Publications

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease primarily affecting motor neurons. Neurofilament light chain (NfL) is the most established prognostic biomarker; however, its diagnostic resolution is limited, particularly within intermediate concentration ranges, and it does not capture the molecular heterogeneity of ALS. This study aimed to identify complementary cerebrospinal fluid (CSF) biomarkers and pathway-specific signatures through a non-targeted multiomic approach. We performed SWATH-MS-based proteomics and LC-MS/MS lipidomics on CSF from ALS patients stratified by survival (ALS-SS and ALS-LS) and healthy controls. Weighted protein co-expression network analysis (WPCNA) was applied to identify biologically coherent protein modules associated with disease phenotype and progression. Top biomarker candidates were further evaluated using immunoassays in an independent cohort. Post-mortem ALS spinal cord tissues were analyzed to explore the pathophysiological relevance of identified proteins. CSF proteomic profiles robustly distinguished ALS patients from controls and stratified patient subgroups by survival, revealing a molecular signature characterized by inflammation, downregulation of detoxification mechanisms, and synaptic dysregulation in aggressive disease forms. In contrast, lipidomic profiles showed limited discriminatory power. WPCNA identified modular proteomic signatures capturing ALS heterogeneity, and machine learning models based on these profiles yielded optimal biomarker panels for diagnosis and prognosis. CXCL7 emerged as a promising complementary biomarker, and shed light in disease physiopathology. Immunoassay validation supported the diagnostic and prognostic potential of CXCL7 and its association with survival time. Histopathological analysis further confirmed CXCL7 localization in anterior horn motor neurons, despite no detectable changes in whole spinal cord lysates at late disease stages. Comprehensive CSF proteomic profiling, combined with network-based analysis, enhances our understanding of ALS molecular heterogeneity and provides a framework for precision biomarker discovery. CXCL7 complements NfL as a diagnostic and prognostic biomarker, supporting improved patient stratification and advancing the development of personalized therapeutic strategies in ALS.

BACKGROUND: Amyotrophic Lateral Sclerosis (ALS) remains an incurable disease, with limited treatment options, and riluzole is the most widely available drug. We evaluated survival in a large cohort of patients with ALS, comparing those treated with riluzole to those who were not. METHODS: Using data from the PRECISION-ALS database, we retrospectively analyzed patients with ALS who were treated with 100 mg of riluzole daily at the time of diagnosis. ALSFRS-R slope from onset to diagnosis (ΔFRS) was calculated. Based on the ΔFRS distribution, we defined fast progressors as patients having a ΔFRS > 1.17, intermediate progressors as those with 1.17 > ΔFRS > 0.31 and slow progressors as those with a ΔFRS < 0.31 points per month. We used Kaplan-Meier curves and Cox proportional hazards model to explore the association of riluzole use with patient survival since diagnosis. RESULTS: Out of the 5842 patients with available riluzole data, 4847 (82.9%) received riluzole. The overall survival significantly differed between patients treated and not treated with riluzole (HR 0.70, 95%CI 0.69, 0.79), independently of sex, site of onset, age at onset and diagnostic delay. Patients treated with riluzole exhibited a 7 month longer median survival than those who did not receive riluzole (17.6 months, IQR 9.7, 29.9 vs 10.7 months, IQR 4.3, 23.4; p = 2 × 10-16). The relationship between riluzole use and extended survival varied across ΔFRS strata, being only evident among fast progressors (HR = 0.50, 95% 0.40, 0.63). CONCLUSIONS: Treatment with riluzole is an independent prognostic factor in ALS. The extended survival related to riluzole use was only evident among fast-progressing patients.

