Clinical and immunologic characteristics of melanoma-associated retinopathy syndrome: eleven new cases and a review of 51 previously published cases

Autoantibodies in Melanoma-Associated Retinopathy Recognize an Epitope Conserved Between TRPM1 and TRPM3

Purpose

Melanoma-associated retinopathy (MAR) is a paraneoplastic syndrome associated with malignant melanoma and the presence of anti-retinal autoantibodies, including autoantibodies against transient receptor potential melanopsin 1 (TRPM1), a cation channel expressed by both melanocytes and retinal bipolar cells. The goal of this study was to further map the antigenic epitope.

Methods

Patient sera were tested by immunofluorescence and Western blotting on HEK293 cells transfected with enhanced green fluorescent protein (EGFP)-TRPM1 fusion constructs and mouse retina sections.

Results

The epitope recognized by MAR patient sera was mapped to a region encoded by exons 9 and 10 of the human TRPM1 gene. This region of TRPM1 is highly conserved with TRPM3, and indeed MAR sera were found to cross-react with TRPM3, a closely related channel expressed in the retinal pigment epithelium (RPE).

Conclusions

These results indicate that TRPM1 autoantibodies in MAR patient sera recognize a short, intracellular segment of TRPM1. Cross-reactivity with TRPM3 in the RPE may account for other visual symptoms that are experienced by some MAR patients such as retinal and RPE detachments. We propose that TRPM1 autoantibodies are generated in response to abnormal TRPM1 polypeptides encoded by an alternate mRNA splice variant expressed by malignant melanocytes.

Efficacy of rituximab in non-paraneoplastic autoimmune retinopathy

Background

Autoimmune retinopathy (AIR) is a rare but potentially blinding condition that is often underdiagnosed. Common features in AIR presentation include rapidly progressive vision loss with abnormal electrophysiological responses of the retina associated with positive anti-retinal antibodies. AIR is also challenging to treat, and thus, the introduction of new potential therapeutic agents is welcomed. The goal of this communication is to assess the effects of rituximab infusions on electroretinogram (ERG) responses and visual function outcomes in patients with non-paraneoplastic autoimmune retinopathy (npAIR).

Results

Following infusion(s), three out of five patients showed no evidence of disease progression or improved, while two patients continued to progress on ERG. One patient demonstrated improvement in visual acuity (2 lines) in both eyes. ERG responses provided objective monitoring of patients’ visual function and response to immunosuppression over time.

Conclusions

These findings suggest that patients with npAIR unresponsive to other immunosuppression therapies may benefit from rituximab infusion, although stabilization rather than improvement was more frequently the outcome in our case series. Furthermore, regularly scheduled ERG follow-up examinations are recommended for monitoring patients’ progression during treatment.

Introducing MARCo: Histoserological Findings of a Multi-Organic Paraneoplastic Syndrome in Cutaneous Melanoma Patients

Introduction

Cutaneous melanoma (CM) is an aggressive skin cancer entity, causing most skin cancer-related deaths. Autoimmune disorders have been described as potential paraneoplastic complications. The purpose of this study was to elucidate the possibility of a combinatory paraneoplastic affection of the retina and cochlea in patients with CM.

Methods

Sera samples from CM patients were used for indirect immunofluorescence on histological retinal and cochlear sections. Furthermore, the serum specimen of a patient with symptomatic affection of both organs was analyzed by multiplex ELISA (enzyme-linked immunosorbent assay) for various cytokines including CD163 (cluster of differentiation 163).

Results

Eleven patients were diagnosed with CM. Autoantibodies against structures of the inner ear were confirmed in all patients who were tested positive for antiretinal antibodies as well. CD163 was significantly elevated in the double-symptomatic patient, who developed metastatic disease.

Conclusion

Paraneoplastic disease of CM can affect more than one organ and this affect may be correlated with the individual prognosis. Therefore, a thorough anamnesis is needed to avoid missing potential symptoms.

MEK inhibitor-associated retinopathy (MEKAR) in metastatic melanoma: Long-term ophthalmic effects

BACKGROUND

Mitogen-activated protein kinase kinase (MEK) inhibitors have aroused considerable interest in oncology. Activity has been demonstrated in various types of cancer, especially melanoma. MEK inhibitors induce a transient retinopathy, considered to be a class effect. At present, only sparse data are available on retinal effects with long-term MEK inhibition.

PATIENTS AND METHODS

In this prospective, observational study, patients with advanced melanoma participating in different phase 1/2 or phase 3 clinical trials were treated with the MEK inhibitor binimetinib, with a v-Raf murine sarcoma viral oncogene homolog B (BRAF) inhibitor, or with combination therapy. They underwent regular ophthalmological examinations including determination of visual function, biomicroscopy, dilated fundoscopy and optical coherence tomography (OCT) for a period of up to 2 years. Retinopathy was diagnosed on defined OCT criteria.

RESULTS

Sixty-two patients were investigated between 1st October 2011 and 31st July 2015: 13 were treated with the MEK inhibitor binimetinib alone, 10 with a selective BRAF inhibitor, and 39 with combination therapy. In 92% of patients on monotherapy and 100% of those on combination treatment, binimetinib caused dose-related lesions with serous neuroretinal detachments and oedema, strongly dependent on the time after medication. With continued treatment, retinal volume and thickness decreased to levels below baseline, without any apparent functional deficits or changes in structural integrity.

