Anne E. Visser

Analysis of amyotrophic lateral sclerosis as a multistep process: a population-based modelling study

Summary Background Amyotrophic lateral sclerosis shares characteristics with some cancers, such as onset being more common in later life, progression usually being rapid, the disease affecting a particular cell type, and showing complex inheritance. We used a model originally applied to cancer epidemiology to investigate the hypothesis that amyotrophic lateral sclerosis is a multistep process. Methods We generated incidence data by age and sex from amyotrophic lateral sclerosis population registers in Ireland (registration dates 1995–2012), the Netherlands (2006–12), Italy (1995–2004), Scotland (1989–98), and England (2002–09), and calculated age and sex-adjusted incidences for each register. We regressed the log of age-specific incidence against the log of age with least squares regression. We did the analyses within each register, and also did a combined analysis, adjusting for register. Findings We identified 6274 cases of amyotrophic lateral sclerosis from a catchment population of about 34 million people. We noted a linear relationship between log incidence and log age in all five registers: England r2=0·95, Ireland r2=0·99, Italy r2=0·95, the Netherlands r2=0·99, and Scotland r2=0·97; overall r2=0·99. All five registers gave similar estimates of the linear slope ranging from 4·5 to 5·1, with overlapping confidence intervals. The combination of all five registers gave an overall slope of 4·8 (95% CI 4·5–5·0), with similar estimates for men (4·6, 4·3–4·9) and women (5·0, 4·5–5·5). Interpretation A linear relationship between the log incidence and log age of onset of amyotrophic lateral sclerosis is consistent with a multistage model of disease. The slope estimate suggests that amyotrophic lateral sclerosis is a six-step process. Identification of these steps could lead to preventive and therapeutic avenues. Funding UK Medical Research Council; UK Economic and Social Research Council; Ireland Health Research Board; The Netherlands Organisation for Health Research and Development (ZonMw); the Ministry of Health and Ministry of Education, University, and Research in Italy; the Motor Neurone Disease Association of England, Wales, and Northern Ireland; and the European Commission (Seventh Framework Programme).

No mutations in hnRNPA1 and hnRNPA2B1 in Dutch patients with amyotrophic lateral sclerosis, frontotemporal dementia, and inclusion body myopathy

Inclusion body myopathy (IBM) associated with Paget disease of the bone, frontotemporal dementia (FTD), and amyotrophic lateral sclerosis (ALS), sometimes called IBMPFD/ALS or multi system proteinopathy, is a rare, autosomal dominant disorder characterized by progressive degeneration of muscle, brain, motor neurons, and bone with prominent TDP-43 pathology. Recently, 2 novel genes for multi system proteinopathy were discovered; heterogenous nuclear ribonucleoprotein (hnRNP) A1 and A2B1. Subsequently, a mutation in hnRNPA1 was also identified in a pedigree with autosomal dominant familial ALS. The genetic evidence for ALS and other neurodegenerative diseases is still insufficient. We therefore sequenced the prion-like domain of these genes in 135 familial ALS, 1084 sporadic ALS, 68 familial FTD, 74 sporadic FTD, and 31 sporadic IBM patients in a Dutch population. We did not identify any mutations in these genes in our cohorts. Mutations in hnRNPA1 and hnRNPA2B1 prove to be a rare cause of ALS, FTD, and IBM in the Netherlands.

Safety and efficacy of ozanezumab in patients with amyotrophic lateral sclerosis : a randomised, double-blind, placebo-controlled, phase 2 trial

