Effect of type I interferon on experimental autoimmune uveoretinitis in rats

Evaluation of disease activity in uveoretinitis associated with Behçet's disease

Behçet's disease is a multi-organ inflammatory disorder with systemic vasculitis of unknown etiology. Ocular lesions occur in about 70% of patients with Behçet's disease, and it is more frequent and severe in men. The frequency of ocular inflammatory attacks has been used as a main outcome measure to assess the efficacy of therapy on uveoretinitis in patients with Behçet's disease. The ocular Behçet's disease research group of Japan have recently proposed a new scoring system, Behçet's disease ocular attack score 24 (BOS24), to assess the disease activity of ocular Behçet's disease. This review highlights the efficacy and application of the BOS24 scoring system in clinical practice for patients with ocular Behçet's disease. In addition, a new semi-quantitative scoring system to evaluate the degree of retinal vascular leakage on fluorescein angiography reported by our group is described.

[Intraocular inflammation in multiple sclerosis]

Multiple sclerosis (MS) is a chronic inflammatory disorder of the brain and the spinal cord occurring mostly in young adults and is associated with temporary or permanent neurological deficits. An association between uveitis and MS has been recognized for a long time. Current data indicate an approximately 10 times higher prevalence of uveitis in patients with MS compared to the general population. In particular, MS is associated with intermediate uveitis and typically with concomitant retinal vasculitis. The treatment of uveitis should not only take the severity of intraocular inflammation into account but a coordination of the active agents must also consider the neurological manifestations. Since uveitis and MS are pathogenetically based on an immune-mediated genesis, immunomodulatory treatment approaches are dominant but it is important to bear in mind that tumor necrosis factor(TNF)-alpha blocking agents may worsen MS.

The Role of IFN-alpha in Experimental and Clinical Uveitis

PURPOSE

IFN-α is the only treatment capable of inducing long-term remission in some patients with ocular Behçet's disease. In this review, we focus on immune mechanisms of IFN-α in animal models and patients and compare the outcome of different clinical studies.

METHODS

Review of literature using PubMed and Google and original data from rat models with monophasic/chronic or relapsing experimental autoimmune uveitis treated with IFN-α.

RESULTS

The role of IFN-α and its effect on various cell types were investigated, in some cases with contradictory results. Some patients respond very well to IFN-α treatment, while others are non-responders, which was reflected in the uveitis rat models: relapsing uveitis was ameliorated, the monophasic/chronic disease even aggravated.

CONCLUSIONS

Despite intensive investigations in patients and animal models, the immune mechanisms explaining the therapeutic effect of IFN-α in ocular Behçet's disease are not yet fully understood and need further investigation.

Efficacy of immunomodulatory therapy with interferon-β or glatiramer acetate on multiple sclerosis-associated uveitis

AIM

To analyse the role of interferon-β or glatiramer acetate in reducing the inflammatory episodes of intra-ocular inflammation in multiple sclerosis-associated uveitis.

METHOD

A study was conducted on a non-randomised, retrospective case series of 13 patients with proven multiple sclerosis and uveitis (minimum follow-up, 12 months). All patients were given immunomodulatory treatment (interferon-β or glatiramer acetate) to control the course of the multiple sclerosis. Patients were compared to themselves before initiating the treatment, in order to assess the difference in uveitis episodes. The main outcome measurements were the number of uveitis episodes with/without immunomodulatory treatment.

RESULTS

Uveitis was bilateral in 10 (77%) out of 13 patients. Intermediate uveitis was observed in 11 patients, retinal vasculitis in 3 patients, and one patient was classified as a posterior uveitis. The patients had a mean of 4.15±3.1 episodes of uveitis (range 1-10) during the follow-up period (148.6±84.3 months). When compared to their pre-treatment status, patients on treatment with interferon-β or glatiramer acetate showed a significant decrease of 0.36 episodes of ocular inflammation per year (P=.02). Mild side effects related to immunomodulatory treatment were observed in 6 (46%) patients, 3 (23%) patients with a flu-like syndrome, and 3 (23%) patients with a skin rash.

