Epidemiology Of Myasthenia Gravis Research Articles

Epidemiology, Patient Characteristics, and Treatment Patterns of Myasthenia Gravis in Taiwan: A Population-Based Study.

Myasthenia gravis (MG) is a chronic neuromuscular disease leading to significant disease burden. This study aimed to investigate the epidemiology of MG in Taiwan. A retrospective study was conducted using the Taiwan National Health Insurance Research Database. Prevalent patients with MG diagnosis (either ocular or generalized MG) from 2013 to 2019 were identified, and 2813 patients with initial MG diagnosis from 2014 to 2019 were further defined as the incident cohort. Patient characteristics, treatment patterns, and the occurrence of MG-related events were analyzed. The number of prevalent patients with MG increased from 4476 in 2013 to 5752 in 2019, with the prevalence rate increasing from 19 to 24 per 100,000 population. The incidence rate also slightly increased from 1.9 to 2.3 per 100,000 population during the study period. Almost all incident patients (99%, n = 2791) received MG-related treatment during the follow-up period. Among 1876 patients who received monotherapy as their initial treatment in the outpatient setting, the mean time from the index date to initial treatment was 48.8 (standard deviation 164.3) days, and most patients received acetylcholinesterase inhibitors (88.5%, n = 1661) as their initial treatment. During the first year after the index date, 133 (4.7%) incident patients experienced their first myasthenic crisis, and 96.2% of these events occurred within 3months. The prevalence of MG increased steadily in Taiwan, and the treatment of patients with MG was consistent with guidelines. Despite a high treatment rate, patients still experienced MG-related events, highlighting the limitation of current treatments and emphasizing the need for early intervention and novel treatment approaches.

Epidemiology of myasthenia gravis in France: Incidence, prevalence, and comorbidities based on national healthcare insurance claims data

BackgroundThe European literature has reported high variability in the incidence and prevalence rates of myasthenia gravis (MG), but no specific epidemiological data for France have been published. This study aimed to assess the incidence and prevalence rates of myasthenia gravis in France based on data extracted from the French National Health Insurance Claims Database (the SNIIRAM database). MethodsWe conducted a retrospective repeated cross-sectional population study from 2008 to 2018 using a representative sample of the French population (Échantillon généraliste des bénéficiaires) covered by health insurance. We calculated the incidence, prevalence, and sex ratio of MG and screened for comorbidities associated with MG (standardized to the general population). ResultsIn total, 331 MG patients were identified between 2008 and 2018. The average incidence of MG in France was 50 per million person-years, while the mean prevalence was 465 per million people. The female-to-male ratio was 1.33. The Incidence of MG gradually increased from 40years of age for women and 60 for men. Thymoma was present for 5.1% of MG patients and a thymectomy was performed for 4.7%. Thyroid disease was the most prevalent autoimmune comorbidity, affecting approximately 8.5% of cases. MG patients had an increased cancer risk, with a standardized rate ratio of 2.38 (95% CI: 1.64–3.46). ConclusionThe incidence and prevalence rates of MG are significantly higher than those previously reported in the literature and the incidence increases with age. The excess risk of cancer raises concerns for MG patients, in particular, concerning the management of immunosuppressive drugs.

Epidemiology of myasthenia gravis in Denmark, Finland and Sweden: a population-based observational study

BackgroundIncidence and prevalence rates of myasthenia gravis (MG) vary considerably across studies, and mortality risk is rarely addressed. We examined the prevalence and incidence rates, mortality and factors associated with...

Epidemiology of seropositive myasthenia gravis in Sardinia: A population-based study in the district of Sassari.

