Liquid Biopsy in Neurological Diseases

Liquid biopsy; MicroRNA; Neurological diseasesBiòpsia líquida; MicroARN; Malalties neurològiquesBiopsia líquida; MicroARN; Enfermedades neurológicasThe most recent and non-invasive approach for studying early-stage biomarkers is liquid biopsy. This implies the extraction and analysis of non-solid biological tissues (serum, plasma, saliva, urine, and cerebrospinal fluid) without undergoing invasive procedures to determine disease prognosis. Liquid biopsy can be used for the screening of several components, such as extracellular vesicles, microRNAs, cell-free DNA, cell-free mitochondrial and nuclear DNA, circulating tumour cells, circulating tumour DNA, transfer RNA, and circular DNA or RNA derived from body fluids. Its application includes early disease diagnosis, the surveillance of disease activity, and treatment response monitoring, with growing evidence for validating this methodology in cancer, liver disease, and central nervous system (CNS) disorders. This review will provide an overview of mentioned liquid biopsy components, which could serve as valuable biomarkers for the evaluation of complex neurological conditions, including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, multiple sclerosis, epilepsy, stroke, traumatic brain injury, CNS tumours, and neuroinfectious diseases. Furthermore, this review highlights the future directions and potential limitations associated with liquid biopsy.S.M. was supported by the grant from Instituto Salud Carlos III (PI20/01697)

Increased NLRP3 Inflammasome Activation and Pyroptosis in Patients With Multiple Sclerosis With Fingolimod Treatment Failure

Inflammasome; Pyroptosis; Multiple sclerosisInflamasoma; Piroptosis; Esclerosis múltipleInflamasoma; Piroptosi; Esclerosi múltipleBackground and Objectives Inflammasomes are involved in the pathogenesis of different neuroimmune and neurodegenerative diseases, including multiple sclerosis (MS). In a previous study by our group, the nucleotide-binding oligomerization domain, leucine-rich repeat receptor and pyrin-domain–containing 3 (NLRP3) inflammasome was reported to be associated with the response to interferon-beta in MS. Based on recent data showing the potential for the oral therapy fingolimod to inhibit NLRP3 inflammasome activation, here we investigated whether fingolimod could also be implicated in the response to this therapy in patients with MS. Methods NLRP3 gene expression levels were measured by real-time PCR in peripheral blood mononuclear cells at baseline and after 3, 6, and 12 months in a cohort of patients with MS treated with fingolimod (N = 23), dimethyl fumarate (N = 21), and teriflunomide (N = 21) and classified into responders and nonresponders to the treatment according to clinical and radiologic criteria. In a subgroup of fingolimod responders and nonresponders, the percentage of monocytes with an oligomer of ASC was determined by flow cytometry, and the levels of interleukin (IL)-1β, IL-18, IL-6, tumor necrosis factor (TNF)α, and galectin-3 were quantified by ELISA. Results NLPR3 expression levels were significantly increased in fingolimod nonresponders after 3 (p = 0.03) and 6 months (p = 0.008) of treatment compared with the baseline but remained similar in responders at all time points. These changes were not observed in nonresponders to the other oral therapies tested. The formation of an oligomer of ASC in monocytes after lipopolysaccharide and adenosine 5′-triphosphate stimulation was significantly decreased in responders (p = 0.006) but increased in nonresponders (p = 0.0003) after 6 months of fingolimod treatment compared with the baseline. Proinflammatory cytokine release from stimulated peripheral blood mononuclear cells was comparable between responders and nonresponders, but galectin-3 levels on cell supernatants, as a marker of cell damage, were significantly increased in fingolimod nonresponders (p = 0.02). Discussion The differential effect of fingolimod on the formation of an inflammasome-triggered ASC oligomer in monocytes between responders and nonresponders could be used as a response biomarker after 6 months of fingolimod treatment and suggests that fingolimod may exert their beneficial effects by reducing inflammasome signaling in a subset of patients with MS.MCIN/AEI/10.13039/501100011033 (grant PID2020-116709RB-I00)—Fundación Séneca (grant 20859/PI/18) and the Instituto Salud Carlos III (grant DTS21/00080). L. Hurtado-Navarro was supported by the fellowship 21214/FPI/19 (Fundación Séneca, Región de Murcia, Spain)

Serum Levels of CXCL13 Are Associated With Teriflunomide Response in Patients With Multiple Sclerosis

