The North Star ambulatory assessment (NSAA) is a functional motor outcome measure in Duchenne muscular dystrophy (DMD), widely used in clinical trials and natural history studies, as well as in... Show moreThe North Star ambulatory assessment (NSAA) is a functional motor outcome measure in Duchenne muscular dystrophy (DMD), widely used in clinical trials and natural history studies, as well as in clinical practice. However, little has been reported on the minimal clinically important difference (MCID) of the NSAA. The lack of established MCID estimates for NSAA presents challenges in interpreting the significance of the results of this outcome measure in clinical trials, natural history studies and clinical practice. Combining statistical approaches and patient perspectives, this study estimated MCID for NSAA using distribution-based estimates of 1/3 standard deviation (SD) and standard error of measurement (SEM), an anchor-based approach, with six-minute walk distance (6MWD) as the anchor, and evaluation of patient and parent perception using participant-tailored questionnaires. The MCID for NSAA in boys with DMD aged 7 to 10 years based on 1/3 SD ranged from 2.3–2.9 points, and that on SEM ranged from 2.9–3.5 points. Anchored on the 6MWD, the MCID for NSAA was estimated as 3.5 points. When the impact on functional abilities was considered using participant response questionnaires, patients and parent perceived a complete loss of function in a single item or deterioration of function in one to two items of the assessment as an important change. Our study examines MCID estimates for total NSAA scores using multiple approaches, including the impact of patient and parent perspective on within scale changes in items based on complete loss of function and deterioration of function, and provides new insight on evaluation of differences in these widely used outcome measure in DMD. Show less
Anthony, K.; Ala, P.; Catapano, F.; Meng, J.H.; Domingos, J.; Perry, M.; ... ; Muntoni, F. 2023
Duchenne muscular dystrophy (DMD) is caused by the lack of dystrophin, but many patients have rare revertant fibers that express dystrophin. The skeletal muscle pathology of DMD patients includes... Show moreDuchenne muscular dystrophy (DMD) is caused by the lack of dystrophin, but many patients have rare revertant fibers that express dystrophin. The skeletal muscle pathology of DMD patients includes immune cell infiltration and inflammatory cascades. There are several strategies to restore dystrophin in skeletal muscles of patients, including exon skipping and gene therapy. There is some evidence that dystrophin restoration leads to a reduction in immune cells, but dystrophin epitopes expressed in revertant fibers or following genome editing, cell therapy, or microdystrophin delivery after adeno-associated viral gene therapy may elicit T cell production in patients. This may affect the efficacy of the therapeutic intervention, and potentially lead to serious adverse events. To confirm and extend previous studies, we performed annual enzyme- linked immunospot interferon-gamma assays on peripheral blood mononuclear cells from 77 pediatric boys with DMD recruited into a natural history study, 69 of whom (89.6%) were treated with corticosteroids. T cell responses to dystrophin were quantified using a total of 368 peptides spanning the entire dystrophin protein, organized into nine peptide pools. Peptide mapping pools were used to further localize the immune response in one positive patient. Six (7.8%) patients had a T cell-mediated immune response to dystrophin at at least one time point. All patients who had a positive result had been treated with corticosteroids, either prednisolone or prednisone. Our results show that similar to 8% of DMD individuals in our cohort have a pre-existing T cell-mediated immune response to dystrophin, despite steroid treatment. Although these responses are relatively low level, this information should be considered a useful immunological baseline before undertaking clinical trials and future DMD studies. We further highlight the importance for a robust, reproducible standard operating procedure for collecting, storing, and shipping samples from multiple centers to minimize the number of inconclusive data. Show less
Introduction/Aims: Mutations amenable to skipping of specific exons have been associated with different motor progression in Duchenne muscular dystrophy (DMD). Less is known about their association... Show moreIntroduction/Aims: Mutations amenable to skipping of specific exons have been associated with different motor progression in Duchenne muscular dystrophy (DMD). Less is known about their association with long-term respiratory function. In this study we investigated the features of respiratory progression in four DMD genotypes relevant in ongoing exon-skipping therapeutic strategies. Methods: This was a retrospective longitudinal study including DMD children followed by the UK NorthStar Network and international AFM Network centers (May 2003 to October 2020). We included boys amenable to skip exons 44, 45, 51, or 53, who were older than 5 years of age and ambulant at first recorded visit. Subjects who were corticosteroid-naive or enrolled in interventional clinical trials were excluded. The progression of respiratory function (absolute forced vital capacity [FVC] and calculated as percent predicted [FVC%]) was compared across the four subgroups (skip44, skip45, skip51, skip53). Results: We included 142 boys in the study. Mean (standard deviation) age at first visit was 8.6 (2.5) years. Median follow-up was 3 (range, 0.3-8.3) years. In skip45 and skip51, FVC% declined linearly from the first recorded visit. From the age of 9 years, FVC% declined linearly in all genotypes. Skip44 had the slowest (2.7%/year) and skip51 the fastest (5.9%/year) annual FVC% decline. The absolute FVC increased progressively in skip44, skip45, and skip51. In skip53, FVC started declining from 14 years of age. Discussion: The progression of respiratory dysfunction follows different patterns for specific genotype categories. This information is valuable for prognosis and for the evaluation of exon-skipping therapies. Show less
