Immunogenetic study of sympathetic ophthalmia

Bilateral exudative retinal detachments after subretinal gene therapy with voretigene neparvovec-rzyl for RPE65 Leber Congenital Amaurosis

Purpose

To report panuveitis with exudative retinal detachments in a healthy 27-year-old woman with biallelic mutations in the RPE65 gene, who underwent bilateral sequential gene therapy with subretinal administration of voretigene neparvovec-rzyl.

Observations

Visual acuity improved for 30 days after surgery as oral corticosteroids were tapered. At postoperative week 6, vision declined due to sudden onset uveitis and exudative retinal detachments in both eyes. HLA Class II typing revealed the haplotype associated with sympathetic ophthalmia and Vogt-Koyanagi-Harada (VKH). The inflammation improved after corticosteroid, mycophenolate mofetil, and adalimumab therapy while vision remained poor.

Conclusions and Importance

Surgically-induced sympathetic ophthalmia is a plausible explanation for the clinical findings; surgery of both eyes within one week would conceal the inciting eye. VKH or inflammation related to the gene therapy are other possible etiologies but severe bilateral panuveitis has not been reported with voretigene neparvovec-rzyl. Informed consent for gene therapy surgery should include a discussion of the rare complication of sympathetic ophthalmia following vitrectomy surgery.

Vision Outcomes of Long-Term Immunomodulatory and Steroid Therapy in Sympathetic Ophthalmia

PURPOSE

To compare vision acuity outcomes of long-term steroid therapy compared with immunomodulatory therapy for treatment of sympathetic ophthalmia.

DESIGN

Single-center, retrospective, comparative clinical study.

METHODS

Patients with sympathetic ophthalmia treated from March 2005 to October 2022 with at least 1 year of follow-up were included. Visual acuity outcomes were compared by steroid and immunomodulatory treatment modality.

RESULTS

Thirty-five patients with sympathetic ophthalmia were included in the study, with follow-up ranging from 1 to 17 years. Higher rates of vision loss correlated with longer periods of active uveitis and steroid treatment. Lower rates of vision loss correlated with longer periods of uveitis remission on immunomodulatory therapy alone and drug-free remission. Treatment with alkylating agents or combination therapy with an antimetabolite, a biologic-response modifier, and cyclosporine are more likely to result in sympathetic ophthalmia remission.

CONCLUSION

Immunomodulatory therapy leads to superior vision outcomes in cases of steroid-resistant or recurrent sympathetic ophthalmia. Steroid therapy may be useful for acute or recalcitrant sympathetic uveitis but is insufficient for long-term inflammatory control. PRéCIS: This manuscript describes a retrospective analysis of vision outcomes in patients with sympathetic ophthalmia. Results indicate that long-term immunomodulatory therapy is associated with better vision outcomes than long-term steroid therapy for sympathetic ophthalmia treatment.

Association Between HLA Polymorphisms and Sympathetic Ophthalmia in Han Chinese

PURPOSE

Sympathetic ophthalmia (SO) is considered as an autoimmune disease with unclear mechanisms. This study investigated the relationship between HLA polymorphisms and SO.

METHODS

HLA typing was performed using the LABType reverse SSO DNA typing method. The allele and haplotype frequencies were assessed using the PyPop software. Statistical significance of genotype distributions between 116 patients and 84 healthy individuals (control) was determined using Fisher's exact test or Pearson's chi-squared test.

RESULTS

The SO group had a higher frequency of HLA-DRB1 * 04:05, HLA-DQB1 * 04:01, DRB1 * 04:05-DQB1 * 04:01 haplotype   as compared to the control group (Pc < 0.001 for all).

CONCLUSION

This study revealed that DRB1 * 04:05 and DQB1 * 04:01 alleles, as well as DRB1 * 04:05-DQB1 * 04:01 haplotye could be potential risk factors for SO.

Case report: Sympathetic ophthalmia after vitrectomies in a patient with Von Hippel-Lindau syndrome

Background

Sympathetic ophthalmia (SO) is a rare but sight-threatening uveitis, and most observations have been made after typical manifestations occur. This report focuses on the choroidal changes detected by multimodal imaging at the presymptomatic stage of SO, which is implicated in the early recognition of SO.