CONCLUSIONS

Interferon β or glatiramer acetate could be effective in reducing the uveitis episodes in patients with multiple sclerosis-associated uveitis, and was well tolerated in most patients.

Peripheral Vasculitis, Intermediate Uveitis and Interferon Use in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. A 40-year-old female patient with a 12-year history of MS was admitted to our clinic with blurred vision and floaters in her right eye for about 1 month. Here, we share the findings and the management of intermediate uveitis and retinal periphlebitis in an MS case being treated with interferon beta-1a for 7 years.

MicroRNAs in retina during development of experimental autoimmune uveoretinitis in rats

PURPOSE

To determine the changes in the expression profiles of microRNAs (miRNAs) in retinas during the development of experimental autoimmune uveoretinitis (EAU) in rats.

METHODS

The levels of interleukin-1β (IL-1β) and monocyte chemoattractant protein-1 (MCP-1) were measured in aqueous humour samples and supernatants of homogenised posterior eye cups obtained from Lewis rats immunised with interphotoreceptor retinoid binding protein peptide (R14) and complete Freund's adjuvant. Microarray analysis was performed to determine the miRNA profiles in the retina of eyes with EAU on days 0 (baseline), 7, 14 and 21 after immunisation.

RESULTS

The levels of IL-1β and MCP-1 in the aqueous humour and the supernatants of posterior eye cups were significantly elevated in eyes with EAU, and the levels corresponded with the stage of the EAU. On day 14 after immunisation, the expressions of nine miRNAs (miRNA-223, 142-5p, 142-3p, 21, 146a, 146b, 1949, 1188-3p and 193) were significantly elevated, and the expressions of four miRNAs (miRNA-181a, 183*, 124* and 331) were downregulated relative to the baseline. Quantitative PCR analyses confirmed the elevation of miRNA-223 and miRNA-146 and the downregulation of miRNA-181a in retinas with EAU on day 14 after immunisation. In situ hybridisation confirmed increased expression of miR-223 and miR-146 in retinas with EAU.

CONCLUSIONS

Several miRNAs were significantly increased or decreased in retinas during the course of EAU. The expression of miR-223 and miR-146a corresponded with the clinical score of the EAU and elevation of IL-1β/MCP-1 in the eye with EAU. Further studies are required to clarify the role of miRNA in eyes with autoimmune uveoretinitis.

[Uveitis in multiple sclerosis : Overview and perspectives]

The association of uveitis and multiple sclerosis (MS) is less well known than the association between optic neuritis and MS even though MS patients suffer ten times more often from uveitis than the normal population. In this group of patients, intermediate uveitis presenting with periphlebitis and "snowbanks" or "snowballs", as well as granulomatous anterior uveitis play an important role. Simultaneous occurrence of MS and uveitis could be due to the fact that both neural and ocular tissues have the same embryological origin or could be the consequence of an immunological reaction following an Epstein-Barr virus infection. The aim is to find a drug for these patients that treats both MS and uveitis. Currently various studies with different drugs already used successfully in MS patients are under investigation for use in the treatment of uveitis. There is some evidence that interferon beta is effective in macular edema associated with uveitis. Other substances, such as daclizumab, natalizumab and fingolimod also seem to be promising.

Role of the retinal vascular endothelial cell in ocular disease

Retinal endothelial cells line the arborizing microvasculature that supplies and drains the neural retina. The anatomical and physiological characteristics of these endothelial cells are consistent with nutritional requirements and protection of a tissue critical to vision. On the one hand, the endothelium must ensure the supply of oxygen and other nutrients to the metabolically active retina, and allow access to circulating cells that maintain the vasculature or survey the retina for the presence of potential pathogens. On the other hand, the endothelium contributes to the blood-retinal barrier that protects the retina by excluding circulating molecular toxins, microorganisms, and pro-inflammatory leukocytes. Features required to fulfill these functions may also predispose to disease processes, such as retinal vascular leakage and neovascularization, and trafficking of microbes and inflammatory cells. Thus, the retinal endothelial cell is a key participant in retinal ischemic vasculopathies that include diabetic retinopathy and retinopathy of prematurity, and retinal inflammation or infection, as occurs in posterior uveitis. Using gene expression and proteomic profiling, it has been possible to explore the molecular phenotype of the human retinal endothelial cell and contribute to understanding of the pathogenesis of these diseases. In addition to providing support for the involvement of well-characterized endothelial molecules, profiling has the power to identify new players in retinal pathologies. Findings may have implications for the design of new biological therapies. Additional progress in this field is anticipated as other technologies, including epigenetic profiling methods, whole transcriptome shotgun sequencing, and metabolomics, are used to study the human retinal endothelial cell.