Introduction The aim of this study was to report 36-month longitudinal changes using the North Star Ambulatory Assessment (NSAA) in ambulant patients affected by Duchenne muscular dystrophy... Show moreIntroduction The aim of this study was to report 36-month longitudinal changes using the North Star Ambulatory Assessment (NSAA) in ambulant patients affected by Duchenne muscular dystrophy amenable to skip exons 44, 45, 51 or 53. Materials and methods We included 101 patients, 34 had deletions amenable to skip exon 44, 25 exon 45, 19 exon 51, and 28 exon 53, not recruited in any ongoing clinical trials. Five patients were counted to skip exon 51 and 53 since they had a single deletion of exon 52. Results The difference between subgroups (skip 44, 45, 51 and 53) was significant at 12 (p = 0.043), 24 (p = 0.005) and 36 months (p <= 0.001). Discussion Mutations amenable to skip exons 53 and 51 had lower baseline values and more negative changes than the other subgroups while those amenable to skip exon 44 had higher scores both at baseline and at follow up. Conclusion Our results confirm different progression of disease in subgroups of patients with deletions amenable to skip different exons. This information is relevant as current long term clinical trials are using the NSAA in these subgroups of mutations. Show less
Catapano, F.; Scaglioni, D.; Maresh, K.; Ala, P.; Domingos, J.; Selby, V.; ... ; Muntoni, F. 2020
Aim: To perform cross-sectional and longitudinal miRNA profiling in plasma from Duchenne muscular dystrophy (DMD) subjects and find non-invasive biomarkers in DMD. Subjects/materials & methods:... Show moreAim: To perform cross-sectional and longitudinal miRNA profiling in plasma from Duchenne muscular dystrophy (DMD) subjects and find non-invasive biomarkers in DMD. Subjects/materials & methods: Plasma was collected from 14 age and sex matched controls and 46 DMD subjects. Free-circulating and extracellular vesicle (EV)-derived miRNA expression was measured by RT-qPCR. Results: Free-circulating and EVs derived miR-29c-3p and miR-133a-3p are dysregulated in DMD subjects. Free-circulating and EV-derived miR-29c-3p are reduced in DMD subjects undergoing daily corticosteroid treatment. Free-circulating miR-1-3p and miR-122-5p are longitudinally upregulated in ambulant DMD subjects. Conclusion: We detected novel free-circulating and EV-derived dysregulated miRNAs in plasma from DMD subjects and characterized the longitudinal profile of free-circulating miRNA on plasma from DMD subjects. Show less
Hogrel, J.Y.; Decostre, V.; Ledoux, I.; Antonio, M. de; Niks, E.H.; Groot, I. de; ... ; Servais, L. 2020
Objective The main aim was to explore the changes in hand-grip strength in patients with Duchenne muscular dystrophy (DMD) aged 5-29 years. Secondary aims were to test the effect of mutation,... Show moreObjective The main aim was to explore the changes in hand-grip strength in patients with Duchenne muscular dystrophy (DMD) aged 5-29 years. Secondary aims were to test the effect of mutation, ambulatory status and glucocorticoid use on grip strength and its changes over time and to compute the number of subjects needed for a clinical trial to stabilize grip strength. Methods The analysis was performed on data collected during five international natural history studies on a cohort of DMD patients. Two hundred and two patients with genetically proven DMD were pooled from five different natural history studies. Excepting 13 patients with only one visit, the mean duration of follow-up was 2.2 +/- 1.6 years. A total of 977 measurement points were collected. Grip strength was measured on the dominant side with a high precision dynamometer. The analysis was performed using absolute values and normalized values expressed in percentage of predicted values for age. Results For absolute values, grip strength typically increased in ambulatory boys and decreased in non-ambulatory patients. However, when normalized, grip strength was already reduced at age 5 years and thereafter continued to fall away from normal values. The weaker the patients, the less strength they are prone to lose over again. Interpretation Grip strength constitutes a sensitive and continuous outcome measure that can be used across all stages of DMD. Its measurement is easy to standardized, can be used in ambulatory and non-ambulatory patients and does not present any floor or ceiling effect. It is thus attractive as an outcome measure in therapeutic trials. Show less
