Lang, Mary

Subretinal and intravitreal injection of retinal gene therapy is associated with serious adverse events and poor efficacy. We sought to improve retinal gene therapy delivery by developing fibrin hydrogel encapsulated adeno-associated virus (FE-AAV). Here we investigate conditions for storage and stability for FE-AAV. FE-AAV containing 1.9 × 109 genome copies of AAV2/2-CMV-GFP was manufactured using fibrinogen reconstituted in 0.01 M sodium citrate, pH 7 (NaC) or phosphate-buffered saline containing 0.001% (v/v) Pluronic F68 (F68). Samples were stored at either −80 °C or 4 °C for up to 16 weeks. Changes in transduction efficiency, and mechanical and physical properties were evaluated. In vitro transduction was significantly (p < 0.05) reduced for FE-AAV manufactured with NaC. In contrast, we observed no change in transduction through 16 weeks for FE-AAV made with F68. Physical changes occurred in FE-AAV stored at −80 °C. In contrast to FE-AAV formulated with NaC, FE-AAV formulated with F68 and stored at 4 °C for 16 weeks was essentially equivalent to freshly made FE-AAV and retained the ability to transduce retinal pigment epithelial (RPE) cells in the pig eye. We conclude that FE-AAV formulated with F68 and stored at 4 °C is stable and shows potential for retinal gene therapy for at least 4 months following manufacture.

Seronegative neuromyelitis optica spectrum disorder (NMOSD) is a diagnostic challenge. This study aimed to characterize misapplication of the 2015 international criteria for seronegative NMOSD. We reviewed 35 consecutive seronegative NMOSD referrals to a tertiary center. Two (6%) met formal criteria, and 2 (6%) were clinically suspected of NMOSD without fulfilling radiologic supportive criteria. Alternative diagnoses were common including multiple sclerosis (37%), optic neuritis (14%), functional neurologic disorder (11%), and other (38%). Immunosuppression with rituximab was used in 3 of 4 patients with functional neurologic disorder. Misapplication of the 2015 criteria is common, and alternative explanations in seronegative NMOSD patients should be strongly considered.