Regulatory effects of IFN-β on the development of experimental autoimmune uveoretinitis in B10RIII mice

Background

Experimental autoimmune uveoretinitis (EAU) serves as a model for human intraocular inflammation. IFN-β has been used in the treatment of certain autoimmune diseases. Earlier studies showed that it ameliorated EAU; however, the mechanisms involved in this inhibition are still largely unknown.

Methodology/Principal Findings

B10RIII mice were immunized with interphotoreceptor retinoid-binding protein (IRBP) peptide 161–180 in Complete Freund's adjuvant. Splenocytes from different time points after immunization were used to evaluate the expression of IFN-β. An increased expression of IFN-β was observed during EAU and its highest expression was observed on day 16, 3 days after the peak of intraocular inflammation. Splenocytes and draining lymph node cells from mice immunized with IRBP_161-180 on day 13 and control mice were activated with anti-CD3/anti-CD28 antibodies or IRBP_161-180 to evaluate the production of IFN-γ and IL-17. The results showed that IFN-γ and IL-17 were significantly higher in immunized mice as compared to the control mice when exposed to anti-CD3/anti-CD28 antibodies. However, the production of IFN-γ and IL-17 was detected only in immunized mice, but not in the control mice when stimulated with IRBP_161-180. Multiple subcutaneous injections of IFN-β significantly inhibited EAU activity in association with a down-regulated expression of IFN-γ, IL-17 and an enhanced IL-10 production. In an in vitro system using cells from mice, IFN-β suppressed IFN-γ production by CD4⁺CD62L⁻ T cells, IL-17 production by CD4⁺CD62L^+/- T cells and proliferation of CD4⁺CD62L^+/- T cells. IFN-β inhibited the secretion of IL-6, but promoted the secretion of IL-10 by monocytes. IFN-β-treated monocytes inhibited IL-17 secretion by CD4⁺CD62L^+/- T cells, but did not influence IFN-γ expression and T cell proliferation.

Conclusions/Significance

IFN-β may exert its inhibitory effect on EAU by inhibiting Th1, Th17 cells and modulating relevant cytokines. IFN-β may provide a potential treatment for diseases mediated by Th1 and Th17 cells.

Relapse of Vogt-Koyanagi-Harada Disease during Interferon-α and Ribavirin Therapy in a Case of Chronic Viral Hepatitis C

A 60-year-old woman, who had been diagnosed with and treated for Vogt-Koyanagi-Harada (VKH) disease 17 years before, was receiving pegylated interferon-? and ribavirin therapy for chronic hepatitis C virus. Three weeks after the start of therapy, she complained of visual blurring, eye pain, and an increased hearing loss. Based on a slit lamp and fundus examination, she was diagnosed with a relapse of VKH disease. After discontinuation of the pegylated interferon-α and ribavirin therapy and administration of corticosteroid therapy, her visual acuity returned to 1.0 in both eyes without ocular inflammation, and remained stable thereafter. When interferon therapy is administered to hepatitis C virus patients, those who also have a history of VKH disease must be closely monitored for ophthalmologic complications.

Interferons and their potential in the treatment of ocular inflammation

Since their discovery in the 1950s interferons have been the scope of investigation in many diseases as therapeutic as well as pathogenetic factors. We know they have immune stimulatory and immune regulatory effects. This apparently counter-intuitive mechanism can be summarized as immunomodulatory action and seems to be very effective in a number of ocular inflammatory diseases. We review the current knowledge of interferons in immunity and autoimmunity and show their use in clinical ophthalmologic practice.

