B- and T-Cell Responses After SARS-CoV-2 Vaccination in Patients With Multiple Sclerosis Receiving Disease Modifying Therapies: Immunological Patterns and Clinical Implications

BackgroundVaccination campaign to contrast the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has raised the issue of vaccine immunogenicity in special populations such as people with multiple sclerosis (PwMS) on highly effective disease modifying treatments (DMTs). While humoral responses to SARS-CoV-2 mRNA vaccines have been well characterized in the general population and in PwMS, very little is known about cell-mediated responses in conferring protection from SARS-CoV-2 infection and severe coronavirus disease-2019 (COVID-19).MethodsPwMS on ocrelizumab, fingolimod or natalizumab, vaccinated with two doses of mRNABNT162b2 (Comirnaty®) vaccine were enrolled. Anti-Spike (S) and anti-Nucleoprotein (N) antibody titers, IFN-gamma production upon S and N peptide libraries stimulation, peripheral blood lymphocyte absolute counts were assessed after at least 1 month and within 4 months from vaccine second dose administration. A group of age and sex matched healthy donors (HD) were included as reference group. Statistical analysis was performed using GraphPad Prism 8.2.1.ResultsThirty PwMS and 9 HDs were enrolled. All the patients were negative for anti-N antibody detection, nor reported previous symptoms of COVID-19. Peripheral blood lymphocyte counts were assessed in PwMS showing: (i) reduction of circulating B-lymphocytes in PwMS on ocrelizumab; (ii) reduction of peripheral blood B- and T-lymphocyte absolute counts in PwMS on fingolimod and (iii) normal B- and T-lymphocyte absolute counts with an increase in circulating CD16+CD56+ NK-cells in PwMS on natalizumab. Three patterns of immunological responses were identified in PwMS. In patients on ocrelizumab, anti-S antibody were lacking or reduced, while T-cell responses were normal. In patients on fingolimod both anti-S titers and T-cell mediated responses were impaired. In patients on natalizumab both anti-S titers and T-cell responses were present and comparable to those observed in HD.ConclusionsThe evaluation of T-cell responses, anti-S titers and peripheral blood lymphocyte absolute count in PwMS on DMTs can help to better characterize the immunological response after SARS-CoV-2 vaccination. The evaluation of T-cell responses in longitudinal cohorts of PwMS will help to clarify their protective role in preventing SARS-CoV-2 infection and severe COVID-19. The correlation between DMT treatment and immunological responses to SARS-CoV-2 vaccines could help to better evaluate vaccination strategies in PwMS.

A molecular view of human amyloid-β folds

Structures of amyloid-β fibrils suggest Alzheimer’s disease–modifying strategies

Disease-Modifying Drug Uptake and Health Service Use in the Ageing MS Population

BackgroundEvidence regarding the efficacy or effectiveness of the disease-modifying drugs (DMDs) in the older multiple sclerosis (MS) population is scarce. This has contributed to a lack of evidence-based treatment recommendations for the ageing MS population in practice guidelines. We examined the relationship between age (<55 and ≥55 years), DMD exposure and health service use in the MS population.MethodsWe conducted a population-based observational study using linked administrative health data from British Columbia, Canada. We selected all persons with MS and followed from the most recent of their first MS or demyelinating event, 18th birthday or 01-January-1996 (index date) until the earliest of emigration, death or 31-December-2017 (study end). We assessed DMD exposure status over time, initially as any versus no DMD, then by generation (first or second) and finally by each individual DMD. Age-specific analyses were conducted with all-cause hospitalizations and number of physician visits assessed using proportional means model and negative binomial regression with generalized estimating equations.ResultsWe included 19,360 persons with MS (72% were women); 10,741/19,360 (56%) had ever reached their 55th birthday. Person-years of follow-up whilst aged <55 was 132,283, and 93,594 whilst aged ≥55. Any DMD, versus no DMD in the <55-year-olds was associated with a 23% lower hazard of hospitalization (adjusted hazard ratio, aHR0.77; 95%CI 0.72-0.82), but not in the ≥55-year-olds (aHR0.95; 95%CI 0.87-1.04). Similar patterns were observed for the first and second generation DMDs. Exposure to any (versus no) DMD was not associated with rates of physician visits in either age group (<55 years: adjusted rate ratio, aRR1.02; 95%CI 1.00-1.04 and ≥55 years: aRR1.00; 95%CI 0.96-1.03), but variation in aRR was observed across the individual DMDs.ConclusionOur study showed beneficial effects of the DMDs used to treat MS on hospitalizations for those aged <55 at the time of exposure. In contrast, for individuals ≥55 years of age exposed to a DMD, the hazard of hospitalization was not significantly lowered. Our study contributes to the broader understanding of the potential benefits and risks of DMD use in the ageing MS population.

