Publications by authors named "W-Ludo van der Pol"

Objectives: Solidarity-based healthcare systems are being challenged by the incremental costs of new and expensive medicines for cancer and rare diseases. To regulate reimbursement of such drugs, the Dutch government introduced a policy instrument known as the Coverage Lock (CL) in 2015. Little is known about the public opinion regarding such policy instruments and their consequences, i.

View Article and Find Full Text PDF

The availability of three therapies for the neuromuscular disease spinal muscular atrophy (SMA) highlights the need to match patients to the optimal treatment. Two of these treatments (nusinersen and risdiplam) target splicing of , but treatment outcomes vary from patient to patient. An incomplete understanding of the complex interactions among SMA genetics, SMN protein and mRNA levels, and gene-targeting treatments, limits our ability to explain this variability and identify optimal treatment strategies for individual patients.

View Article and Find Full Text PDF

Background And Objective: Proximal spinal muscular atrophy (SMA) is caused by deficiency of the ubiquitously expressed survival motor neuron protein. Although primarily a hereditary lower motor neuron disease, it is probably also characterized by abnormalities in other organs. Brain abnormalities and cognitive impairment have been reported in severe SMA.

View Article and Find Full Text PDF

Background And Objectives: Polyneuropathy associated with an immunoglobulin M (IgM) monoclonal gammopathy is characterized by slowly progressive, predominantly distal sensorimotor deficits, sensory ataxia, and electrophysiologic features of demyelination. IgM antibodies against myelin-associated glycoprotein (MAG) are present in serum from most patients. Nerve damage most likely results from the concerted action of binding of anti-MAG antibodies to nerves, followed by complement activation.

View Article and Find Full Text PDF

Background And Purpose: Complement factor C2 is a potential therapeutic target in immune-mediated neuropathies. However, literature suggests that classical complement pathway activation may proceed to C3 in the absence of C2, a so-called "C2 bypass." Here, we evaluated a C2 bypass mechanism during complement activation by pathogenic human IgM from patients with immune-mediated neuropathies.

View Article and Find Full Text PDF

High-precision measurement tools are needed to measure relevant changes in strength and power in children with neuromuscular diseases. The aim of this study was to determine the feasibility (i), reproducibility (ii), and validity (iii) of isokinetic dynamometry in this population. Isometric and isokinetic knee and elbow flexion and extension were measured twice on the same day.

View Article and Find Full Text PDF

Background And Purpose: There are concerns for safety regarding SARS-CoV-2 vaccines for patients with autoimmune neuromuscular disease. We compared daily functioning using disease-specific patient-reported outcome measures (PROMs) before and after SARS-CoV-2 vaccinations.

Methods: In this substudy of a prospective observational cohort study (Target-to-B!), patients with myasthenia gravis (MG), chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and idiopathic inflammatory myopathy (IIM) vaccinated against SARS-CoV-2 were included.

View Article and Find Full Text PDF
Article Synopsis
  • * One key treatment is the gene therapy called onasemnogene abeparvovec (Zolgensma®), which is effective for patients with specific genetic profiles, although its broad usage raises concerns about safety for less clear cases.
  • * A European expert group has investigated the use of Zolgensma® for older and heavier SMA patients, resulting in 12 consensus statements that reflect the evolving understanding of its effectiveness based on new clinical and real-world evidence.
View Article and Find Full Text PDF

The Hammersmith Functional Motor Scale-Expanded (HFMSE) is a validated outcome measure for monitoring changes in functional strength in patients with spinal muscular atrophy (SMA). The objective of this study was to explore changes in HFMSE item-scores in children with SMA types 2 and 3a treated with nusinersen over a period of six to twenty months. We stratified patients according to motor ability (sitting and walking), and calculated numbers and percentages for each specific improvement (positive score change) or decrease (negative score change) for the total group and each subgroup and calculated frequency distributions of specific score changes.

View Article and Find Full Text PDF
Article Synopsis
  • The study explores how patients on immunosuppressants (ISPs) respond to SARS-CoV-2 infections compared to healthy controls, particularly looking at antibody levels post-infection.
  • Patients with immune-mediated inflammatory diseases (IMIDs) on different ISP therapies showed variable antibody responses, with those on anti-CD20 and sphingosine-1 phosphate therapies having lower antibody levels.
  • Despite lower antibody titers, the breakthrough infections in these patients were mostly mild, indicating that ISPs may not severely impede the overall immune response to SARS-CoV-2.
View Article and Find Full Text PDF

Background: Multifocal motor neuropathy (MMN) is a rare, chronic immune-mediated polyneuropathy characterized by asymmetric distal limb weakness. An important feature of MMN is the presence of IgM antibodies against gangliosides, in particular GM1 and less often GM2. Antibodies against GM1 bind to motor neurons (MNs) and cause damage through complement activation.

View Article and Find Full Text PDF

Background And Aims: To further substantiate the role of antibody-mediated complement activation in multifocal motor neuropathy (MMN) immunopathology, we investigated the distribution of promotor polymorphisms of genes encoding the membrane-bound complement regulators CD46, CD55, and CD59 in patients with MMN and controls, and evaluated their association with disease course.

