Case Report: Anti-LGI1 Encephalitis Following COVID-19 Vaccination.

Anti-leucine rich glioma inactivated 1 (LGI1) autoimmune encephalitis (AE) is characterized by cognitive impairment or rapid progressive dementia, psychiatric disorders, faciobrachial dystonic seizures (FBDS) and refractory hyponatremia. Since December 2020, millions of people worldwide have been vaccinated against COVID-19. Several soft neurological symptoms like pain, headache, dizziness, or muscle spasms are common and self-limited adverse effects after receiving the COVID-19 vaccine. However, several major neurological complications, despite the unproven causality, have been reported since the introduction of the COVID-19 vaccine. Herein, we describe a 48 years old man presenting with rapidly progressive cognitive decline and hyponatremia diagnosed with anti LGI1 AE, occurring shortly after the second dose of mRNA COVID -19 vaccine and possibly representing a severe adverse event related to the vaccination. Response to high dose steroid therapy was favorable. As millions of people worldwide are currently receiving COVID-19 vaccinations, this case should serve to increase the awareness for possible rare autoimmune reactions following this novel vaccination in general, and particularly of anti-LGI1 AE.

Reversible primary adrenal insufficiency related to anti-programmed cell-death 1 protein active immunotherapy: Insight into an unforeseen outcome of a rare immune-related adverse event.

The immune checkpoint inhibitors (ICPi) revolutionize the cancer therapeutics, though not being devoid of toxicity. The immune-related primary adrenal insufficiency (PAI) is a rare, yet potentially life-threatening, adverse event, posing diagnostic and therapeutic challenges. We report the first case of reversible PAI related to nivolumab (programmed cell-death 1 protein inhibitor) in a 42-year-old male with metastatic rectal adenocarcinoma. PAI manifested as profound fatigue, disorientation, hypotension, hyperpigmentation of palmar creases, and hyponatremia without hyperkalemia 16 weeks after initiation of nivolumab. Due to impending adrenal crisis, intravenous stress doses of hydrocortisone and hydration with normal saline were initiated. When the state of patient was stabilized, PAI was confirmed through 250 µg Synacthen test 24 h after temporary cessation of hydrocortisone. Hydrocortisone was fixed at maintenance dose, while mineralocorticoid substitution was not required. PAI was ascribed to nivolumab based on history, physical examination, and laboratory work-up with emphasis on positivity of anti-21-hydroxylase antibodies and exclusion of other causes of PAI by normal imaging of adrenal glands on computed tomography (CT). Reevaluation of adrenal function during follow up demonstrated complete recovery. A review of literature concerning the immune-related PAI indicated that the complete recovery of adrenal function, the normal CT imaging, and the positivity of anti-21-hydroxylase antibodies observed in our patient are exceptional findings of immune-related PAI. Finally, heightened suspicion of immune-related PAI in case of hyponatremia without hyperkalemia and constant vigilance for diagnosis of rare, but real, reversibility of immune-related PAI are of paramount importance.

Clinical characteristics of autoimmune GFAP astrocytopathy.

The clinical features of autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy remain to be elucidated. We describe here the clinical features of 14 patients with GFAP astrocytopathy confirmed by detection of GFAP-IgG in cerebrospinal fluid (CSF). The novel findings of this study are as follows. First, over half of the patients presented with movement disorders (tremor, myoclonus, and ataxia), autonomic dysfunction (mainly urinary dysfunction), and hyponatremia. Second, most patients showed transient elevation of adenosine deaminase activity levels in CSF. Finally, some patients showed bilateral hyperintensities in the posterior part of the thalamus on brain magnetic resonance imaging.

Low Baseline Serum Sodium Concentration Is Associated with Poor Clinical Outcomes in Metastatic Non-Small Cell Lung Cancer Patients Treated with Immunotherapy.

BACKGROUND: A consistent percentage of patients with metastatic non-small cell lung cancer (NSCLC) derives no or only marginal benefit from immunotherapy (IO). OBJECTIVE: Since serum sodium has been linked to both prognosis in NSCLC and modulation of immune cells activity, we aimed to assess the association between low baseline serum sodium concentration (≤ 135 mEq/L) and clinical outcomes of patients with metastatic NSCLC treated with IO. PATIENTS AND METHODS: We included metastatic NSCLC patients treated with checkpoint inhibitors in our department from April 2013 to April 2018 with available baseline serum sodium concentration. Demographics, clinical and pathological characteristics were collected. Survival analyses were performed using the Kaplan-Meier method and the Cox proportional-hazards model. RESULTS: Of 197 patients included, 26 (13%) presented low baseline serum sodium concentration. Patients in the low sodium cohort experienced a poorer disease control rate (OR 0.36; 95% CI, 0.15-0.86; Wald test P = .02), median overall survival (OS) (2.8 vs. 11.6 months; HR 3.00; 95% CI, 1.80-4.80; P < .001) and progression-free survival (PFS) (1.8 vs. 3.3 months; HR 2.60; 95% CI, 1.70-3.90; P < .001) compared to patients in the control cohort. At multivariate analyses, low baseline serum sodium concentration was independently associated with disease control and OS, but not with PFS. CONCLUSIONS: Our study showed for the first time that low baseline serum sodium concentration is associated with impaired clinical outcomes in patients with metastatic NSCLC treated with IO. The role of serum sodium concentration in this setting warrants further pre-clinical and clinical investigation.

Episodic bradycardia as neurocardiac prodrome to voltage-gated potassium channel complex/leucine-rich, glioma inactivated 1 antibody encephalitis.

IMPORTANCE: Voltage-gated potassium channel complex antibody (VGKCc-Ab) encephalitis is an immunotherapy-responsive syndrome usually associated with causative antibodies that target the leucine-rich, glioma inactivated 1 (LGI1) protein. Although it is expressed throughout the brain, LGI1 is not known to be expressed in cardiac tissue. We describe a novel neurocardiac prodrome of VGKCc-Ab/LGI1-encephalitis. OBSERVATIONS: Among 14 patients with VGKCc/LGI1-Ab encephalitis evaluated in the University of California, San Francisco Autoimmune Encephalitis Clinic and Rapid Dementia Research Program, 3 patients (2 men and 1 woman; aged 53, 55, and 64 years) exhibited episodic bradycardia that preceded the onset of encephalopathy by approximately 2 months and was severe enough to lead to pacemaker implantation. Serum LGI1-Ab results were positive when tested at the time of the subsequent encephalopathy. All 3 patients developed hyponatremia; none had faciobrachial dystonic seizures or malignancy. Brain magnetic resonance imaging was abnormal in 2 cases. None of the patients experienced further symptomatic bradyarrythmias after 1.7 to 7 years of follow-up. CONCLUSIONS AND RELEVANCE: Episodic bradycardia is a distinctive neurocardiac prodrome of VGKCc/LGI1-Ab encephalitis. The neuroanatomical localization most likely relates to insular and temporal lobe involvement, cortical regions that modulate cardiac autonomic function. Further study is needed to determine if recognition of this neurocardiac prodrome and earlier institution of immunosuppression can prevent the development of encephalopathy.