Introduction of a cell-based assay against native aquaporin-4– high specificity and sensitivity for neuromyelitis optica

Neuromyelitis optica (NMO) is chronic demyelinating autoimmune disorder of the central nervous system with partial patho-etiological overlap to multiple sclerosis (MS). Recently, an antibody response against the waterchannel protein aquaporin-4 (AQP-4) has been established as diagnostic biomarker for NMO. Current assay methodologies consist of indirect immunofluorescence and radioimmunoprecipitation assays, respectively. Here we report on a cell-based flow cytometry assay: The human glioblastoma cell line LN18 was stably transfected using a lentiviral vector to overexpress human AQP-4. Expression was monitored b…