CONCLUSIONS

Binimetinib induces a specific retinopathy with daily fluctuations depending on the time interval after medication. The retinopathy partially recovers, but can still be detected many months later. Retinal thinning, possible first signs of retinal atrophy have been observed after long-term treatment, but, so far, without functional relevance.

Paraneoplastic Syndromes in Neuro-Ophthalmology

BACKGROUND

Paraneoplastic syndromes that affect the visual pathways and present with neuro-ophthalmologic signs or symptoms may involve the afferent or efferent systems. Afferent syndromes may involve the optic nerve or retina and, in some cases, these may be associated with systemic neurologic disease. Efferent symptoms typically affect eye movements and may involve the neuromuscular junction or involuntary eye movements.

EVIDENCE ACQUISITION

Literature review and personal clinical and research experience.

RESULTS

Diagnosis of paraneoplastic syndromes relies on clinical and laboratory evaluations. In the appropriate clinical setting, the presence of specific antibodies may help confirm the diagnosis.

CONCLUSIONS

In some cases, the visual pathway disturbance precedes a diagnosis of malignancy. Astute observation and selective evaluation and management are critical to establish the correct diagnosis and institute therapeutic approaches that can be sight or life saving.

Non-Paraneoplastic Autoimmune Retinopathy: The First Case Report in Korea

Autoimmune retinopathy (AIR) is an immune-mediated retinopathy, resulting from an immunologic process caused by the aberrant recognition of retinal antigens as autoantigens. The diagnosis of AIR involves the detection of antiretinal antibodies with concurrent clinical and electrophysiological evidence of retinopathy. A 40-year-old patient presented with progressive loss of bilateral vision over several months. A fundus examination was unremarkable. Spectral domain optical coherence tomography revealed a blurred photoreceptor ellipsoid zone at the subfoveal region in both eyes with more prominent disruption in the left eye. Full-field electroretinography (ERG) showed relatively normal rod and cone responses in the right eye, and decreased photopic bwaves with minimal attenuation of a-waves in the left eye. Multifocal ERG demonstrated slightly reduced amplitude of the inner segment ring in the right eye and decreased amplitudes and delayed latencies of all modalities in the left eye. The patient was suspected to have AIR and it was supported by positive Western blots for 23-kDa protein, enolase (46-kDa), aldolase (40-kDa), 62-kDa and 78-kDa proteins and by immunohistochemical staining of human retinal bipolar and ganglion cells. Despite the immunosuppressive treatment, the destruction of the retinal photoreceptors progressed, and immunosuppressive interventions produced very little visual improvement. We report on what is, to the best of our knowledge, the very first case of serologically confirmed nonparaneoplastic AIR in Korea.

Exudative Polymorphous Vitelliform Retinopathy: Importance of Early Recognition of the Condition in Patients with Metastatic Melanoma

Introduction

Because of the advent of monoclonal antibodies in the treatment of metastatic melanoma, patients with this disease are surviving longer. Early recognition of the disease has therefore become even more important.

Case report

We present a patient with vitelliform maculopathy, a paraneoplastic retinal maculopathy that is under-recognized. Clinically the retinal findings of serous detachments and pigmentary macular changes are remarkable, while at the same time these patients have surprisingly very few symptoms. This is in contrast to patients who develop melanoma associated retinopathy (MAR) who are very symptomatic early in the disease, but with more subtle retinal findings.

Conclusion

Monoclonal antibody treatment is changing the survival rates in metastatic disease making early diagnosis even more important. Exudative polymorphous vitelliform maculopathy (EPVM) needs to be recognized early to avoid delay in diagnosis of metastatic disease.

Autoimmunity in visual loss

There are a number of autoimmune disorders which can affect visual function. There are a very large number of mechanisms in the visual pathway which could potentially be the targets of autoimmune attack. In practice it is the retina and the anterior visual pathway (optic nerve and chiasm) that are recognised as being affected in autoimmune disorders. Multiple Sclerosis is one of the commonest causes of visual loss in young adults because of the frequency of attacks of optic neuritis in that condition, however the basis of the inflammation in Multiple Sclerosis and the confirmation of autoimmunity is lacking. The immune process is known to be highly unusual in that it is not systemic and confined to the CNS compartment. Previously an enigmatic partner to Multiple Sclerosis, Neuromyelitis Optica is now established to be autoimmune and two antibodies - to Aquaporin4 and to Myelin Oligodendrocyte Glycoprotein - have been implicated in the pathogenesis. The term Chronic Relapsing Inflammatory Optic Neuropathy is applied to those cases of optic neuritis which require long term immunosuppression and hence are presumed to be autoimmune but where no autoimmune pathogenesis has been confirmed. Optic neuritis occurring post-infection and post vaccination and conditions such as Systemic Lupus Erythematosus and various vasculitides may cause direct autoimmune attack to visual structures or indirect damage through occlusive vasculopathy. Chronic granulomatous disorders such as Sarcoidosis affect vision commonly by a variety of mechanisms, whether and how these are placed in the autoimmune panoply is unknown. As far as the retina is concerned Cancer Associated Retinopathy and Melanoma Associated Retinopathy are well characterised clinically but a candidate autoantibody (recoverin) is only described in the former disorder. Other, usually monophasic, focal retinal inflammatory disorders (Idiopathic Big Blind Spot Syndrome, Acute Zonal Occult Outer Retinopathy and Acute Macular Neuroretinitis) are of obscure pathogenesis but an autoimmune disorder of the post-infectious type is plausible. Visual loss in autoimmunity is an expanding field: the most significant advances in research have resulted from taking a well characterised phenotype and making educated guesses at the possible molecular targets of autoimmune attack.

