2016.02.04
Clinicopathological features in anterior visual pathway in neuromyelitis optica
（Ann Neurol., 79: 605-624. doi:10.1002/ana.24608）
Mariko Hokari, MD,1 Akiko Yokoseki, MD, PhD,1 Musashi Arakawa, MD, PhD,1 Etsuji Saji, MD, PhD,1 Kaori Yanagawa, MD, PhD,1 Fumihiro Yanagimura, MD,1 Yasuko Toyoshima, MD, PhD,2 Kouichirou Okamoto, MD, PhD,3 Satoshi Ueki, MD, PhD,4 Tetsuhisa Hatase, MD, PhD,5 Riuko Ohashi, MD, PhD,6 Takeo Fukuchi, MD, PhD,5 Kohei Akazawa, PhD,7 Mitsunori Yamada, MD, PhD,8 Akiyoshi Kakita, MD, PhD,2 Hitoshi Takahashi, MD, PhD,2 Masatoyo Nishizawa, MD, PhD,1 and Izumi Kawachi, MD, PhD1
1Department of Neurology, Brain Research Institute, Niigata University;
2Department of Pathology, Brain Research Institute, Niigata University;
3Department of Neurosurgery, Brain Research Institute, Niigata University;
4Center for Integrated Human Brain Science, Brain Research Institute, Niigata University;
5Department of Ophthalmology, Niigata University;
6Department of Pathology, Niigata University Medical and Dental Hospital;
7Department of Medical Informatics, Niigata University Medical and Dental Hospital;
8Department of Brain Disease Research, Shinshu University School of Medicine
Abstract
Objective: Neuromyelitis optica spectrum disorder (NMOsd) is an autoimmune disorder of the central nervous system characterized by aquaporin-4 (AQP4) autoantibodies. The aim of this study was to elucidate the characteristics of involvement of the anterior visual pathway (AVP) and neurodegeneration via glia-neuron interaction in NMOsd.
Methods: Thirty Japanese patients with serologically verified NMOsd were assessed with a neuro-ophthalmological study. Using 27 tissue blocks from 13 other cases of NMOsd, we performed neuropathological analysis of glial and neuroaxonal involvement in the AVP.
Results: The AVP involvement in NMOsd was characterized by the following, compared to multiple sclerosis: (1) longitudinally extensive optic neuritis (ON); (2) more severe visual impairment and worse prognosis for ON; (3) unique AQP4 dynamics, including loss of AQP4 immunoreactivity on astrocytes with complement activation in ON lesions, loss of AQP4 immunoreactivity on Müller cells with no deposition of complement in the retinas, and densely packed AQP4 immunoreactivity on astrocytes in gliosis of secondary anterograde/retrograde degeneration in the optic nerves and retinal nerve fiber layer (RNFL); and (4) more severe neurodegeneration, including axonal accumulation of degenerative mitochondria and transient receptor potential melastatin 4 channel with complement-dependent astrocyte pathology in ON lesions, mild loss of horizontal cells, and RNFL thinning and loss of ganglion cells with abundance of AQP41 astrocytes, indicating secondary retrograde degeneration after ON.
Interpretation: Severe and widespread neuroaxonal damage and unique dynamics of astrocytes/Müller cells with alterations of AQP4 were prominent in the AVP and may be associated with poor visual function and prognosis in NMOsd.