The global incidence and prevalence of myasthenia gravis (MG) range between 6-31/million and 10-37/100,000, respectively. Sardinia is a high-risk region for different immune-mediated disorders, but the epidemiology of MG remains unclear. We determined the epidemiology of MG with acetylcholine receptor (AChR)-immunoglobulin G (IgG) and muscle-specific tyrosine kinase (MuSK)-IgG in the district of Sassari (North-Western Sardinia; population, 325,288). From the laboratory of the University Hospital of Sassari (reference for AChR/MuSK-IgG testing in Sardinia since 1998) and the main neurology units in Sardinia, we retrospectively identified MG patients with (1) AChR-IgG and/or MuSK-IgG positivity by radioimmunoprecipitation assay; and (2) residency in the district of Sassari. Incidence (January 2010-December 2019) and prevalence (December 31, 2019) were calculated. A total of 202 patients were included (incident, 107; prevalent, 180). Antibody specificities were AChR (n = 187 [93%]) and MuSK (n = 15 [7%]). The crude MG incidence (95% confidence interval) was 32.6 (26.8-39.2)/million, while prevalence was 55.3 (47.7-63.9)/100,000. After age-standardization to the world population, incidence decreased to 18.4 (14.3-22.5)/million, while prevalence decreased to 31.6 (26.1-37.0)/100,000. Among incident cases, age strata (years) at MG onset were: <18 (2%), 18-49 (14%), 50-64 (21%), and ≥65 (63%). Sardinia is a high-risk region for MG, with a prevalence that exceeds the European threshold for rare disease. Identification of the environmental and genetic determinants of this risk may improve our understanding of disease pathophysiology.

Myastenia gravis: features of epidemiology, pathogenesis, treatment and relation to thymomas

Мyasthenia gravis is a common disease, for adequate treatment of which early detection, knowledge of its clinical manifestations and possible methods of therapy is required. This review provides up-to-date information regarding the issues of myasthenia gravis. The aim of the paper: to systematize the latest scientific data on the pathogenesis, genetic characteristics, methods of treatment of myasthenia gravis, as well as to identify the relationship between myasthenia gravis and other diseases. The following databases were used to search for published studies: Pubmed, Web of Science, EBSCOhost and Scopus. The search was carried out in the time period from the date of establishment of the corresponding database until October 2022. Following search terms were used: “myasthenia gravis”, “myasthenia treatment”, “myasthenia epidemiological features”, “myasthenia and thymoma “myasthenia pathogenesis””. Тhe main studies on the epidemiology of myasthenia gravis are indicated, the key clinical forms and their pathogenetic characteristics, the relationship between myasthenia gravis and thymoma, and the main methods of treatment are also given.

Epidemiology of Antibody-positive Myasthenia Gravis in Sardinia, Italy (P2-5.027)

<h3>Objective:</h3> To determine the incidence and prevalence of myasthenia gravis (MG) associated with acetylcholine receptor (AchR)-IgG and muscle tyrosine kinase (MuSK)-IgG in the district of Sassari (Sardinia; Italy). <h3>Background:</h3> The global mean incidence and prevalence of MG have been assessed at ≈15 (range, 4–29)/million and 20 (range, 2–37)/100,000, respectively. The island of Sardinia is a recognized area at higher risk for different immune-mediated disorders (<i>e.g</i>., multiple sclerosis), but the epidemiology of MG remains unclear. <h3>Design/Methods:</h3> From the Neurochemistry Laboratory of the University-Hospital of Sassari (reference laboratory for AchR-IgG/MuSK-IgG testing in the island since 1998) we retrospectively identified patients with: 1) AchR-IgG (titer ≥0.5 nmol/L) and/or MuSK-IgG (titer ≥100 pg/ml) positivity by radioimmunoprecipitation assay; 2) available medical records; and 3) residence within the district of Sassari. Incidence (January 2010-December 2019) and prevalence (on January 1, 2020; population 325,288) were calculated. <h3>Results:</h3> Among 517 antibody-positive patients identified, 183 were included (incident, 97; prevalent, 165). We excluded 334 patients due to: 1) missing clinical information (n=65); 2) residency outside the Sassari district (n=168); 3) not classifiable as incident or prevalent (n=56); and 4) clinical phenotype not consistent with MG (n=45; median AchR-IgG titer, 0.7 [range, 0.5–5.5] nmol/L). The crude MG prevalence was 50.7/100,000 (95% CI, 43.4–58.9), whereas incidence was 29.8/1,000,000 person-years (95% CI, 24.3–36.2). Antibody specificities were AchR in 170 (92.9%; median titer 5.7 [range, 0.5–22]) and MuSK in 13 (7.1%; median titer 1,255 [range, 136–1,730]). Among incidence cases, age at disease onset was distributed as: &lt;18 years (n=2; 2%); 18–50 years (n=14; 14.4%); 51–65 years (n=25; 25.8%); and &gt;65 years (n=56; 57.7%). In 45 (46.4%) incident cases, MG was initially restricted to ocular muscles. <h3>Conclusions:</h3> We report the highest incidence and prevalence of MG worldwide. The environmental and genetic determinants of MG risk in the Sardinian population need to be investigated. <b>Disclosure:</b> Dr. Zara has nothing to disclose. Dr. DEIANA has nothing to disclose. Prof. Sotgiu has nothing to disclose. Dr. Ortu has nothing to disclose. Stefano Sotgiu has nothing to disclose. Gregorio Spagni has nothing to disclose. Dr. Damato has nothing to disclose. Dr. Solla has nothing to disclose. Dr. Sechi has nothing to disclose.