Paramagnetic rim lesions are associated with pathogenic CSF profiles and worse clinical outcomes in multiple sclerosis: a retrospective cross-sectional study

Background and Objective: Paramagnetic rims have been observed as a feature of some MS lesions on susceptibility-sensitive MRI and indicate ongoing inflammation, principally consisting of compartmentalized activated microglia/macrophages. We investigated clinical, MRI, and intrathecal (cerebrospinal fluid, CSF) associations of paramagnetic rim lesions (PRL) using 3T MRI in MS. Methods: This is a retrospective, cross-sectional analysis of patients at a single neuroimmunology clinic. All patients had standardized 3T MRI using a multiecho T2*-weighted sequence with susceptibility postprocessing (SWAN protocol, GE) as part of the inclusion criteria. SWAN-derived filtered phase maps and corresponding T2-FLAIR images were manually reviewed by one expert rater blinded to clinical data, and PRL were determined based on qualitative assessment of hypointense paramagnetic edges on corresponding T2-hyperintense lesions. Descriptive statistics, t-tests, ANOVA, and linear regression determined demographic, clinical, MRI, and intrathecal profile associations with the presence of one or more PRL. Results: One hundred and forty-seven (147) MS patients were included in this analysis (2 clinically isolated syndrome, 118 relapsing-remitting, 14 secondary progressive, 13 primary progressive). Baseline mean age was 48.8 years, disease duration 12.8 years, and median EDSS 2, with 79% women. Seventy-five percent of patients were receiving a disease-modifying therapy, and 79 patients (54%) had available cerebrospinal fluid (CSF) analysis. Sixty-three patients (43%) had at least 1 PRL. PRL status (presence or absence) did not vary by sex or EDSS but was associated with younger age (51 vs 46 years; p=0.01) and shorter disease duration (14.5 vs 10.5 years; p=0.01). PRL status was also associated with worse disease (MS severity score: 2.8 vs 3.7; p=0.05) and blood-brain barrier disruption as determined by higher protein and pathologically elevated albumin quotient, as well as the presence of CSF oligoclonal bands (all p≤0.05); there was no association with immunoglobulin index or synthesis rate. PRL status was additionally associated with higher burden of T2-hyperintense cerebral lesion volume (T2LV), higher age-adjusted cerebral brain volume loss (especially of gray matter), and poorer performance on multiple clinical measures, including the 9-hole peg test and symbol digit modalities test (but not timed 25-foot walk speed). Clinical and intrathecal profiles remained associated with PRL after adjustment for age and in many cases T2LV as well. Sensitivity analyses limited to subgroups of patients without disease activity at the time of CSF sampling remained supportive of results. Patients with PRL were being treated with higher-efficacy disease-modifying therapies at the time of the data query. Conclusions: PRL, an emerging noninvasive biomarker of chronic cerebral neuroinflammation in MS, are confirmed to be associated with greater disease severity and newly shown to be associated with intrathecal inflammation and blood-brain-barrier disruption.

Cellular and humoral immunity to SARS-CoV-2 infection in multiple sclerosis patients on ocrelizumab and other disease-modifying therapies: a multi-ethnic observational study