BACKGROUND Neurite outgrowth inhibitor A (Nogo-A) is thought to have a role in the pathophysiology of amyotrophic lateral sclerosis (ALS). A monoclonal antibody against Nogo-A showed a positive effect in the SOD1G93A mouse model of ALS, and a humanised form of this antibody (ozanezumab) was well tolerated in a first-in-human trial. Therefore, we aimed to assess the safety and efficacy of ozanezumab in patients with ALS. METHODS This randomised, double-blind, placebo-controlled, phase 2 trial was done in 34 centres in 11 countries. Patients aged 18-80 years with a diagnosis of familial or sporadic ALS were randomly assigned (1:1), centrally according to a computer-generated allocation schedule, to receive ozanezumab (15 mg/kg) or placebo as intravenous infusions over 1 h every 2 weeks for 46 weeks, followed by assessments at week 48 and week 60. Patients and study personnel were masked to treatment assignment. The primary outcome was a joint-rank analysis of function (ALS Functional Rating Scale-Revised) and overall survival, analysed at 48 weeks in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01753076, and with GSK-ClinicalStudyRegister.com, NOG112264, and is completed. FINDINGS Between Dec 20, 2012, and Nov 1, 2013, we recruited 307 patients, of whom 303 were randomly assigned to receive placebo (n=151) or ozanezumab (n=152). The adjusted mean of the joint-rank score was -14·9 (SE 13·5) for the ozanezumab group and 15·0 (13·6) for the placebo group, with a least squares mean difference of -30·0 (95% CI -67·9 to 7·9; p=0·12). Overall, reported adverse events, serious adverse events, and adverse events leading to permanent discontinuation of study drug or withdrawal from study were similar between the treatment groups, except for dyspepsia (ten [7%] in the ozanezumab group vs four [3%] in the placebo group), depression (11 [7%] vs five [3%]), and diarrhoea (25 [16%] vs 12 [8%]). Respiratory failure was the most common serious adverse event (12 [8%] vs seven [5%]). At week 60, the number of deaths was higher in the ozanezumab group (20 [13%]) than in the placebo group (16 [11%]), mainly as a result of respiratory failure (ten [7%] vs five [3%]). Two deaths were considered related to the study drug (bladder transitional cell carcinoma in the ozanezumab group and cerebrovascular accident in the placebo group). INTERPRETATION Ozanezumab did not show efficacy compared with placebo in patients with ALS. Therefore, Nogo-A does not seem to be an effective therapeutic target in ALS. FUNDING GlaxoSmithKline.

Prognosis for patients with amyotrophic lateral sclerosis: development and validation of a personalised prediction model

BACKGROUND Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive, fatal motor neuron disease with a variable natural history. There are no accurate models that predict the disease course and outcomes, which complicates risk assessment and counselling for individual patients, stratification of patients for trials, and timing of interventions. We therefore aimed to develop and validate a model for predicting a composite survival endpoint for individual patients with ALS. METHODS We obtained data for patients from 14 specialised ALS centres (each one designated as a cohort) in Belgium, France, the Netherlands, Germany, Ireland, Italy, Portugal, Switzerland, and the UK. All patients were diagnosed in the centres after excluding other diagnoses and classified according to revised El Escorial criteria. We assessed 16 patient characteristics as potential predictors of a composite survival outcome (time between onset of symptoms and non-invasive ventilation for more than 23 h per day, tracheostomy, or death) and applied backward elimination with bootstrapping in the largest population-based dataset for predictor selection. Data were gathered on the day of diagnosis or as soon as possible thereafter. Predictors that were selected in more than 70% of the bootstrap resamples were used to develop a multivariable Royston-Parmar model for predicting the composite survival outcome in individual patients. We assessed the generalisability of the model by estimating heterogeneity of predictive accuracy across external populations (ie, populations not used to develop the model) using internal-external cross-validation, and quantified the discrimination using the concordance (c) statistic (area under the receiver operator characteristic curve) and calibration using a calibration slope. FINDINGS Data were collected between Jan 1, 1992, and Sept 22, 2016 (the largest data-set included data from 1936 patients). The median follow-up time was 97·5 months (IQR 52·9-168·5). Eight candidate predictors entered the prediction model: bulbar versus non-bulbar onset (univariable hazard ratio [HR] 1·71, 95% CI 1·63-1·79), age at onset (1·03, 1·03-1·03), definite versus probable or possible ALS (1·47, 1·39-1·55), diagnostic delay (0·52, 0·51-0·53), forced vital capacity (HR 0·99, 0·99-0·99), progression rate (6·33, 5·92-6·76), frontotemporal dementia (1·34, 1·20-1·50), and presence of a C9orf72 repeat expansion (1·45, 1·31-1·61), all p<0·0001. The c statistic for external predictive accuracy of the model was 0·78 (95% CI 0·77-0·80; 95% prediction interval [PI] 0·74-0·82) and the calibration slope was 1·01 (95% CI 0·95-1·07; 95% PI 0·83-1·18). The model was used to define five groups with distinct median predicted (SE) and observed (SE) times in months from symptom onset to the composite survival outcome: very short 17·7 (0·20), 16·5 (0·23); short 25·3 (0·06), 25·2 (0·35); intermediate 32·2 (0·09), 32·8 (0·46); long 43·7 (0·21), 44·6 (0·74); and very long 91·0 (1·84), 85·6 (1·96). INTERPRETATION We have developed an externally validated model to predict survival without tracheostomy and non-invasive ventilation for more than 23 h per day in European patients with ALS. This model could be applied to individualised patient management, counselling, and future trial design, but to maximise the benefit and prevent harm it is intended to be used by medical doctors only. FUNDING Netherlands ALS Foundation.