Case presentation

A 21-year-old woman suffered from decreased vision in the right eye and was diagnosed with retinal capillary hemangioblastomas associated with Von Hippel-Lindau syndrome. The patient underwent two 23-G pars plana vitrectomies (PPVs), soon after which typical signs of SO manifested. SO resolved quickly after the oral administration of prednisone and remained stable during the follow-up of more than 1 year. The retrospective analysis revealed preexisting bilaterally increased choroidal thickness, dots of flow void on the choroid, and choriocapillaris en-face slabs in optical coherence tomography angiography (OCTA) after the first PPV, which were all reversed by corticosteroid treatment.

Conclusion

The case report highlights the involvement of the choroid and choriocapillaris at the presymptomatic stage of SO after the first inciting event. Abnormally thickened choroid and flow void dots suggested that SO had started and an ensuing surgery would run the risk of exacerbating SO. OCTA scanning of both eyes should be ordered routinely for patients with a history of trauma or intraocular surgeries, especially before the next surgical intervention. The report also suggests that non-human leukocyte antigen gene variation may also regulate the progression of SO, which requires further laboratory investigations.

Sympathetic Ophthalmia - An Overview

INTRODUCTION

Sympathetic ophthalmia (SO) is rare, bilateral granulomatous panuveitis that typically occurs following penetrating or perforating ocular trauma or surgery. This review aims to provide an update on the etiopathogenesis, clinical presentations, diagnosis and treatment of SO.

METHODS

Reports cited in MEDLINE database, that analyzed SO in at least 5 patients, published prior to December 1st, 2021 were included.

RESULTS

Initially, SO was associated with penetrating ocular trauma, however, various studies reported an increased incidence of SO after surgical procedures including vitreoretinal surgeries. Multimodal imaging including fluorescein and indocyanine green angiography, optical coherence tomography (OCT) and OCT angiography have added further insights into the understanding of SO. While pulse dose corticosteroids & immunosuppressive drugs are still the treatment of choice, TNF-α blockers & other biologic drugs represent new promising agents.

CONCLUSION

There is a growing pool of evidence in understanding the pathogenesis of SO. Novel treatment options have provided better prognosis for this potentially blinding condition.

Sympathetic Ophthalmia: Where Do We Currently Stand on Treatment Strategies?

Sympathetic ophthalmia is a rare bilateral diffuse granulomatous panuveitis that usually results from surgical or penetrating trauma to one eye. The symptoms range from impaired near vision to pain, photophobia, and loss of visual acuity. Anterior segment manifestations include bilateral acute uveitis with mutton-fat keratic precipitates and posterior segment findings include vitritis, multifocal neurosensory retinal detachment, choroiditis, optic nerve edema, and Dalen-Fuchs nodules. The diagnosis is clinical. Ancillary investigations include fundus fluorescein angiography, indocyanine green angiography, optical coherence tomography (OCT), ultrasound B scan, and autofluorescence imaging. The management options include corticosteroids (topical and systemic) as the first line along with immunomodulatory therapy started at the presentation of the disease. Recent advances include imaging with OCT-angiography, enhanced depth imaging-OCT (EDI-OCT, choroidal vascular index/CVI), targeting IL-23/IL-17 pathway, and use of biologics for the management of this rare entity. Recent advances in early diagnosis and prompt treatment has led to improved final visual outcomes in both the sympathizing and exciting eye. This review is aimed at giving a comprehensive overview of sympathetic ophthalmia along with a special emphasis on current treatment strategies and recent advances.

The Ruptured Globe, Sympathetic Ophthalmia, and the 14-Day Rule

PURPOSE

Prophylactic enucleation of a ruptured globe with no light perception within 14 days of injury to prevent sympathetic ophthalmia (SO) has been an established dictum in academic teaching for more than 100 years. This treatment strategy was originally based on observation, speculation, and careful thought, but there was never any scientific proof. This review summarizes and updates the current state of our knowledge about globe rupture and SO, examines the origin and validity of the 14-day rule, and emphasizes the importance of trying to save the traumatized eye whenever possible.

METHODS

A comprehensive literature review of SO and globe rupture was performed.

