Environmental Enrichment, Age, and PPARα Interact to Regulate Proliferation in Neurogenic Niches

Peroxisome proliferator-activated receptor alpha (PPARα) ligands have been shown to modulate recovery after brain insults such as ischemia and irradiation by enhancing neurogenesis. In the present study, we investigated the effect of the genetic deletion of PPARα receptors on the proliferative rate of neural precursor cells (NPC) in the adult brain. The study was performed in aged Pparα −/− mice exposed to nutritional (treats) and environmental (games) enrichments for 20 days. We performed immunohistochemical analyses of cells containing the replicating cell DNA marker 5-bromo-2′ -deoxyuridine (BrdU+) and the immature neuronal marker doublecortin (Dcx+) in the main neurogenic zones of the adult brain: subgranular zone of dentate gyrus (SGZ), subventricular zone of lateral ventricles (SVZ), and/or hypothalamus. Results indicated a reduction in the number of BrdU+ cells in the neurogenic zones analyzed as well as Dcx+ cells in the SGZ during aging (2, 6, and 18 months). Pparα deficiency alleviated the age-related reduction of NPC proliferation (BrdU+ cells) in the SVZ of the 18-months-old mice. While no genotype effect on NPC proliferation was detected in the SGZ during aging, an accentuated reduction in the number of Dcx+ cells was observed in the SGZ of the 6-months-old Pparα −/− mice. Exposing the 18-months-old mice to nutritional and environmental enrichments reversed the Pparα −/−-induced impairment of NPC proliferation in the neurogenic zones analyzed. The enriched environment did not modify the number of SGZ Dcx+ cells in the 18 months old Pparα −/− mice. These results identify PPARα receptors as a potential target to counteract the naturally observed decline in adult NPC proliferation associated with aging and impoverished environments.Grant sponsor: 7th Framework Programme of European Union. Grant number: HEALTH-F2-2008-223713, REPROBESITY to FR. Grant sponsor: Instituto de Salud Carlos III (ISCIII), Ministerio de Economía y Competitividad (MINECO), UEERDF. Grant numbers: PI13/02261 to FR. and CP12/03109 to JS. Grant sponsor: Red de Trastornos Adictivos, ISCIII, MINECO. Grant number: RD12/0028/0001 to FR. Grant sponsor: Plan Nacional Sobre Drogas, Ministerio de Sanidad y Consumo. Grant number: PNSD2010/143 and PNSD2015/047 to JS. Grant sponsor: Fundació La Marató de TV3. Grant number: 386/C/2011. Grant sponsor: Consejería de Economía, Innovación y Ciencia, Junta de Andalucía, UE/ERDF. Grant numbers: PI45403 and CTS-8221 to FR. Grant sponsor: Consejería de Salud, Junta de Andalucía, UE/ERDF. Grant number: SAS111224 to FR. JS, FP and AS hold “Miguel Servet” research contracts from the National System of Health, ISCIII (grant numbers: CP12/03109, CP14/00212 and CP14/00173, respectively

SARS-CoV-2 vaccination and multiple sclerosis: a large multicentric study on relapse risk after the third booster dose

Background: COVID-19 vaccines have been recommended to people with multiple sclerosis (pwMS) and, to ensure durable immunity, a third booster dose has been administered in several countries. Data about potential risks associated with the third booster dose in pwMS, such as vaccine-triggered disease exacerbations, are still scarce. Objective: To investigate whether the administration of a third booster dose of mRNA COVID-19 vaccines was associated with an increased risk of short-term disease reactivation in a large cohort of pwMS. Methods: We retrospectively selected 1265 pwMS who received a third booster dose of an mRNA COVID-19 vaccine. Demographic and clinical data were collected, including the presence, number and characteristics of relapses in the 60 days prior to and after the third booster dose. Results: In the selected cohort, the relapse rate in the two months after administration of the third booster dose of mRNA COVID-19 vaccines did not increase when compared with the prior two months. Indeed, the percentage of pwMS experiencing relapses in the 60 days following the administration of the third booster dose was 2.1%, similar to the percentage recorded in 60 days prior to vaccination, which was 1.9%. Conclusions: The third booster dose of mRNA COVID-19 vaccines appeared to be safe for pwMS