Non-infectious pediatric uveitis: an update on immunomodulatory management

Pediatric non-infectious uveitis remains a rare but potentially sight-threatening group of diseases. However, early screening and treatment can improve outcomes. No single agent has proven to be efficacious in all cases. A wide variety of long-term immunomodulatory treatments are available; these agents differ in both their potency and side effect profiles. Corticosteroids remain an extremely valuable form of treatment in the short-term management of uveitis. Other major groups of immunomodulatory treatments include the calcineurin inhibitors and antimetabolites such as methotrexate, which is frequently used as the first-line agent. The biologics, including anti-tumor necrosis factor agents and interferons, are newer and potentially very useful therapies although side effects limit their use. Successful outcomes may be achieved with appropriate immunosuppressant therapy given early in the disease, although clinical trials are required to define the true efficacy of this strategy.

Upregulation of neurotrophic factor-related gene expression in retina with experimental autoimmune uveoretinitis by intravitreal injection of tacrolimus (FK506)

AIM

The current study was designed to determine whether intravitreal injection of tacrolimus (FK506) modulates the gene expression of neurotrophic factor-related molecules in the retina from eyes with induced experimental autoimmune uveoretinitis (EAU) in rats.

METHODS

Rats were immunised with interphotoreceptor retinoid binding protein peptide (R14) and given intravitreal injection of tacrolimus on day 12 after immunisation. As control, immunised rats received intravitreal injection of vehicle. On day 15 after immunisation, changes in the genetic programme associated with neuroprotection and inflammatory responses in the retinas from both groups were determined by DNA microarray analyses and confirmed by real-time PCR analyses.

RESULTS

The gene expression of inflammatory responses was markedly reduced in tacrolimus-treated eyes. Genes for molecules associated with neuroprotection (oestrogen receptor, erythropoietin receptor, gamma-aminobutyric acid receptor, protein kinase C, glial cell line-derived neurotrophic factor receptor, fibroblast growth factor and neuropeptide Y receptor) were upregulated in the retinas from tacrolimus-treated eyes.

CONCLUSIONS

Intravitreal injection of tacrolimus modulated the genes related to neuroprotection in the retina during the ongoing process of EAU. This treatment may be useful for the neuroprotection of retina with severe uveitis as well as for immunosuppression in the uveitic eyes.

The expression pattern of interferon-inducible proteins reflects the characteristic histological distribution of infiltrating immune cells in different cutaneous lupus erythematosus subsets

BACKGROUND

Plasmacytoid dendritic cells and type I interferons (IFNs) are supposed to play a central proinflammatory role in the pathogenesis of cutaneous lupus erythematosus (LE). The IFN-inducible chemokines CXCL9 and CXCL10 are involved in recruiting CXCR3+ effector lymphocytes from the peripheral blood into skin lesions of LE. We hypothesized that the expression pattern of IFN-inducible proteins reflects the characteristic distribution of the inflammatory infiltrate in different subsets of cutaneous LE.

OBJECTIVES

To test this hypothesis in patients with LE.

METHODS

Lesional skin biopsies taken from patients with different subsets of LE [chronic discoid LE (CDLE), n = 12; subacute cutaneous LE (SCLE), n = 5; LE tumidus (LET), n = 4; LE profundus (LEP), n = 6] were investigated by immunohistochemistry using monoclonal antibodies to the lymphocyte surface markers CD3, CD4, CD8, CD20 and CD68, the cytotoxic proteins Tia1 and granzyme B, the chemokine receptor CXCR3, the specifically type I IFN-inducible protein myxovirus protein A (MxA) and the chemokines CXCL9 and CXCL10.

RESULTS

The expression pattern of MxA followed the distribution of the inflammatory infiltrate typically seen in the investigated cutaneous LE subsets. In CDLE and SCLE, expression was focused in the epidermis and upper dermis, while in LET a perivascular and in LEP a subcutaneous pattern was found. Similar findings were obtained for CXCL9 and CXCL10.