INTRODUCTION: Respiratory function typically deteriorates as ALS progresses and is associated with shorter survival. This study aims to describe respiratory function and the prevalence of noninvasive ventilation (NIV) along the disease trajectory using prospective data from the PRECISION ALS project. METHODS: We included 3449 ALS patients from six European population-based cohorts. All had comparable assessments of vital capacity, percent predicted (VC%) (58.1% had multiple assessments) and 56% had assessments of the revised ALS Functional Rating Scale (ALSFRS-R). The data were analyzed in relation to survival, NIV, and genetic status (C9orf72, SOD1, FUS, and TARDBP). RESULTS: In those with a survival time of 1-4 years from diagnosis, the median VC% declined from 91 to 97% at the first assessment to 47-50% at the last assessment 6 months before death. In those with longitudinal assessments, the median VC% declined an average of 24 percentage points per year. Over time, there was an increase in respiratory symptoms relative to general functional impairment, as measured by the ALSFRS-R, and VC% was strongly associated with shorter survival. The confirmed prevalence of NIV was approximately 3%, 15%, and 25% in patients with a VC% of >80, 50-80, and <50, respectively. CONCLUSION: There was a trend of worsening respiratory function over time and an increase in respiratory symptoms relative to general functional impairment. Survival was strongly associated with respiratory function. In those with impaired respiratory function, there was significant variation in the introduction of NIV.

OBJECTIVE: To investigate the association between C9orf72, SOD1, FUS and TARDBP variants on the clinical trajectory of ALS patients in Europe. METHODS: Nine ALS centers with population-based registries provided data on demographic and disease characteristics - at diagnosis and longitudinally - as part of PRECISION ALS. These data were harmonized and collated for analysis. RESULTS: 21,820 ALS patients were identified, 9,887 underwent genetic testing for at least one of the 4 genes of interest. 9.8% of patients carried a hexanucleotide expansion in C9orf72; 2.9% carried a pathogenic variant in SOD1; 1.4% carried a pathogenic variant in TARDBP; and 0.8% carried a pathogenic variant in FUS. Only one p.A5V variant was identified in this dataset. The most frequently identified SOD1 variant was p.D91A, with evidence of other variant clusters in Belgium, Italy and the United Kingdom. TARDBP variants were clustered in the Netherlands and Italy. Earlier ages of onset were demonstrated compared to wild-type populations; C9orf72 59.58 (IQR 62.5, p < 2.2e-16), SOD1 54.19 (IQR 19.4, p = 6.304e-14), TARDBP 58.30 (IQR 16.23, p = 0.00024) and FUS 51.16 (IQR 25.08, p = 1.58e-06). C9orf72 was more bulbar (p < 0.0001) in onset and SOD1 more spinal (p < 0.0001). Those carrying variants spent distinctly different periods in each of the King's stages. CONCLUSIONS: Genetic forms of ALS have an earlier age of onset, have distinct patterns in their sites of disease onset, and progress differently as compared to populations without such major-effect genes. There is also evidence of disease clusters across Europe suggestive of founder effects.

Introduction: ALS, a neurodegenerative disorder, exhibits variable incidence and prevalence across various databases consulted. Among these, PRO-ACT stands out as the most extensive publicly accessible repository of aggregated ALS clinical trial information. The estimated male-female ratio is greater for men at younger ages, which tends to equalize with aging. If specific measures are not taken to address this, this higher male prevalence could result in a higher inclusion of men in clinical trials, which could lead to biases in the observed results, preventing the proper assessment of differences between sexes. Our aim was to describe the demographic dates of the population included in ALS clinical trials in the last 8 years at Spanish national reference centers, with special interest in female participation. Methodology: Retrospective and descriptive observational study using databases of national reference centers. Results: We analyzed the databases of 4 neurological Spanish reference centers during a period of 8 years. A total number of 426 subjects were included. A greater participation of the male sex was evident in all the studies evaluated, representing 64.55% of the subjects included. This predominance has not varied significantly over the last 8 years. Our results correlate with the data published in PRO-ACT to date, where men represent 60% of the total number of participants. Conclusion: The predominance of the male sex in ALS clinical trials is a consistent and invariable finding and is known as Yentl's syndrome. This phenomenon prevents the principle of neutrality of medicine, allowing for purely partial knowledge.