Audiovestibular disorders as autoimmune reaction in patients with melanoma

Melanoma is an aggressive form of cancer derived from neuroectodermal melanocytes. Melanocytes are present in the skin and hair follicles, as well as in the eye (iris and choroids), the leptomeninges, the anal canal and the inner ear. In the inner ear melanocytes are found both in the intermediate layer of the stria vascularis of the cochlea and in the dark cells of the vestibular organs. They are believed to play an important role in the production of endolymphatic potentials and in the maintenance of normal volumes of the inner ear fluids. Recently, audiovestibular dysfunctions have been demonstrated in patients treated with immunotherapy for metastatic melanoma and have been related to an autoimmune attack on the normal melanocytes of the inner ear. Melanoma is an immunogenic tumor type frequently associated with spontaneous autoimmune manifestations which seem to be associated with better prognosis. The melanoma-associated antigens are also expressed in normal melanocytes in the skin, eye and ear. We hypothesize that inner ear melanocytes could be a target of an autoimmune process in patients affected by melanoma. The immune system could produce antibodies that cross-react with both the melanoma cells and the labyrinth melanocytes causing an altered homeostasis of endolymphatic liquids and provoking some labyrinthic disorders such as vertigo, hearing loss, aural fullness and tinnitus resembling or influencing Ménière's disease. In this perspective, audiovestibular disorders could be interpreted as an attempt by the individual immune system to develop anti-tumor response. In patients affected by melanoma an autoimmune genesis has already been advocated for ocular symptoms in melanoma-associated retinopathy, where the cross-reaction happens against retinal cells. A possible role of inner ear melanocytes should be considered as a potential cause of audiovestibular disorders. Further research is needed to demonstrate a connection between melanoma and labyrinth dysfunctions such as in melanoma-associated retinopathy.

Paraneoplastic retinopathy associated with systemic follicular cell lymphoma

The authors describe two rare cases of autoimmune retinopathy associated with follicular cell lymphoma, including a 54-year-old man who experienced nyctalopia for 1 year (patient 1) and a 59-year-old man who had bilateral loss of central vision for 6 months (patient 2). Visual field testing of patient 1 revealed nonspecific defects, and multifocal electroretinogram (ERG) testing showed mildly subnormal amplitudes more pronounced in the left than the right eye. Serologic testing detected antibodies against a 47-kD protein, presumed to be alpha-enolase. Goldmann perimetry of patient 2 showed dense central scotomas, and a full-field ERG revealed reduced amplitudes of bright scotopic responses. Serological testing yielded anti-bipolar cell antibodies. A variable presentation of autoimmune retinopathy can occur in the setting of follicular cell lymphoma. Disparate serum autoantibodies may have mediated the pathogenesis of retinal degeneration in these two patients and could explain the difference in course and severity of retinopathy.

Repeatability of mesopic visual acuity measurements using high- and low-contrast ETDRS letter charts

PURPOSE

To determine the repeatability of mesopic high-contrast (HC) and low-contrast (LC) visual acuity (VA) measurements made at distance and near in healthy young individuals. While the repeatability of photopic VA is well-known, there is a lack of information with regard to the repeatability of VA measured under low luminance conditions.

METHODS

In two different sessions 1 week apart, best-corrected monocular VA was determined using HC (96 %) and LC (10 %) ETDRS charts under mesopic luminance conditions (0.75 cd/m(2)) at distance (HCD, LCD) and near (HCN, LCN) in 47 healthy subjects aged 22.9 ± 6.8 years. Repeatability was estimated by the Bland and Altman method, whereby the mean difference (MD) and the 95 % limits of agreement were determined as the coefficient of repeatability (COR).

RESULTS

Mean logMAR VA values were HCD = 0.09, LCD = 0.44, HCN = 0.21, and LCN = 0.57. Mean differences in measurements between sessions 1 and 2 were not significant, and low in clinical terms (≤1 letter). Repeatability was better for the distance measurements at both high and lowcontrast (COR HCD ±0.11 and COR LCD ±0.11 logMAR vs COR HCN ±0.15 and COR LCN ±0.16 logMAR), and MDs were also slightly closer to zero for the distance measurements. Similar repeatability was observed between HC and LC VA, both at distance and near.

CONCLUSIONS

In mesopic conditions, ETDRS charts offer repeatable best-corrected monocular VA measurements. The criterion for a significant change in logMAR VA was 1 line at distance and 1.5 lines at near.

Spontaneous improvement of rod system function in a patient with melanoma-associated retinopathy

PURPOSE

To report spontaneous improvement of rod visual function in a patient with melanoma-associated retinopathy (MAR).

METHODS

Electroretinography (ERG), and dark-adapted psychophysical thresholds were performed on a male patient with the MAR syndrome, during four visits over a period of almost 7 years.

RESULTS

There was a spontaneous, subjective improvement in night vision and a decrease in the severity of photopsias of the patient's left eye between the initial and most recent visits. Both the dark-adapted rod-isolated and maximal-flash b-wave ERG amplitude also improved his initial visit to the most recent visit. By comparison, the light-adapted brief-flash and flicker ERG amplitudes were initially within the range of normal in the left eye but showed a subsequent reduction in amplitude. The ERG response of the right eye was only measured at the most recent visit, but gave a dark-adapted response that was similar to that of the left eye on the initial visit, and a light-adapted response that was similar to that of the left eye on the most recent visit. Rod sensitivity was substantially better in the left eye than in the right eye by psychophysical testing, although the right eye did show a noticeable level of improvement in rod thresholds between the initial and most recent visits.