CONCLUSIONS

Our results demonstrate a close morphological association between the expression pattern of IFN-inducible proteins and the distribution of CXCR3+ CD3+ lymphocytes in all investigated subsets of cutaneous LE. This supports the importance of an IFN-driven inflammation in this condition. Infiltrating lymphocytes carrying CXCL10 in their granules might amplify the lesional inflammation and be responsible for the chronic course of this disease.

Interferon-alpha2a and Vogt-Koyanagi-Harada disease: a double-edged sword?

Successful therapy based on the use of interferon-alpha has been reported in different types of severe chronic uveitis. The immunomodulatory effects of this drug, combined with its antiviral properties seem to contribute to its efficacy in the treatment of different forms of severe and refractory uveitis such as Vogt-Koyanagi-Harada disease, Behçet-associated uveitis, or even human herpes virus 8 (HHV-8) associated uveitis. At the same time, severe ocular complications have been reported in patients treated with interferon-alpha for chronic viral hepatitis C. Among these complications, six cases of Vogt-Koyanagi-Harada-like disease have been described.We report a small case series of two patients with refractory Vogt-Koyanagi-Harada disease, treated with interferon-alpha and discuss the potential benefits or detrimental role of interferon therapy in these patients.

Intravitreal injection of Tacrolimus (FK506) suppresses ongoing experimental autoimmune uveoretinitis in Rats

AIM

To determine whether intravitreal injection of tacrolimus suppresses ongoing experimental autoimmune uveoretinitis (EAU) in rats.

METHODS

Rats were immunised with interphotoreceptor retinoid-binding protein peptide (R14) and given an intravitreal injection of tacrolimus on day 12 after immunisation. Intraocular inflammation was assessed by slit-lamp biomicroscopy and histopathological examination. Interferon gamma and tumour necrosis factor alpha protein levels in the ocular tissues were measured. Gene expression of chemokines was determined in ocular tissues by reverse transcription-polymerase chain reaction. To evaluate the systemic effect of intravitreal injection of tacrolimus, delayed-type hypersensitivity was measured by ear swelling.

RESULTS

Clinical and pathological scores showed that ocular inflammation of tacrolimus-treated eyes was markedly less than that of vehicle-treated eyes. The amount of interferon gamma and tumour necrosis factor alpha was considerably inhibited in tacrolimus-treated eyes. The gene expression of monocyte chemattractant protein-1 (MCP-1) and regulated upon activation, normal T cell expressed and secreted (RANTES) was markedly reduced in tacrolimus-treated eyes. Delayed-type hypersensitivity responses were not impaired in tacrolimus-treated rats.

CONCLUSIONS

Intravitreal injection of tacrolimus was highly effective in suppressing the ongoing process of EAU without any side effects on systemic cellular immunity. This treatment may be useful in the management of patients with severe uveitis.

INTERFERON ALFA-2A: A NEW TREATMENT OPTION FOR LONG LASTING REFRACTORY CYSTOID MACULAR EDEMA IN UVEITIS?

PURPOSE

To perform a prospective pilot study to evaluate interferon alfa-2a (IFN alfa-2a) for the treatment of refractory cystoid macular edema (CME) in endogenous uveitis.

METHODS

IFN alfa-2a was administered at an initial dose of 3 or 6 million IU (depending on body weight) per day subcutaneously. Afterwards IFN alfa-2a was tapered slowly over 6 months and finally discontinued. If CME relapsed IFN alfa-2a was reinstituted and tapered slowly again to evaluate the lowest maintenance dose to keep remission.

RESULTS

A total of 15 eyes of 8 patients with refractory CME due to intermediate or posterior uveitis were included. Ineffective pretreatment consisted of systemic steroids and acetazolamide (all patients) and at least one additional immunosuppressant (6 patients). Six of 8 patients (11 eyes) responded well to IFN alfa-2a and CME resolved completely during 6 months treatment. One patient was lost to follow-up after IFN alfa-2a was stopped. In 1 patient (1 eye) even 19 months after cessation of IFN alfa-2a no recurrence of CME occurred. In 4 patients (8 eyes) IFN alfa-2a had to be reinstituted because CME relapsed. All 4 patients responded again. During a mean follow-up period of 16.4 months since restart of therapy we succeeded in all 4 patients to taper IFN alfa-2a to maintenance doses between 1.5 million IU every second and every sixth day without a recurrence of CME in any of the 8 eyes.

