SARS-CoV-2 antibodies in inflammatory neurological conditions: a multicentre retrospective comparative study.

It is well established that neurological and non-neurological autoimmune disorders can be triggered by viral infections. It remains unclear whether SARS-CoV-2 infection induces similar conditions and whether they show a distinctive phenotype. We retrospectively identified patients with acute inflammatory CNS conditions referred to our laboratory for antibody testing during the pandemic (March 1 to August 31, 2020). We screened SARS-COV-2 IgA/IgG in all sera by ELISA and confirmed the positivity with additional assays. Clinical and paraclinical data of SARS-COV-2-IgG seropositive patients were compared to those of seronegative cases matched for clinical phenotype, geographical zone, and timeframe. SARS-CoV-2-IgG positivity was detected in 16/339 (4%) sera, with paired CSF positivity in 3/16. 5 of these patients had atypical demyelinating disorders and 11 autoimmune encephalitis syndromes. 9/16 patients had a previous history of SARS-CoV-2 infection and 6 of them were symptomatic. In comparison with 32 consecutive seronegative controls, SARS-CoV-2-IgG-positive patients were older, frequently presented with encephalopathy, had lower rates of CSF pleocytosis and other neurological autoantibodies, and were less likely to receive immunotherapy. When SARS-CoV-2 seropositive versus seronegative cases with demyelinating disorders were compared no differences were seen. Whereas seropositive encephalitis patients less commonly showed increased CSF cells and protein, our data suggest that an antecedent symptomatic or asymptomatic SARS-CoV-2 infection can be detected in patients with autoimmune neurological conditions. These cases are rare, usually do not have specific neuroglial antibodies.

Autoimmune Encephalitis After SARS-CoV-2 Infection: Case Frequency, Findings, and Outcomes.

BACKGROUND AND OBJECTIVES: Autoimmune encephalitis (AE) cases after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported, but the frequency is unknown. We aimed to determine the frequency and diagnostic features of coronavirus disease 2019 (COVID-19)-related AE. METHODS: Residual sera from 556 consecutive Mayo Clinic Rochester patients (laboratory cohort) who underwent autoimmune encephalopathy neural immunoglobulin G (IgG) evaluation were tested for total antibodies against the SARS-CoV-2 spike glycoprotein using a Food and Drug Administration-authorized chemiluminescence assay (October 2019-December 2020). Clinical records from patients with a positive SARS-CoV-2 antibody result and available research consent were reviewed. This laboratory cohort was cross-referenced with the Department of Neurology's COVID-19-related consultative experience (encephalopathy cohort, n = 31). RESULTS: Eighteen of the laboratory cohort (3%) were SARS-CoV-2 antibody positive (April-December 2020). Diagnoses were as follows: AE, 2; postacute sequelae of SARS CoV-2 infection (PASC), 3; toxic-metabolic encephalopathy during COVID-19 pneumonia, 2; diverse non-COVID-19 relatable neurologic diagnoses, 9; unavailable, 2. Five of the encephalopathy cohort had AE (16%, including the 2 laboratory cohort cases that overlapped), representing 0.05% of 10,384 patients diagnosed and cared for with any COVID-19 illness at Mayo Clinic Rochester in 2020. The 5 patients met definite (n = 1), probable (n = 1), or possible (n = 3) AE diagnostic criteria; median symptom onset age was 61 years (range, 46-63); 3 were women. All 5 were neural IgG negative and 4 tested were SARS-CoV-2 PCR/IgG index negative in CSF. Phenotypes (and accompanying MRI and EEG findings) were diverse (delirium [n = 5], seizures [n = 2], rhombencephalitis [n = 1], aphasia [n = 1], and ataxia [n = 1]). No acute disseminated encephalomyelitis cases were encountered. The 3 patients with possible AE had spontaneously resolving syndromes. One with definite limbic encephalitis was immune therapy responsive but had residual mood and memory problems. One patient with probable autoimmune rhombencephalitis died despite immune therapy. The remaining 26 encephalopathy cohort patients had toxic-metabolic diagnoses. DISCUSSION: We encountered occasional cases of AE in our 2020 COVID-19 experience. Consistent with sporadic reports and small case series during the COVID-19 pandemic, and prior experience of postinfectious AE, our cases had diverse clinical presentations and were neural IgG and CSF viral particle negative. Application of diagnostic criteria assists in differentiation of AE from toxic-metabolic causes arising in the setting of systemic infection.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Encephalitis Is a Cytokine Release Syndrome: Evidences From Cerebrospinal Fluid Analyses.

BACKGROUND: Recent findings indicated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related neurological manifestations involve cytokine release syndrome along with endothelial activation, blood brain barrier dysfunction, and immune-mediated mechanisms. Very few studies have fully investigated the cerebrospinal fluid (CSF) correlates of SARS-CoV-2 encephalitis. METHODS: Patients with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection and encephalitis (COV-Enc), encephalitis without SARS-CoV-2 infection (ENC), and healthy controls (HC) underwent an extended panel of CSF neuronal (neurofilament light chain [NfL], T-tau), glial (glial fibrillary acidic protein [GFAP], soluble triggering receptor expressed on myeloid cells 2 [sTREM2], chitinase-3-like protein 1 [YKL-40]) and inflammatory biomarkers (interleukin [IL]-1ß, IL-6, Il-8, tumor necrosis factor [TNF] α, CXCL-13, and ß2-microglobulin). RESULTS: Thirteen COV-Enc, 21 ENC, and 18 HC entered the study. In COV-Enc cases, CSF was negative for SARS-CoV-2 real-time PCR but exhibited increased IL-8 levels independently from presence of pleocytosis/hyperproteinorracchia. COV-Enc patients showed increased IL-6, TNF- α, and ß2-microglobulin and glial markers (GFAP, sTREM2, YKL-40) levels similar to ENC but normal CXCL13 levels. Neuronal markers NfL and T-tau were abnormal only in severe cases. CONCLUSIONS: SARS-CoV-2-related encephalitis were associated with prominent glial activation and neuroinflammatory markers, whereas neuronal markers were increased in severe cases only. The pattern of CSF alterations suggested a cytokine-release syndrome as the main inflammatory mechanism of SARS-CoV-2-related encephalitis.

Genetic counseling, virtual visits, and equity in the era of COVID-19 and beyond.

Overnight, as a result of the COVID-19 pandemic, telehealth rapidly transitioned from limited application to widespread implementation. The field of genetic counseling was well positioned to make this transition to virtual care since there is generally less of a need for patients to be seen in-person for physical exams or urgent care. Going forward, virtual visits will presumably become a mainstay in the provision of genetic services and it is anticipated that clinics will adopt "hybrid" models with both in-person and virtual visit options. This commentary highlights the successes and challenges in the rapid implementation of virtual visits, focusing on who has benefited versus who has been challenged or left behind. We also discuss genetic testing considerations, including the additional steps required for patients and clinicians when testing is ordered outside of the clinical setting, which can result in delays or a lack of testing altogether. Future research considerations are presented to address the needs among the most vulnerable and help ensure equitable access and benefit.