COVID-19 Severity in Multiple Sclerosis: Putting Data Into Context

Background and objectives: It is unclear how multiple sclerosis (MS) affects the severity of COVID-19. The aim of this study is to compare COVID-19-related outcomes collected in an Italian cohort of patients with MS with the outcomes expected in the age- and sex-matched Italian population. Methods: Hospitalization, intensive care unit (ICU) admission, and death after COVID-19 diagnosis of 1,362 patients with MS were compared with the age- and sex-matched Italian population in a retrospective observational case-cohort study with population-based control. The observed vs the expected events were compared in the whole MS cohort and in different subgroups (higher risk: Expanded Disability Status Scale [EDSS] score > 3 or at least 1 comorbidity, lower risk: EDSS score ≤ 3 and no comorbidities) by the χ2 test, and the risk excess was quantified by risk ratios (RRs). Results: The risk of severe events was about twice the risk in the age- and sex-matched Italian population: RR = 2.12 for hospitalization (p < 0.001), RR = 2.19 for ICU admission (p < 0.001), and RR = 2.43 for death (p < 0.001). The excess of risk was confined to the higher-risk group (n = 553). In lower-risk patients (n = 809), the rate of events was close to that of the Italian age- and sex-matched population (RR = 1.12 for hospitalization, RR = 1.52 for ICU admission, and RR = 1.19 for death). In the lower-risk group, an increased hospitalization risk was detected in patients on anti-CD20 (RR = 3.03, p = 0.005), whereas a decrease was detected in patients on interferon (0 observed vs 4 expected events, p = 0.04). Discussion: Overall, the MS cohort had a risk of severe events that is twice the risk than the age- and sex-matched Italian population. This excess of risk is mainly explained by the EDSS score and comorbidities, whereas a residual increase of hospitalization risk was observed in patients on anti-CD20 therapies and a decrease in people on interferon

DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France

We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39–3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18–0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon

Symptomatic COVID-19 course and outcomes after three mRNA vaccine doses in multiple sclerosis patients treated with high-efficacy DMTs

Background: Little is known about COVID-19 course and outcomes after a third booster dose of mRNA vaccine against SARS-CoV-2 (mRNA-Vax) in patients with multiple sclerosis (pwMS) treated with ocrelizumab (OCR) and fingolimod (FNG), which showed a weakened immune response to mRNA-vax. Objectives: The aim of this study was to evaluate COVID-19 course and outcomes in pwMS on OCR and FNG after receiving the third dose of mRNA-Vax and to compare it with pwMS on natalizumab (NTZ). Methods: Inclusion criteria: >18 years of age, being treated with OCR/FNG/NTZ since the first mRNA-Vax dose; COVID-19 after a third booster dose of mRNA-Vax; no steroids use. Results: Overall, 290 pwMS (79 NTZ, 126 OCR, and 85 FNG) from 17 Italian MS centers were included. Age, Expanded Disability Status Scale (EDSS) score, MS phenotype, disease, and treatment duration were significantly different across groups. PwMS who had COVID-19 on OCR and FNG compared with those on NTZ were slightly more symptomatic with higher hospitalization rates (11.1% vs 7.1% vs 1.3%, respectively). Regression models showed that the majority of the differences observed were not related to the disease-modifying treatments (DMTs) used. No fatal cases were observed. Conclusion: Our results support the effectiveness of the third booster dose of mRNA-Vax against severe forms of COVID-19 in pwMS treated with OCR and FNG

Symptomatic COVID-19 course and outcomes after three mRNA vaccine doses in multiple sclerosis patients treated with high-efficacy DMTs

