Longitudinal assessment of blood-borne musculoskeletal disease biomarkers in the DE50-MD dog model of Duchenne muscular dystrophy

Background: Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease caused by mutations in the dystrophin gene. Due to their phenotypic similarity to human patients, large animal models are invaluable tools for pre-clinical trials. The DE50-MD dog is a relatively new model of DMD, and carries a therapeutically-tractable mutation lying within the hotspot for human patients, making it especially valuable. Prior to conducting therapeutic trials using this novel animal model, it is essential to establish a panel of viable biomarkers. Methods: We evaluated a panel of blood-borne biomarkers of musculoskeletal disease in the DE50-MD dog. Venous blood samples were obtained monthly throughout an 18-month study period in DE50-MD (N=18) and wild-type (WT) control (N=14) dogs. A panel of potential plasma/serum biomarkers of DMD was measured and their theoretical utility in future clinical trials determined using sample size calculations. Results: Compared to WT dogs, DE50-MD dogs had substantially higher circulating creatine kinase (CK) activities, myomesin-3 (MYOM3), and the dystromiRs miR-1, miR-133a and miR-206, but significantly lower serum myostatin concentrations. An age-associated pattern, similar to that observed in DMD patients, was seen for CK and MYOM3. Sample size calculations suggested that low cohort sizes (N≤3) could be used to detect up to a 50% improvement in DE50-MD results towards WT levels for each biomarker or a combination thereof (via principal component analysis); as few as N=3 animals should enable detection of a 25% improvement using a combined biomarker approach (alpha 0.05, power 0.8). Conclusions: We have established a panel of blood-borne biomarkers that could be used to monitor musculoskeletal disease or response to a therapeutic intervention in the DE50-MD dog using low numbers of animals. The blood biomarker profile closely mimics that of DMD patients, supporting the hypothesis that this DMD model would be suitable for use in pre-clinical trials.

Musculoskeletal Diseases in Marfan Syndrome – A Nationwide Registry Study.

BackgroundMarfan syndrome is associated with abnormalities in the musculoskeletal system including scoliosis, pectus deformities, protrusio acetabuli, and foot deformities. Over a life span, many patients with Marfan syndrome will need treatment; however, the musculoskeletal morbidity over a life span is not well described. The aim of the present study was to assess the overall burden of musculoskeletal disease in patients with Marfan syndrome.Materials and MethodsA registry-based, nationwide epidemiological study of patients with a Ghent II verified Marfan syndrome diagnosis from 1977-2014. Each patient was matched on age, and sex with up to 100 controls from the background population.ResultsWe identified 407 patients with Marfan syndrome and 40,700 controls and compared their musculoskeletal diagnoses and surgical treatments using Cox proportional hazards regression (HR). The risk of a registration of a musculoskeletal diagnosis in patients with Marfan syndrome was significantly increased compared to controls (HR: 1.94 (1.69-2.24). One out of six with Marfan syndrome was registered with scoliosis (HR: 36.7 (27.5-48.9). Scoliosis was more common in women with Marfan syndrome compared to men (HR: 4.30 (1.73-1.08)). One out of 11 were registered with a pectus deformity HR: 40.8 (28.1-59.3), and one out of three with a deformity of the foot (HR: 1.9 (1.6-2.3)). The proportion of patients with Marfan syndrome (94/407) that underwent musculoskeletal surgery was also significantly higher (HR: 1.76 (1.43-2.16)). The major areas of surgery were the spine, pectus correction, and surgery of the foot/ancle. Ten patients with Marfan syndrome had elective orthopedic surgery without being recognized and diagnosed with Marfan syndrome until later in life. None of these had scoliosis, pectus deformity or a foot deformity.Among patients with an aortic dissection, the age at dissection was 34.3 years in those with at least one major musculoskeletal abnormality. In patients without a major abnormality the age at dissection was 45.1 years (p<0.01).ConclusionsThe extend of musculoskeletal disease is quite significant in Marfan syndrome and many will need corrective surgery during their life span. Surgeons should be aware of undiagnosed patients with Marfan syndrome when treating patients with a Marfan syndrome like-phenotype.

Message from the new EULAR President and Steering Group

The last decade witnessed the ascendancy of rheumatology to become one of the most dynamic and progressive across the fields of medicine. During the COVID-19 pandemic our discipline emerged at the forefront of molecular medicine with the rapid uptake of immune-modulatory therapeutics and depth of immune pathogenesis understanding contributing fundamentally to the COVID-19 response. The European Alliance of Associations for Rheumatology (EULAR) played a fundamental and vital role in this response in guiding rheumatic and musculoskeletal disease (RMD) therapeutics, vaccine use and even treatment innovations in the context of COVID-19 itself. Given this remarkable contribution, it is timely to reflect on EULAR—what is it and for what does it stand? At its core, EULAR represents people with RMDs, including their national societies, health professionals in rheumatology and scientific societies of rheumatology across the European nations. Our mission is to reduce the burden of RMDs on individuals and society and improve the treatment and prevention of RMDs. In this message from the new EULAR President and Steering Group, we present the most relevant activities of EULAR, its strategic aims and the concept of the EULAR family, a fantastic team of people working together across the three pillars of medical, health professional and patient societies.

Longitudinal study of medical downgrades in the Royal Air Force

IntroductionAs the focus of the Royal Air Force (RAF) shifts from sustained to contingency operations and the number of personnel is reduced, the burden of retained, medically downgraded personnel may affect operational readiness. The main aims were: to define the prevalence of morbidity leading to permanent medical downgrading; to determine at risk populations and identify areas for improvement.MethodDatabase of personnel referred to the RAF Medical Board was analysed from January 2012 to October 2013 and January 2017 to December 2019. Patients were excluded if they did not require a formal medical board; incomplete and duplicate entries were also excluded. The primary reason for medical downgrade was categorised with an ICD-10 code. Further subanalysis compared musculoskeletal disease with age, individual trade groups and anatomic region.Results2% of RAF service personnel were permanently downgraded annually. Musculoskeletal disease was the leading cause for permanent downgrade across both periods: 58% and 49%. Female personnel were at a greater risk of musculoskeletal downgrade compared with males. Spinal and knee pathology were the leading cause for downgrading among ‘high risk’ personnel. Personnel downgraded due to musculoskeletal pathology were often retained in a limited role with 10% and 5% retained as medically fully deployable. 14% and 12% of personnel downgraded due to musculoskeletal pathology were medically discharged.ConclusionMusculoskeletal disease was the leading cause for permanent medical downgrades in the RAF. A greater proportion of downgraded personnel with musculoskeletal conditions were retained in service with medical limitations rather than medically discharged.