Tetsuya Akaishi1, Toshiyuki Takahashi2, Ichiro Nakashima3, Michiaki Abe4, Tadashi Ishii4, Masashi Aoki5, Kazuo Fujihara6. 1. Department of Neurology, Tohoku University School of Medicine, Sendai, Miyagi, Japan; Department of Education and Support for Regional Medicine, Tohoku University Hospital, Sendai, Miyagi, Japan. Electronic address: t-akaishi@med.tohoku.ac.jp. 2. Department of Neurology, Tohoku University School of Medicine, Sendai, Miyagi, Japan; Department of Neurology, National Hospital Organization Yonezawa National Hospital, Yonezawa, Yamagata, Japan. 3. Department of Neurology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan. 4. Department of Education and Support for Regional Medicine, Tohoku University Hospital, Sendai, Miyagi, Japan. 5. Department of Neurology, Tohoku University School of Medicine, Sendai, Miyagi, Japan. 6. Department of Multiple Sclerosis Therapeutics, Fukushima Medical University, Fukushima, Japan.
Abstract
INTRODUCTION: Neuromyelitis optica spectrum disorder (NMOSD) is characterized by the presence of serum anti-aquaporin 4 (AQP4) antibody. However, the significance of changes in the serum titer as a marker of disease severity or relapse prediction is unknown. METHODS: We collected clinical data and serum antibody titers by cell-based assay from 45 NMOSD patients for whom more than one titer measurement taken in 6-12 month interval periods was available. The AQP4-IgG titer was measured by a live cell-based assay method, and the serum titer levels between the acute phase and preceding chronic phase were compared. In addition, we evaluated the correlation between the serum titer and relapse frequency while following the clinical course of the enrolled NMOSD patients. RESULTS: Serum AQP4-IgG titer was not elevated in the acute phase, compared to that of the preceding chronic phase, irrespective of the clinical phenotypes. Moreover, there was no correlation between the titer at onset and relapse frequency in 10 years post-onset or neurological disability at 5 and 10 years after onset. The titer was slightly elevated several months before relapses in about half of the cases, but the change was trivial and may not be applicable for clinical use. CONCLUSION: Although evaluating the positivity of serum AQP4-IgG at the onset is necessary, the titer level does not reflect the ongoing disease activity or the following neurological prognosis. Repeated follow-up of titer levels may not be useful for the management of NMOSD patients.
INTRODUCTION:Neuromyelitis optica spectrum disorder (NMOSD) is characterized by the presence of serum anti-aquaporin 4 (AQP4) antibody. However, the significance of changes in the serum titer as a marker of disease severity or relapse prediction is unknown. METHODS: We collected clinical data and serum antibody titers by cell-based assay from 45 NMOSDpatients for whom more than one titer measurement taken in 6-12 month interval periods was available. The AQP4-IgG titer was measured by a live cell-based assay method, and the serum titer levels between the acute phase and preceding chronic phase were compared. In addition, we evaluated the correlation between the serum titer and relapse frequency while following the clinical course of the enrolled NMOSDpatients. RESULTS: Serum AQP4-IgG titer was not elevated in the acute phase, compared to that of the preceding chronic phase, irrespective of the clinical phenotypes. Moreover, there was no correlation between the titer at onset and relapse frequency in 10 years post-onset or neurological disability at 5 and 10 years after onset. The titer was slightly elevated several months before relapses in about half of the cases, but the change was trivial and may not be applicable for clinical use. CONCLUSION: Although evaluating the positivity of serum AQP4-IgG at the onset is necessary, the titer level does not reflect the ongoing disease activity or the following neurological prognosis. Repeated follow-up of titer levels may not be useful for the management of NMOSDpatients.
Authors: Alessandro Dinoto; Elia Sechi; Eoin P Flanagan; Sergio Ferrari; Paolo Solla; Sara Mariotto; John J Chen Journal: Front Neurol Date: 2022-03-23 Impact factor: 4.003