Circulating Anti-Endothelial Cell Antibodies in Patients with Geographic Atrophy Related to Dry Age-Related Macular Degeneration.

Background and Objectives: Age-related macular degeneration (AMD) is one of the leading causes of central vision loss among elderly patients, and its dry form accounts for the majority of cases. Although several causes and mechanisms for the development and progression of AMD have previously been identified, the pathogenesis of this complex disease is still not entirely understood. As inflammation and immune system involvement are strongly suggested to play a central role in promoting the degenerative process and stimulating the onset of complications, we aimed to analyze the frequency of serum anti-retinal (ARAs) and anti-endothelial cell antibodies (AECAs) in patients with dry AMD and to determine their relationship with the clinical features of the disease, notably the area of geographic atrophy (GA). Materials and Methods: This study included 41 patients with advanced-stage dry AMD and 50 healthy controls without AMD, matched for gender and age. ARAs were detected by indirect immunofluorescence using monkey retina as an antigen substrate, and the presence of AECAs was determined using cultivated human umbilical vein endothelial cells and primate skeletal muscle. Results: ARAs were detected in 36 (87.8%) AMD patients (titers ranged from 1:20 to 1:320) and in 16 (39.0%) (titers ranged from 1:10 to 1:40) controls (p = 0.0000). Twenty of the forty-one patients (48.8%) were positive for AECAs, while in the control group, AECAs were present only in five sera (10.0%). The titers of AECAs in AMD patients ranged from 1:100 to 1:1000, and in the control group, the AECA titers were 1:100 (p = 0.0001). There were no significant correlations between the presence of AECAs and disease activity. Conclusions: This study demonstrates a higher prevalence of circulating AECAs in patients with dry AMD; however, no correlation was found between the serum levels of these autoantibodies and the area of GA.

Anti-retinal IgG antibodies in patients with early and advanced type 2 macular telangiectasia.

Type 2 idiopathic macular telangiectasia (MacTel-2) is a progressive adult-onset macular disease associated with bilateral perifoveal vascular changes, Muller cell degeneration and increased blood-retinal barrier permeability. The pathophysiological mechanisms of MacTel-2 remain unclear, however it was previously reported that anti-retinal antibodies in MacTel-2 patients are a significant feature of the disease. In this study, we aimed to compare the prevalence of anti-retinal antibodies in patients MacTel-2, healthy controls and patients with other retinal diseases. MacTel-2 patients diagnosed with multimodal imaging were enrolled and their disease severities were graded using spectral-domain optical coherence tomography. For comparison, patients with age-related macular degeneration (AMD), inherited retinal diseases (IRDs) or no retinal disease (healthy controls) were recruited as controls. Blood serum samples were screened for immunoglobulin G anti-retinal antibodies by western blotting, followed by densitometry analysis. Odds ratios (OR) with 95% confidence intervals (CI) were calculated and p < 0.05 considered statistically significant. Overall, anti-retinal antibody-positive cases were older (64 ± 15 vs 53 ± 17 years, p < 0.001) and females were more likely to develop anti-retinal antibodies (OR: 2.41, CI: 1.12-5.18). The frequency of anti-retinal antibody detection in MacTel-2 patients (n = 42, 36%) was not significantly different from healthy controls (n = 52, 25%) or IRD patients (n = 18, 25%) and the majority of MacTel-2 patients had no anti-retinal antibodies. In contrast, the frequency of anti-retinal antibody detection was significantly higher in patients with AMD (n = 15, 73%, p < 0.001). The lack of a greater anti-retinal antibody frequency or specificity in the MacTel-2 cohort suggests that antibody mediated immunological mechanisms may play a less significant role in MacTel-2 disease pathogenesis.

Comparison of clinical characteristics in patients with acute zonal occult outer retinopathy according to anti-retinal antibody status.