Background: Although self-expandable metal stent (SEMS) placement as bridge to surgery (BTS) in patients with left-sided obstructing colonic cancer has shown promising short-term results, it is... Show moreBackground: Although self-expandable metal stent (SEMS) placement as bridge to surgery (BTS) in patients with left-sided obstructing colonic cancer has shown promising short-term results, it is used infrequently owing to uncertainty about its oncological safety. This population study compared long-term oncological outcomes between emergency resection and SEMS placement as BTS.Methods: Through a national collaborative research project, long-term outcome data were collected for all patients who underwent resection for left-sided obstructing colonic cancer between 2009 and 2016 in 75 Dutch hospitals. Patients were identified from the Dutch Colorectal Audit database. SEMS as BTS was compared with emergency resection in the curative setting after 1: 2 propensity score matching.Results: Some 222 patients who had a stent placed were matched to 444 who underwent emergency resection. The overall SEMS-related perforation rate was 7.7 per cent (17 of 222). Three-year locoregional recurrence rates after SEMS insertion and emergency resection were 11-4 and 13.6 per cent (P= 0-457), disease-free survival rates were 58-8 and 52.6 per cent (P= 0-175), and overall survival rates were 74-0 and 68-3 per cent (P= 0.231), respectively. SEMS placement resulted in significantly fewer permanent stomas (23.9 versus 45.3 per cent; P < 0-001), especially in elderly patients (29.0 versus 57.9 per cent; P < 0-001). For patients in the SEMS group with or without perforation, 3-year locoregional recurrence rates were 18 and 11.0 per cent (P= 0.432), disease-free survival rates were 49 and 59.6 per cent (P= 0-717), and overall survival rates 61 and 75.1 per cent (P= 0.529), respectively.Conclusion: Overall, SEMS as BTS seems an oncologically safe alternative to emergency resection with fewer permanent stomas. Nevertheless, the risk of SEMS-related perforation, as well as permanent stoma, might influence shared decision-making for individual patients. Show less
Background. The time interval between CRT and surgery in rectal cancer patients is still the subject of debate. The aim of this study was to first evaluate the nationwide use of restaging magnetic... Show moreBackground. The time interval between CRT and surgery in rectal cancer patients is still the subject of debate. The aim of this study was to first evaluate the nationwide use of restaging magnetic resonance imaging (MRI) and its impact on timing of surgery, and, second, to evaluate the impact of timing of surgery after chemoradiotherapy (CRT) on short- and long-term outcomes.Methods. Patients were selected from a collaborative rectal cancer research project including 71 Dutch centres, and were subdivided into two groups according to time interval from the start of preoperative CRT to surgery (< 14 and ae14 weeks).Results. From 2095 registered patients, 475 patients received preoperative CRT. MRI restaging was performed in 79.4% of patients, with a median CRT-MRI interval of 10 weeks (interquartile range [IQR] 8-11) and a median MRI-surgery interval of 4 weeks (IQR 2-5). The CRT-surgery interval groups consisted of 224 (< 14 weeks) and 251 patients (>= 14 weeks), and the long-interval group included a higher proportion of cT4 stage and multivisceral resection patients. Pathological complete response rate (n = 34 [15.2%] vs. n = 47 [18.7%], p = 0.305) and CRM involvement (9.7% vs. 15.9%, p = 0.145) did not significantly differ. Thirty-day surgical complications were similar (20.1% vs. 23.1%, p = 0.943), however no significant differences were found for local and distant recurrence rates, disease-free survival, and overall survival.Conclusions. These real-life data, reflecting routine daily practice in The Netherlands, showed substantial variability in the use and timing of restaging MRI after preoperative CRT for rectal cancer, as well as time interval to surgery. Surgery before or after 14 weeks from the start of CRT resulted in similar short- and long-term outcomes. Show less
Catapano, F.; Domingos, J.; Perry, M.; Ricotti, V.; Phillips, L.; Servais, L.; ... ; Muntoni, F. 2018
Aim A Snapshot study design eliminates changes in treatment and outcome over time. This population based Snapshot study aimed to determine current practice and outcome of rectal cancer treatment... Show moreAim A Snapshot study design eliminates changes in treatment and outcome over time. This population based Snapshot study aimed to determine current practice and outcome of rectal cancer treatment with published landmark randomized controlled trials as a benchmark.Method In this collaborative research project, the dataset of the Dutch Surgical Colorectal Audit was extended with additional treatment and long-term outcome data. All registered patients who underwent resection for rectal cancer in 2011 were eligible. Baseline characteristics and outcome were evaluated against the results of the Dutch TME trial and the COLOR II trial from which the original datasets were obtained.Results A total of 71 hospitals participated, and data were completed for 2102 out of the potential 2633 patients (79.8%). Median follow-up was 41 (interquartile range 25-47) months. Overall circumferential resection margin (CRM) involvement was 9.3% in the Snapshot cohort and 18.5% in the Dutch TME trial. CRM positivity after laparoscopic resection was 7.8% in the Snapshot and 9.5% in the COLOR II trial. Three-year overall local recurrence rate in the Snapshot was 5.9%, with a disease-free survival of 67.1% and overall survival of 79.5%. Benchmarking with the randomized controlled trials revealed an overall favourable long-term outcome of the Snapshot cohort.Conclusion This study showed that current rectal cancer care in a large unselected Dutch population is of high quality, with less positive CRM since the TME trial and oncologically safe implementation of minimally invasive surgery after the COLOR II trial. Show less
Ricotti, V.; Eagle, M.; Butler, J.; Decostre, V.; Deborah, R.; Moraux, A.; ... ; Muntoni, F. 2015
