Southern Alberta Vasculitis Patient Registry: Creation and Utility

INTRODUCTION Vasculitides encompass a group of rare diseases where inflammation of vessels causes multisystem organ damage. Incidence, currently estimated to be 10-20/million/year, shows an increasing trend in both children and adults [1]. Due to the nature of the disease, patients need ongoing follow-up to prevent relapse, avert organ damage, and control factors associated with increased mortality. However, vasculitides can be difficult to diagnose due to the diversity of presentation and lack of disease-specific diagnostic tools. As with other rare diseases, the limited number of patients impairs recruitment into clinical trials, impedes research, and hinders the generation of evidence-based treatment recommendations and protocols [2]. Moreover, the low patient numbers provide a barrier to obtaining reliable rare disease prevalence statistics and to gaining a clear understanding of the natural history of specific vasculitides. To address some of these limitations, we propose to generate a prospective vasculitis registry for patients in Southern Alberta. This initial registry will serve as a foundation for collaboration with other centres at the provincial, national, and international levels (Figure 1). The establishment of such a registry will create a framework for knowledge translation, discovery, and best practice management. METHODS Recruitment will initially be limited to patients with vasculitis residing in Southern Alberta referred to the Rheumatology division in Calgary through the central triage system. Ethics approval was obtained in May 2012. Patients complete written informed consent at their baseline visit. Upon consenting, the patients are examined yearly by Dr. Aurore Fifi-Mah, a Rheumatologist at the South Health Campus in Calgary, Alberta. Patients also complete yearly clinical case report forms and a Patient Quality of Life form (SF-36). Patient consent also extends to the collection of de-identified sera for storage in the Mitogen Advanced Diagnostics Laboratory in Calgary, Alberta, under the direction of Dr. Fritzler. These sera will be analyzed for the presence of new target antibodies and proteins to enhance understanding of the pathogenesis and prognosis of vasculitis. As this is an observational study, no power calculation is involved. Descriptive analysis will be used to summarize participant characteristics and comorbid conditions. RESULTS The initial project infrastructure has been successfully established. To date, 107 patients have been recruited with the following diagnosis (patient numbers are in brackets): ANCA-associated Vasculitis (12), Behcet’s Disease (7), Connective Tissue Disease (6), CNS Vasculitis (4), Cryoglobulinemia (1), Giant Cell Arteritis (9), IgA Vasculitis (5), Leukoclastic Angiitis (11), Neurosarcoidosis (1), NMDA Receptor Encephalitis (1), Polyarteritis Nodosa (11), Polymyalgia Rheumatica (13), Takayasu’s Arteritis (6), and Vasculitis Associated with Other Disease (20).DISCUSSION AND CONCLUSIONS The establishment of a Southern Alberta Vasculitis Patient Registry addresses the pervasive issues of inaccurate rare disease statistics, inadequate understanding of disease natural history, and limited diagnostic and treatment regimes. Through systematic collection and analysis of data, the registry will create a foundation of knowledge on which to build informed, standardized models of care. Moreover, the additional benefit of serum analysis may permit the discovery of specific biomarkers and prognostic factors to classify and predict the future course of different vasculitis subtypes. This will permit individualized, patient-centred treatment. The extension of this project to include centres provincially, nationally, and internationally would magnify the utility of the initial project. The previous establishment of provincially-based vasculitis research centres through CanVasc expedites project expansion

Duchenne muscular dystrophy: Canadian paediatric neuromuscular physicians survey

Background: Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy in childhood. Method: To assess the current care of paediatric DMD patients in Canada, a questionnaire was mailed to 17 physicians who were members of the Canadian paediatric neuromuscular group. Areas of enquiry included; 1) multidisciplinary team composition; 2) means of DMD diagnosis; 3) corticosteroid use; surveillance and management for: 4) orthopaedic, 5) respiratory and 6) cardiac complications and 7) health maintenance (nutrition & immunizations). Results: Completed surveys were returned by 14/17 (82%) of physicians. Twelve respondents followed DMD patients. All centres had multidisciplinary teams, including respirology (11/12), child neurology or physiatry (11), physiotherapy (9), occupational therapy (9) and orthopaedic surgery (7). Deflazacort 0.9mg/kg/d was used at all centres, which was continued after loss of independent ambulation (11), along with routine calcium and vitamin D supplementation (10). Night splints were prescribed at all centres. Routine surveillance studies included pulmonary function testing (11), sleep studies (10), EKG/echocardiogram (10), bone density (DEXA) scans (10), spine radiography (9), and dietician referral (4). Conclusion: Paediatric DMD patients are receiving relatively consistent care in multidisciplinary clinics across Canada, in accordance with recommended guidelines for DMD