PURPOSE: To evaluate the clinical characteristics of patients with acute zonal occult outer retinopathy (AZOOR), according to the presence or absence of anti-retinal antibodies (ARAs) that are frequently detected in autoimmune retinopathy. METHODS: Retrospective observational case series. This study included 33 patients with acute-stage AZOOR who had been followed up for more than 6 months after the initial visit. The median follow-up period was 26 months. Immunoblot analyses were used to detect autoantibodies for recoverin, carbonic anhydrase II, and α-enolase in serum from these patients. Main outcome measures comprised clinical factors at the initial and final visits, including best-corrected visual acuity, mean deviation on Humphrey perimetry, and retinal morphology, which were statistically compared between patients with AZOOR who exhibited ARAs and those who did not. RESULTS: At least one serum ARA was detected in 42% of patients with AZOOR. There were no significant differences in clinical factors between the two groups, including follow-up period, best-corrected visual acuity and mean deviation at the initial and final visits, a-wave amplitude on single-flash electroretinography at the initial visit, and frequencies of improvement of the macular ellipsoid zone and AZOOR recurrence. CONCLUSIONS: Our findings suggest that the presence of ARAs did not influence visual outcomes or outer retinal morphology in patients with AZOOR.

Comparison of clinical characteristics in patients with Vogt-Koyanagi-Harada disease with and without anti-retinal antibodies.

PURPOSE: To compare the clinical characteristics of Vogt-Koyanagi-Harada (VKH) disease patients with and without anti-retinal antibodies (ARAs) that are frequently detected in autoimmune retinopathy. METHODS: Using immunoblot analyses, serum autoantibodies for recoverin, carbonic anhydrase II, and α-enolase were examined in 20 treatment-naïve patients with VKH disease. Clinical factors before and after systemic corticosteroid therapy, including best-corrected visual acuity (BCVA) and macular outer retinal morphology, were statistically compared between patients with VKH disease with and without ARAs. RESULTS: Serum ARAs were detected in 50.0% of patients with VKH disease. There were no significant differences in clinical factors between the two groups, including final BCVA, frequency of uveitis recurrence, and recovery of the macular ellipsoid zone after systemic corticosteroid therapy. CONCLUSIONS: Our results suggest that the detected ARAs did not influence visual outcomes, the chronicity of uveitis, or outer retinal morphology in patients with VKH disease.

Detection of serum anti-retinal antibodies in the Chinese patients with presumed autoimmune retinopathy.

PURPOSE: To explore the presence of serum anti-retinal antibodies (ARAs) in the Chinese patients with presumed autoimmune retinopathy (AIR). METHODS: Twenty-three Chinese patients with presumed AIR, disease controls including 40 RP patients, 22 bilateral uveitis patients, 18 acute zonal outer occult retinopathy (AZOOR) patients, and 30 healthy donors were included. Serum samples of all the subjects were obtained and analyzed for the presence of four ARAs including recoverin, α-enolase, carbonic anhydraseII (CAII), and collapsin response-mediated protein (CRMP)-5 by Western bolt assay. RESULTS: ARAs were present in the serum of either presumed AIR patients, disease control, or healthy donors. One or more ARAs were present in the 78.2% of presumed AIR while they were indicated in the 35.0% of RP patients (p < 0.01) and 33.3% of healthy donors (p < 0.01). The prevalence of ARAs in the bilateral uveitis and AZOOR was 63.3% and 100% respectively. Positive rate of α-enolase antibody present in the presumed AIR, disease control, and healthy donors was 73.9%, 47.5%, and 33.3% respectively. Positive rate of CAII antibody present above groups was 52.1%, 50%, and 33.3% respectively. Recoverin antibody seemed to be specifically present in the serum of patients with cancer-associated retinopathy. CONCLUSION: Presence of serum ARAs including recoverin, α-enolase, CAII, or CRMP-5 in the Chinese patients with presumed AIR occurred significantly more often than RP patients and healthy donors. Seropositivity of ARAs had diagnostic value for the presumed AIR but mere presence was not sufficient for the diagnosis due to identification of them in the healthy controls and other retinal diseases.

Autoimmune Retinopathy: An Immunologic Cellular-Driven Disorder.

