) during a 6-month follow-up and 49.97% (95% CI 16.19%-83.03%) during a 6- to 12-month follow-up with the latter showing a significantly higher response rate (p=0.0472). BCVA improvement was 62.2% (95% CI 33.17%-87.11%) during a 6-month follow-up and 56.86% (95% CI 20.91%-89.05%) during a 6- to 12-month follow-up with no significant difference between the two (p=0.3705). Increased IOP remained at 7.11% (95% CI 3.46%-12.68%) for both a 6-month follow-up and up to a 12-month follow-up duration. The CS-sparing effect of sirolimus was also well demonstrated. A reduction in CMT was observed, and only minor drug-related adverse events were reported in all the studies reviewed.

Conclusion

This review provided evidence that sirolimus is a promising treatment option for controlling inflammatory activity, improving visual acuity, and sparing CS use with minor adverse events for NIU.

Real-world evidence of treatment for relapse of noninfectious uveitis in tertiary centers in Japan: A multicenter study

Noninfectious uveitis (NIU), which pathogenesis is often autoimmune nature, occurs as a symptom of systemic syndromes or only in the eye. The standard treatment of NIU is local, topical, and oral administration of corticosteroids (CS) in combination with immunomodulatory therapy (IMT). However, additional therapeutic strategies involving topical and systemic administration of CS or others to treat relapse or exacerbation of ocular inflammation in NIU which present as various ocular manifestations have not been established. The aim of this study was to investigate therapeutic strategies used for various ocular inflammations in relapse or exacerbation of NIU and to evaluate factors associated with the treatment pattern in Japan. The subjects were 198 eyes of 156 NIU patients with relapse or exacerbation of ocular inflammation at 6 university hospitals in Japan. The most frequent disease was sarcoidosis in 23.7% of the cases, followed by Behçet disease (BD) in 21.2%, Vogt-Koyanagi-Harada (VKH) disease in 13.6%, acute anterior uveitis (AAU) in 5.6%, tubulointerstitial nephritis and uveitis syndrome (TINU) in 4.0%, and juvenile idiopathic arthritis (JIA)-associated uveitis in 3.0%. Common ocular findings were worsened anterior inflammation (AI) in 67.2% of the cases, vitreous opacity (VO) in 46.5%, macular edema (ME) in 26.8%, retinal vasculitis (RV) in 23.7%, serous retinal detachment (SRD) in 9.1%, and optic perineuritis (OPN) in 4.0%. Reinforcement of betamethasone eye drop (ED) monotherapy for only AI in both unilateral and bilateral AI, sub-tenon injection of triamcinolone acetonide (STTA) for unilateral posterior inflammation including VO and ME, and systemic therapy using CS and/or IMT for bilateral anterior and posterior inflammation were significantly more frequent. Frequencies of exacerbated individual ocular findings in sarcoidosis and BD were similar, and severe ocular inflammation associated with panuveitis required both topical and systemic therapies. These results demonstrate that reinforcement of betamethasone EDs, topical administration of triamcinolone acetonide, and long-term administration of systemic corticosteroids are the major therapeutic strategies, and reinforcement of betamethasone EDs was used for exacerbated AI independently from its use for posterior inflammation. In addition, STTA was preferentially used for VO and ME associated with posterior inflammation.

CD83+ CCR7+ NK cells induced by interleukin 18 by dendritic cells promote experimental autoimmune uveitis

Natural killer (NK) cells have been reported to play a pathological role in autoimmune uveitis. However, the mechanisms regarding NK cells in uveitis and factors that affect NK-cell activation in this condition remain unclear. Here, we report that the number of CD3- NK1.1+ CD83+ CCR7+ cells is increased in the inflamed eyes within a mouse model of experimental autoimmune uveitis (EAU), and these cells express elevated levels of NKG2D, CD69 and IFN-γ. Adoptively transferring CD83+ CCR7+ NK cells aggravates EAU symptoms and increases the number of CD4+ IFN-γ+ T cells and dendritic cells (DCs) within the eye. These CD83+ CCR7+ NK cells then promote the maturation of DCs and IFN-γ expression within T cells as demonstrated in vitro. Furthermore, IL-18, as primarily secreted by DCs in the eyes, is detected to induce CD83+ CCR7+ NK cells. In EAU mice, anti-IL-18R antibody treatment also decreases retinal tissue damage, as well as the number of infiltrating CD83+ CCR7+ NK cells, T cells and DCs in the inflamed eyes and spleens of EAU mice. These results suggest that CD83+ CCR7+ NK cells, as induced by IL-18 that primarily secreted by DCs, play a critical pathological role in EAU. Anti-IL-18R antibody might serve as a potential therapeutic agent for uveitis through its capacity to inhibit CD83+ CCR7+ NK cells infiltration.