RESULTS

SO is a rare disorder that may potentially occur following traumatic globe rupture as well as following a variety of other intraocular surgeries. Vitreoretinal surgery may be a more common cause than trauma according to some studies. SO may still occur despite having the eye removed within 14 days of the trauma. A variety of new medications including biologic agents are now available to treat SO with improved efficacy in suppressing the associated ocular inflammation and allowing retention of some useful vision. Removing the traumatized, blind eye may have other important psychological consequences associated with it that require consideration before eye removal is carried out. Retaining the blind, phthisical, disfigured eye avoids phantom vision and phantom pain associated with enucleation as well as providing a good platform to support and move an overlying prosthetic eye. Data on the occurrence of SO following evisceration and enucleation with and without predisposing factors confirms the exceedingly low risk.

CONCLUSION

Most civilian open globe injuries can be successfully repaired with modern, advanced microsurgical techniques currently available. Because of the exceedingly low risk of SO, even with the severity of open globe trauma during military conflicts being more devastating as a result of the blast and explosive injuries, today every attempt is made to primarily close the eye rather than primarily enucleate it, providing there is enough viable tissue to repair. The 14-day rule for eye removal after severe globe ruptures is not scientifically supported and does not always protect against SO, but the safe time period for prophylactic eye removal is not definitively known. In the exceptional cases where SO does occur, several new medications are now available that may help treat SO. We advocate saving the ruptured globe whenever possible and avoiding prophylactic enucleation to prevent the rare occurrence of SO. When an eye requires removal, evisceration is an acceptable alternative to enucleation in cases that do not harbor intraocular malignancy.

Sympathetic Ophthalmia - a Contribution to Immunology, Clinic and Current Imaging

BACKGROUND

Sympathetic ophthalmia (SO) is a rare inflammation of an operated or injured eye that spreads to the fellow eye. It is typically a bilateral granulomatous panuveitis. The traumatized eye is referred to as inciting eye and the fellow eye as sympathizing eye. The pathophysiology of the disease is not entirely understood, but there is strong evidence of an autoimmune genesis.

PATIENTS/MATERIAL AND METHODS

A selective literature search on epidemiology, immunology, clinical features and risk factors of SO was carried out. In addition, our own experience using multimodal imaging for this clinical entity was introduced.

RESULTS

In the literature, the incidence after traumatic eye injuries is 0.1 - 3% and approximately 0.01% after intraocular surgery. Among the iatrogenic causes, vitreoretinal surgery has the highest rate of SO, presumably due to disruption of the blood-retinal barrier and involvement of retinal and choroidal tissue, which are susceptible to anterior traction, phthisis and chronic inflammation. In 90% of patients, the disease develops within a year following the eliciting event and is associated with a potentially bilateral risk of blindness. Typical symptoms include bilateral visual impairment with photophobia, dull pain and photopsia. The spectrum of clinical manifestations ranges from granulomatous anterior uveitis and vitritis, to choroiditis, serous retinal detachment and Dalen-Fuchs nodules in the context of posterior involvement. The diagnosis of SO is generally based on clinical presentation and is supported by imaging methods. These primarily comprise fluorescein and indocyanine green angiography, which are increasingly being supplemented by non-invasive methods such as optical coherence tomography. They can provide important information for assessment of severity, differential diagnosis as well as for disease monitoring. The differential diagnosis includes i. a. Vogt-Koyanagi-Harada syndrome, ocular sarcoidosis and the rare phacoanaphylactic endophthalmitis. Immediate systemic high-dose steroid therapy is used as initial treatment. The course of the disease is often relapsing to chronic progressive. Immunomodulators such as ciclosporine A, azathioprine, cyclophosphamide, mycophenolate mofetil, and biologics are increasingly being used and contribute to the significantly better prognosis of the disease. Generally, SO can be triggered by any kind of intraocular intervention.

CONCLUSION

SO remains a threatening clinical diagnosis that poses diagnostic and therapeutic challenges. It can be triggered post-traumatic, but also any intraocular surgery. This should be taken into account when assessing the indication for intraocular eye surgery, especially in eyes with reduced visual outcome.