Autoimmune retinopathy (AIR) was often mistaken for retinitis pigmentosa (RP), due to an overlap of clinical findings, but increasingly has been recognized as a unique entity in the last decade. AIR has distinctive features: sudden onset of photopsias and scotomata in patients with no family history of RP, followed by visual field and central vision loss. Initially, retina exams are normal with no sign of pigment deposits or retinal degeneration. A family history of autoimmune diseases (all types) occurs in 60% of patients. One hallmark of AIR has been the presence of anti-retinal autoimmune antibodies (ARAs) in patients' sera, but patients can continue to have ARAs even when the disease has been quiescent for years. The accumulation of ARAs represents a breakdown of retinal immune tolerance with many different immunoreactive bands found at different reference weights in AIR patients. We began investigating cellular immunity using flow cytometry and found abnormal distributions (>2 StDev) of increased memory lymphocytes and NK cells and decreased regulatory B cell subsets in many AIR patients compared to normal controls. Culture of patient lymphocytes with small amounts (25 µg) of recoverin protein for 6 days led to significant elevations of interferon gamma (IFNγ) and in some cases tumor necrosis factor alpha (TNFα) production. We found the IFNγ/IL-10 ratio in response to recoverin was elevated in patients with more active disease (defined by visual field contraction between visits), but in some patients, there also appeared to be independent factors influencing severity, suggesting other autoimmune mechanisms were at play. These cellular immune parameters may provide improved markers for active AIR.

Acute progressive paravascular placoid neuroretinopathy with negative-type electroretinography in paraneoplastic retinopathy.

PURPOSE: Paraneoplastic retinopathy can be the first manifestation of systemic malignancy. A subset of paraneoplastic retinopathy is characterized by negative-type electroretinography (ERG) without fundus abnormality. Here we describe the multimodal imaging and clinico-pathological correlation of a unique case of acute progressive paravascular placoid neuroretinopathy with suspected retinal depolarizing bipolar cell dysfunction preceding the diagnosis of metastatic small cell carcinoma of the prostate. METHODS: ERG was performed according to the International Society for Clinical Electrophysiology of Vision standards. Imaging modalities included near-infrared reflectance, blue-light autofluorescence, fluorescein and indocyanine green angiographies, spectral domain optical coherence tomography, ultra-widefield colour and green-light autofluorescence imaging, microperimetry and adaptive optics imaging. Patient serum was screened for anti-retinal antibodies using western blotting. Immunostaining and histological analyses were performed on sections from human retinal tissues and a patient prostate biopsy. RESULTS: Serial multimodal retinal imaging, microperimetry and adaptive optics photography demonstrated a paravascular distribution of placoid lesions characterized by hyper-reflectivity within the outer nuclear layer resembling type 2 acute macular neuroretinopathy. There was no visible lesion within the inner nuclear layer despite electronegative-type ERG. Six months later, the patient presented with metastatic small cell carcinoma of the prostate. Tumour cells were immunopositive for glyceraldehyde-3-phosphate dehydrogenase, enolase and recoverin as well as neuroendocrine markers. The patient's serum reacted to cytoplasmic and nuclear antigens in the prostate biopsy and in human retina. Anti-retinal antibodies against several antigens were detected by both commercial and in-house western blots. CONCLUSIONS: A spectrum of autoreactive anti-retinal antibodies is associated with a unique phenotype of acute progressive paravascular placoid neuroretinopathy resulting in degeneration of photoreceptor cells, inner retinal dysfunction and classic electronegative ERG in paraneoplastic retinopathy. Detailed clinical, functional and immunological phenotyping of paraneoplastic retinopathy illustrated the complex mechanism of paraneoplastic syndrome.

Comparison of Clinical and Immunological Features of Para- and Non-Paraneoplastic Autoimmune Retinopathy in Chinese - A Series of 48 Cases.