Effect of an Injectable Fluocinolone Acetonide Insert on Recurrence Rates in Chronic Noninfectious Uveitis Affecting the Posterior Segment: Twelve-Month Results

PURPOSE

To assess the safety and efficacy of an intravitreal fluocinolone acetonide (FA) insert to manage inflammation associated with chronic noninfectious posterior uveitis.

DESIGN

Multicenter, randomized, prospective, doubled-masked, sham-controlled, 3-year phase 3 clinical trial.

PARTICIPANTS

One hundred twenty-nine participants with recurrent noninfectious posterior uveitis were assigned randomly to FA insert (n = 87) or sham injection (n = 42). The more severely affected eye in participants with bilateral disease was designated as the study eye.

METHODS

The insert (FA, 0.18 mg) was injected into the vitreous cavity; sham injection mimicked the insert delivery procedure. Ophthalmic examinations, OCT, and ocular tolerability and discomfort assessments were conducted; study visits were on days 7 and 28 and months 2, 3, 6, 9, and 12. Uveitis recurrence was treated as needed. The 6-month recurrence rate was the primary outcome measure.

RESULTS

The 6-month (28% and 91%) and 12-month (38% and 98%) uveitis recurrence rates were significantly lower (P < 0.001) with FA insert vs. sham, respectively. Fewer recurrences per study eye (mean, 0.7 vs. 2.5), lower incidence of 15-letter or more decrease in best-corrected visual acuity (14% vs. 31%), and reduced systemic (19% vs. 40%) and local (7% vs. 62%) uveitis adjunctive treatments were observed with FA insert vs. sham, respectively. The FA insert group showed higher rates of cataract. Intraocular pressure-lowering treatment use was similar between groups. No deaths, treatment-related study discontinuations, or unanticipated safety signals were observed through 12 months.

CONCLUSIONS

Chronic noninfectious posterior uveitis was managed successfully in this study population; FA insert eyes experienced fewer uveitis recurrence episodes, required fewer adjunctive treatments, and demonstrated less visual acuity loss compared with sham eyes. The FA insert treatment group showed higher rates of cataract; delivery by injection was not associated with an increase in ocular adverse events or any other safety measures not typically associated with local steroid use, suggesting the procedure is appropriate for an office setting.

Pathological roles of the homeostatic chemokine CXCL12

CXCL12 is a CXC chemokine that traditionally has been classified as a homeostatic chemokine. It contributes to physiological processes such as embryogenesis, hematopoiesis and angiogenesis. In contrast to these homeostatic functions, increased expression of CXCL12 in general, or of a specific CXCL12 splicing variant has been demonstrated in various pathologies. In addition to this increased or differential transcription of CXCL12, also upregulation of its receptors CXC chemokine receptor 4 (CXCR4) and atypical chemokine receptor 3 (ACKR3) contributes to the onset or progression of diseases. Moreover, posttranslational modification of CXCL12 during disease progression, through interaction with locally produced molecules or enzymes, also affects CXCL12 activity, adding further complexity. As CXCL12, CXCR4 and ACKR3 are broadly expressed, the number of pathologies wherein CXCL12 is involved is growing. In this review, the role of the CXCL12/CXCR4/ACKR3 axis will be discussed for the most prevalent pathologies. Administration of CXCL12-neutralizing antibodies or small-molecule antagonists of CXCR4 or ACKR3 delays disease onset or prevents disease progression in cancer, viral infections, inflammatory bowel diseases, rheumatoid arthritis and osteoarthritis, asthma and acute lung injury, amyotrophic lateral sclerosis and WHIM syndrome. On the other hand, CXCL12 has protective properties in Alzheimer's disease and multiple sclerosis, has a beneficial role in wound healing and has crucial homeostatic properties in general.

Soluble CD83 Alleviates Experimental Autoimmune Uveitis by Inhibiting Filamentous Actin-Dependent Calcium Release in Dendritic Cells

Soluble CD83 (sCD83) is the extracellular domain of the membrane-bound CD83 molecule, and known for its immunoregulatory functions. Whether and how sCD83 participates in the pathogenesis of uveitis, a serious inflammatory disease of the eye that can cause visual disability and blindness, is unknown. By flow cytometry and imaging studies, we show that sCD83 alleviates experimental autoimmune uveitis (EAU) through a novel mechanism. During onset and recovery of EAU, the level of sCD83 rises in the serum and aqueous humor, and CD83⁺ leukocytes infiltrate the inflamed eye. Systemic or topical application of sCD83 exerts a protective effect by decreasing inflammatory cytokine expression, reducing ocular and splenic leukocyte including CD4⁺ T cells and dendritic cells (DCs). Mechanistically, sCD83 induces tolerogenic DCs by decreasing the synaptic expression of co-stimulatory molecules and hampering the calcium response in DCs. These changes are caused by a disruption of the cytoskeletal rearrangements at the DC–T cell contact zone, leading to altered localization of calcium microdomains and suppressed T-cell activation. Thus, the ability of sCD83 to modulate DC-mediated inflammation in the eye could be harnessed to develop new immunosuppressive therapeutics for autoimmune uveitis.