OBJECTIVE: Map time to key clinical milestones in amyotrophic lateral sclerosis (ALS), highlighting underlying genotypic and phenotypic prognostic factors. BACKGROUND: Understanding the ALS disease trajectory and factors influencing the heterogeneous disease course is important to guide clinical care and stratify individuals to effectively assess therapeutics in clinical trials. METHODS: Population-based datasets from nine European ALS care centers were collated. Time-to-event analysis was conducted for key clinical milestones: symptom onset, diagnosis, gastrostomy insertion, noninvasive ventilation (NIV) initiation, and survival. Independent prognostic factors were determined. RESULTS: 21,820 people with ALS from nine ALS centers were included. Median age of symptom onset was 63.9 years. Median diagnostic delay was 1.0 years, with median survival of 33.7 months from onset. Prognostic factors for survival included age at onset, baseline vital capacity, progression rate, diagnostic delay, site of onset, and C9orf72-positive status. SOD1 variants D91A and G94C had protective prognostic effects in the whole cohort. Median time from diagnosis to gastrostomy insertion in bulbar-onset disease was 2.34 years. Median time from diagnosis to NIV initiation in those diagnosed between 2010 and 2019 was 3.61 years. Significant differences between ALS clinical center cohorts were seen in time to gastrostomy insertion, time to NIV initiation, and in overall survival time. CONCLUSION: Our analysis of a large, well-defined, population-based European cohort provides detailed insight into the natural history of ALS, highlighting phenotypic and genetic factors affecting time to key clinical milestones. Further study is needed to determine the drivers in observed differences between ALS clinical center cohorts in time to clinical interventions and overall survival.

OBJECTIVE: To characterize the natural history of the revised ALS functional rating scale (ALSFRS-R) over a 24-month period following initial assessment, and to assess its associations with survival. METHODS: Longitudinal ALSFRS-R measurements and survival data were obtained from seven population-based, European cohorts. Different models for the ALSFRS-R trajectory were evaluated, including tests for linearity and between-cohort differences. We employed a joint modeling framework to factor in mortality, thereby aiming to derive a more precise estimate of the population's rate of decline, while simultaneously delineating its relationship with survival. RESULTS: In total, 7,030 patients were included who produced 31,746 ALSFRS-R measurements during a follow-up period of 10,285 person-years. There was substantial evidence for a non-linear time trend within all cohorts (all p < 0.001), with faster progression rates at the beginning of follow-up. The average rate over 24 months was 0.89 points per month; 95% of the patients had a rate between 0.04 and 1.96. Overall, two components of the ALSFRS-R trajectory were found to be associated with survival: (1) the actual value of the ALSFRS-R total score and (2) the rate of change at any given time (both p < 0.001). CONCLUSIONS: Functional loss in ALS follows a decelerating trajectory, where the current functional status and the rate of change have a direct impact on the patient' s probability of survival. Given the pivotal role of the ALSFRS-R in drug development, these results help to separate treatment benefit from the disease's natural trajectory and to estimate the impact on survival.

OBJECTIVE: To gather comprehensive insights regarding current neuropsychological assessment practices in PRECISION-ALS, a pan-European research and industry consortium, to propose areas which can be harmonized and facilitate more robust cross-country comparisons. METHODS: Representatives from PRECISION-ALS sites were surveyed with a semi-structured interview, gathering information on how people with ALS are assessed for cognitive/behavioral change, including how they are initially screened, classified as impaired/unimpaired, and followed up longitudinally. Assessment practices across PRECISION-ALS sites were summarized using descriptive analysis. RESULTS: Ten of the eleven PRECISION-ALS sites perform cognitive and/or behavioral screening at least once during the course of the disease, using the Edinburgh Cognitive and Behavioral ALS Screen, either for clinical or research purposes. All centers categorize impairment, but differ how it is defined, with some using local norms, and others using other countries' norms. Most sites account for age and education, but differ in how these factors are considered. Longitudinal protocols vary in terms of the number of assessments, time intervals, and use of alternative versions. Behavioral screening is more consistently implemented, with the ECAS caregiver interview as the standard tool, however there is a lack of clarity in how this data is applied. Many sites supplement cognitive and behavioral screening with additional measures of mood and/or neuropsychiatric symptoms. CONCLUSIONS: These findings illustrate areas of commonality and divergence in neuropsychological screening practices. Site-specific variations are likely to confound research involving cross-country data-sharing. PRECISION-ALS, in generating prospective population-based datasets, will provide agreed harmonized protocols for neuropsychological assessment across participating sites.

