Current available therapies control Myasthenia gravis (MG) reasonably well, but Health Related Quality of life (HRQOL) remains lower than expected. The aim was provide insights in how HRQOL in MG stands across borders and time, compare the scores to general population controls and other chronic disorders and assess the impact of potential predictors for quality of life such as a) clinical characteristics b) antibodies c) thymoma and d) treatment in a population-based cohort.MethodsWe designed a population-based cross-sectional study including 858 patients, 373 from Norway and 485 from the Netherlands. The Short Form Health Survey 36 (SF-36) and a cross-cultural validated questionnaire were used. Data were in addition compared to the general population, other chronic diseases and previous studies.ResultsMean physical composite score was 59.4 and mental composite score 69.0 with no differences between the countries. The mean HRQOL score was lower in patients with bulbar and generalized symptoms (p < 0.001) compared to sex and age adjusted healthy controls, but not in patients with ocular symptoms or patients in remission. Multivariate analysis revealed that female gender, generalized symptoms and use of secondary immunosuppressive drugs at the time of testing were risk factors for reduced HRQOL.ConclusionsRemission and absence of generalized symptoms were favorable factors for HRQOL in MG patients. Historically, the HRQOL levels have not changed since 2001 and no new clinical predictors could be detected in this exhaustive population-based study. Further studies should explore the impact of non clinical factors like ethnic variations, socio-economic and hormonal factors on HRQOL.Electronic supplementary materialThe online version of this article (doi:10.1186/s12955-015-0298-1) contains supplementary material, which is available to authorized users.

Autoantibodies against three different postsynaptic antigens and one presynaptic antigen at the neuromuscular junction are known to cause myasthenic syndromes. The mechanisms by which these antibodies cause muscle weakness vary from antigenic modulation and complement-mediated membrane damage to inhibition of endogenous ligand binding and blocking of essential proteinprotein interactions. These mechanisms are related to the autoantibody titre, specific epitopes on the target proteins and IgG autoantibody subclass. We here review the role of specific autoantibody-binding epitopes in myasthenia gravis, their possible relevance to the pathophysiology of the disease and potential implications of epitope mapping knowledge for new therapeutic strategies.

Objectives: To compare the prevalence of myasthenia gravis (MG) subgroups based on immunological markers and clinical presentation in two geographically complete MG populations in northern Europe. Methods: This cross-sectional study included all living MG patients in Norway and a regional cohort from the Netherlands. Patients were identified using their hospital registration codes. Medical charts of subjects >16 years were reviewed. Inclusion criteria were clinical MG, a positive antibody test for acetylcholine receptor (AChR MG) or muscle-specific kinase (MuSK MG), or if seronegative MG, confirmed by an electrophysiological test. Results: 1,205 MG patients (534 Norwegians and 671 Dutch) fulfilled the criteria, giving a higher point prevalence in the Netherlands (167/million, 95% CI 155-180) than in Norway (138/million, 95% CI 126-150). In particular, rates of AChR MG (143 vs. 111/million), MuSK MG (6.5 vs. 0.5/million), and ocular phenotype (62 vs. 24/million) were higher in the Netherlands. Conclusion: Novel findings are an AChR MG geographical north-south gradient and a 2.6-fold more ocular MG patients in the Netherlands than in Norway. The MuSK MG latitudinal gradient supports the notion of a north-south gradient in Europe, with a higher prevalence in the south. The variation is probably explained by genetic differences between the populations, in addition to environmental interactions.

ObjectiveTo study survival and to characterize long-term functional impairments and health-related quality of life (HRQOL) of patients with Lambert-Eaton myasthenic syndrome (LEMS). MethodsIn this observational study, survival of patients with LEMS, separately for nontumor (NT) and small cell lung cancer (SCLC), was compared to that of the Dutch general population and patients with SCLC. Disease course in patients with LEMS was recorded retrospectively. Several scales for functional impairments and health-related quality of life were assessed. ResultsWe included 150 patients with LEMS. Survival was similar to that of the general population in 65 patients with NT-LEMS. Tumor survival was significantly longer in 81 patients with SCLC-LEMS compared to patients with non-LEMS SCLC (overall median survival 17 vs 7.0 months, p < 0.0001). At diagnosis, 39 (62%) of 63 patients with complete follow-up data were independent for activities of daily living, improving to 85% at the 1-year follow-up. The physical HRQOL composite score (55.9) was significantly lower than in the general population (76.3, p < 0.0001) and comparable to that of patients with myasthenia gravis (60.5). The mental HRQOL composite score was 71.8 in patients with LEMS, comparable to that of the general population (77.9, p = 0.19) and patients with myasthenia gravis (70.3). ConclusionsThis study shows that patients with NT-LEMS have normal survival. Patients with SCLC-LEMS have an improved tumor survival, even after correction for tumor stage. A majority of patients with LEMS report a stable disease course and remain or become independent for selfcare after treatment. MORE ONLINE

