Are Anti-Retinal Autoantibodies a Cause or a Consequence of Retinal Degeneration in Autoimmune Retinopathies?

Non-paraneoplastic autoimmune retinopathy: multimodal testing characteristics of 13 cases

BACKGROUND

Non-paraneoplastic autoimmune retinopathy (npAIR) is a rare autoimmune disease that primarily affects retinal photoreceptor function and results in profound and often times permanent vision loss. Delay in diagnosis and treatment initiation may contribute to the poor visual prognosis.

METHODS

A retrospective chart review of all patients diagnosed with autoimmune retinopathy at the University of Wisconsin-Madison Eye Clinics between January 2012 and January 2017 was performed. Twenty eyes of 15 patients had evidence of any form of autoimmune retinopathy through a combination of symptoms, ocular findings, visual fields, optical coherence tomography, fundus autofluorescence, full-field and multifocal electroretinography, and serum anti-retinal antibodies. Clinical records were also analyzed for demographic data, systemic comorbidities, visual acuity, treatment employed, and disease progression.

RESULTS

We identified 18 eyes from 13 patients who fit the criteria for non-paraneoplastic autoimmune retinopathy. Sixty-nine percent of patients were female with a mean age of symptom onset of 56.9 ± 20.3 years. Sixty-seven percent of eyes had an associated autoimmune condition, most commonly hypothyroidism. Serum testing revealed a preponderance of antibodies against carbonic anhydrase II, while imaging revealed characteristic changes. Fundus autofluorescence most commonly showed hyperautofluorescence around the macula. The delayed diagnosis led to a larger reduction in the horizontal extent of ellipsoid zone in 1-mm perifoveal area on optical coherence tomography with resulting visual decline. There was no difference in the change of visual acuity when stratifying for patients with autoimmune conditions (p = 0.52) or treatment status (p = 0.50). None of the patients who received treatment developed contralateral eye involvement or experienced disease progression based on visual acuity or symptoms.

CONCLUSION

Non-paraneoplastic autoimmune retinopathy has a wide and often challenging to diagnose spectrum of clinical symptoms and imaging findings. Immunosuppressive therapy can be considered empiric in the face of a suggestive presentation and can be initiated after an evaluation of clinical findings and multimodal testing, though treatment does not appear to affect regeneration of the ellipsoid zone on OCT or impact visual acuity. Treatment should be primarily used to prevent disease progression and contralateral eye involvement.

TRIAL REGISTRATION

N/A.

Anti-Fumarase Antibody as a Predictor of Functional Efficacy of Anti-VEGF Therapy for Diabetic Macular Edema

Purpose

To evaluate whether baseline titers of anti-fumarase antibody are associated with visual prognosis after anti-VEGF treatment for diabetic macular edema (DME).

Methods

In this retrospective study, we investigated 52 eyes of 52 DME patients who received intravitreal injections of anti-VEGF drugs (ranibizumab or aflibercept) after blood sampling at baseline. Optical coherence tomography (OCT) images were obtained at every monthly visit. The serum titer of anti-fumarase antibody at baseline was measured using ELISA. We evaluated the relationship between the titer of anti-fumarase antibody at baseline and visual acuity (VA) improvement at 12 months.

Results

The serum titer of anti-fumarase IgG was related to the logMAR visual acuity (VA; R = 0.329, P = 0.017) and the disrupted ellipsoid zone (EZ; R = 0.364, P = 0.008) at baseline. The titer of this autoantibody was not associated with logMAR VA (R = -0.007, P = 0.980) but was associated with VA improvement (R = 0.465, P < 0.001) at 12 months upon anti-VEGF treatment. The transverse length of the disrupted EZ line was shortened at 12 months (P < 0.001), and restoration of the EZ line was correlated to the autoantibody titer (R = 0.396, P = 0.004) compared with the decrease in central subfield (CSF) thickness. Multivariate analysis showed that pretreatment logMAR VA (β = 0.296, P = 0.045) and the autoantibody titer (β = 0.328, P = 0.017) were associated with VA improvement after anti-VEGF treatment. In contrast, the titer was not associated with logMAR VA at 12 months.

Conclusions

Anti-fumarase antibody is a novel serum biomarker predicting better functional efficacy of anti-VEGF treatment for DME.

Clinical and molecular characterization of non-syndromic retinal dystrophy due to c.175G>A mutation in ceroid lipofuscinosis neuronal 3 (CLN3)

PURPOSE

Mutation of the CLN3 gene, associated with juvenile neuronal ceroid lipofuscinosis, has recently been associated with late-onset, non-syndromic retinal dystrophy. Herein we describe the multimodal imaging, immunological and systemic features of an adult with compound heterozygous CLN3 mutations.

METHODS

A 50-year-old female with non-syndromic retinal dystrophy from the age of 36 years underwent multimodal retinal imaging, electroretinography, neuroimaging, immunological studies and genetic testing. CLN3 transcripts were amplified from patient leukocytes by reverse transcriptase polymerase chain reaction and characterized by Sanger sequencing.

RESULTS

Visual acuity declined to 6/12 and 6/76 due to asymmetrical central scotoma. ERG responses became electronegative and patient's serum contained anti-retinal antibodies. Final visual acuity stabilized at 6/60 bilaterally 3 years after peri-ocular steroid and rituximab infusion. Genetic testing revealed compound heterozygous CLN3 mutations: the 1.02 kb deletion and a novel missense mutation (c.175G>A). In silico, analyses predicted the c.175G>A mutation disrupted an exonic splice enhancer site in exon 3. In patient leukocytes, CLN3 expression was reduced and novel CLN3 transcripts lacking exon 3 were detected.

CONCLUSIONS

Our case study shows that (1) non-syndromic CLN3 disease leads to rod and delayed primary cone degeneration resulting in constricting peripheral field and enlarging central scotoma and, (2) the c.175G>A CLN3 mutation, altered splicing of the CLN3 gene. Overall, we provide comprehensive clinical characterization of a patient with non-syndromic CLN3 disease.