Critical issues in ALS case-control studies: the case of the Euro-MOTOR study

Abstract Backround: Political and sociocultural differences between countries can affect the outcome of clinical and epidemiological studies in ALS. Cross-national studies represent the ideal process by which risk factors can be assessed using the same methodology in different geographical areas. Methods: A survey of three European countries (The Netherlands, Ireland and Italy) has been conducted in which incident ALS patients and matched controls were recruited in a population-based study based on age, gender and area of residency, under the Euro-MOTOR systems biology programme of research. Findings: We have identified strengths and limitations during the trajectory of the Euro-MOTOR study, from the research design to data analysis. We have analysed the implications of factors including cross-national differences in healthcare systems, sample size, types of matching, the definition of exposures and statistical analysis. Conclusions: Addressing critical methodological aspects of the design of the Euro-MOTOR project minimises bias and will facilitate scientific assessment of the independent role of well-defined exposures.

Exploring the fitness hypothesis in ALS: a population-based case-control study of parental cause of death and lifespan

Objective To investigate the theory of premorbid fitness in amyotrophic lateral sclerosis (ALS), we studied whether a common genetic profile for physical or cardiovascular fitness was manifest in progenitors leading to less cardiovascular death and a longer lifespan in parents of patients with ALS compared with parents of controls. Methods Patient and disease characteristics, levels of physical activity, parental cause and age of death were obtained using a structured questionnaire from a population-based, case–control study of ALS in the Netherlands. Logistic regression was used for the analyses of parental cause of death and levels of physical activity. Cox proportional hazard models were applied to study the association between parental survival and ALS, or specific patient subgroups. All models were adjusted for age at inclusion, level of education, body mass index, diabetes, hypercholesterolaemia and hypertension. Results 487 patients and 1092 controls were included. Parents of patients died less frequently from a cardiovascular disease compared with parents of controls (OR=0.78, p=0.009). Their survival, however, was neither significantly longer nor shorter. Neither rates of cardiovascular causes of death, nor survival of parents was related to the extent to which patients were physically active in leisure time (all p>0.05). Conclusions Exploring the fitness hypothesis in the pathogenesis of ALS, our findings provide evidence for a shared mechanism underlying a favourable cardiovascular fitness profile and ALS susceptibility.

No association between Borrelia burgdorferi antibodies and amyotrophic lateral sclerosis in a case–control study

Previous studies, mostly case reports and uncontrolled studies, provide a low level of evidence for the hypothesized link between Lyme disease and amyotrophic lateral sclerosis (ALS). In order to make evidence‐based recommendations regarding testing for Borrelia burgdorferi antibodies in the diagnostic work‐up for ALS, the objective of this study was to explore the evidence for an association between these antibodies and ALS in a case–control design including age‐, gender‐ and residency‐matched controls.

