The staining was observed under a fluorescence microscope. == 2.5. they were double positive for antibodies to the VGKC complex including LGI1. No antibodies against theN-methyl-D-aspartate receptor (NMDAR), contactin-associated protein 2 (Caspr2), -aminobutyric acid-B receptor (GABABR), or -amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) were detected in the 19 patients. Among the remaining 14 who were positive only for anti-NAE antibodies, the median age was 62.5 (2083) years, 9 (64%) were women, and 8 (57%) showed acute onset, with less than 2 weeks between onset and admission. Consciousness disturbance (71%) and memory disturbance (64%) were frequently observed, followed by psychiatric symptoms (50%) and seizures (43%). The frequency of these symptoms significantly differed between the acute- and subacute-onset groups. Abnormalities in cerebrospinal fluid and electroencephalogram were commonly observed (92% for both). Tumors were not recognized in any cases. All patients responded to immunotherapy or spontaneously remitted, thereby fulfilling the criteria of HE. This study exhibited that LE associated with anti-NAE antibodies is usually a nonparaneoplastic LE and various limbic symptoms that depend on the onset type. Favorable therapeutic efficacy suggests that this LE can be considered a clinical subtype of HE and that anti-NAE antibodies may be a encouraging indicator of the need for immunotherapy. == 1. Introduction == Limbic encephalitis (LE) is one of the most common forms of encephalitis and predominantly affects the limbic system.[1]Consciousness disturbance, psychiatric symptoms, and memory disturbance are common symptoms in patients with LE. Excluding herpes virus infection, autoimmune mechanisms account for the majority of the pathogenesis of LE.[2,3]Indeed, autoantibodies against numerous antigens, such as theN-methyl-D-aspartate receptor (NMDAR), voltage-gated potassium channel (VGKC) complex that includes leucine-rich glioma inactivated 1 (LGI1) and contactin-associated protein 2 (Caspr2), -aminobutyric acid-B receptor (GABABR), and -amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor 1 and 2 (AMPAR1/2), have been identified in autoimmune LE, especially in paraneoplastic LE associated with neoplasms.[49]The identification of antibodies would not only help clarify the pathogenesis of LE but would also be useful for the diagnosis and prognostic predictions of Sildenafil LE because both the clinical features and the efficacy of LE therapies are generally related to the type of antibodies.[3,9,10]However, there are still many autoimmune forms of LE, especially nonparaneoplastic LE, for which the related antibodies remain unidentified. We previously discovered autoantibodies against the NH2-terminal of -enolase (NAE) in the serum of patients with Hashimoto encephalopathy (HE) using proteomic analyses and exhibited the high specificity of these antibodies for HE.[11,12]HE is an autoimmune encephalopathy Sildenafil associated with Hashimoto thyroiditis, also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis.[1316]Our recent case statement described a patient with autoimmune LE and serum anti-NAE antibodies who was diagnosed with HE based on positive serum antithyroid antibodies and responsiveness to immunotherapy,[17]suggesting that patients with LE and anti-NAE antibodies could respond to immunotherapy and that LE associated with anti-NAE antibodies may Sildenafil be a clinical subtype of HE. In this study, we conducted clinical analyses of a large number of patients with LE and anti-NAE antibodies who were suspected of having HE to clarify the clinical and immunological features of LE associated with anti-NAE antibodies. We also sought to evaluate the clinical power Rabbit Polyclonal to Cytochrome P450 26C1 of anti-NAE antibodies in LE by analyzing the therapeutic efficacy of immunotherapy to determine whether LE associated with anti-NAE antibodies is usually a type of HE. == 2. Materials and methods == ==.