OBJECTIVE: To examine the working status of people living with ALS (plwALS), the identity of their caregivers, the amount of informal care provided to them, and how these factors change over time. METHODS: Data from nine specialist European ALS centers and previously funded projects, such as ALSCarE, were collated. The cohort was stratified into progression groups based on the calculated ΔFRS and compared longitudinally. RESULTS: Twenty-one thousand eight hundred and twenty patients were identified at the time of data analysis. One thousand one hundred and eighty-four had working status data. Two hundred and thirty-seven patients in this group were followed in the form of semi-structured interviews. Within the 1184 patient group, 45% were identified as in "paid employment" prior to diagnosis, taking a median of 12 months to leave the workforce post-onset. Eighty-three percent of patients were no longer working 20 months post-diagnosis. Informal care hours increased over time, and were primarily provided by spouses and children. In those less than 12 months from symptom onset, the median number of care hours per week was 15.0 (IQR 63.8), rising to 60.0 (IQR 154.0) 48-96 months after onset. There was a significant relationship between ALSFRS-R total score and hours of care delivered (r = -0.47, p < 0.001). CONCLUSION: Up to 45% of plwALS are working prior to diagnosis and their working status changes rapidly, taking an average of 12 months to leave the workforce. Caregiver input increases over time, proportional to ALSFRS-R score. Caregivers are primarily spouses and children. Further work is needed to comprehensively capture this information and calculate its true socioeconomic impact.

OBJECTIVES: The aim of this study was to identify biomarkers of cancer-related cognitive impairment (CRCI) in patients with small-cell lung cancer (SCLC). METHODS: Patients with SCLC were prospectively recruited between 2019 and 2023 and evaluated using neuropsychological (NPS) battery; structural MRI; and serologic analysis of neuronal antibodies, cytokines, brain-derived neurotrophic factor (BDNF), and cognitive-related single nucleotide variants (SNVs). Voxel-based morphometry and tract-based analysis assessed gray and white matter integrity. One month after completing chemotherapy, patients were re-evaluated. RESULTS: Fifty-two patients were initially evaluated: 16 (31%) exhibited cognitive impairment (CI), primarily affecting executive functioning. MRI disclosed gray matter damage in precuneus and fusiform-parahippocampal regions, linked to visuospatial abilities and memory, and white matter damage in cingulum and corpus callosum. After chemotherapy, 31 patients were re-evaluated: 10 (32%) exhibited CI, of whom 7 (23%) had persistent CI and 3 (10%) developed de novo CI (chemobrain). The chemobrain group had higher smoking exposure (60 vs 44 pack-years, p = 0.05) while the persistent CI group had more advanced disease at diagnosis (80% vs 20%, p = 0.004), compared to the never CI group (15/31, 48%). DISCUSSION: CRCI affected one-third of our patients with SCLC at diagnosis while chemobrain was uncommon and primarily associated with tobacco use. These findings underscore the role of early biomarkers in predicting CRCI and its persistence in patients with SCLC.

Posterior reversible encephalopathy syndrome (PRES) is a well-defined clinicoradiological syndrome that can arise in various clinical settings, most commonly in association with hypertensive states. However, less typical causes, including hematologic disorders, have also been reported. A 47-year-old male with CALR-mutated essential thrombocythemia (ET) on chronic aspirin therapy developed progressive headache, drowsiness, nausea, and blindness. Workup revealed worsening thrombocytosis (1,250 × 10⁹/L) with unremarkable blood pressure, craniocervical AngioTac, and systemic assessment. PRES secondary to ET exacerbation was suspected. Hydroxyurea was initiated, leading to platelet reduction and symptom improvement. Brain MRI showed bilateral parieto-occipital Fluid-Attenuated Inversion Recovery (FLAIR) hyperintensities. At four months, only mild visual disturbances persisted, with follow-up MRI showing near-complete resolution. ET decompensation may trigger PRES even with normal blood pressure, highlighting the importance of platelet monitoring to prevent complications. All reported cases involved middle-aged males with severe thrombocytosis (>700 × 10⁹/L) and symptom resolution following ET treatment and platelet reduction.