CONCLUSIONS

These findings document the potential for spontaneous improvement in electrophysiological and psychophysical rod function, as well as in subjective symptoms, in patients with the MAR syndrome.

Case of paraneoplastic retinopathy with retinal ON-bipolar cell dysfunction and subsequent resolution of ERGs

PURPOSE

To report a patient with cancer-associated retinopathy and retinal ON-bipolar cell dysfunction who had a resolution of the electroretinograms (ERGs) after a resection of an ovarian cancer and chemotherapy.

CASE REPORT

A 71-year-old Japanese female patient visited us complaining of night blindness and photopsia in both eyes for 6 months. Her visual acuity was 20/20 in both eyes, and fundus examination, fluorescence angiography, and optical coherence tomography showed no abnormalities in both eyes. The rod responses of the ERGs were absent and bright-flash ERGs were electronegative. The ON responses of the focal macular ERGs and full-field long-flash ERGs were absent. These ERG findings indicate an ON-bipolar cell dysfunction. A general physical examination revealed the presence of ovarian cancer. After resection of the ovarian cancer and adjuvant chemotherapy, the ERGs of the left eye completely recovered within 2 years and those of right eye recovered subsequently. The autoantibody against transient receptor potential melastatin 1 (TRPM1) was not detected in the serum.

CONCLUSION

Our case demonstrates that retinal ON-bipolar dysfunction can be caused by ovarian cancer. Our case indicates that some autoantibodies against other than TRPM1 might cause transient dysfunction of retinal ON-bipolar cells.

Paraneoplastic vitelliform retinopathy in a patient with treated choroidal melanoma

PURPOSE

To describe a peculiar case of paraneoplastic vitelliform maculopathy/retinopathy in a patient with treated choroidal melanoma.

METHODS

A case report of a 58-year-old woman with a history of treated choroidal melanoma 16 years before developing visual changes in the setting of metastatic choroidal melanoma.

RESULTS

We demonstrate bilateral, multifocal vitelliform subretinal lesions and focal, neurosensory retinal detachment associated with metastatic melanoma.

CONCLUSION

Paraneoplastic vitelliform maculopathy/retinopathy should be considered in patients with or without a history of melanoma, who have unexplained serous, vitelliform retinal detachments, especially with atypical or absence of leakage on fluorescein angiography.

Exacerbation of audiovestibular symptoms in a patient with Ménière's disease and choroidal melanoma

We report the case of a man affected by a unilateral Ménière's disease who, after being free from vertigo spells and tinnitus for more than ten years, manifested an exacerbation of symptoms just before the diagnosis of a choroidal melanoma. Melanoma is an aggressive form of cancer derived from neuroectodermal melanocytes. Melanocytes are present in the inner ear where they contribute to the production of endolymphatic potentials and to the maintenance of normal volumes of the inner ear fluids. A possible autoimmune connection between the exacerbation of audiovestibular symptoms and melanoma is discussed.

Transient MEK inhibitor-associated retinopathy in metastatic melanoma

BACKGROUND

Melanoma is one of the most aggressive skin cancers. Recently, selective MEK inhibitors have shown efficacy in patients with advanced BRAF- and NRAS-mutant melanoma. Soon after the initiation of clinical oncology trials with MEK inhibitors, it was observed that some participants developed an eye condition resembling central serous chorioretinopathy. The present article addresses the clinical features and management of these MEK inhibitor-associated retinal syndromes.

PATIENTS AND METHODS

Thirty-two patients with advanced cutaneous melanoma were treated with the selective MEK inhibitor binimetinib (MEK162) in three different Phase 1b or 2 clinical trials. Twenty patients on binimetinib monotherapy and 12 on binimetinib plus RAF inhibitor [pan-kinase RAF inhibitor RAF265 (n = 7) or selective BRAF inhibitor encorafenib (LGX818) (n = 5)] combination therapy underwent ophthalmological examinations at regular intervals, including determination of best corrected visual acuity, perimetry, colour vision testing, dilated fundus examination, and multimodal imaging.

RESULTS

Grade 1-2 bilateral retinopathies with multiple lesions were observed in 13 of 20 patients on binimetinib monotherapy, 4 of 7 patients on binimetinib plus RAF265 combination therapy, and 2 of 5 patients on binimetinib plus encorafenib combination therapy. In this study population, the rate ranged from 40% to 65%. Retinopathy events appeared during the first 4 weeks, and in some cases, during the first few days of treatment. Patients reported mild and only short-lived visual symptoms. Optical coherence tomography revealed neuroretinal elevations. Central retinal thickness and volume showed dose-dependent increases after the start of treatment, followed by a marked decrease despite continued treatment, which was associated with symptom resolution. No vascular abnormalities were found with fluorescein and indocyanine green angiography.

CONCLUSIONS

Treatment with the selective MEK inhibitor binimetinib as a single agent or in combination with RAF inhibitors induced transient retinopathy with multiple bilateral lesions in some patients. Binimetinib-induced retinopathy was usually mild, self-limiting, and tolerable as visual function was not seriously impaired.