Multicentre, cross-cultural, population-based, case–control study of physical activity as risk factor for amyotrophic lateral sclerosis

Objective To investigate the association between physical activity (PA) and amyotrophic lateral sclerosis (ALS) in population-based case–control studies in three European countries using a validated and harmonised questionnaire. Methods Patients with incident ALS and controls were recruited from five population-based registers in The Netherlands, Ireland and Italy. Demographic and data regarding educational level, smoking, alcohol habits and lifetime PA levels in both leisure and work time were gathered by questionnaire, and quantified using metabolic equivalent of task scores. Logistic regression models adjusting for PA-related factors were used to determine the association between PA and ALS risk, and forest plots were used to visualise heterogeneity between regions. Results 1557 patients and 2922 controls were included. We found a linear association between ALS and PA in leisure time (OR 1.07, P=0.01) and occupational activities (OR 1.06, P<0.001), and all activities combined (OR 1.06, P<0.001), with some heterogeneity between regions: the most evident association was seen in the Irish and Italian cohorts. After adjustment for other occupational exposures or exclusion of patients with a C9orf72 mutation, the ORs remained similar. Conclusion We provide new class I evidence for a positive association between PA and risk of ALS in a large multicentre study using harmonised methodology to objectively quantify PA levels, with some suggestions for population differences.

A case-control study of hormonal exposures as etiologic factors for ALS in women: Euro-MOTOR

Objective: To investigate the role of hormonal risk factors for amyotrophic lateral sclerosis (ALS) among women from 3 European countries. Methods: ALS cases and matched controls were recruited over 4 years in Ireland, Italy, and the Netherlands. Hormonal exposures, including reproductive history, breastfeeding, contraceptive use, hormonal replacement therapy, and gynecologic surgical history, were recorded with a validated questionnaire. Logistic regression models adjusted for age, education, study site, smoking, alcohol, and physical activity were used to determine the association between female hormones and ALS risk. Results: We included 653 patients and 1,217 controls. Oral contraceptive use was higher among controls (odds ratio [OR] 0.65, 95% confidence interval [CI] 0.51–0.84), and a dose-response effect was apparent. Hormone replacement therapy (HRT) was associated with a reduced risk of ALS only in the Netherlands (OR = 0.57, 95% CI 0.37–0.85). These findings were robust to sensitivity analysis, but there was some heterogeneity across study sites. Conclusions: This large case-control study across 3 different countries has demonstrated an association between exogenous estrogens and progestogens and reduced odds of ALS in women. These results are at variance with previous findings, which may be partly explained by differential regulatory, social, and cultural attitudes toward pregnancy, birth control, and HRT across the countries included. Our results indicate that hormonal factors may be important etiologic factors in ALS; however, a full understanding requires further investigation.

Association between alcohol exposure and the risk of amyotrophic lateral sclerosis in the Euro-MOTOR study

Objectives Several studies focused on the association between alcohol consumption and amyotrophic lateral sclerosis (ALS), although with inconsistent findings. Antioxidants may play a role since lyophilised red wine was found to prolong SOD1 mice lifespan. The aim of this international population-based case–control study performed in Ireland, The Netherlands and Italy was to assess the role of alcohol, and red wine in particular, in developing ALS. Methods Euro-MOTOR is a case–control study where patients with incident ALS and controls matched for gender, age and area of residency were recruited in a population-based design. Logistic regression models adjusted for sex, age, cohort, education, leisure time physical activity, smoking, heart problems, hypertension, stroke, cholesterol and diabetes were performed. Results 1557 patients with ALS and 2922 controls were enrolled in the study. Exposure to alcohol drinking was not significantly associated with ALS risk. A stratified analysis of exposure to alcohol by cohort revealed significant ORs in The Netherlands and in Apulia, with opposite directions (respectively 0.68 and 2.38). With regard to red wine consumption, only in Apulia the double-fold increased risk (OR 2.53) remained significant. A decreased risk was found for current alcohol drinkers (OR 0.83), while a significantly increased risk was detected among former drinkers (OR 1.63). Analysis of cumulative exposure to alcohol revealed no significant associations with ALS risk. Conclusion With few exceptions, no significant association was found between alcohol consumption and ALS. The study of the association between alcohol and ALS requires a thorough exploration, especially considering the role of different type of alcoholic beverages.