PURPOSE: To characterize and compare clinical and immunological features of para(p)-autoimmune retinopathy (AIR) and non-para(np)-AIR and to assess the clinical significance of the presence of serum anti-retinal antibodies (ARAs). METHODS: We retrospectively reviewed 48 Chinese patients with p-AIR or np-AIR who took comprehensive ophthalmic examinations and lab tests of the presence of serum ARAs. RESULTS: p-AIR patients differed from np-AIR patients in terms of disease progression, ocular inflammation, findings of OCT, FFA, and presence of ARAs. No significant difference was found in the band number of serum ARAs between AIR patients and healthy controls. The prevalence of antibodies to recoverin and ɑ-enolase in the sera of p-AIR was significantly higher than that of the healthy individuals. CONCLUSION: While having many similar clinical signs, patients with p-AIR or np-AIR nevertheless displayed unique characteristics. Detection of ARAs subtypes, rather than their quantity, may be helpful in evaluating the conditions in the verified instances.

Anti-retinal Antibodies in Sarcoidosis.

PURPOSE: To measure, characterize, and evaluate the clinical significance of anti-retinal antibodies in patients with sarcoid uveitis. SUBJECTS/METHODS: Prospective study of anti-retinal antibodies in 45 patients with biopsy-proven sarcoidosis (25 with and 20 without uveitis). Results were compared with patients with confirmed infectious uveitis (n = 40) and non-infectious uveitis (n = 40). RESULTS: Among sarcoidosis patients, anti-retinal antibodies were positive in 23/25 patients with uveitis and in 15/20 without uveitis [P = ns]. The most common antigens recognized were carbonic anhydrase II (14/23) and α-enolase (6/23). Anti-carbonic anhydrase II autoantibodies were infrequently detected in sarcoidosis patients without uveitis (2 out 15, P < .001), in patients with infectious uveitis (1 out 18, P < .001), and in patients with non-infectious uveitis (8 out 37, P < .001). CONCLUSIONS: Anti-retinal antibodies recognizing carbonic anhydrase II are common in sarcoid uveitis. Although not fully sensitive and specific, they might be a useful non-invasive diagnostic tool for the diagnosis of sarcoid uveitis.

Autoimmune Retinopathy, Testing, and Its Controversies.

Purpose of review: The purpose of this revision is to sumarize the most important clinical features of the autoimune retinopathies (AIRs). Recent findings: AIRs are a group of inflammatory conditions affecting the retina characterized by progressive unexplained visual loss, abnormalities and contraction in visual fields, photoreceptor and electroretinographic dysfunction, and the presence of circulating anti-retinal antibodies. The pathogenesis of AIR remains unclear and various antiretinal antibodies have been associated to the disease. The diagnosis of AIR is based on a particular clinical presentation along with the detection of serum antiretinal antibodies. Numerous anti-inflammatory therapeutic alternatives have been described for the treatment of AIR, nevertheless there is no consensus on treatment protocol. Summary: Because of its association with different types of malignant tumors, the early diagnosis, multi-disciplinary approach and prompt treatment should be warranted.

Combination Treatment with Rituximab and Bortezomib in a Patient with Non-Paraneoplastic Autoimmune Retinopathy.

PURPOSE: To describe outcomes of combined rituximab and bortezomib treatment for non-paraneoplastic autoimmune retinopathy. CASE: A 37-year-old female developed photopsias and reduced vision. Electroretinography, optical coherence tomography, and positive serum anti-retinal antibodies were consistent with autoimmune retinopathy. A negative malignancy work-up specified her non-paraneoplastic presentation. Given absence of response to periocular steroids, azathioprine, and methotrexate, a combination of rituximab and bortezomib was initiated as fifth-line therapy. RESULTS: There was no significant improvement in the patient's symptoms or visual function following treatment. The full field electroretinogram amplitudes were reduced with progressive outer retinal degeneration evident on optical coherence tomography. Post-treatment anti-retinal antibody testing demonstrated the persistence of antibodies and revealed additional antibodies not previously detected. CONCLUSION: Combined rituximab and bortezomib treatment did not result in significant clinical improvement and there was evidence of disease progression. Further prospective studies are required to assess the efficacy of immunotherapy in patients with autoimmune retinopathy.

Non-paraneoplastic related retinopathy: clinical challenges and review.

