Anti-TRPM1 autoantibody-positive unilateral melanoma associated retinopathy (MAR) triggered by immunotherapy recapitulates functional and structural details of TRPM1-associated congenital stationary night blindness.

Purpose: To describe the retinal phenotype of an unusual case of anti-TRPM1 autoantibody-positive unilateral melanoma-associated retinopathy (MAR) triggered by nivolumab therapy and compare with the phenotype of TRPM1-associated Congenital Stationary Night Blindness (TRPM1-CSNB). Observations: Unilateral MAR was diagnosed 3 months after starting nivolumab therapy for consolidation of a successfully treated melanoma. Retinal autoantibodies against TRPM1 were identified. ffERG, microperimetry and static chromatic perimetry confirmed unilateral ON-Bipolar Cell (ON-BPC) dysfunction and central rod sensitivity losses in the left eye; the contralateral eye was normal. There was borderline ganglion cell (GCL) and inner nuclear layer (INL) thinning, but a significantly thinner inner plexiform layer (IPL) in the affected compared to the unaffected eye. Longitudinal reflectivity profiles (LRPs) demonstrated an abnormal inner plexiform layer (IPL) lamination in the involved eye. Nearly identical changes were documented in two cases of TRMP1-cCSNB and in a case of anti-TRPM1 autoantibody-negative MAR. The functional changes partially recovered with discontinuation of the medication without added immunosuppression. Conclusions and Importance: Comparisons between the affected and unaffected eye in this unilateral MAR case revealed inner retinal abnormalities and abnormal lamination of the IPL associated with the classical retina-wide ON-BPC dysfunction, and localized central rod-mediated sensitivity losses. A nearly identical structural phenotype in two cases of cCSNB and a case of anti-TRPM1 autoantibody-negative MAR supports a specific structural-functional phenotype for these conditions with ON-BPC dysfunction.

Appearance and resolution of numerous bilateral gass plaques in probable Susac syndrome.

Purpose: To describe a patient with a unique retinal phenotype of probable Susac syndrome. Observations: A 47-year-old female who presented with bilateral tinnitus and vision changes was found to have bilateral sensorineural hearing loss and many bilateral retinal arteriolar Gass plaques. She had bilateral scotomas corresponding with temporal thinning and atrophy of the inner nuclear layer (INL) on OCT. Retinal examination and fluorescein angiography demonstrated minimal arteriolar wall hyperfluorescence with no evidence of acute branch retinal artery occlusion. She developed daily headaches. MRI of the brain was normal with no corpus callosal lesions. She was diagnosed with probable Susac syndrome based on the above findings. Conclusions and importance: Our patient's bilateral high frequency sensorineural hearing loss, numerous bilateral Gass plaques, and headaches are most likely attributable to Susac syndrome. While BRAO is considered a cornerstone of retinal involvement in Susac syndrome, it may only be appreciable angiographically in the acute setting, and it is important to recognize Gass plaques as a significant diagnostic marker of disease.

Congenital Retinal Macrovessel and Cavernous Hemangioma in Cowden Syndrome - A Case Report and Review of Literature.

PURPOSE: To describe a case of unilateral congenital retinal macrovessel with a retinal cavernous hemangioma in a patient with Cowden syndrome (CS). In addition, we summarize previously reported cases of ocular findings in CS in the literature. METHODS: Observational case report and literature review. RESULTS: A 45-year-old white female with Cowden syndrome presented for routine ocular examination. She had a history of thyroid carcinoma, fallopian para-tubal cyst, chromophobe type renal cell carcinoma, multiple benign skin lesions, and macrocephaly. At presentation, she was asymptomatic with good vision. On dilated fundus examination, the right eye revealed a congenital retinal macrovessel and retinal cavernous hemangioma. Previously performed genetic testing revealed a pathogenic c.46dupT mutation in the PTEN gene which was consistent with CS. CONCLUSION: Our patient had a history of multiple malignancies and hamartomas consistent with her genetic diagnosis of CS. We incidentally discovered a congenital retinal macrovessel with a retinal cavernous hemangioma. Patients with CS should be referred for interdisciplinary evaluation including routine ocular examinations.

Histone deacetylase inhibitors modulate KATP subunit transcription in HL-1 cardiomyocytes through effects on cholesterol homeostasis.

Histone deacetylase inhibitors (HDIs) are under investigation for the treatment of a number of human health problems. HDIs have proven therapeutic value in refractory cases of cutaneous T-cell lymphoma. Electrocardiographic ST segment morphological changes associated with HDIs were observed during development. Because ST segment morphology is typically linked to changes in ATP sensitive potassium (KATP) channel activity, we tested the hypothesis that HDIs affect cardiac KATP channel subunit expression. Two different HDIs, romidepsin and trichostatin A, caused ~20-fold increase in SUR2 (Abcc9) subunit mRNA expression in HL-1 cardiomyocytes. The effect was specific for the SUR2 subunit as neither compound causes a marked change in SUR1 (Abcc8) expression. Moreover, the effect was cell specific as neither HDI markedly altered KATP subunit expression in MIN6 pancreatic ß-cells. We observe significant enrichment of the H3K9Ac histone mark specifically at the SUR2 promoter consistent with the conclusion that chromatin remodeling at this locus plays a role in increasing SUR2 gene expression. Unexpectedly, however, we also discovered that HDI-dependent depletion of cellular cholesterol is required for the observed effects on SUR2 expression. Taken together, the data in the present study demonstrate that KATP subunit expression can be epigenetically regulated in cardiomyocytes, defines a role for cholesterol homeostasis in mediating epigenetic regulation and suggests a potential molecular basis for the cardiac effects of the HDIs.