Background: Little is known about COVID-19 course and outcomes after a third booster dose of mRNA vaccine against SARS-CoV-2 (mRNA-Vax) in patients with multiple sclerosis (pwMS) treated with ocrelizumab (OCR) and fingolimod (FNG), which showed a weakened immune response to mRNA-vax. Objectives: The aim of this study was to evaluate COVID-19 course and outcomes in pwMS on OCR and FNG after receiving the third dose of mRNA-Vax and to compare it with pwMS on natalizumab (NTZ). Methods: Inclusion criteria: >18 years of age, being treated with OCR/FNG/NTZ since the first mRNAVax dose; COVID-19 after a third booster dose of mRNA-Vax; no steroids use. Results: Overall, 290 pwMS (79 NTZ, 126 OCR, and 85 FNG) from 17 Italian MS centers were included. Age, Expanded Disability Status Scale (EDSS) score, MS phenotype, disease, and treatment duration were significantly different across groups. PwMS who had COVID-19 on OCR and FNG compared with those on NTZ were slightly more symptomatic with higher hospitalization rates (11.1% vs 7.1% vs 1.3%, respectively). Regression models showed that the majority of the differences observed were not related to the disease-modifying treatments (DMTs) used. No fatal cases were observed. Conclusion: Our results support the effectiveness of the third booster dose of mRNA-Vax against severe forms of COVID-19 in pwMS treated with OCR and FNG

Exposure to natalizumab throughout pregnancy: effectiveness and safety in an Italian cohort of women with multiple sclerosis

Objective: Assessing the risk of clinical and radiological reactivation during pregnancy and post partum in women with multiple sclerosis (MS) treated with natalizumab (NTZ) throughout pregnancy (LONG_EXP) compared with women interrupting treatment before (NO_EXP) and within >-30 days and ≤90 days from conception (SHORT_EXP), and describing newborns' outcomes. Methods: Maternal clinical and radiological outcomes and obstetric and fetal outcomes were retrospectively collected and compared among groups (NO_EXP, SHORT_EXP, LONG_EXP). Predictors of clinical and radiological reactivation were investigated through univariable and multivariable analysis. Results: 170 eligible pregnancies from 163 women referring to 29 Italian MS centres were included. Annualised relapse rate (ARR) was significantly lower in LONG_EXP (n=66, 0.02 (0.001-0.09)) compared with NO_EXP (n=31, 0.43 (0.21-0.75), p=0.002) and SHORT_EXP (n=73, 0.46 (0.30-0.66), p=0.0004) during pregnancy, and in LONG_EXP (0.12 (0.05-0.24)) compared with SHORT_EXP (0.30 (0.17-0.50), p=0.008) during post partum. Gadolinium-enhancing (Gd+) lesions were less frequent in LONG_EXP (n=6/50, 2.00%) compared with NO_EXP (n=9/21, 42.86%) and SHORT_EXP after delivery (n=17/49, 34.69%, p=0.010).Delaying NTZ resumption after delivery significantly increased the risk of relapses (OR=1.29 (95% CI 1.07 to 1.57), p=0.009) and Gd+ lesions (OR=1.49 (95% CI 1.17 to 1.89, p=0.001). Newborns' weight, length, head circumference and gestational age did not differ among groups after adjusting for confounders. Anaemia was tracked in 4/69 LONG_EXP newborns. Congenital anomaly rate was within the expected range for the untreated MS population. Conclusions: Our findings indicate that in women with MS treated with NTZ before conception, continuation of NTZ throughout pregnancy and its early resumption after delivery mitigate the risk of clinical and radiological reactivation. This approach has no major impact on newborns' outcomes

Exposure to natalizumab throughout pregnancy: effectiveness and safety in an Italian cohort of women with multiple sclerosis

Assessing the risk of clinical and radiological reactivation during pregnancy and post partum in women with multiple sclerosis (MS) treated with natalizumab (NTZ) throughout pregnancy (LONG_EXP) compared with women interrupting treatment before (NO_EXP) and within >-30 days and ≤90 days from conception (SHORT_EXP), and describing newborns' outcomes