Choroidal atrophy in a patient with paraneoplastic retinopathy and anti-TRPM1 antibody

The purpose of this paper is to report choroidal atrophy in a patient with cancer-associated retinopathy who had autoantibodies against the transient receptor potential cation channel, subfamily M, member 1 (TRPM1). A 69-year-old man visited our clinic in July 2010 with complaints of blurred vision and night blindness in both eyes. The full-field electroretinograms were negative type, indicating ON bipolar cell dysfunction. General physical examination revealed small cell carcinoma of the lung, and Western blot of the patient’s serum showed autoantibodies against TRPM1. We diagnosed this patient with cancer-associated retinopathy and retinal ON bipolar dysfunction due to anti-TRPM1 autoantibody. We followed him for more than 2 years from the initial visit and his symptoms have not changed. However, consistent with the choroidal hypopigmentation of the fundus, spectral domain optical coherence tomography showed a decrease in choroidal thickness of about one third over a 2-year follow-up period. We suggest that this case of gradually progressive choroidal atrophy was caused by the autoantibody against TRPM1 directly, because TRPM1 is expressed not only on ON bipolar cells but also on melanocytes. These findings indicate that we should be aware of choroidal thickness in patients with paraneoplastic retinopathy who have retinal ON bipolar dysfunction with the anti-TRPM1 antibody.

Autoantibodies to transient receptor potential cation channel, subfamily M, member 1 in a Japanese patient with melanoma-associated retinopathy

PURPOSE

To report a case of melanoma-associated retinopathy (MAR) in a Japanese patient found to have autoantibodies to transient receptor potential cation channel, subfamily M, member 1 (TRPM1).

CASE

An 82-year-old man presented with blurred vision OS as well as night blindness and photopsia OU. Fundus photography, fluorescein angiography, and spectral domain-optical coherence tomography findings were essentially normal. Goldmann perimetry revealed a relative central scotoma, including the blind spot in the right eye, as well as a relative scotoma around a blind spot OS. The full-field scotopic electroretinograms showed a "negative-type" pattern OU, suggestive of extensive bipolar cell dysfunction. Systemic examination revealed that the patient had malignant melanoma of the anus with lung metastasis. Autoantibodies to TRPM1 were detected in the serum of the patient by immunoblot analysis. Vitreous opacity developed during follow-up. The visual symptoms and vitreous opacity of the patient were markedly improved after oral prednisolone therapy. The patient died as a result of widespread metastasis of the melanoma at 11 months after his first visit.

CONCLUSION

The present case is the first reported instance of MAR positive for autoantibodies to TRPM1 in an Asian patient.

Diagnostic features of the autoimmune retinopathies

The term autoimmune retinopathy encompasses a spectrum of rare autoimmune diseases that affect retinal function, often but not exclusively at the level of the photoreceptor. They typically present with painless visual loss, which may be accompanied by normal fundus examination. Some are progressive, often rapidly. They present a diagnostic challenge because there are no standardised clinical or laboratory based diagnostic criteria. Included within the spectrum are cancer-associated retinopathy, melanoma-associated retinopathy and presumed non-paraneoplastic autoimmune retinopathy. Differentiation from other retinopathies can be challenging, with overlap in symptoms, signs, and investigation findings, and an absence of pathognomonic features. However, technological developments in ophthalmic imaging and serological investigation over the past decade are adding novel dimensions to the investigation and classification of patients with these rare diseases. This review addresses the clinical, imaging, and serological features of the autoimmune retinopathies, and discusses the relative strengths and limitations of candidate diagnostic features.

Autoimmune retinopathy

PURPOSE OF REVIEW

Autoimmune retinopathy (AIR) is an immune-mediated disorder characterized by progressive visual loss, abnormal electroretinographic and visual field findings in the presence of circulating anti-retinal antibodies. This review highlights advances made toward understanding the pathophysiology, clinical manifestations, and trends in the management of AIR.

RECENT FINDINGS

The pathophysiology of AIR is likely antibody-mediated. AIR serum autoantibodies are variable in their size and retinal tissue they target and can also be present in healthy controls and multiple autoimmune diseases. Rarely, AIR may be associated with dysregulated self-tolerance mechanisms in the thymus. Despite progress in research, our understanding of AIR remains incomplete. Lack of standardized methods for anti-retinal antibody testing continues to challenge the interpretation of seropositivity. Conventional immunosuppressives have been further studied, and promising immunomodulatory therapies, such as targeted B-cell therapy, have been introduced. Newer imaging modalities such as fundus autofluorescence and spectral domain optical coherence tomography may be helpful in diagnosis, monitoring progression of disease and response to treatment.

SUMMARY

AIR is a rare but vision-threatening disease whose pathogenesis is poorly defined. Lack of standardized clinical or laboratory criteria further complicates the diagnosis and management. Despite recent progress, further basic science research into the autoimmune process is needed. Prospective controlled clinical trials with immunomodulatory therapy can help define future treatment paradigms.