Activation of the interleukin-23/interleukin-17 signalling pathway in autoinflammatory and autoimmune uveitis

Uveitis is a group of diseases characterized by intraocular inflammation, of which some are driven by autoinflammatory or autoimmune responses, such as Vogt-Koyanagi-Harada disease, Behçet's disease, uveitis associated with spondyloarthritis, ocular sarcoidosis, sympathetic ophthalmia and birdshot chorioretinopathy. These entities have various clinical forms, but genetic and biomarker data suggest that they share a common molecular basis, activation of the Interleukin (IL)-23/IL-17 pathway. Multiple factors including genetic predisposition, various cytokine imbalances, infectious agents and gut alterations are found to trigger an aberrant response of this pathway. The enhanced activity of the IL-23/IL-17 pathway is committed to the expansion and pathogenicity of Th17 cells. Evidence from animal models demonstrates that the development of pathogenic Th17 cells is responsible for the induction of experimental autoimmune uveitis. Further findings indicate that retinal pigment epithelium (RPE) cells may be a target of IL-17. IL-17 triggers downstream inflammatory cascades and causes dysfunction of RPE cells, which may affect retinal barrier function and thereby promote intraocular inflammation. Currently, several emerging drugs blocking the IL-23/IL-17 pathway have been assessed for the treatment of uveitis in pilot studies. The purpose of this is to summarize updated biological knowledge and preliminary clinical data, providing the rationale for further development and evaluation of novel drugs targeting the IL-23/IL-17 pathway in autoinflammatory and autoimmune uveitis. Future studies may focus on translational medicine targeting the IL-23/IL-17 pathway for the improvement of diagnosis and treatment of uveitis. In conclusion, activation of the IL-23/IL-17 pathway is a critical biological event and can be an important target for the treatment of autoinflammatory and autoimmune uveitis.

Effective Arrestin-Specific Immunotherapy of Experimental Autoimmune Uveitis with RTL: A Prospect for Treatment of Human Uveitis

PURPOSE

To evaluate the immunotherapeutic efficacy of recombinant T cell receptor ligands (RTLs) specific for arrestin immunity in treatment of experimental autoimmune uveitis (EAU) in humanized leukocyte antigen (HLA-DR3) transgenic (Tg) mice.

METHODS

We generated de novo recombinant human DR3-derived RTLs bearing covalently tethered arrestin peptides 291-310 (RTL351) or 305-324 (RTL352). EAU was induced by immunization of HLA-DR3 mice with arrestin or arrestin peptide and treated with RTLs by subcutaneous delivery. T cell proliferation and cytokine expression was measured in RTL-treated and control mice.

RESULTS

RTL351 prevented the migration of cells outside of the spleen and the recruitment of inflammatory cells into the eye, and provided full protection against inflammation from EAU induced with arrestin or arrestin peptides. RTL351 significantly inhibited T cell proliferation and secretion of inflammatory cytokines interleukin 2 (IL-2), interferon γ (IFN-γ), IL-6, and IL-17 and chemokines (macrophage inflammatory proteins [MIP-1a] and regulated and normal T cell expressed and secreted [RANTES]), which is in agreement with the suppression of intraocular inflammation. RTL350 ("empty," no peptide) and RTL352 were not effective.

CONCLUSIONS

Immunotherapy with a single RTL351 successfully prevented and treated arrestin-induced EAU in HLA-DR3 mice and provided proof of concept for therapy of autoimmune uveitis in human patients. The beneficial effects of RTL351 should be attributed to a significant decrease in Th1/Th17 mediated inflammation.

TRANSLATIONAL RELEVANCE

Successful therapies for autoimmune uveitis must specifically inhibit pathogenic inflammation without inducing generalized immunosuppression. RTLs can offer such an option. The single retina-specific RTLs may have a value as potential immunotherapeutic drug for human autoimmune uveitis because they effectively prevent disease induced by multiple T cell specificities.