Epidemiology of myasthenia gravis in the province of Ourense (Galicia, Spain).

Myasthenia gravis (MG) is an autoimmune disease affecting nerve transmission at the level of the neuromuscular junction, and typically causes fluctuating muscle weakness. Epidemiological studies show an increase in MG prevalence, particularly among the older population. We performed a retrospective epidemiological study to determine the incidence and prevalence of MG in the province of Ourense (Galicia, Spain), characterised by population ageing. Patients were selected from our clinical neuromuscular diseases database by searching for patients with an active prescription for pyridostigmine bromide. Incidence was estimated for the period 2009-2018. We calculated prevalence at 31/12/2018. According to census data for the province of Ourense, the population on 1/1/2019 was 307 651, of whom 96 544 (31.4%) were aged ≥ 65 years. We identified 80 cases of MG, with a prevalence rate of 260 cases/1 000 000 population (95% CI, 202.7-316.4), rising to 517.9/1 000 000 population in those aged ≥ 65 (95% CI, 363.2-672.9). Cumulative incidence in the study period was 15.4 cases per 1 000 000 person-years. Early onset (≤ 50 years) was recorded in 29.1% of cases. The prevalence of MG in our health district is one of the highest published figures, and the disease is highly prevalent in the older population.

Estimation of myasthenia gravis prevalence in Italy using real-world data

Few data are available regarding the epidemiology of Myasthenia Gravis (MG) in Italy during the most recent years. The study aims to evaluate the MG prevalence in a real-world setting and to estimate the number of patients currently living with MG in Italy.

Myasthenia Gravis in Poland: National Healthcare Database Epidemiological Study

Introduction: Myasthenia gravis (MG) is a rare autoimmune disorder of the neuromuscular junction. MG epidemiology has not been studied in Poland in a nationwide study before. Methods: Our epidemiological data were drawn from the National Health Fund (Narodowy Fundusz Zdrowia, NFZ) database; an MG patient was defined as a person who received at least once medical service coded in ICD-10 as MG (G70) and at least 2 reimbursed prescriptions for pyridostigmine bromide (Mestinon^®) or ambenonium chloride (Mytelase^®) in 2 consecutive years. Results: On 1st of January 2019, 8,702 patients with MG were receiving symptomatic treatment (female:male ratio: 1.65:1). MG incidence was 2.36/100,000. The mean age of incident cases in 2018 was 61.37 years, 59.17 years for women and 64.12 years for men. Incidence of early-onset MG (<50 years) was 0.80/100,000 and 4.98/100,000 for late-onset MG (LOMG), with male predominance in LOMG. Prevalence was 22.65/100,000. In women, there was a constant increase in prevalence of symptomatic MG from the first decade of life up to 80–89 years. In men, an increase in prevalence appeared in the 6th decade. The highest prevalence was observed in the age group of 80–89 years: 59.65/100,000 in women and 96.25/100,000 in men. Conclusions: Our findings provide information on epidemiology of MG in Poland and can serve as a tool to evaluate healthcare resources needed for MG patients.