Degeneration of retinal on bipolar cells induced by serum including autoantibody against TRPM1 in mouse model of paraneoplastic retinopathy

The paraneoplastic retinopathies (PRs) are a group of eye diseases characterized by a sudden and progressive dysfunction of the retina caused by an antibody against a protein in a neoplasm. Evidence has been obtained that the transient receptor potential melastatin 1 (TRPM1) protein was one of the antigens for the autoantibody against the ON bipolar cells in PR patients. However, it has not been determined how the autoantibody causes the dysfunction of the ON bipolar cells. We hypothesized that the antibody against TRPM1 in the serum of patients with PR causes a degeneration of retinal ON bipolar cells. To test this hypothesis, we injected the serum from the PR patient, previously shown to contain anti-TRPM1 antibodies by westerblot, intravitreally into mice and examined the effects on the retina. We found that the electroretinograms (ERGs) of the mice were altered acutely after the injection, and the shape of the ERGs resembled that of the patient with PR. Immunohistochemical analysis of the eyes injected with the serum showed immunoreactivity against bipolar cells only in wild-type animals and not in TRPM1 knockout mice,consistent with the serum containing anti-TRPM1 antibodies. Histology also showed that some of the bipolar cells were apoptotic by 5 hours after the injection in wild type mice, but no bipolar cell death was found in TRPM1 knockout mice, . At 3 months, the inner nuclear layer was thinner and the amplitudes of the ERGs were still reduced. These results indicate that the serum of a patient with PR contained an antibody against TRPM1 caused an acute death of retinal ON bipolar cells of mice.

Diagnosis of occult melanoma using transient receptor potential melastatin 1 (TRPM1) autoantibody testing: a novel approach

PURPOSE

To report the first case of melanoma-associated retinopathy (MAR) and underlying occult melanoma diagnosed based on the presence of serum transient receptor potential melastatin 1 (TRPM1) autoantibodies.

DESIGN

Interventional case report with basic science correlation.

PARTICIPANTS

One patient with MAR.

INTERVENTION

Testing for the presence of serum TRPM1 autoantibodies.

MAIN OUTCOME MEASURES

Diagnosis of an occult melanoma involving the axillary lymph nodes (unknown primary site) and MAR based on the presence of TRPM1 autoantibodies in the patient's serum.

RESULTS

The patient's clinical exam was remarkable for mild intraocular inflammation in both eyes and retinal hemorrhages with an apparent choroidal neovascularization in the left eye, which was confirmed by fluorescein angiography and indocyanine green angiography testing. Humphrey visual field 30-2 SITA-fast (Humphrey Visual Field Analyzer, Carl Zeiss Meditec, Inc, Dublin, CA) demonstrated diffuse depression in both eyes out of proportion to the clinical exams, prompting electroretinography testing that revealed an electronegative response. Dark-adapted thresholds were markedly elevated and mediated by cones. Due to concern for MAR, a systemic work-up for melanoma was performed by the primary care physician that was unrevealing. Given our continued clinical suspicion for MAR, the patient's serum was sent for evaluation for TRPM1 autoantibodies. The patient's serum applied to normal human retina exhibited positivity in the inner nuclear layer. Application of the patient's serum to wild-type and TRPM1 knockout mouse retina revealed strongly labeled bipolar cells in the wild-type retina, but not in the TRPM1 knockout retina, indicating TRPM1-dependent immunoreactivity. The antigen was confirmed as TRPM1 by labeling of TRPM1-transfected human embryonic kidney 293 cells. Additional systemic work-up prompted by this finding resulted in identification of an occult metastatic melanoma involving the axillary lymph nodes with an unknown primary site. The patient underwent surgical excision of the occult melanoma without evidence of other sites of metastases. He also received intravenous immunoglobulin therapy and his vision has stabilized.

CONCLUSIONS

This is the first reported case of a melanoma-associated retinopathy diagnosed utilizing the innovative approach of testing for serum TRPM1 autoantibodies.

Serum TRPM1 autoantibodies from melanoma associated retinopathy patients enter retinal on-bipolar cells and attenuate the electroretinogram in mice

Melanoma-associated retinopathy (MAR) is a paraneoplastic syndrome associated with cutaneous malignant melanoma and the presence of autoantibodies that label neurons in the inner retina. The visual symptoms and electroretinogram (ERG) phenotype characteristic of MAR resemble the congenital visual disease caused by mutations in TRPM1, a cation channel expressed by both melanocytes and retinal bipolar cells. Four serum samples from MAR patients were identified as TRPM1 immunoreactive by 1. Labeling of ON-bipolar cells in TRPM1+/+ but not TRPM1−/− mouse retina, 2. Labeling of TRPM1-transfected CHO cells; and 3. Attenuation of the ERG b-wave following intravitreal injection of TRPM1-positive MAR IgG into wild-type mouse eyes, and the appearance of the IgG in the retinal bipolar cells at the conclusion of the experiment. Furthermore, the epitope targeted by the MAR autoantibodies was localized within the amino-terminal cytoplasmic domain of TRPM1. Incubation of live retinal neurons with TRPM1-positive MAR serum resulted in the selective accumulation of IgG in ON-bipolar cells from TRPM1+/+ mice, but not TRPM1−/− mice, suggesting that the visual deficits in MAR are caused by the uptake of TRPM1 autoantibodies into ON-bipolar cells, where they bind to an intracellular epitope of the channel and reduce the ON-bipolar cell response to light.

Delayed presentation of melanoma-associated retinopathy and subsequent resolution with cytoreduction surgery

BACKGROUND

To present a case of melanoma-associated retinopathy (MAR) which manifested 26 months prior to a formal diagnosis of melanoma.

METHODS

Case report.