BACKGROUND: The 2024 revision of the McDonald criteria introduces specific recommendations for diagnosing late-onset multiple sclerosis (LOMS). One of the following criteria must be met: spinal cord lesions, positive cerebrospinal fluid (CSF) findings, or fulfilment of the Select-6 criteria (i.e., six or more central vein signs on brain magnetic resonance imaging (MRI)). OBJECTIVES: To evaluate the sensitivity of the 2024 McDonald criteria in patients with LOMS and to identify the most sensitive diagnostic test. METHODS: This cross-sectional, observational, retrospective study included patients diagnosed with LOMS (onset ≥50 years of age) who were followed at the Multiple Sclerosis Clinic of Bellvitge University Hospital. Clinical records, MRI scans, and CSF analyses were reviewed to assess the presence of spinal cord lesions, central vein signs and oligoclonal bands (OCBs). The sensitivity of the 2024 recommended LOMS criteria was analysed. RESULTS: 115 patients met at least one of the proposed 2024 LOMS diagnostic criteria, resulting in a sensitivity of 100 %. Of these, 10.4 % fulfilled all three criteria, 52.1 % met two criteria (most commonly OCBs and spinal lesions). The remaining 37.4 % met only one: 53.5 % had spinal lesions, 46.5 % were positive for OCBs, and none met only the Select-6 criterion. The difference between the proportions meeting the OCB and spinal cord lesion criteria was not statistically significant (p = 0.581), but both were significantly more common than meeting the Select-6 criterion (p < 0.001). CONCLUSIONS: The 2024 McDonald criteria maintain high sensitivity for diagnosing LOMS. CSF analysis and spinal MRI are the most valuable tools, whereas the Select-6 criteria exhibited a lower diagnostic value.

Objective: Primary Lateral Sclerosis (PLS) is a progressive neurodegenerative disease with no current therapy. So far, the lack of a specific evaluation instrument has been a barrier for clinical trials. The Primary Lateral Sclerosis Functional Rating Scale (PLSFRS) is a novel tool designed to specifically assess disease progression and functional impairment in patients with PLS. We sought to translate and validate the PLSFRS to the Spanish language. Methods: We back-translated the PLSFRS scale to Spanish and assessed a cohort of 10 PLS patients by two independent raters. Both inter- and intrarater reliability were evaluated, with assessments conducted through both in-person and over-the-phone interviews. Results: The PLSFRS demonstrated excellent inter- and intrarater reliability for the total score (ICC = 0.90-1.00) and for most subdomains (ICC > 0.90). Agreement between in-clinic and over-the-phone assessments was similarly strong. Squared weighted kappa coefficients for individual items indicated substantial to almost perfect agreement. Bland-Altman analysis revealed no significant systematic bias, with mean differences close to zero and acceptable limits of agreement. Conclusion: This study demonstrates high reliability for the Spanish version of the PLSFRS scale.

This study aims to develop a Machine Learning (ML) model to predict the initial diagnosis of Amyotrophic Lateral Sclerosis (ALS). To predict ALS, a stacked model combining four ML algorithms—logistic Regression, Decision Tree, Random Forest, and Extreme Gradient Boosting—was implemented. The analysis utilized healthcare administrative data from Catalonia, encompassing 2,924,590 elderly individuals from 2014 to 2021, which were linked to socioeconomic factors and medication records. The stacked model successfully predicted first-time ALS diagnoses, achieving an AUC of 0.86, with an accuracy of 0.86, specificity of 0.88, and sensitivity of 0.84. The most influential predictors included immunization encounters, South American origin, general medical and special examinations, hypertensive heart disease, and counseling. Other relevant features were sciatica, heart failure, liver metastases, healthcare use patterns, and chronic conditions such as hypertension, kidney disease, and hypercholesterolemia. These features reflect early clinical symptoms and healthcare usage patterns relevant to ALS detection. Machine Learning models, particularly stacked approaches, show promising results in predicting ALS diagnoses using administrative health data. Continued research is necessary to improve detection strategies and support their integration into healthcare systems.