Sympathetic ophthalmia: to the twenty-first century and beyond

Sympathetic ophthalmia is a rare bilateral granulomatous inflammation that follows accidental or surgical insult to the uvea of one eye. Onset of sympathetic ophthalmia can be insidious or acute, with recurrent periods of exacerbation. Clinical presentation shows mutton-fat keratic precipitates, choroidal infiltrations, and Dalen-Fuchs nodules. Histopathology reveals diffuse or nodular granulomatous inflammation of the uvea. Prevention and treatment strategies for sympathetic ophthalmia are currently limited to two modalities, enucleation of the injured eye and immunosuppressive therapy, aimed at controlling inflammation. The etiology and pathophysiology of the disease is still unclear but is largely thought to be autoimmune in nature. Recent insight on the molecular pathology of the disease as well as developments in imaging technology have furthered both the understanding on the autoimmune process in sympathetic ophthalmia and the targeting of prevention and treatment strategies for the future.

Uveitis-associated epitopes of retinal antigens are pathogenic in the humanized mouse model of uveitis and identify autoaggressive T cells

Noninfectious uveitis is a leading cause of blindness and thought to involve autoimmune T cell responses to retinal proteins (e.g., retinal arrestin [soluble-Ag (S-Ag)]). There are no known biomarkers for the disease. Susceptibility is associated with HLA, but little is known about susceptible class II alleles or the potentially pathogenic epitopes that they present. Using a humanized HLA-transgenic mouse model of S-Ag-induced autoimmune uveitis, we identified several susceptible and resistant alleles of HLA-DR and -DQ genes and defined pathogenic epitopes of S-Ag presented by the susceptible alleles. The sequences of these epitopes overlap with some previously identified peptides of S-Ag ("M" and "N"), known to elicit memory responses in lymphocytes of uveitis patients. HLA-DR-restricted, S-Ag-specific CD4(+) T cells could be detected in blood and draining lymph nodes of uveitic mice with HLA class II tetramers and transferred the disease to healthy mice. Importantly, tetramer-positive cells were detected in peripheral blood of a uveitis patient. To our knowledge, these findings provide the first tangible evidence that an autoimmune response to retina is causally involved in pathogenesis of human uveitis, demonstrating the feasibility of identifying and isolating retinal Ag-specific T cells from uveitis patients and may facilitate their development as biomarkers for the disease.

A look at autoimmunity and inflammation in the eye

Autoimmune and inflammatory uveitis are a group of potentially blinding intraocular inflammatory diseases that arise without a known infectious trigger and are often associated with immunological responses to unique retinal proteins. In the United States, about 10% of the cases of severe visual handicap are attributed to this group of disorders. As I discuss here, experimental models of ocular autoimmunity targeting retinal proteins have brought about a better understanding of the basic immunological mechanisms involved in the pathogenesis of uveitis and are serving as templates for the development of novel therapies.

HLA typing in uveitis: use and misuse

PURPOSE

To evaluate the role of HLA typing as a diagnostic test in patients with uveitis.

DESIGN

Perspective derived from a literature review and analysis of reported results.

METHODS

Published data on the HLA associations of several uveitis entities and their prevalence among patients and the general population were used to calculate the positive predictive value of HLA testing as a diagnostic test for these disorders.

RESULTS

For nearly all diagnostic entities evaluated (including multiple sclerosis-associated intermediate uveitis, birdshot chorioretinitis, sympathetic ophthalmic, Behçet disease, and Vogt-Koyanagi-Harada disease), the positive predictive value was low (< 0.50), indicating the limited usefulness of routinely applied HLA typing as a diagnostic test. HLA-B27 testing may be of value in identifying a previously undiagnosed or misdiagnosed spondyloarthropathy among patients with recurrent acute anterior uveitis.

CONCLUSIONS

In general, HLA typing has limited usefulness as a diagnostic test in patients with uveitis.

A review of pediatric uveitis: part II. Autoimmune diseases and treatment modalities

Uveitis is a manifestation of complex processes that can represent an infectious process or a dysfunction of the immune system that may have grave effects on the eye. Although infectious causes, once properly identified, may be successfully treated by addressing the inciting organism with recognized interventions, the immune-modulated chronic forms of uveitis often provide more complex challenges in management. Recent strides in understanding the inflammatory pathway and better bioengineering capabilities have resulted in some new modalities of treatment.

