AUTHOR=Duan Yinghui , Wang Xin , Duan Xiaoyu , Gao Hanqing , Ji Xiaopei , Xiao Xinyi , Zhu Feng , Xue Qun 

TITLE=Neuromyelitis optica spectrum disorders associated with AQP4-positive-cancer—A case series

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.1071519

DOI=10.3389/fneur.2022.1071519

ISSN=1664-2295

ABSTRACT=Neuromyelitis optica spectrum disorders (NMOSD) are autoimmune, astrocytopathic diseases affecting the central nervous system (CNS), especially the central optic nervous and spinal cord. AQP4-IgG is the dominant pathogenic antibody and can be detected in about 80% of NMOSD patients. Although only a few cases were reported of NMOSD associated with cancer, they demonstrate the potential paraneoplastic link between cancer and NMOSD. Here we report three NMOSD cases associated with cancer, which are teratoma and lung adenocarcinoma, teratoma, and transverse colon adenocarcinoma respectively. Pathological staining of tumor sections all revealed a high AQP4 expression. After tumor removal, all cases were stable and suffered no further relapses, which reveals the potential paraneoplastic mechanism between cancer and NMOSD. One of our patient's serum AQP4-IgG was transiently slightly elevated even though AQP4 was highly expressed on tumor cells, which indicates that AQP4 is not the main pathogenic antibody but might be induced by other underlying pathogenic antibody-antigen reactions.