Origin and significance of leucine-rich glioma-inactivated 1 antibodies in cerebrospinal fluid.

BACKGROUND: Whether antibodies against leucine-rich glioma-inactivated 1 (LGI1-Abs) in cerebrospinal fluid (CSF) are partially transferred from serum and the impact of CSF-LGI1-Ab positivity on clinical features and prognosis are unclear. Therefore, we aim to investigate the differences in serum titers, clinical features, and outcomes between LGI1-Ab CSF-positive and LGI1-Ab CSF-negative patients. METHODS: Retrospective analysis of serum titers and clinical features according to CSF LGI1-Ab status. In addition, univariate and multivariate logistic regression were performed to identify predictors of worse outcomes. RESULTS: A total of 60 patients with anti-LGI1 encephalitis and positive serum LGI1-Abs were identified, of whom 8 (13.3%) patients were excluded due to the absence of CSF LGI1-Ab testing. Among the remaining 52 patients, 33 (63.5%) were positive for LGI1-Abs in CSF. CSF-positive patients were more likely to have high serum titers (≥ 1:100) than CSF-negative patients (p = 0.003), and Spearman's correlation analysis showed a positive correlation between CSF and serum titers in CSF-positive patients (r2 = 0.405, p = 0.019). Psychiatric symptoms and hyponatremia were more frequent in CSF-positive patients (p < 0.05). Both univariate and multivariate logistic regression analyses showed that CSF LGI1-Ab positivity and delayed immunotherapy are independent risk factors for incomplete recovery (modified Rankin Scale (mRS) > 0 at last follow-up). CONCLUSIONS: LGI1-Ab CSF-positive patients have higher serum titers, and their CSF titers are positively correlated with serum titers, indicating a possible peripheral origin of CSF LGI1-Abs. CSF-positive patients more often present with psychiatric symptoms, hyponatremia, and worse outcomes, suggesting more severe neuronal damage.

Predictive value of persistent antibodies at 6 months for relapse in neuronal surface antibody-associated autoimmune encephalitis.

BACKGROUND: For patients with neuronal surface antibody-associated autoimmune encephalitis (NSAE) whose clinical symptoms gradually improve, the recommended course of immunotherapy in China is about 6 months. We aim to explore the relationship between persistent antibody positivity when immunotherapy is discontinued at 6 months and subsequent relapse. METHODS: Prospective inclusion of NSAE patients with clinical remission after 6-month immunotherapy. Their antibody titers and other clinical data were collected at onset and 6 months later. Based on the antibody test results at 6 months, patients were divided into an antibody-persistent group and an antibody-negative conversion group, and then the rate of relapse between the two groups were compared. RESULTS: The study included 28 NSAE patients who were antibody-positive at diagnosis. After 6-month immunotherapy, there were 16 (57.1%) cases with persistent antibodies and 12 (42.9%) cases with antibody-negative conversion. In the acute phase of onset, seizures were more common in patients with persistent antibodies (87.5% vs. 50.0%, p = 0.044). During a mean follow-up period of 22 months, patients with persistent antibodies were more likely to experience relapse than those with antibody-negative conversion (37.5% vs. 0.0%, p = 0.024). There were no significant differences in antibody types, CSF findings, results of MRI and EEG, tumor combination, immunotherapy, and long-term outcome between the two groups (p > 0.05). CONCLUSIONS: For patients with persistent antibodies when immunotherapy is discontinued at 6 months, persistent antibody positivity was associated with a higher relapse rate.

RAE1 promotes nitrosamine-induced malignant transformation of human esophageal epithelial cells through PPARα-mediated lipid metabolism.

Esophageal cancer (EC) is the sixth cause of cancer-related deaths and still is a significant public health problem globally. Nitrosamines exposure represents a major health concern increasing EC risks. Exploring the mechanisms induced by nitrosamines may contribute to the prevention and early detection of EC. However, the mechanism of nitrosamine carcinogenesis remains unclear. Ribonucleic acid export 1 (RAE1), has an important role in mediating diverse cancer types, but, to date, there has been no study for any functional role of RAE1 in esophageal carcinogenesis. Here, we successfully verified the nitrosamine-induced malignant transformation cell (MNNG-M) by xenograft tumor model, based on which it was found that RAE1 was upregulation in the early stage of nitrosamine-induced esophageal carcinogenesis and EC tissues. RAE1 knockdown led to severe blockade in G2/M phase and significant inhibition of proliferation of MNNG-M cells, whereas RAE1 overexpression had the opposite effect. In addition, peroxisome proliferator-activated receptor-alpha (PPARα), was demonstrated as a downstream target gene of RAE1, and its down-regulation reduced lipid accumulation, resulting in causing cells accumulation in the G2/M phase. Mechanistically, we found that RAE1 regulates the lipid metabolism by maintaining the stability of PPARα mRNA. Taken together, our study reveals that RAE1 promotes malignant transformation of human esophageal epithelial cells (Het-1A) by regulating PPARα-mediated lipid metabolism to affect cell cycle progression, and offers a new explanation of the mechanisms underlying esophageal carcinogenesis.

Clinical risk factors for recurrence of myelin oligodendrocyte glycoprotein antibody-associated disease.

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a CNS demyelinating disease that targets myelin oligodendrocyte glycoprotein and recurs in approximately 50% of patients after the initial episode. Multiple relapses may have adverse consequences, but the factors influencing relapse are unclear. This study analyzed the clinical risk factors for relapse in patients with MOGAD. METHODS: Twenty-four MOGAD patients diagnosed at the Department of Neurology, First Hospital of Shanxi Medical University from March 2018 to November 2020 were retrospectively analyzed in this study. The patients were divided into a monophasic course and a relapsing course according to their disease process. The patients' epidemiological characteristics, clinical symptoms, laboratory tests, imaging features, and regression were summarized. Comparisons were made between the monophasic and relapsing course to identify the possible factors associated with the clinical features and recurrence. RESULTS: At a mean follow-up of 15 months (range: 8 to 24 months), seventeen of the 24 patients (70.8%) had monophasic disease, and 7 (29.2%) had relapsing disease. Among the 24 patients, 17 patients (70.9%) had low Myelin oligodendrocyte glycoprotein antibody (MOG-IgG) serum titers (<1:100), and 7 patients (29.1%) had high MOG-IgG serum titers (≥1:100). Compared to the monophasic course group, patients in the relapsing course group had higher serum antibody titers (71.4% vs. 11.7%, P = 0.035). Onset phenotypes included encephalitis (50%), myelitis (45.8%), and optic neuritis (45.8%), with 66.7% of patients starting with a single phenotype and 33.3% starting with two or more phenotypes. Optic neuritis was more common in the relapsing course group (85.7%) than the monophasic course group (29.4%) (P = 0.023). There was no significant difference between the two groups in the proportion of myelitis and encephalitis. A previous history or background of immunological disease was present in 33.3% of patients, with a significantly higher proportion in the relapsing course group than in the monophasic course group (71.4% vs. 17.6%, P = 0.021). Regarding ancillary examinations, the relapsing course group was more likely to have CSF leukocytes higher than 50/mm3 than the monophasic course group (60% vs. 0, P = 0.045), while there was no difference in the number and site distribution of the lesions on MRI. CONCLUSIONS: Our study suggests that the most common clinical manifestations of MOGAD are diminished visual acuity, limb/facial numbness, and ocular/orbital pain. The onset phenotype consisting of optic neuritis, a history of immune disease, high antibody titers (≥1:100), and high cerebrospinal fluid leukocytes (above 50/mm3) suggests a high likelihood of MOGAD recurrence.