Immunogenetics of ocular inflammatory disease

Ocular inflammatory disease comprises of a diverse group of clinical entities that may result from autoimmune processes, infections, or both. While many individual ocular inflammatory diseases are quite rare, ocular inflammation is one of the more common causes of visual disability, including blindness, in the developed world. Better understanding of ocular inflammatory disease is an important step in designing more sophisticated therapies that may help prevent loss of visual function for these patients.

Acute anterior uveitis and HLA-B27

Acute anterior uveitis is the most common form of uveitis. HLA-B27-associated acute anterior uveitis is a distinct clinical entity that has wide-ranging medical significance due to its ocular, systemic, immunologic, and genetic features. The association between HLA-B27 and the spectrum of HLA-B27-associated inflammatory diseases remains one of the strongest HLA-disease associations known to date. This review examines acute anterior uveitis with particular focus on HLA-B27-associated acute anterior uveitis, including the epidemiology, immunopathology, association with HLA-B27 and its subtypes, clinical features, complications, prognosis, and potential new therapies such as anti-TNFalpha therapy and oral HLA-B27-peptide tolerance. There have been substantial recent advances in both clinical and basic scientific research in this field, including studies of the various animal models of acute anterior uveitis and the HLA-B27 transgenic animals, and these are summarized in this review. To the ophthalmologist, HLA-B27-associated acute anterior uveitis is an important clinical entity that is common, afflicts relatively young patients in their most productive years, and is associated with significant ocular morbidity due to its typically recurrent attacks of inflammation and its potentially vision-threatening ocular complications. Furthermore, to the ophthalmologist and the internist, HLA-B27-associated acute anterior uveitis is also of systemic importance due to its significant association with extraocular inflammatory diseases.

Comparative study of two sets of criteria for the diagnosis of Vogt-Koyanagi-Harada's disease

PURPOSE

The Vogt-Koyanagi-Harada's (VKH) Disease Committee established the "Revised diagnostic criteria for VKH disease" in 2001. The purpose of the present study was to assess the concordance between these criteria and the traditional Sugiura's diagnosis system.

DESIGN

Observational case series.

METHODS

The medical records of patients previously diagnosed with VKH disease based upon Sugiura's criteria at the Uveitis Survey Clinic of the Hokkaido University Hospital between 1991 and 2003 were retrospectively reevaluated using the VKH Committee's revised diagnostic criteria for VKH disease.

RESULTS

Sugiura's criteria were used to identify 169 patients with VKH disease. All patients were Japanese, and 95 cases (56%) were women. Mean age at the time of their first visit to our clinic was 44.7 +/- 13.9 years (range, 9 to 74 years). Using the VKH Committee's new criteria, 91.7% of the previously diagnosed VKH patients were classified as having the disease. Of this group, 11.8% were classified as complete, 71% incomplete, and 8.9% as probable VKH disease.

CONCLUSIONS

The VKH Committee's revised diagnostic criteria proved useful for VKH disease diagnosis, as the concordance rate for the two criteria was more than 90%. However, patients who had prior cataract surgery or who lacked signs of serous retinal detachment were not classified as having VKH disease because of exclusion by the VKH Committee's new criteria.

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.

A humanized model of experimental autoimmune uveitis in HLA class II transgenic mice

Experimental autoimmune uveitis (EAU) is a disease of the neural retina induced by immunization with retinal antigens, such as interphotoreceptor retinoid-binding protein (IRBP) and arrestin (retinal soluble antigen, S-Ag). EAU serves as a model for human autoimmune uveitic diseases associated with major histocompatibility complex (HLA) genes, in which patients exhibit immunological responses to retinal antigens. Here we report the development of a humanized EAU model in HLA transgenic (TG) mice. HLA-DR3, -DR4, -DQ6, and -DQ8 TG mice were susceptible to IRBP-induced EAU. Importantly, HLA-DR3 TG mice developed severe EAU with S-Ag, to which wild-type mice are highly resistant. Lymphocyte proliferation was blocked by anti-HLA antibodies, confirming that antigen is functionally presented by the human MHC molecules. Disease could be transferred by immune cells with a Th1-like cytokine profile. Antigen-specific T cell repertoire, as manifested by responses to overlapping peptides derived from S-Ag or IRBP, differed from that of wild-type mice. Interestingly, DR3 TG mice, but not wild-type mice, recognized an immunodominant S-Ag epitope between residues 291 and 310 that overlaps with a region of S-Ag recognized by uveitis patients. Thus, EAU in HLA TG mice offers a new model of uveitis that should represent human disease more faithfully than currently existing models.