Autoimmune retinopathy (AIR) is a rare inflammatory condition characterized by progressive visual loss, abnormalities in visual fields and electroretinographic exams, along with presence of circulating anti-retinal antibodies. There are two main forms of AIR: paraneoplastic AIR (pAIR) and presumed non-paraneoplastic AIR (npAIR). NpAIR is considered a diagnosis of exclusion, since it is typically made after other causes of retinopathy have been investigated and the absence of malignancy is confirmed. Work-up of a npAIR case is challenging since there are no standartizaded protocols for diagnosis and treatment. The treatment regimen may vary from case to case, and it can be best guided by a set of parameters including electrophysiological responses, visual outcomes, and presence of anti-retinal antibodies. The purpose of this review is to summarize the principal clinical features, investigation, and management of npAIR.

A case report of acute zonal occult outer retinopathy.

PURPOSE: To describe the diagnostic complexities of a patient with acute zonal occult outer retinopathy. CASE REPORT: A healthy female presented with acute bilateral visual field loss and photopsia. On initial examination, her visual acuity, colour vision, fundus examination and fluorescein angiography were normal. Fundus autofluorescence, however, revealed scattered hyperautofluorescence in both eyes and electrodiagnostic tests were abnormal. A differential diagnosis including acute zonal occult outer retinopathy was postulated and serology requested. The patient's past medical history included both breast and endometrial cancer and raised the possibility of cancer-associated retinopathy. A normal full-body positron emission tomography scan, negative antibodies for cancer-associated retinopathy and abnormal electroretinogram led to a diagnosis of acute zonal occult outer retinopathy. CONCLUSION: It has been more than 20 years since Gass first described the syndrome of acute zonal occult outer retinopathy. Typically affecting young, healthy females, acute zonal occult outer retinopathy is characterised by photopsia, minimal fundoscopic changes and electroretinographic abnormalities. Visual field loss is permanent and often associated with slow-progressing degeneration of the retinal pigment epithelial cells. Retinal photoreceptor dysfunction is an uncommon and unrecognised cause of acute visual loss. Acute zonal occult outer retinopathy should be considered as a differential diagnosis in those patients with deceptively normal fundal examinations, abnormal electroretinograms and visual field loss.

Autoimmune retinopathy: A case report from India.

A first case report of autoimmune retinopathy (AIR) from India. A middle-aged female patient presented with subacute loss of vision in both eyes. Clinical examination revealed a near normal fundus in both the eyes. A presumed diagnosis of nonparaneoplastic AIR was made based on clinical features and suggestive investigations. Early detection and management with steroids or immunosuppression may be beneficial to patients with AIR.

False-positive anti-retinal antibodies as a cause of psychogenic vision loss.

PURPOSE: To report a case of psychogenic vision loss caused by false-positive anti-retinal antibody testing. METHODS: We describe a case of visual and systemic symptoms following anti-retinal antibody detection. The case was analyzed for clinical presentation, diagnosis, and consequences of false-positive testing. RESULTS: The patient presented with decreased vision without detectable pathology on ophthalmic examination. Tests were ordered in search of a diagnosis, including an antibody test. Following detection of anti-retinal antibodies, the patient developed worsening visual symptoms and systemic manifestations. A repeat antibody test performed at our institution revealed negative results, which, in conjunction with lack of visual field expansion, confirmed our suspicion of psychogenic vision loss. CONCLUSIONS: Laboratory screening may be limited by test specificity and can lead to false-positive results, affecting the patient psychologically and clinically. Care must be taken in patients with positive anti-retinal antibodies to ensure the presence of definitive disease before initiation of treatment.

A curious case of glaucoma?

An 84-year-old woman diagnosed with primary open-angle glaucoma was referred because her optic nerve appearance did not account for her visual field deficits. Further evaluation showed loss of color vision and rapid progression of visual field defects. Electroretinography revealed abnormal scotopic and photopic responses. Blood samples were positive for anti-retinal antibodies, but a malignancy work-up was negative, consistent with non-paraneoplastic autoimmune retinopathy.