RESULTS

A 72-year-old female presented with bilateral continuous photopsia consistent with MAR of 7-months duration. At this point, visual function appeared normal with the exception of mildly impaired colour vision (10/17 Ishihara plates). The flash electroretinographic (ERG) revealed extinguished rod responses, a normal a-wave and reduced b-wave (electronegative ERG) on the maximal combined response, absent oscillatory potentials and broadened a-wave trough on the cone response. Multifocal ERG (mfERG) responses were delayed and demonstrated atypical morphology. Nineteen months after the initial presentation, her visual symptoms had progressed significantly with constant debilitating photopsia in combination with 13 kg weight loss. Biopsy of a now evident left axillary mass demonstrated a metastatic high-grade malignant melanoma. No primary was detected, and an axillary lymph node clearance was undertaken. Subsequently, visual symptoms resolved with corresponding improvement in the ERG over the next 18 months. Rod responses recovered such that the amplitude was at the lower limit of normal and the mfERG response delay lessened. Unfortunately, the melanoma recurred and the patient passed away 6 months later. Visual symptoms did not recur.

CONCLUSION

We present a case which demonstrates MAR may precede the formal diagnosis of melanoma by up to 26 months. The potential for improvement in the rod visual function persists over a period of years with normalisation of an electronegative waveform. In this case, cytoreductive surgery resulted in complete resolution of the MAR, which did not return even with a recurrence of the tumour.

Autoantibody against transient receptor potential M1 cation channels of retinal ON bipolar cells in paraneoplastic vitelliform retinopathy

Background

Paraneoplastic retinopathy is caused by the cross-reaction of neoplasm-directed autoantibodies against retinal antigens and results in retinal damage. Paraneoplastic vitelliform retinopathy, a presumed paraneoplastic retinopathy with features of atypical melanoma-associated retinopathy, has recently been reported in patients with metastatic melanoma. Ocular ultrastructure and its autoantibody localization of paraneoplastic vitelliform retinopathy are still indefinable. This is the first report of anti-transient receptor potential M1 antibody directly against human retinal bipolar dendritic tips in a melanoma patient with paraneoplastic vitelliform retinopathy.

Case presentation

We present a pair of postmortem eyes of an 80-year-old male with metastatic cutaneous melanoma, who developed paraneoplastic vitelliform retinopathy. The autopsied eyes were examined with light microscopy, immunohistochemistry, and transmission electron microscopy. Microscopically, the inner nuclear layer and outer plexiform layer were the most affected retinal structures, with local thinning. The lesions extended to the outer nuclear layer, resulting in focal retinal degeneration, edema, and atrophy. No active inflammation or melanoma cells were observed. Immunohistochemistry showed tightly compact bipolar cell nuclei (protein kinase C alpha/calbindin positive) with blur/loss of ON bipolar cell dendritic tips (transient receptor potential M1 positive) in diffusely condensed outer plexiform layer. The metastatic melanoma cells in his lung also showed immunoreactivity against transient receptor potential M1 antibody. Transmission electron microscopy illustrated degenerated inner nuclear layer with disintegration of cells and loss of cytoplasmic organelles. These cells contained many lysosomal and autophagous bodies and damaged mitochondria. Their nuclei appeared pyknotic and fragmentary. The synapses in the outer plexiform layer were extensively degenerated and replaced with empty vacuoles and disintegrated organelles.

Conclusion

This case provides a convincing histological evidence of melanoma-associated autoantibodies directly against transient receptor potential M1 channels that target the ON bipolar cell structures in the inner nuclear and outer plexiform layers in paraneoplastic vitelliform retinopathy.

Paraneoplastic vitelliform retinopathy: clinicopathologic correlation and review of the literature

Traditionally, the paraneoplastic retinopathies have been classified into two groups: melanoma-associated retinopathy (MAR) and cancer-associated retinopathy. MAR occurs in individuals with metastatic cutaneous or uveal melanoma and is characterized by nyctalopia, photopsias, and variable vision loss. In most cases, the fundus is essentially normal in appearance. More recently, there have been multiple reports of a MAR-like retinopathy with associated detachments of the retinal pigment epithelium and neurosensory retina. Such a clinical presentation has been termed paraneoplastic vitelliform retinopathy. We describe an 80-year-old man with metastatic cutaneous melanoma who developed paraneoplastic vitelliform retinopathy. For the first time, histopathology from enucleation specimens provides a clinicopathologic disease correlation with focal abnormalities in the inner nuclear and outer plexiform layers.

Acute exudative paraneoplastic polymorphous vitelliform maculopathy in five cases

BACKGROUND AND OBJECTIVE

To evaluate clinical features, course, and outcome of patients with acute exudative paraneoplastic polymorphous vitelliform maculopathy (AEPPVM).

PATIENTS AND METHODS

Retrospective case series of 5 patients.

RESULTS

There were 3 males and 2 females, with a median age of 74 years. The primary neoplasms were cutaneous melanoma (n = 2), choroidal melanoma (n = 1), lung adenocarcinoma (n = 1), and lung plus breast adenocarcinoma (n = 1). The mean interval between the diagnosis of the primary neoplasm and the diagnosis of AEPPVM was 42 months. The presenting symptom was blurred vision in all cases. Ophthalmoscopy disclosed multifocal localized shallow serous detachments of the post-equatorial neurosensory retina with yellow-white subretinal debris confirmed by optical coherence tomography (OCT). There was a mean of 21 individual sites of detachment per eye, each measuring a mean of approximately 0.8 millimeter in diameter. Fundus autofluorescence depicted hyperautofluorescence corresponding to the detachments. After mean follow-up of 5 months, three patients had died of metastases. Of the two survivors, one showed resolution of lesions and the other was unchanged.

