TY - JOUR
T1 - Repeated follow-up of AQP4-IgG titer by cell-based assay in neuromyelitis optica spectrum disorders (NMOSD)
AU - Akaishi, Tetsuya
AU - Takahashi, Toshiyuki
AU - Nakashima, Ichiro
AU - Abe, Michiaki
AU - Ishii, Tadashi
AU - Aoki, Masashi
AU - Fujihara, Kazuo
N1 - Funding Information:
T. Akaishi and T. Takahashi report no disclosures. I. Nakashima received speaker honoraria and travel funding from Mitsubishi Tanabe Pharma, Biogen Japan, and Novartis Pharmaceuticals and received research support from LSI Medience Corporation. M. Abe, T. Ishii, and M. Aoki report no disclosures. K. Fujihara received speaker honoraria and travel funding from Bayer, Biogen Japan, Eisai, Mitsubishi Tanabe, Novartis, Astellas, Takeda, Asahi Kasei Medical, Daiichi Sankyo, and Nihon Pharmaceutical and received research support from Bayer, Biogen, Asahi Kasei Medical, The Chemo-Sero-Therapeutic Research Institute, Teva, Mitsubishi Tanabe Pharma, Teijin, Chugai, Ono, Nihon Pharmaceutical, and Genzyme.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/3/15
Y1 - 2020/3/15
N2 - 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.
AB - 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.
KW - Aquaporin 4
KW - Autoantibody
KW - Neuromyelitis optica spectrum disorders
KW - Relapse
KW - Titration
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U2 - 10.1016/j.jns.2020.116671
DO - 10.1016/j.jns.2020.116671
M3 - Article
C2 - 31927341
AN - SCOPUS:85077650549
VL - 410
JO - Journal of the Neurological Sciences
JF - Journal of the Neurological Sciences
SN - 0022-510X
M1 - 116671
ER -