Infectious Agents as Potential Drivers of α-Synucleinopathies

α-synucleinopathies, encompassing Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, are devastating neurodegenerative diseases for which available therapeutic options are scarce, mostly because of our limited understanding of their pathophysiology. Although these pathologies are attributed to an intracellular accumulation of the α-synuclein protein in the nervous system with subsequent neuronal loss, the trigger(s) of this accumulation is/are not clearly identified. Among the existing hypotheses, interest in the hypothesis advocating the involvement of infectious agents in the onset of these diseases is renewed. In this article, we aimed to review the ongoing relevant factors favoring and opposing this hypothesis, focusing on (1) the potential antimicrobial role of α-synuclein, (2) potential entry points of pathogens in regard to early symptoms of diverse α-synucleinopathies, (3) pre-existing literature reviews assessing potential associations between infectious agents and Parkinson's disease, (4) original studies assessing these associations for dementia with Lewy bodies and multiple system atrophy (identified through a systematic literature review), and finally (5) potential susceptibility factors modulating the effects of infectious agents on the nervous system. © 2022 International Parkinson and Movement Disorder Society.

Antiherpetic drugs: a potential way to prevent Alzheimer's disease?

Background

Considering the growing body of evidence suggesting a potential implication of herpesviruses in the development of dementia, several authors have questioned a protective effect of antiherpetic drugs (AHDs) which may represent a new means of prevention, well tolerated and easily accessible. Subsequently, several epidemiological studies have shown a reduction in the risk of dementia in subjects treated with AHDs, but the biological plausibility of this association and the impact of potential methodological biases need to be discussed in more depth.

Methods

Using a French medico-administrative database, we assessed the association between the intake of systemic AHDs and the incidence of (i) dementia, (ii) Alzheimer’s disease (AD), and (iii) vascular dementia in 68,291 subjects over 65 who were followed between 2009 and 2017. Regarding potential methodological biases, Cox models were adjusted for numerous potential confounding factors (including proxies of sociodemographic status, comorbidities, and use of healthcare) and sensitivity analyses were performed in an attempt to limit the risk of indication and reverse causality biases.

Results

9.7% of subjects (n=6642) had at least one intake of systemic AHD, and 8883 incident cases of dementia were identified. Intake of at least one systemic AHD during follow-up was significantly associated with a decreased risk of AD (aHR 0.85 95% confidence interval [0.75–0.96], p=0.009) and, to a lesser extent with respect to p values, to both dementia from any cause and vascular dementia. The association with AD remained significant in sensitivity analyses. The number of subjects with a regular intake was low and prevented us from studying its association with dementia.

Conclusions

Taking at least one systemic AHD during follow-up was significantly associated with a 15% reduced risk of developing AD, even after taking into account several potential methodological biases. Nevertheless, the low frequency of subjects with a regular intake questions the biological plausibility of this association and highlights the limits of epidemiological data to evaluate a potential protective effect of a regular treatment by systemic AHDs on the incidence of dementia

Supplementary Information

The online version contains supplementary material available at 10.1186/s13195-021-00950-0.

Interaction between APOE4 and herpes simplex virus type 1 in Alzheimer's disease

INTRODUCTION

Numerous results suggest the implication of infectious agents in the onset of Alzheimer's disease (AD).

METHODS

In the Bordeaux-3C prospective cohort, we assessed the impact of herpes simplex virus type 1 (HSV-1) infection on the incidence of AD according to apolipoprotein E (APOE) status, a genetic susceptibility factor. Cox models were performed to estimate the 10-year risk of AD associated with anti-HSV antibodies in 1037 participants according to APOE4 status.

RESULTS

Among APOE4 carriers, subjects for whom the frequency of HSV-1 reactivation is supposed to be high, that is, immunoglobulin M (IgM) positive or elevated levels of IgG, had an increased risk of AD with adjusted hazard ratios (HRs) of 3.68 (1.08-12.55) and 3.28 (1.19-9.03), respectively. No significant association was found in APOE4-negative subjects.

DISCUSSION

These results, in accordance with a solid pathophysiological rationale, suggest a role for HSV-1 in AD development among subjects with a genetic susceptibility factor, the APOE4 allele.

Differential rates of cesarean delivery by maternal geographical origin: a cohort study in France

BACKGROUND

In many Western countries, higher rates of cesarean have been described among migrant women compared to natives of receiving countries. We aimed to estimate this difference comparing women originating from France and Sub-Saharan Africa (SSA), identify the clinical situations explaining most of this difference and assess whether maternal origin was independently associated with cesarean risk.

METHODS

The PreCARE prospective multicenter cohort study was conducted in 2010-2012 in the north Paris area. Our sample was restricted to 1500 women originating from Sub-Saharan Africa and 2206 from France. Profiles of cesarean section by maternal origin were described by the Robson classification. Independent associations between maternal origin and 1) cesarean before labor versus trial of labor, then 2) intrapartum cesarean versus vaginal delivery were assessed by logistic regression models to adjust for other maternal and pregnancy characteristics.

RESULTS

Rates of cesarean for women originating from France and SSA were 17 and 31%. The Robson 5A category "unique uterine scar, single cephalic ≥37 weeks" was the main contributor to this difference. Within this category, SSA origin was associated with cesarean before labor after adjustment for medical risk factors (adjusted odds ratio [aOR] = 2.30 [1.12-4.71]) but no more significant when adjusting on social deprivation (aOR = 1.45 [0.63-3.31]). SSA origin was associated with cesarean during labor after adjustment for both medical and social factors (aOR = 2.95 [1.35-6.44]).