A population-based study of dystrophin mutations in Canada

Introduction: We carried out a population-based study of dystrophin mutations in patients followed by members of the Canadian Paediatric Neuromuscular Group (CPNG) over a ten-year period. Objectives: We aimed to describe the changes in diagnostic testing for dystrophinopathy and to determine the frequency of dystrophin mutations from 2000 to 2009. Methods: De-identified data containing the clinical phenotypes, diagnostic methods, and mutational reports from dystrophinopathy patients followed by CPNG centres from January 2000 to December 2009 were analyzed using descriptive statistics. Results: 773 patients had a confirmed diagnosis of dystrophinopathy based on genetic testing (97%), muscle biopsy (2%), or family history (1%). 573 (74%) had complete deletion/duplication analysis of all 79 exons or whole gene sequencing, resulting in 366 (64%) deletions, 64 (11%) duplications, and 143 (25%) point mutations. The percentage of patients who were diagnosed using currently accepted genetic testing methods varied across Canada, with a mean of 63% (SD 23). 246 (43%) mutations involved exons 45 to 53. The top ten deletions (n=147, 26%) were exons 45-47, 45-48, 45, 45-50, 45-55, 51, 45-49, 45-52, 49-50, and 46-47. 169 (29%) mutations involved exons 2 to 20. The most common duplications (n=29, 5.1%) were exons 2, 2-7, 2-17, 3-7, 8-11, 10, 10-11, and 12. Conclusion: This is the most comprehensive report of dystrophin mutations in Canada. Consensus guidelines regarding the diagnostic approach to dystrophinopathy will hopefully reduce the geographical variation in mutation detection rates in the coming decade

Cluster randomised trials in the medical literature: two bibliometric surveys

Background: Several reviews of published cluster randomised trials have reported that about half did not take clustering into account in the analysis, which was thus incorrect and potentially misleading. In this paper I ask whether cluster randomised trials are increasing in both number and quality of reporting. Methods: Computer search for papers on cluster randomised trials since 1980, hand search of trial reports published in selected volumes of the British Medical Journal over 20 years. Results: There has been a large increase in the numbers of methodological papers and of trial reports using the term 'cluster random' in recent years, with about equal numbers of each type of paper. The British Medical Journal contained more such reports than any other journal. In this journal there was a corresponding increase over time in the number of trials where subjects were randomised in clusters. In 2003 all reports showed awareness of the need to allow for clustering in the analysis. In 1993 and before clustering was ignored in most such trials. Conclusion: Cluster trials are becoming more frequent and reporting is of higher quality. Perhaps statistician pressure works

The Canadian Neuromuscular Disease Registry: Connecting Patients to National and International Research Opportunities

Introduction Patient registries serve an important role in rare disease research, particularly for the recruitment and planning of clinical trials. The Canadian Neuromuscular Disease Registry was established with the primary objective of improving the future for neuromuscular (NM) patients through the enablement and support of research into potential treatments. Methods In this report, we discuss design and utilization of the Canadian Neuromuscular Disease Registry with special reference to the paediatric cohort currently enrolled in the registry. Results As of July 25, 2017, there are 658 paediatric participants enrolled in the registry, 249 are dystrophinopathies (229 are Duchenne muscular dystrophy), 57 are myotonic dystrophy participants, 98 spinal muscular atrophy participants and 65 are limb girdle muscular dystrophy. A total of 175 patients have another NM diagnosis. The registry has facilitated 20 clinical trial inquiries, 5 mail-out survey studies and 5 other studies in the paediatric population. Discussion The strengths of the registry are discussed. The registry has proven to be an invaluable tool to NM disease research and has increased Canada’s visibility as a competitive location for the conduct of clinical trials for NM therapies

Glycogen Storage Disease Type Ia in Canines: A Model for Human Metabolic and Genetic Liver Disease

A canine model of Glycogen storage disease type Ia (GSDIa) is described. Affected dogs are homozygous for a previously described M121I mutation resulting in a deficiency of glucose-6-phosphatase-α. Metabolic, clinicopathologic, pathologic, and clinical manifestations of GSDIa observed in this model are described and compared to those observed in humans. The canine model shows more complete recapitulation of the clinical manifestations seen in humans including “lactic acidosis”, larger size, and longer lifespan compared to other animal models. Use of this model in preclinical trials of gene therapy is described and briefly compared to the murine model. Although the canine model offers a number of advantages for evaluating potential therapies for GSDIa, there are also some significant challenges involved in its use. Despite these challenges, the canine model of GSDIa should continue to provide valuable information about the potential for generating curative therapies for GSDIa as well as other genetic hepatic diseases

Pretreatment HLADQA1-HLADRB1 Testing for the Prevention of Azathioprine-Induced Pancreatitis in Inflammatory Bowel Disease: A Prospective Cohort Study

