A multi-modal study to characterize the spectrum and frequency of sublytic astrocytopathy in neuromyelitis optica

Takeaway

  • This study focusing on morphological features of neuromyelitis optica (NMO) in autopsied central nervous system (CNS) astrocytes demonstrated that NMO is a global astrocytopathy characterized by a wide range of morphologies, including sublytic reactions, other signs of degeneration and emperipolesis. Astrocyte reactivity in NMO may not involve direct IgG binding to a cell and is also observed in non-lesional areas of astrocytes that retain aquaporin-4 (AQP4) protein.

Why this matters

  • NMO can be distinguished from other CNS demyelinating diseases by detecting the expression of AQP4, which is expressed predominantly in astrocytes.

  • Classical astrocytic reactions such as astrogliosis are nonspecific and generally studied in the CNS diseases which do not selectively target astrocytes.

  • Astrocytic response in a cell-specific attack can be potentially identified in NMO, since the primary driver of NMO neuropathology is AQP4-specific IgG.