Methods: We used Sanger sequencing to genotype five common polymorphisms in the promotor regions of CD46, CD55, and CD59 in 133 patients with MMN and 380 controls. We correlated each polymorphism to clinical parameters.

View Article and Find Full Text PDF

Background: Hereditary proximal spinal muscular atrophy (SMA) is characterized by abnormal alpha motor neuron function in brainstem and spinal cord. Bulbar dysfunction, including limited mouth opening, is present in the majority of patients with SMA but it is unknown if and how these problems change during disease course.

Objective: In this prospective, observational, longitudinal natural history study we aimed to study bulbar dysfunction in patients with SMA types 2 and 3.

View Article and Find Full Text PDF

Background: Spinal muscular atrophy (SMA) is caused by deficiency of survival motor neuron (SMN) protein. Intrathecal nusinersen treatment increases SMN protein in motor neurons and has been shown to improve motor function in symptomatic children with SMA.

Objective: We used quantitative MRI to gain insight in microstructure and fat content of muscle during treatment and to explore its use as biomarker for treatment effect.

View Article and Find Full Text PDF

Exercise therapy as part of the clinical management of patients with neuromuscular diseases (NMDs) is complicated by the limited insights into its efficacy. There is an urgent need for sensitive and non-invasive quantitative muscle biomarkers to monitor the effects of exercise training. Therefore, the objective of this systematic review was to critically appraise and summarize the current evidence for the sensitivity of quantitative, non-invasive biomarkers, based on imaging and electrophysiological techniques, for measuring the effects of physical exercise training.

View Article and Find Full Text PDF

Spinal muscular atrophy (SMA) is a severe, monogenetic, neuromuscular disease. A thorough understanding of its genetic cause and the availability of robust models has led to the development and approval of three gene-targeting therapies. This is a unique and exciting development for the field of neuromuscular diseases, many of which remain untreatable.

View Article and Find Full Text PDF

Objective: Electrophysiological techniques are emerging as an aid in identifying prognostic or therapeutic biomarkers in patients with spinal muscular atrophy (SMA), but electrophysiological assessments may be burdensome for patients. We, therefore, assessed feasibility and tolerability of multimodal peripheral non-invasive electrophysiological techniques in a cohort of patients with SMA.

Methods: We conducted a single center, longitudinal cohort study investigating the feasibility and tolerability of applying multimodal electrophysiological techniques to the median nerve unilaterally.

View Article and Find Full Text PDF

Objective: Antibody- and complement-mediated peripheral nerve inflammation are central in the pathogenesis of MMN. Here, we studied innate immune responses to endotoxin in patients with MMN and controls to further our understanding of MMN risk factors and disease modifiers.

Methods: We stimulated whole blood of 52 patients with MMN and 24 controls with endotoxin and collected plasma.

View Article and Find Full Text PDF

Background: Patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressants (ISPs) may have impaired long-term humoral immune responses and increased disease activity after SARS-CoV-2 infection. We aimed to investigate long-term humoral immune responses against SARS-CoV-2 and increased disease activity after a primary SARS-CoV-2 infection in unvaccinated IMID patients on ISPs.

Methods: IMID patients on active treatment with ISPs and controls (i.

View Article and Find Full Text PDF

Background: Hereditary spinal muscular atrophy (SMA) is a motor neuron disorder with a wide range in severity in children and adults. Two therapies that alter splicing of the Survival Motor Neuron 2 (SMN2) gene, i.e.

View Article and Find Full Text PDF

Background: Daily application of mechanical insufflation-exsufflation (MI-E) is used increasingly in patients with neuromuscular diseases (NMDs) to prevent pulmonary congestion and thereby respiratory tract infections, although its beneficial effect remains uncertain. We, therefore, conducted a systematic review, registered in PROSPERO (CRD42020158278), to compile available evidence for daily MI-E use in subjects with NMDs and stable respiratory condition.

Methods: We performed a systematic comprehensive search of MEDLINE, Embase, CINAHL, and Web of Science up to December 23, 2021.

View Article and Find Full Text PDF

Background: Spinal Muscular Atrophy (SMA) is characterized by progressive and predominantly proximal and axial muscle atrophy and weakness. Respiratory muscle weakness results in impaired cough with recurrent respiratory tract infections, nocturnal hypoventilation, and may ultimately lead to fatal respiratory failure in the most severely affected patients. Treatment strategies to either slow down the decline or improve respiratory muscle function are wanting.

View Article and Find Full Text PDF

Background: Progressive lung function decline, resulting in respiratory failure, is an important complication of spinal muscular atrophy (SMA). The ability to predict the need for mechanical ventilation is important. We assessed longitudinal patterns of lung function prior to chronic respiratory failure in a national cohort of treatment-naïve children and adults with SMA, hypothesizing an accelerated decline prior to chronic respiratory failure.

View Article and Find Full Text PDF