No abstract

We studied the effect and safety of ephedrine as add-on treatment for patients with myasthenia gravis with acetylcholine receptor antibodies (AChR MG), who do not sufficiently respond to standard treatment. Four patients with AChR MG were included in a placebo-controlled, double-blind, and randomised, multiple crossover series of n-of-1 trials. Each n-of-1 trial consisted of 3 cycles, in which two 5-day intervention periods were followed by 2 days washout. In each cycle, ephedrine 50 mg daily in 2 doses was compared with placebo in the alternate treatment period. Primary outcome was a change in QMG score. Add-on treatment with ephedrine compared with placebo improved QMG score by 1.0 point (95% confidence interval 0.21-1.79), which was significant for the group of trial patients as well as for the population treatment effect. Ephedrine also showed a significant trial average treatment effect for all secondary outcomes, improving MG Composite by 2.7, MG-ADL by 1.0 and VAS score for muscle strength by 1.1. Adverse events were mild and included palpitations, tremor and restlessness. Although all ECGs were normal, ephedrine prolonged the corrected QT interval. Ephedrine as add-on treatment for myasthenia gravis resulted in a small but consistent reduction of symptoms and weakness in patients with moderate disease severity.

IntroductionMyasthenia gravis (MG), a rare neuromuscular disease, is often initially treated using acetylcholinesterase inhibitors. Patients who do not respond adequately depend on the use of corticosteroids or other immunosuppressive medication, but these may have serious side effects. Clinical observations suggest that ephedrine can diminish, postpone or even prevent the need for immunosuppressive therapy when added to acetylcholinesterase inhibitors or low-dose prednisone. In the Netherlands, ephedrine is not licensed for MG nor is reimbursement guaranteed. MG is a rare condition, and ephedrine might be indicated only in a subset of patients. Thus, randomised controlled trials comparing large groups are difficult to conduct. We, therefore, aim to aggregate data from a small series of n-of-1 trials (also known as single patient trials) to assess the effect of ephedrine as add-on treatment for MG.Methods and analysisSingle-centre, placebo-controlled, double-blind, randomised, multiple crossover n-of-1 studies in 4 adult patients with generalised MG who show inadequate improvement on pyridostigmine and/or immunosuppressive drugs. Each n-of-1 trial has 3 cycles of two 5-day intervention periods. Treatment: 25 mg ephedrine or placebo, twice daily. Main outcome measure: Quantitative Myasthenia Gravis (QMG) test. Statistical analysis: fixed effects linear model for QMG for all patients combined. Secondary outcome measures: Clinical: effects on MG-Composite and MG-Activities of Daily Living (MG-ADL) scales; QMG at individual level; adverse events. Acceptability of trial design: number of patients eligible and enrolled; number of treatment cycles completed; patients’ and caregivers’ experiences.Ethics and disseminationThis study was approved by the Medical Ethics Committee of Leiden University Medical Center, No. P14.108. Results of the trial will be reported in a peer-reviewed publication. Regulatory stakeholders will comment on the suitability of the trial for market authorisation and reimbursement purposes.Trial registration numberThis study is registered under EudraCT number 2014-001355-23, protocol no. 40960, V.1.0, registration date 27 March 2014.

Microaspiration of Pseudomonas aeruginosa contributes to the pathogenesis of nosocomial pneumonia. Trappin-2 is a host defense peptide that assists with the clearance of P. aeruginosa through undefined mechanisms. A model of macrophage interactions with replicating P. aeruginosa (strain PA01) in serum-free conditions was developed, and the influence of subantimicrobial concentrations of trappin-2 was subsequently studied. PA01 that was pre-incubated with trappin-2 (at concentrations that have no direct antimicrobial effects), but not control PA01, was cleared by alveolar and bone marrow-derived macrophages. However, trappin-2-enhanced clearance of PA01 was completely abrogated by CD14- null macrophages. Fluorescence microscopy demonstrated the presence of trappin-2 on the bacterial cell surface of trappin-2-treated PA01. In a murine model of early lung infection, trappin-2-treated PA01 was cleared more efficiently than control PA01 2 hours of intratracheal instillation. Furthermore, trappin-2-treated PA01 up-regulated the murine chemokine CXCL1/KC after 2 hours with a corresponding increase in neutrophil recruitment 1 hour later. These in vivo trappin-2-treated PA01 effects were absent in CD14-deficient mice. Trappin-2 appears to opsonize P. aeruginosa for more efficient, CD14-dependent clearance by macrophages and contributes to the induction of chemokines that promote neutrophil recruitment. Trappin-2 may therefore play an important role in innate recognition and clearance of pathogens during the very earliest stages of pulmonary infection.