Immunopathology of the noninfectious posterior and intermediate uveitides

The posterior and intermediate uveitides share an underlying immune etiology; however, they can be clinically and immunopathologically distinguished. Although the initiating stimuli for posterior and intermediate uveities are not known, it is believed that an exogenous agent (such as a bacterium or a virus) or an endogenous molecule may induce disease. In either case, T-helper lymphocytes in conjunction with human leukocyte antigens are likely to be involved. This review examines the epidemiology, histology, immunopathology, and theories of pathogenesis of several posterior and intermediate uveitides, including sympathetic ophthalmia, Vogt-Koyanagi-Harada syndrome, Behçet's disease, sarcoidosis, intermediate uveitis, white dot syndromes, and birdshot retinochoroidopathy.

Humoral immune response directed against LEDGF in patients with VKH

Vogt-Koyanagi-Harada disease is an autoimmune systemic disorder. In Vogt-Koyanagi-Harada disease, inflammatory disorders occur in multiple organs containing melanocytes, including uvea (resulting in acute bilateral panuveitis), skin (resulting in vitiligo and alopecia), central nervous system (resulting in meningitis) and inner ears (resulting in hearing loss and tinnitus). These inflammatory aspects are attributed to the destruction of melanocytes through immunological mechanisms. Studies have been carried out to elucidate the exact etiology and target autoantigen in Vogt-Koyanagi-Harada disease, but much remains to be investigated. Identification of target autoantigen is important to understand the etiology of autoimmune diseases, and for development of antigen-specific immuno-modulation therapy. To identify the target autoantigens in Vogt-Koyanagi-Harada disease, we made use of an immunoscreening of a bovine uveal cDNA expression library with serum samples obtained from patients with Vogt-Koyanagi-Harada disease. We identified an immunoreactive cDNA clone that encodes bovine lens epithelium derived growth factor. mRNA of human lens epithelium derived growth factor was determined by reverse transcription-polymerase chain reaction and it was expressed in human uvea, retina and melanocytes. Immunoglobulin G (IgG) autoantibodies were quantitated in an enzyme-linked immunosorbent assay, using recombinant human lens epithelium derived growth factor. The prevalence of IgG anti-lens epithelium derived growth factor autoantibodies in patients with Vogt-Koyanagi-Harada disease was significantly higher than that in healthy controls (66.7% versus 21.6%, P<0.001). On the other hand, the prevalence of the autoantibody in patients with panuveitis of other etiology, Behçet's disease and sarcoidosis, was almost same as that in healthy controls. These results suggest that the humoral immune response agonist lens epithelium derived growth factor is not a mere secondary phenomena caused by uveal tissue damage.

Immunogenetics and clinical phenotype of sympathetic ophthalmia in British and Irish patients

BACKGROUND/AIMS

Sympathetic ophthalmia (SO) is a classic example of autoimmune disease where human leucocyte antigen (HLA) genomic associations could provide further understanding of mechanisms of disease. This study sought to assess HLA genetic polymorphism in British and Irish patients with SO, and to assess whether HLA gene variants are associated with clinical phenotype or disease severity.

METHODS

High resolution DNA based HLA typing using polymerase chain reaction sequence specific primers was performed in 27 patients with SO and 51 matched healthy controls. Clinical phenotype and markers of disease severity were determined prospectively in 17 newly diagnosed patients and from medical record review and repeat clinical examination in 10 previously diagnosed patients.

RESULTS

HLA-Cw*03 (p=0.008), DRB1*04 (p=0.017), and DQA1*03 (p=0.014) were significantly associated with SO. For class II alleles at higher resolution, only HLA-DRB1*0404 (relative risk (RR) = 5.6, p = 0.045) was significantly associated with SO. The highest relative risk for any of the associated haplotypes was with HLA-DRB1*0404-DQA1*0301 (RR=10.9, p=0.019). Patients with the DRB1*04-DQA1*03 associated haplotype were significantly more likely to develop SO earlier, with fewer inciting ocular trauma events, and to require more systemic steroid therapy to control inflammatory activity.

