背景:原发性干燥综合征(SS)是一种具有多种神经系统表现的慢性系统性自身免疫性疾病。SS与抗水通道蛋白4抗体(AQP4-IgG)阳性视神经脊髓炎谱系障碍(NMOSD)相关,中枢神经系统(CNS)的脱髓鞘性自身免疫性疾病。有趣的是,有渗透性脱髓鞘综合征(ODS)的报道,一种非炎症性疾病,在SS和肾小管酸中毒(RTA)的情况下,这两者都是ODS尚未确定的风险因素。
方法:进行文献检索,以确定SS患者ODS的病例报告。收集了这些患者的临床和实验室特征的详细信息。此外,我们搜索了SS患者的NMOSD。我们在SS-ODS和SS-NMOSD患者中寻找共存的RTA。我们还筛选了没有基础SS的RTA中的ODS报告。
结论:我们确定了15名患者(所有女性,中位年龄40岁),SS中的ODS,所有这些患者均患有RTA。在没有基础SS的RTA中,只有三例报告的ODS病例。我们确定了总共67例SS-NMOSD患者,其中只有3人(4.5%)有RTA。因此,与NMOSD不同,SS中ODS的发展需要由共病RTA引起的长期渗透或电解质异常。15例ODS和SS-RTA患者,表现出异质性的临床表现和结局。最常见的症状是四肢瘫痪,15名患者中有14名患者。15名患者中有11名具有以下特征之一,单独或组合:感觉恶化,足底伸肌反应,吞咽困难/构音障碍,和面神经麻痹.后四种表现在7例患者发病时出现,其余4例患者在病程中出现。15例患者中只有4例出现眼瘫,并且是晚期表现。一名患有广泛的长段脊髓炎和随后的ODS的患者死亡,但是大多数患者康复了,没有明显的后遗症。都没有低钠血症,而所有患者均有低钾血症和/或高钠血症。低钾血症导致肾性尿崩症(NDI),随后钠迅速升高,由此产生的渗透压可能解释SS-RTA中ODS的发生。星形胶质细胞中的水通道蛋白(AQP)与ODS有关,肾AQP在NDI中下调。针对AQP的抗体存在于一些SS患者中。因此,有缺陷的AQP是所有相关疾病的共同联系,即SS,NDI,和ODS,免疫介导的AQP功能障碍的发病机制。
结论:迄今为止未报道的SS-RTA和ODS之间的关联可能与ODS的发展有关。在SS-RTA的设置中,当弛缓性四肢轻瘫患者对钾的校正没有反应或随着钠的升高而出现其他神经系统特征时,必须怀疑ODS。AQPs的功能缺陷可能是连接脱髓鞘中枢神经系统病变的可能机制。SS,和RTA。在这些条件下评估AQP功能和针对AQP的血清抗体的研究是必要的。
BACKGROUND: Primary Sjögren\'s syndrome (SS) is a chronic systemic autoimmune disease with varied neurological manifestations. SS is associated with anti-
aquaporin-4 antibody (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD), a demyelinating autoimmune disorder of the central nervous system (CNS). Intriguingly, there are reports of osmotic demyelinating syndrome (ODS), a supposedly non-inflammatory disorder, in the context of SS and renal tubular acidosis (RTA), both of which are not yet established risk factors for ODS.
METHODS: A literature search was undertaken to identify case reports of ODS in patients with SS. Details of the clinical and laboratory features of these patients were compiled. Additionally, we searched for NMOSD in patients with SS. We looked for co-existing RTA in patients with SS-ODS as well as SS-NMOSD. We also screened for reports of ODS in RTA without underlying SS.
CONCLUSIONS: We identified 15 patients (all women, median age 40 years) with ODS in SS, and all of these patients had comorbid RTA. There were only three reported cases of ODS in RTA without underlying SS. We identified a total of 67 patients with SS-NMOSD, of whom only 3 (4.5%) had RTA. Hence, unlike NMOSD, the development of ODS in SS requires a prolonged osmotic or electrolyte abnormality caused by the comorbid RTA. The 15 patients with ODS and SS -RTA, showed heterogeneous clinical manifestations and outcomes. The most common symptom was quadriparesis, seen in 14 of the 15 patients. Eleven of the 15 patients had one of the following features, either alone or in combination: worsening of the sensorium, extensor plantar response, dysphagia/dysarthria, and facial palsy. The latter four manifestations were present at the onset in 7 patients and later in the course of the illness in the remaining 4 patients. Ocular palsy was seen in only four of the 15 patients and was a late manifestation. One patient who had extensive long-segment myelitis and subsequent ODS died, but most patients recovered without significant sequelae. None had hyponatremia, while all patients had hypokalemia and/or hypernatremia. Hypokalemia causing nephrogenic diabetes insipidus (NDI) followed by rapid rise in sodium and the resultant osmotic stress could potentially explain the occurrence of ODS in SS-RTA.
Aquaporin (AQP) in astrocytes is implicated in ODS, and renal AQP is downregulated in NDI. Antibodies against AQPs are present in some patients with SS. Defective AQP is therefore a common link underlying all the connected diseases, namely SS, NDI, and ODS, raising the possibility of immune-mediated AQP dysfunction in the pathogenesis.
CONCLUSIONS: The hitherto unreported association between SS-RTA and ODS may implicate SS and/or RTA in the development of ODS. In the setting of SS-RTA, ODS must be suspected when a patient with flaccid quadriparesis does not respond to the correction of potassium or develops additional neurological features along with a rise in sodium. Defective functions of AQPs may be a possible mechanism linking demyelinating CNS lesions, SS, and RTA. Studies evaluating AQP functions and serum antibodies against AQPs in these conditions are warranted.