Objective: To determine the impact of MS disease-modifying therapies (DMTs) on the development of cellular and humoral immunity to SARS-CoV-2 infection. Methods: MS patients aged 18-60 were evaluated for anti-nucleocapsid and anti-Spike RBD antibody with electro-chemiluminescence immunoassay; antibody responses to Spike protein, RBD, N-terminal domain with multiepitope bead-based immunoassays (MBI); live virus immunofluorescence-based microneutralization assay; T-cell responses to SARS-CoV-2 Spike using TruCulture ELISA; and IL-2 and IFNγ ; ELISpot assays. Assay results were compared by DMT class. Spearman correlation and multivariate analyses were performed to examine associations between immunologic responses and infection severity. Results: Between 1/6/2021 and 7/21/2021, 389 MS patients were recruited (mean age 40.3 years; 74% female; 62% non-White). Most common DMTs were ocrelizumab (OCR) - 40%; natalizumab - 17%, Sphingosine 1-phosphate receptor (S1P) modulators -12%; and 15% untreated. 177 patients (46%) had laboratory evidence of SARS-CoV-2 infection; 130 had symptomatic infection, 47 - asymptomatic. Antibody responses were markedly attenuated in OCR compared to other groups (p≤0.0001). T-cell responses (IFNγ) were decreased in S1P (p=0.03), increased in natalizumab (p<0.001), and similar in other DMTs, including OCR. Cellular and humoral responses were moderately correlated in both OCR (r=0.45, p=0.0002) and non-OCR (r=0.64, p<0.0001). Immune responses did not differ by race/ethnicity. COVID-19 clinical course was mostly non-severe and similar across DMTs; 7% (9/130) were hospitalized. Interpretation: DMTs had differential effects on humoral and cellular immune responses to SARS-CoV-2 infection. Immune responses did not correlate with COVID-19 clinical severity in this relatively young and non-disabled group of MS patients.

Two-step screening method to identify α-synuclein aggregation inhibitors for Parkinson’s disease

Parkinson’s disease is a neurodegenerative disease characterized by the formation of neuronal inclusions of α-synuclein in patient brains. As the disease progresses, toxic α-synuclein aggregates transmit throughout the nervous system. No effective disease-modifying therapy has been established, and preventing α-synuclein aggregation is thought to be one of the most promising approaches to ameliorate the disease. In this study, we performed a two-step screening using the thioflavin T assay and a cell-based assay to identify α-synuclein aggregation inhibitors. The first screening, thioflavin T assay, allowed the identification of 30 molecules, among a total of 1262 FDA-approved small compounds, which showed inhibitory effects on α-synuclein fibrilization. In the second screening, a cell-based aggregation assay, seven out of these 30 candidates were found to prevent α-synuclein aggregation without causing substantial toxicity. Of the seven final candidates, tannic acid was the most promising compound. The robustness of our screening method was validated by a primary neuronal cell model and a Caenorhabditis elegans model, which demonstrated the effect of tannic acid against α-synuclein aggregation. In conclusion, our two-step screening system is a powerful method for the identification of α-synuclein aggregation inhibitors, and tannic acid is a promising candidate as a disease-modifying drug for Parkinson’s disease.

An Argument for Simple Tests of Treatment of Alzheimer’s Disease

Two potential disease-modifying approaches for dementia are being vigorously tested: the early targeting of the neuropathology of Alzheimer’s disease (AD) and multi-domain lifestyle interventions to promote resilience to neuropathology. We apply the “web of information” model of clinical translation to both approaches to argue firstly that tests of treatments aiming to achieve clinically meaningful outcomes should remain simple, and secondly, that building clinically-meaningful treatments should be kept separate from public health policy which means promoting wide-reaching action against risk factors now with available information.

Retrotransposons as a Source of DNA Damage in Neurodegeneration

The etiology of aging-associated neurodegenerative diseases (NDs), such as Parkinson’s disease (PD) and Alzheimer’s disease (AD), still remains elusive and no curative treatment is available. Age is the major risk factor for PD and AD, but the molecular link between aging and neurodegeneration is not fully understood. Aging is defined by several hallmarks, some of which partially overlap with pathways implicated in NDs. Recent evidence suggests that aging-associated epigenetic alterations can lead to the derepression of the LINE-1 (Long Interspersed Element-1) family of transposable elements (TEs) and that this derepression might have important implications in the pathogenesis of NDs. Almost half of the human DNA is composed of repetitive sequences derived from TEs and TE mobility participated in shaping the mammalian genomes during evolution. Although most TEs are mutated and no longer mobile, more than 100 LINE-1 elements have retained their full coding potential in humans and are thus retrotransposition competent. Uncontrolled activation of TEs has now been reported in various models of neurodegeneration and in diseased human brain tissues. We will discuss in this review the potential contribution of LINE-1 elements in inducing DNA damage and genomic instability, which are emerging pathological features in NDs. TEs might represent an important molecular link between aging and neurodegeneration, and a potential target for urgently needed novel therapeutic disease-modifying interventions.