BACKGROUND AND OBJECTIVES: To identify biomarkers associated with treatment response in patients with multiple sclerosis (MS) treated with the oral therapies teriflunomide, dimethyl fumarate (DMF), and fingolimod. METHODS: Serum levels of IL-6, IL-17, TNF-α, granulocyte-macrophage colony-stimulating factor, IL-10, interferon-gamma (IFN-γ) IL-1β, and chemokine ligand 13 (CXCL13) were measured at baseline and 12 months with single molecule array (Simoa) assays in a cohort of patients with MS treated with teriflunomide (N = 19), DMF (N = 22), and fingolimod (N = 25) and classified into "no evidence of disease activity" (NEDA) and EDA patients after 1 year of treatment. RESULTS: Serum CXCL13 and TNF-α levels were significantly decreased after treatment with teriflunomide in NEDA compared with EDA patients after 1 year of treatment (p = 0.008 for both cytokines). These findings were validated in an independent cohort of patients with MS treated with teriflunomide (N = 36) and serum CXCL13, and TNF-α levels were again significantly reduced in NEDA patients (p < 0.0001 for CXCL13 and p = 0.003 for TNF-α). CXCL13, but not TNF-α, showed good performance to classify NEDA and EDA patients according to a cut-off value of 9.64 pg/mL based on the change in CXCL13 levels between baseline and 12 months, with a sensitivity of 75% and specificity of 82% in the original cohort, and sensitivity of 65.4% and specificity of 60% in the validation cohort. DISCUSSION: Altogether, these results point to CXCL13 as a treatment response biomarker to teriflunomide in relapsing-remitting patients with MS, and the change in CXCL13 levels during the first year of treatment can be used in clinical practice to identify optimal responders to teriflunomide

A single-dose strategy for immunization with live attenuated vaccines is an effective option before treatment initiation in multiple sclerosis patients

Multiple sclerosis; Infections; VaccinationEsclerosi múltiple; Infeccions; VacunacióEsclerosis múltiple; Infecciones; VacunaciónBackground: Mumps-Measles-Rubella (MMR) and Varicella zoster vaccines (VAR) are live attenuated vaccines, usually administered in a two-dose scheme at least 4 weeks apart. However, single-dose immunization schemes may also be effective and can reduce delays in immunosuppressive treatment initiation in patients with multiple sclerosis (pwMS) who need to be immunized. Objectives: To evaluate the immunogenicity of a single-dose attempt (SDA) versus the standard immunization scheme (SIS) with VAR and/or MMR in pwMS. Methods: Retrospective observational study in pwMS vaccinated against VAR and/or MMR. We compared seroprotection rates and antibody geometric mean titers (GMTs) between the two strategies. Results: Ninety-six patients were included. Thirty-one patients received VAR and 67 MMR. In the SDA group, the seroprotection rate was 66.7% (95% confidence interval (CI): 53.3–78.3) versus 97.2% (95% CI: 85.5–99.9) in the SIS (p < 0.001). For the seroprotected patients, GMTs were similar for both schemes. Conclusion: An SDA of VAR and/or MMR vaccines could be sufficient to protect almost two-thirds of patients. Testing immunogenicity after a single dose of VZ and/or MMR could be included in routine clinical practice to achieve rapid immunization.This study has been funded by Instituto de Salud Carlos III (ISCIII) through the project PI19/01606 and co-funded by the European Union and ECTRIMS clinical fellowship awarded to René Carvajal from 2021 to 2022

Humoral and Cellular Responses to SARS-CoV-2 in Convalescent COVID-19 Patients With Multiple Sclerosis

Information about humoral and cellular responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and antibody persistence in convalescent (COVID-19) patients with multiple sclerosis (PwMS) is scarce. The objectives of this study were to investigate factors influencing humoral and cellular responses to SARS-CoV-2 and its persistence in convalescent COVID-19 PwMS. This is a retrospective study of confirmed COVID-19 convalescent PwMS identified between February 2020 and May 2021 by SARS-CoV-2 antibody testing. We examined relationships between demographics, MS characteristics, disease-modifying therapy (DMT), and humoral (immunoglobulin G against spike and nucleocapsid proteins) and cellular (interferon-gamma [IFN-γ]) responses to SARS-CoV-2. A total of 121 (83.45%) of 145 PwMS were seropositive, and 25/42 (59.5%) presented a cellular response up to 13.1 months after COVID-19. Anti-CD20-treated patients had lower antibody titers than those under other DMTs (p < 0.001), but severe COVID-19 and a longer time from last infusion increased the likelihood of producing a humoral response. IFN-γ levels did not differ among DMT. Five of 7 (71.4%) anti--CD20-treated seronegative patients had a cellular response. The humoral response persisted for more than 6 months in 41/56(81.13%) PwMS. In multivariate analysis, seropositivity decreased due to anti-CD20 therapy (OR 0.08 [95% CI 0.01-0.55]) and increased in males (OR 3.59 [1.02-12.68]), whereas the cellular response decreased in those with progressive disease (OR 0.04 [0.001-0.88]). No factors were associated with antibody persistence. Humoral and cellular responses to SARS-CoV-2 are present in COVID-19 convalescent PwMS up to 13.10 months after COVID-19. The humoral response decreases under anti-CD20 treatment, although the cellular response can be detected in anti-CD20-treated patients, even in the absence of antibodie