Exploring outcomes and characteristics of myasthenia gravis: Rationale, aims and design of registry – The EXPLORE-MG registry

ObjectivesThough much information exists about the diagnosis, treatment, and epidemiology of myasthenia gravis (MG), a comprehensive data registry and biorepository is critical to better understand disease mechanisms, treatment outcomes, and the impact of treatment strategies. We aimed to design and implement the “Exploring Outcomes and Characteristics of Myasthenia Gravis (EXPLORE-MG) Registry” to address these knowledge gaps. MethodsA web-based, non-interventional, longitudinal, observational disease and outcomes registry was developed; incorporating NIH recommended common data elements for the study of MG. Individuals diagnosed with MG based on prespecified criteria were eligible to participate. The registry was further strengthened by a complementary biorepository. An interim analysis was completed on registry data collected through data-lock in 2017. ResultsA total of 232 MG patients, followed at the Yale MG Clinic from 2011 to 2017, were enrolled, which included 2142 total visit entries. Of the 232 MG patients (mean age 60 years, range 17–99; female:male, 1.04:1), 165 were acetylcholine receptor antibody-positive, 20 were muscle-specific kinase antibody-positive, and 47 were seronegative. This cohort consisted of 64 patients with ocular disease, 168 patients with generalized disease, and 65 patients post-thymectomy, including 20 with thymoma-associated MG. ConclusionsIdentification of key clinical features that may predict treatment responsiveness or provide insight into patient outcomes is essential to improve patient care. As current research focuses on the development of patient-tailored, targeted-treatment regimens, this registry can help provide important clinical and epidemiological data from a large contemporary patient cohort with long-term follow-up. RegistrationClinicalTrials.gov Identifier: NCT03792659

Epidemiology of Myasthenia Gravis in Slovakia in the Years 1977–2015

Purpose: The objective of the study was to evaluate changes of epidemiological parameters in patients with myasthenia gravis (MG) in Slovakia during the period 1977–2015. Methods: Data from medical records of MG patients registered in Slovakia were analyzed. Epidemiological rates (incidence, prevalence, mortality) were assessed for several periods to identify changes and drifts over the period of study. Results: Out of 2,074 patients, 892 were males (43.0%) and 1,193 were females (57.0%). The thymoma associated MG (TAMG) was diagnosed in 123 patients (5.9%). The mean age at onset shifted from 35.8 years in 1977–1989 to 60.0 years in ­2010–2015. The crude incidence increased from 0.36/100,000 in 1977–1989 to 1.74/100,000 in 2010–2015. The average annual incidence of TAMG was 0.05/100,000. Maximum increase of MG incidence was registered among the elderly (≥50 years), particularly in the group of patients in the age range 70–79 years (0.34/100,000 in 1977–1989→7.10/100,000 in 2010–2015) and 80–89 years (0.00/100,000 in 1977–1989→5.31/100,000 in 2010–2015). The crude MG prevalence on December 31, 2015 was 24.75/100,000. The average MG mortality was 0.27/100,000. Conclusion: The age at onset and incidence increased significantly over the study period due to marked increase of MG incidence in elderly, particularly over 70 years. Possible reasons for this trend are discussed.

The epidemiology of myasthenia gravis.