CONCLUSION

AEPPVM is a paraneoplastic retinopathy found in patients with metastatic melanoma or carcinoma. The most salient feature is reduced visual acuity from multifocal shallow retinal detachments less than 1-mm diameter, best depicted on OCT.

A review of current indications, adverse effects, and administration recommendations for intravenous immunoglobulin

OBJECTIVE

To review and summarize the body of literature regarding human intravenous immunoglobulin (hIVIG) therapy in veterinary medicine. Mechanism of action, usage in human medicine, adverse effects of therapy, implications for veterinary use, and administration recommendations are discussed.

DATA SOURCES

Current human and veterinary peer-reviewed medical literature including original research articles and scientific reviews.

HUMAN DATA SYNTHESIS

There are currently 6 labeled uses for hIVIG in human medicine, but preparations are used off-label to successfully treat multiple immune-mediated conditions. To maximize the potential of hIVIG use in animals and identify areas deficient in research, a review of the current literature is warranted.

VETERINARY DATA SYNTHESIS

Investigation of hIVIG therapy in veterinary patients has been limited to the subjects of immune-mediated hemolytic anemia (IMHA), immune-mediated thrombocytopenia (ITP), Evan's syndrome, cutaneous disease, myasthenia gravis (MG), and sudden acquired retinal degeneration (SARDS). Proponents of veterinary hIVIG use believe administration may reduce transfusion requirements and decrease hospitalization time.

CONCLUSION

Immunoglobulin (Ig) has not been shown to decrease transfusion requirements in IMHA patients, but shows great promise for treatment of ITP and dermatological diseases. Although serial transfusion of hIVIG is employed in human medicine, repeated transfusion is not recommended in animals due to risk of severe allergic reaction. Other potential adverse effects of transfusion include delayed hypersensitivity reactions, thromboembolism, renal failure, hypotension, and aseptic meningitis.

Presumed melanoma-associated retinopathy (MAR): a presenting sign of primary small intestinal melanoma?

Melanoma-associated retinopathy is a paraneoplastic retinopathy associated mostly with cutaneous melanoma. In most cases it presents months to years after diagnosis of primary cutaneous melanoma was made or after recurrence. We describe a 55-year-old male patient who presented with symptoms of decreased vision and photopsia. Diagnosis of melanoma-associated retinopathy was made, but no primary cutaneous melanoma was found. 3 months later he developed intestinal perforation due to small intestinal melanoma.

Negative electroretinograms in the pediatric and adult population

Objective To assess the frequency of negative waveform electroretinograms (ERGs) in a tertiary referral center. Design Retrospective chart review. Participants All patients who had an ERG performed at the electrophysiology clinic at Emory University from January 1999 through March 2008 were included in the study. Methods Patients with b-wave amplitude ≤ a-wave amplitude during the dark-adapted bright flash recording, in at least one eye, were identified as having a "negative ERG". Clinical information, such as age, gender, symptoms, best corrected visual acuity, and diagnoses were recorded for these patients when available. Results A total of 1,837 patients underwent ERG testing during the study period. Of those, 73 patients had a negative ERG, for a frequency of 4.0%. Within the adult (≥ 18 years of age) and pediatric populations, the frequencies of a negative ERG were 2.5 and 7.2%, respectively. Among the 73 cases, negative ERGs were more common among male than female patients, 6.7% versus 1.8% (P < 0.0001). Negative ERGs were most common among male children and least common among female adults, 9.6% versus 1.1%, respectively, (P < 0.0001). Overall in this group of patients, the most common diagnoses associated with a negative ERG were congenital stationary night blindness (CSNB, n = 29) and X-linked retinoschisis (XLRS, n = 7). Conclusions The overall frequency of negative ERGs in this large retrospective review was 4.0%. Negative ERGs were most common among male children and least common among female adults. Despite the growing number of new diagnoses associated with negative ERGs, CSNB, and XLRS appear to be the most likely diagnoses for a pediatric patient who presents with a negative ERG.

TRP channel gene expression in the mouse retina

In order to identify candidate cation channels important for retinal physiology, 28 TRP channel genes were surveyed for expression in the mouse retina. Transcripts for all TRP channels were detected by RT-PCR and sequencing. Northern blotting revealed that mRNAs for 12 TRP channel genes are enriched in the retina. The strongest signals were observed for TRPC1, TRPC3, TRPM1, TRPM3, and TRPML1, and clear signals were obtained for TRPC4, TRPM7, TRPP2, TRPV2, and TRPV4. In situ hybridization and immunofluorescence revealed widespread expression throughout multiple retinal layers for TRPC1, TRPC3, TRPC4, TRPML1, PKD1, and TRPP2. Striking localization of enhanced mRNA expression was observed for TRPC1 in the photoreceptor inner segment layer, for TRPM1 in the inner nuclear layer (INL), for TRPM3 in the INL, and for TRPML1 in the outer plexiform and nuclear layers. Strong immunofluorescence signal in cone outer segments was observed for TRPM7 and TRPP2. TRPC5 immunostaining was largely confined to INL cells immediately adjacent to the inner plexiform layer. TRPV2 antibodies stained photoreceptor axons in the outer plexiform layer. Expression of TRPM1 splice variants was strong in the ciliary body, whereas TRPM3 was strongly expressed in the retinal pigmented epithelium.