Bhatti, M. Tariq

Purpose of reviewTo review the clinical characteristics, radiological manifestations and treatment of myelin oligodendrocyte glycoprotein (MOG)-immunoglobulin G (IgG) optic neuritis.Recent findingsSerum antibodies to MOG have recently been found to be a biomarker of MOG-IgG-associated disorder (MOGAD), a demyelinating disease distinct from both multiple sclerosis (MS) and aquaporin-4-IgG neuromyelitis optica spectrum disorder (AQP4-IgG-positive NMOSD). The phenotype of MOGAD is broad and includes optic neuritis, transverse myelitis, and acute demyelinating encephalomyelitis (ADEM). Optic neuritis is the most common presentation in adults, whereas ADEM is the most common presentation in children. Clinical characteristics suggestive of MOG-IgG optic neuritis include recurrent optic neuritis, prominent disc edema, and perineural enhancement of the optic nerve on magnetic resonance imaging. Although the nadir of vision loss is severe with MOG-IgG optic neuritis, the recovery is typically better than AQP4-IgG optic neuritis and therefore has a favorable overall prognosis. Patients with relapsing disease will often need chronic immunotherapy. Rituximab, azathioprine, mycophenolate mofetil, and monthly intravenous immune globulin are the most commonly utilized treatments.SummaryMOGAD is a unique entity that is separate from both MS and AQP4-IgG-positive NMOSD. Recognition of the clinical and radiologic features allow for the correct diagnosis. Future randomized trials will determine the optimal treatment for MOGAD.

Purpose: To assess for ectopic ocular calcification in a series of patients with hypophosphatasia (HPP) treated with asfotase alfa, a recombinant tissue-nonspecific alkaline phosphatase. Methods: This is a retrospective analysis of subjects enrolled at Duke University Medical Center in ENB-009-10 (ClinicalTrials.gov: NCT01163149), a randomized controlled trial of asfotase alfa in adolescents and adults with HPP. Seven patients between the ages of 45 and 66 years diagnosed with HPP based on clinical features and low serum alkaline phosphatase levels were enrolled at our site. Subjects were randomized to receive either daily subcutaneous injections of asfotase alfa or no treatment. After 24 weeks, during the open-label extension phase, all subjects received treatment for at least 4 years. All subjects underwent comprehensive eye examinations at baseline and at 24-week intervals throughout the study to assess for development of ocular calcifications. Results: By week 120, all 7 subjects developed asymptomatic white refractile deposits in the interpalpebral perilimbal conjunctiva. Biopsy of the conjunctival lesions in 2 subjects revealed elastosis with subepithelial calcification. The lesions were nonprogressive and in 5 subjects exhibited some degree of regression. Conclusions: Asfotase alfa was invariably associated with development of mild focal conjunctival calcification, likely through disinhibition of hydroxyapatite crystal propagation. The calcifications were not symptomatic or vision-threatening and should not preclude enzyme replacement therapy for patients with this rare and often debilitating disease.