CONCLUSIONS

Sympathetic ophthalmia is associated with HLA-DRB1*04 and DQA1*03 genotypes in white patients, similar to Japanese patients. Differences in DRB1*04 gene variant associations (-0404 in Britain and Ireland and -0405 in Japan) may have implications for HLA peptide binding in disease initiation. The DRB1*04-DQA1*03 haplotype is a marker of increased SO susceptibility and severity, as in Vogt-Koyanagi-Harada disease, which also has similar clinicopathological and HLA associations.

Tyrosinase family proteins are antigens specific to Vogt-Koyanagi-Harada disease

Vogt-Koyanagi-Harada (VKH) disease (and sympathetic ophthalmia) is an ocular inflammatory disease that is considered to be a cell-mediated autoimmune disease against melanocytes. The purpose of this study was to determine the Ags specific to VKH disease and to develop an animal model of VKH disease. We found that exposure of lymphocytes from patients with VKH disease to peptides (30-mer) derived from the tyrosinase family proteins led to significant proliferation of the lymphocytes. Immunization of these peptides into pigmented rats induced ocular and extraocular changes that highly resembled human VKH disease, and we suggest that an experimental VKH disease was induced in these rats. We conclude that VKH disease is an autoimmune disease against the tyrosinase family proteins.

Ocular and extraocular inflammation induced by immunization of tyrosinase related protein 1 and 2 in Lewis rats

Vogt-Koyanagi-Harada (VKH) disease is an ocular inflammatory disease and is considered to be a cell-mediated, autoimmune disease against melanocytes. To learn more about the mechanisms involved in VKH disease, the identification of the antigens specific to the disease and the development of an animal model are critically important. We have expressed and purified the melanocyte specific proteins, tyrosinase-related protein 1 (TRP1) and 2 (TRP2). Lewis rats developed an ocular and extraocular inflammatory disease 12 days after immunization with TRP1 or TRP2 that was characterized clinically by the infiltration of inflammatory cells and accumulation of massive fibrin in the anterior and posterior chambers of the eye. Histologically, inflammatory cells were found in the anterior and posterior chambers, iris, ciliary body, the choroid, subretinal space and vitreous body. In severe cases, a serous detachment of the retina was observed. In mild cases, focal inflammatory lesions surrounded by normal chorioretinal architecture were observed and the inflammation persisted for more than 42 days after the injection. Some eyes showed accumulation of epithelioid cells in the choroid or the retinal pigment epithelium which were similar to the Dalen-Fuchs nodules found in patients with VKH disease. The alterations of the photoreceptor outer segment and the outer nuclear layer were less severe than in experimental autoimmune uveitis induced by retinal antigens. Extraocular manifestations such as skin lesions and meningitis were also observed. The clinical course and histological findings in these rats resembled the changes in patients with VKH disease.

Prospective surveillance of sympathetic ophthalmia in the UK and Republic of Ireland

AIMS

To establish current epidemiological data, risks, and interventional outcomes of newly diagnosed sympathetic ophthalmia (SO).

METHODS

Prospective surveillance took place of all permanently employed ophthalmologists in the UK and Republic of Ireland by a monthly reporting card through the British Ophthalmological Surveillance Unit. Case ascertainment was made of newly diagnosed SO from July 1997 and questionnaire data were returned at baseline, 6 months, and 1 year after diagnosis.

RESULTS

23 patients with newly diagnosed SO were recruited over 15 months, corresponding to a minimum estimated incidence of 0.03/100 000. Baseline data were available on 18 patients, in whom SO occurred after surgery in 11 patients, after retinal surgery alone in six patients, and after accidental trauma in seven patients. 12 of the 16 patients with 1 year follow up had a visual acuity of 6/12 or better. Good visual outcome was related to prompt and adequate systemic immunosuppressive therapy.

CONCLUSIONS

The incidence of sympathetic ophthalmia is very low. The main current risk is surgery, particularly retinal surgery, but visual prognosis is good if early diagnosis is made and rapid, adequate immunotherapy is commenced.