CONCLUSIONS

The wide difference in cesarean rates between SSA and French native women is mainly explained by the Robson 5A category. Within this group, medical factors alone do not explain the increased risk of cesarean in SSA women.

Efficacy of cloxacillin versus cefazolin for methicillin-susceptible Staphylococcus aureus bacteraemia (CloCeBa): study protocol for a randomised, controlled, non-inferiority trial

INTRODUCTION

Methicillin-susceptible Staphylococcus aureus (MSSA) bacteraemia is a common and severe disease responsible for approximately 65 000 deaths every year in Europe. Intravenous antistaphylococcal penicillins (ASP) such as cloxacillin are the current recommended antibiotics. However, increasing reports of toxicity and recurrent stock-outs of ASP prompted healthcare providers to seek for alternative antibiotic treatment. Based on retrospective studies, cefazolin, a first-generation cephalosporin, is recommended in patients at risk of severe ASP-associated toxicity.We hypothesised that cefazolin has a non-inferior efficacy in comparison to cloxacillin, with a better safety profile for the treatment of MSSA bacteraemia.

METHODS AND ANALYSIS

The CloCeBa trial is an open-label, randomised, controlled, non-inferiority trial conducted in academic centres throughout France. Eligible patients are adults with MSSA bacteraemia without intravascular device or suspicion of central nervous system infection. Patients will be randomised (1:1) to receive either cloxacillin or cefazolin by the intravenous route, for the first 14 days of therapy. The evaluation criteria is a composite criteria of negative blood cultures at day 5, survival, absence of relapse and clinical success at day 90 after randomisation. Secondary evaluation criteria include both efficacy and safety assessments. Three ancillary studies are planned to describe the epidemiology of β-lactamase encoding genes, the ecological impact and pharmacokinetic/pharmacodynamic parameters of cefazolin and cloxacillin. Including 300 patients will provide 80% power to demonstrate the non-inferiority of cefazolin over cloxacillin, assuming 85% success rate with cloxacillin and taking into account loss-to-follow-up, with a 0.12 non-inferiority margin and a one-sided type I error of 0.025.

ETHICS AND DISSEMINATION

This protocol received authorisation from the ethics committee Sud-Est I on 13 November 2017 (2017-87-PP)and French National Agency for Medicines and Health Products (170661A-43). Results will be disseminated to the scientific community through congresses and publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03248063 and 2017-003967-36.

Should Sensory Impairment Be Considered in Frailty Assessment? A Study in the GAZEL Cohort

OBJECTIVES

The assessment of sensory difficulties is sometimes included in the screening of frailty in ageing population. This study aimed to compare the prevalence of frailty and associated risk of adverse outcomes depending on whether sensory difficulties participated in the definition of frailty.

DESIGN

Prospective cohort study - GAZEL cohort.

SETTING

France.

PARTICIPANTS

The 13,128 subjects who completed a questionnaire in 2012.

MEASUREMENTS

According to the Strawbridge questionnaire, subjects were considered frail if they reported difficulties in two domains or more among physical, nutritive, cognitive and sensory domains. The risk of adverse health outcomes was assessed by using logistic regression models (hospitalisations, onset of difficulty in performing movements of everyday life) and multivariate Cox proportional hazards models (mortality).

RESULTS

Mean age was 66.8 +/- 3.4 years and 73.8% were males. The prevalence of frailty varied from 4.4 to 14.2% depending on whether the sensory domain was excluded or included. During follow-up, 182 deaths (1.4%), 479 hospitalisations (3.6%) and 703 cases of new disability (8.0%) were observed. Both definitions of frailty predicted the onset of difficulties to perform everyday movements, with 2 to 3-fold increase in the risk. The inclusion of the sensory domain in the definition made frailty predictive of hospitalisations (Odds Ratio 1.31 [1.01-1.70]) but the association with mortality was only observed when sensory difficulties were ignored (Hazard Ratio 2.28 [1.32-3.92]).

CONCLUSION

The inclusion of a sensory domain into a frailty screening instrument has a major impact in terms of prevalence and modifies the risk profile associated with frailty. In order to develop the use of frailty screening instruments in clinical practice, further researches will need to carefully evaluate the impact on risk prediction of the different domains involved.

[Acute transverse myelitis and Lyme borreliosis: a case report]

Lyme disease is an infectious disease caused by a spirochete of the Borrelia sensu lato group. Its incidence has greatly increased in recent years. The main vector is a tick of the Ixodes family. Clinical manifestations are multiple and show the multi-organ character of the disease. In terms of frequency, joint and neurological presentations, respectively more frequent in North America and Europe, are the main manifestations after cutaneous symptoms, of which erythema migrans is the most common, followed by cardiac and ocular signs. Other signs exist but are anecdotal. Neuroborreliosis manifests itself most often with peripheral facial palsy, but there are other clinical forms, which include acute myelitis (4-5% of neuroborreliosis). We present here the case of a 16-year-old teenager with acute myelitis and meningeal involvement due to Lyme disease, who presented with atypical symptoms (massive and rapid weight loss, vomiting). MRI showed localized marrow edema as well as leptomeningeal and root enhancement. Lumbar puncture showed lymphocytic pleocytosis. Lyme serology was positive both in blood and cerebrospinal fluid. Even if acute myelitis remains exceptional among neuroborreliosis manifestations, this diagnosis has to be thought of when a child presents with unexplained neurological symptoms.