Background: Chronic traumatic brain injury is a condition that predisposes the brain to activate B-cells and produce neural autoantibodies. Anti-adaptor protein 3, subunit B2 (AP3B2) autoantibodies have thus far been associated with diseases affecting the cerebellum or vestibulocerebellum. Through this case report, we aim to broaden the spectrum of anti-AP3B2-associated disease. Case description: We report on a 51-year-old woman with a brain injury approximately 28 years ago who recently underwent neuropsychological testing, magnetic resonance imaging of the brain (cMRI), and cerebrospinal fluid (CSF) analysis. Neural autoantibodies were determined in serum and CSF. Our patient suffered from mild cognitive impairment (amnestic MCI, multiple domains) with stable memory deficits and a decline in verbal fluency and processing speed within a two-year interval after the first presentation in our memory clinic. Brain MRI showed brain damage in the right temporoparietal, frontolateral region and thalamus, as well as in the left posterior border of the capsula interna and white matter in the frontal region. Since the brain damage, she suffered paresis of the upper extremities on the left side and lower extremities on the right side as well as gait disturbance. Our search for autoantibodies revealed anti-AP3B2 autoantibodies in serum. Conclusions: Our report expands the spectrum of symptoms to mild cognitive impairment in addition to a gait disturbance associated with anti-AP3B2 autoantibodies. Furthermore, it is conceivable that a prior traumatic brain injury could initiate the development of anti-AP3B2-antibody-associated brain autoimmunity, reported here for the first time.

中文翻译：

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与血清抗 AP3B2 自身抗体相关的慢性脑损伤中的轻度认知障碍：报告和文献综述


背景：慢性创伤性脑损伤是一种使大脑容易激活 B 细胞并产生神经自身抗体的疾病。迄今为止，抗适配器蛋白 3 B2 亚基 (AP3B2) 自身抗体与影响小脑或前庭小脑的疾病有关。通过本病例报告，我们的目标是拓宽抗 AP3B2 相关疾病的范围。病例描述：我们报告了一名大约 28 年前患有脑损伤的 51 岁女性，她最近接受了神经心理学测试、脑部磁共振成像 (cMRI) 和脑脊液 (CSF) 分析。测定血清和脑脊液中的神经自身抗体。我们的患者在我们的记忆诊所首次就诊后的两年内，患有轻度认知障碍（遗忘性MCI，多个领域），伴有稳定的记忆缺陷，言语流畅性和处理速度下降。脑部 MRI 显示右侧颞顶叶、额外侧区和丘脑、内囊左后缘和额叶区白质出现脑损伤。由于脑损伤，她出现左侧上肢瘫痪、右侧下肢瘫痪以及步态障碍。我们对自身抗体的搜索发现血清中存在抗 AP3B2 自身抗体。结论：除了与抗 AP3B2 自身抗体相关的步态障碍外，我们的报告将症状范围扩大到轻度认知障碍。此外，可以想象，先前的创伤性脑损伤可能会引发抗 AP3B2 抗体相关的脑自身免疫的发展，这是首次报道。