CONCLUSION

IFN alfa-2a can be a treatment option for patients with otherwise treatment resistant uveitic CME.

Interferon as a treatment for uveitis associated with multiple sclerosis

AIM

In addition to optic neuritis (ON), multiple sclerosis (MS) may also involve the eye with a typically bilateral intermediate uveitis. The aim of this pilot study was to evaluate the efficacy of type I interferons (IFN) for the treatment of MS associated uveitis.

METHODS

In this non-randomised, retrospective observational case series 13 patients (eight female, five male) with proved MS and associated uveitis from five uveitis centres who were treated with interferon beta1a were included. Visual acuity (VA), cell count in the aqueous humour and vitreous, as well as the presence of cystoid macula oedema (CMO) were observed.

RESULTS

All except one patient had a bilateral form of intermediate uveitis (total of 24 eyes). Seven patients had documented CMO before IFN treatment (n = 13 eyes). Median duration of treatment was 24.6 months (range 7.9-78.7). VA improved in 17 eyes (comparing VA before therapy and at last follow up); while 10 eyes (36%) improved >or=3 Snellen lines. Aqueous cell count improved by 1.2 (SD 1.1) grades in all eyes. Vitreous cell count improved by 1.7 (1.4) in all eyes. Only two patients still had minimal CMO on last follow up angiographically. CMO resolved after or during IFN treatment in nine eyes.

CONCLUSIONS

IFN has been shown to have beneficial effects in patients with MS and/or ON. As shown in the models of experimental allergic encephalomyelitis (EAE) and uveitis, the neurological and ophthalmological manifestations seem to share similar pathogenic mechanisms. Treatment of MS associated uveitis with IFN appears to have beneficial effects on VA, intraocular inflammation activity, and the presence of CMO.

The role of tumour necrosis factor (TNF-alpha) in experimental autoimmune uveoretinitis (EAU)

The pleiotropic cytokine tumour necrosis factor-alpha (TNF-alpha) is released from cells that include macrophages and T-cells during inflammatory responses, orchestrating the initiation of further leucocytic infiltration via adhesion molecule upregulation, dendritic cell maturation and survival, macrophage activation and driving Th1 T-cells responses within tissues. Exposure to TNF also plays a role in maintaining tissue homeostasis, particularly relating to resident cell responses of both microglia and retinal pigment epithelium. Depending on the balance between duration and dose of TNF exposure, an environment where full expression of inflammatory and autoimmune responses within tissues may occur. In experimental autoimmune uveoretinitis (EAU), increased tissue concentrations of TNF facilitate the on-going T-cell effector responses and macrophage activation. These are responsible for targeted and bystander tissue damage and can be suppressed by anti-TNF therapies, in particular, those directed at the p55 TNF receptor. The ability to suppress disease experimentally has led to the successful translation of anti-TNF therapy for treatment of uveitis in cohort studies and phase I/II trials where, additionally, altered peripheral blood CD4(+) T-cell profiles can be demonstrated following each treatment.

Cytokines in immunotherapy of experimental uveitis

A better understanding of the basic mechanisms of uveitis and of the role of cytokines in experimental ocular inflammation autoimmune diseases should allow us to define new approaches for therapy. Modulation of the cytokine network by either blocking cytokine activity or administration of regulatory Th2 cytokines has shown its efficacy in several experimental autoimmune diseases including uveitis. However, cytokines present pleiotropic activities and thus may exert different effects depending on the autoimmune diseases, making interventions on their production complex. Anti-cytokine therapy or a combination of anti-cytokine drugs, antibodies, and cytokine gene therapy to synergize the therapeutical effects of other treatments appear to be of interest. Improvements in drug delivery and in biotechnology will also allow us to elaborate new and safe immunomodulatory strategies.