AQP4 and neuromyelitis optica: Patients affected by neuromyelitis optica experience attacks of longitudinally extensive transverse myelitis, unilateral or bilateral optic neuritis, among other disabling manifestations, that in some cases may be life-threatening (63) In this disease process, IL-6 appears to be instrumental by promoting plasmablast survival, increasing AQP4-IgG levels, enhancing pro-inflammatory T lymphocyte activation and impairing blood brain barrier (BBB).