INTRODUCTION:Azathioprine-induced pancreatitis is an idiosyncratic and unpredictable response, occurring in up to 7% of azathioprine-exposed patients with inflammatory bowel disease (IBD). The haplotype HLADQA1-HLADRB1*07:01A\u3eC is strongly associated with azathioprine-induced pancreatitis in IBD. We aimed to evaluate whether pretreatment HLADQA1-HLADRB1*07:01A\u3eC screening will reduce the risk of azathioprine-induced pancreatitis.METHODS:Participants with IBD were screened for HLADQA1-HLADRB1*07:01A\u3eC, and participants with a variant genotype were excluded from azathioprine treatment. Wild-type participants were started on azathioprine and followed for 3 months. The incidence of pancreatitis was compared with unscreened historical controls.RESULTS:HLADQA1-HLADRB1*07:01A\u3eC screening resulted in an 11-fold reduction in the incidence of azathioprine-induced pancreatitis (n = 1/328 or 0.30% vs n = 13/373 or 3.4%). In propensity score-matched cohorts (age and sex), HLA DQA1-HLADRB1*07:01A\u3eC screening was significantly associated with a reduction in the incidence of AZA-induced pancreatitis independent of weight, glucocorticoid exposure, and smoking status (adjusted odds ratio = 0.075, 95% confidence interval = 0.01-0.58, P = 0.01). Up to 45% (n = 271/599) of participants were excluded from azathioprine therapy based on the haplotype in the HLADQA1-HLADRB1*07:01A\u3eC-screened cohort.DISCUSSION:HLADQA1-HLADRB1*07:01A\u3eC screening reduced the risk of azathioprine-induced pancreatitis; however, using this strategy to guide the use of azathioprine therapy in IBD may eliminate a large proportion of patients from being eligible for treatment with azathioprine. In regions where there is access to other IBD therapies, and given the short-term and long-term toxicities associated with azathioprine, HLADQA1-HLADRB1*07:01A\u3eC-screening may be a clinically relevant strategy for enhancing the safe use of azathioprine in IBD. In addition, cost-effectiveness analyses are needed to further solidify the utility of HLADQA1-HLADRB1*07:01A\u3eC screening in IBD populations

Modified-release hydrocortisone to provide circadian cortisol profiles

Context: Cortisol has a distinct circadian rhythm regulated by the brain's central pacemaker. Loss of this rhythm is associated with metabolic abnormalities, fatigue, and poor quality of life. Conventional glucocorticoid replacement cannot replicate this rhythm. Objectives: Our objectives were to define key variables of physiological cortisol rhythm, and by pharmacokinetic modeling test whether modified-release hydrocortisone (MR-HC) can provide circadian cortisol profiles. Setting: The study was performed at a Clinical Research Facility. Design and Methods: Using data from a cross-sectional study in healthy reference subjects (n = 33), we defined parameters for the cortisol rhythm. We then tested MR-HC against immediate-release hydrocortisone in healthy volunteers (n = 28) in an open-label, randomized, single-dose, cross-over study. We compared profiles with physiological cortisol levels, and modeled an optimal treatment regimen. Results: The key variables in the physiological cortisol profile included: peak 15.5 mu g/dl (95% reference range 11.7-20.6), acrophase 0832 h(95% confidence interval 0759-0905), nadir less than 2 mu g/dl (95% reference range 1.5-2.5), time of nadir 0018 h (95% confidence interval 2339-0058), and quiescent phase (below the mesor) 1943-0531 h. MR-HC 15 mg demonstrated delayed and sustained release with a mean (SEM) maximum observed concentration of 16.6 (1.4) mu g/dl at 7.41 (0.57) h after drug. Bioavailability of MR-HC 5, 10, and 15 mg was 100, 79, and 86% that of immediate-release hydrocortisone. Modeling suggested that MR-HC 15-20 mg at 2300 h and 10 mg at 0700 h could reproduce physiological cortisol levels. Conclusion: By defining circadian rhythms and using modern formulation technology, it is possible to allow a more physiological circadian replacement of cortisol. (J Clin Endocrinol Metab 94: 1548-1554, 2009

Randomized phase 2 trial and open-label extension of domagrozumab in Duchenne muscular dystrophy.

We report results from a phase 2, randomized, double-blind, 2-period trial (48 weeks each) of domagrozumab and its open-label extension in patients with Duchenne muscular dystrophy (DMD). Of 120 ambulatory boys (aged 6 to \u3c16 \u3eyears) with DMD, 80 were treated with multiple ascending doses (5, 20, and 40 mg/kg) of domagrozumab and 40 treated with placebo. The primary endpoints were safety and mean change in 4-stair climb (4SC) time at week 49. Secondary endpoints included other functional tests, pharmacokinetics, and pharmacodynamics. Mean (SD) age was 8.4 (1.7) and 9.3 (2.3) years in domagrozumab- and placebo-treated patients, respectively. Difference in mean (95% CI) change from baseline in 4SC at week 49 for domagrozumab vs placebo was 0.27 (-7.4 to 7.9) seconds (p = 0.94). There were no significant between-group differences in any secondary clinical endpoints. Most patients had ≥1 adverse event in the first 48 weeks; most were mild and not treatment-related. Median serum concentrations of domagrozumab increased with administered dose within each dose level. Non-significant increases in muscle volume were observed in domagrozumab- vs placebo-treated patients. Domagrozumab was generally safe and well tolerated in patients with DMD. Efficacy measures did not support a significant treatment effect. Clinicaltrials.gov identifiers: NCT02310763 and NCT02907619