Baicalin modulates the Treg/Teff balance to alleviate uveitis by activating the aryl hydrocarbon receptor

Autoimmune uveitis is a sight-threatening ocular inflammatory disorder. Immunological inflammation is regarded as the key to pathogenesis in autoimmune uveitis. Baicalin, the major bioactive component of Scutellaria baicalensis, possesses immunomodulatory properties. However, the role of baicalin in uveitis and its underlying mechanisms remain unclear. In the current study, we found that baicalin treatment obviously inhibited the intraocular inflammatory process in mice with experimental autoimmune uveitis, along with clear declines in infiltrated inflammatory cells and inflammatory cytokine transcription in the retina and draining lymph nodes. Furthermore, baicalin treatment increased the frequency and number of regulatory T cells and decreased the frequency and number of effector T cells (Th1 and Th17 cells) in the draining lymph nodes of mice with experimental autoimmune uveitis. In vitro, baicalin treatment suppressed interphotoreceptor retinoid binding protein-specific CD4+ T cell proliferation and converted CD4+ T cell differentiation. Furthermore, the expression of aryl hydrocarbon receptor was activated by baicalin treatment. Baicalin-mediated modulation of CD4+ T cell differentiation was partially abrogated by the suppression of aryl hydrocarbon receptor. These findings suggest that baicalin modulates the Treg/Teff balance and CD4+ T cell proliferation to ameliorate experimental autoimmune uveitis by activating the aryl hydrocarbon receptor.

Modern Therapeutic Approaches for Noninfectious Ocular Diseases Involving Inflammation

Dry eye disease, age-related macular degeneration, and uveitis are ocular diseases that significantly affect the quality of life of millions of people each year. In these diseases, the action of chemokines, proinflammatory cytokines, and immune cells drives a local inflammatory response that results in ocular tissue damage. Multiple therapeutic strategies are developed to either address the symptoms or abate the underlying cause of these diseases. Herein, the challenges to deliver drugs to the relevant location in the eye for each of these diseases are reviewed along with current and innovative therapeutic approaches that attempt to restore homeostasis within the ocular microenvironment.

NK cells are negatively regulated by sCD83 in experimental autoimmune uveitis

Natural killer (NK) cells represent a subset of lymphocytes that contribute to innate immunity and have been reported to play a role in autoimmune uveitis. However, the mechanisms regulating NK cellular function in this condition remain unclear. Herein, we investigated the status of NK cells in experimental autoimmune uveitis (EAU). We found that the number of CD83+CD3-NK1.1+ cells was increased in the inflamed eyes and spleens of the EAU mouse model. At the recovery stage of EAU, serum concentrations of soluble CD83 (sCD83) were increased. sCD83 treatment relieved retinal tissue damage and decreased the number of infiltrating NK cells in inflamed eyes. Further analysis of the effects of sCD83 treatment in EAU revealed that it reduced: 1) the expressions of CD11b and CD83 in NK cells, 2) the percent of CD11bhighCD27lowCD3-NK1.1+ cells and 3) the secretion of granzyme B, perforin and IFN-γ in NK cells as demonstrated both in vivo and in vitro. When sCD83 treated-NK cells were transferred into EAU mice, retinal tissue damage was relieved. These results demonstrate sCD83 down-regulate NK cellular function and thus provide important, new information regarding the means for the beneficial effects of this agent in the treatment of autoimmune uveitis.

Ophthalmic manifestations in patients with inflammatory bowel disease: A review

Clinical manifestations of inflammatory bowel disease (IBD) are not locally restricted to the gastrointestinal tract, and a significant portion of patients have involvement of other organs and systems. The visual system is one of the most frequently affected, mainly by inflammatory disorders such as episcleritis, uveitis and scleritis. A critical review of available literature concerning ocular involvement in IBD, as it appears in PubMed, was performed. Episcleritis, the most common ocular extraintestinal manifestation (EIM), seems to be more associated with IBD activity when compared with other ocular EIMs. In IBD patients, anterior uveitis has an insidious onset, it is longstanding and bilateral, and not related to the intestinal disease activity. Systemic steroids or immunosuppressants may be necessary in severe ocular inflammation cases, and control of the underlying bowel disease is important to prevent recurrence. Our review revealed that ocular involvement is more prevalent in Crohn’s disease than ulcerative colitis, in active IBD, mainly in the presence of other EIMs. The ophthalmic symptoms in IBD are mainly non-specific and their relevance may not be recognized by the clinician; most ophthalmic manifestations are treatable, and resolve without sequel upon prompt treatment. A collaborative clinical care team for management of IBD that includes ophthalmologists is central for improvement of quality care for these patients, and it is also cost-effective.