Epidemiology is the study of a disease in a population. The epidemiology of myasthenia gravis (MG) has been studied for over 50 years, and over 50 studies have been published in one form or another. The published prevalence has steadily increased, and one can estimate that there are approximately 60,000 patients with MG in the United States. The current trends indicate that, as the population ages, an increasing number of patients with MG can be expected, but the clinical patterns of the disease may change.

Epidemiologic evidence for a changing natural history of myasthenia gravis.

To survey the epidemiologic literature for evidence of an increasing prevalence of myasthenia gravis (MG) over time, and to explore the reasons for the increase. We found population-based reports of the epidemiology of MG by searching bibliographic databases. We used MG, epidemiology, prevalence, incidence, and mortality as search terms. We included population-based studies that reported the number of cases and the time period from which rates were calculated. We performed a regression analysis of rates versus date of study, comparing the slopes of regression lines for prevalence, incidence, and mortality. We performed a second analysis grouping rates by decade of study and calculating a mean rate weighted by the size of the population studied. We calculated 95% confidence intervals for each rate. We included 33 studies from 1950 through 1995. Prevalence and incidence rates increased over time, but the regression line for prevalence significantly exceeded that for incidence. Mortality rates declined slightly. The weighted means for prevalence rose significantly, but there was no significant change in incidence or mortality. The prevalence of MG has increased over the past forty-five years, probably because patients with the disease have longer life spans owing to present-day treatment.

Epidemiology of myasthenia gravis in the province of Trento (northern Italy).

The epidemiology of myasthenia gravis (MG) was studied in the province of Trento (northern Italy) among 444,879 inhabitants. On prevalence day (December 31, 1990) the crude rate was 82.9 per million population: 113 for females and 50.7 for males. The incidence rate was 7.4 per million per year: 10.8 for females and 4.6 for males. Over the same observation period (1981-1990), we calculated a death rate of 1.12 per million population per year. MG predominates in females. Nevertheless, we observed some differences related to age and to presence of thymoma, and our data supports the recognition of three types of MG: (1) predominating in females with a peak frequency at about 20-29 years; (2) affecting both males and females, with a frequency increasing with age, and (3) associated with thymoma.

Epidemiology of myasthenia gravis in province of Trento (North Italy)

Epidemiology of myasthenia gravis in province of Trento (North Italy)

Epidemiology of myasthenia gravis in a north-east area of Italy: II: C. Angelini, G.F. Micaglio, V. Sartori. University of Padova, Regional Neuromuscular Center, Padova. M.P. Riviera, G. Ferrari, E. Fincati, G. Tomelleri, Verona. F. Valassi, Gorizia. C. Marchini, Udine, G. Lovaste, Trento. P. Parisen-Toldin, Vicenza. R. Zanetti, Mirano. E. Pasinato, Bassano. G. Toffolo, Feltre. S. Guzzon, Monselice. A. Todros, M.

Epidemiology of myasthenia gravis in a north-east area of Italy: II: C. Angelini, G.F. Micaglio, V. Sartori. University of Padova, Regional Neuromuscular Center, Padova. M.P. Riviera, G. Ferrari, E. Fincati, G. Tomelleri, Verona. F. Valassi, Gorizia. C. Marchini, Udine, G. Lovaste, Trento. P. Parisen-Toldin, Vicenza. R. Zanetti, Mirano. E. Pasinato, Bassano. G. Toffolo, Feltre. S. Guzzon, Monselice. A. Todros, M.

Myasthenia gravis in the county of Viborg, Denmark.

The epidemiology of myasthenia gravis was studied in a Danish countryside county with 230,760 inhabitants. The incidence rate was 10.4 per million per year and the prevalence rate, 125 per million. The female to male ratio was 1.4 to 1. The diagnoses were delayed from a few hours to 6 years, most frequently on behalf of ophthalmologic diagnoses. A high incidence rate and a considerable diagnostic delay indicate that a number of patients suffering from myasthenia gravis are misdiagnosed, leading to unfortunate psychologic events.

Myasthenia Gravis: A Review

Myasthenia Gravis: A Review