New insights into epidemiological data and impact of the COVID-19 pandemic on IgA vasculitis in children and adults: a French nationwide cohort.

IgA vasculitis (IgAV) is a small size vasculitis for which epidemiologic data are strikingly lacking, especially about the adult form. Additionally, the COVID-19 pandemic seems to have profoundly modified the incidence of this disease. Here, we aimed to establish some relevant epidemiological data in both pediatric and adult IgAV. We performed an observational study using a national database called "BNDMR" on IgAV, which gathers patients managed in the French network of experts on rare diseases. We primarily performed descriptive statistics over the 2010-2022 period. Then, we compared the North-South geographical areas, the seasonality, and the impact of COVID-19 with that of other patients reported in the same centers. We collected data from 1988 IgAV patients. The sex ratio was 1.57 for adults and 1.05 for children. The annual incidence in 2021 was 0.06 for 100,000 adults and 0.50 for 100,000 children. Compared with other diseases reported into the BNDMR, IgAV was more common in the South than in the North of France (OR 4.88 [4.17-5.74] in adults and OR 1.51 [1.35-1.68] in children). IgAV was also observed more frequently in winter and autumn. Strikingly, we observed a decrease in incidence during the COVID-19 pandemic period in children (OR 0.62 [0.47-0.81]). Our study provides both new insights and confirmations of IgAV epidemiological data: winter and autumn seasonality, more pronounced male predominance in adults, decreasing incidence of pediatric IgAV during the COVID-19 pandemic and increasing incidence in the South of France.

Overview of patients' cohorts in the French National rare disease registry.

In France, all patients followed by Rare Disease (RD) expert centers have to be registered in the National Rare Disease Registry (BNDMR). This database collects a minimum data set including diagnosis coded using the Orphanet nomenclature. Overall, 753,660 patients were recorded from 2007 to March 2022 including 493,740 with at least one rare disease diagnosis. Among these rare disease diagnoses, 1,300 diagnoses gathered between 10 and 70 patients and 792 gathered more than 70 patients, corresponding to more than one patient per million inhabitants. A total of 47 rare disease diagnoses with point prevalence or incidence reported in the literature below 1/1,000,000 have more than 70 patients in the BNDMR, suggesting larger BNDMR cohorts than expected from reported literature. As a conclusion, our national RD registry is a great resource to facilitate patients' recruitment in clinical research and a better understanding of RD natural history and epidemiology.

The ongoing French BaMaRa-BNDMR cohort: implementation and deployment of a nationwide information system on rare disease.

BACKGROUND: BaMaRa allows the secure collection and deidentified centralization of medical data from all patients followed-up in a rare disease expert network in France, based on a minimum data set (SDM-MR). The present article describes BaMaRa information system implementation and development across the whole national territory as well as data access requests through BNDMR, the data warehouse which centralizes all BaMaRa data, during the 2015-2020 period. MATERIALS AND METHODS: SDM-MR is made up of 60 interoperable items and is routinely collected through BaMaRa in rare disease centers as part of care and discharged into BNDMR after deidentification and data reconciliation. Data access is regulated by a scientific committee. RESULTS: In total, 668 002 affected patients had an SDM-MR recorded in BNDMR by the end of 2020 with a mean value of 3.4 activities per patients. Data access was provided for 66 projects. CONCLUSION: The BaMaRa-BNDMR infrastructure provides an administrative and epidemiological resources for rare diseases in France.

Impact of the COVID-19 pandemic on the care of rare and undiagnosed diseases patients in France: a longitudinal population-based study.

BACKGROUND: Preliminary data suggest that COVID-19 pandemic has generated a switch from face-to-face to remote care for individuals with chronic diseases. However, few data are available for rare and undiagnosed diseases (RUDs). We aimed to assess the impact of the COVID-19 pandemic on the activities of the French reference network for RUDs in 2020. RESULTS: In this longitudinal retrospective study, we extracted and analyzed the data of the French national registry for RUDs collected between Jan 1, 2019 and Dec 31, 2020. We compared the annual longitudinal evolution of face-to-face and remote care activities between 2019 and 2020 focusing on adult and pediatric patients. Compared to 2019, rare diseases (RD) care activities showed a decrease in 2020 (- 12%) which occurred mostly during the first lockdown (- 45%) but did not catch up completely. This decrease was mainly in face-to-face care activities. Telehealth activities showed a 9-fold increase during the first lockdown and was able to cover for one third of the decrease in RD activities. Finally, the total number of patients receiving care was lower in 2020(- 9%) with a drastic decrease of cases with newly confirmed diagnosis (- 47%). CONCLUSION: Although telehealth was quickly introduced during the COVID-19 pandemic, RUD patient care was strongly affected in France with a decline in the number of patients treated and new patients recruited. This is likely to result in delays in patient diagnosis and care over the next few years.

A multicentre, randomised, double-blind, placebo-controlled trial with the interleukin-1 receptor antagonist anakinra in patients with systemic-onset juvenile idiopathic arthritis (ANAJIS trial).

OBJECTIVES: To assess the efficacy of the interleukin 1 receptor antagonist anakinra in systemic-onset juvenile idiopathic arthritis (SJIA). METHODS: A multicentre, randomised, double-blind, placebo-controlled trial was conducted. The primary objective was to compare the efficacy of a 1-month treatment with anakinra (2 mg/kg subcutaneous daily, maximum 100 mg) with a placebo between two groups each with 12 patients with SJIA. Response was defined by a 30% improvement of the paediatric American College of Rheumatology criteria for JIA, resolution of systemic symptoms and a decrease of at least 50% of both C-reactive protein and erythrocyte sedimentation rate compared with baseline. After month 1 (M1), patients taking placebo were switched to anakinra. Secondary objectives included tolerance and efficacy assessment for 12 months, and analyses of treatment effect on blood gene expression profiling. RESULTS: At M1, 8/12 responders were receiving anakinra and 1 responder receiving placebo (p=0.003). Ten patients from the placebo group switched to anakinra; nine were responders at M2. Between M1 and M12, six patients stopped treatment owing to an adverse event (n=2), lack of efficacy (n=2) or a disease flare (n=2). Blood gene expression profiling at enrollment and at 6 months' follow-up showed one set of dysregulated genes that reverted to normal values in the clinical responders and a different set, including interferon (IFN)-inducible genes, that was induced by anakinra. CONCLUSIONS: Anakinra treatment is effective in SJIA, at least in the short term. It is associated with normalisation of blood gene expression profiles in clinical responders and induces a de novo IFN signature. TRIAL REGISTRATION NUMBER: NCT00339157.

Age at diagnosis in patients with chronic congenital endocrine conditions: a regional cohort study from a reference center for rare diseases.

BACKGROUND: For chronic congenital endocrine conditions, age at diagnosis is a key issue with implications for optimal management and psychological concerns. These conditions are associated with an increase in the risk of comorbid conditions, particularly as  it concerns growth, pubertal development and fertility potential. Clinical presentation and severity depend on the disorder and the patient's age, but diagnosis is often late. OBJECTIVE: To evaluate age at diagnosis for the most frequent congenital endocrine diseases affecting growth and/or development. PATIENTS AND METHODS: This observational cohort study included all patients (n = 4379) with well-defined chronic congenital endocrine diseases-non-acquired isolated growth hormone deficiency (IGHD), isolated congenital hypogonadotropic hypogonadism (ICHH), ectopic neurohypophysis (NH), Turner syndrome (TS), McCune-Albright syndrome (MAS), complete androgen insensitivity syndrome (CAIS) and gonadal dysgenesis (GD)-included in the database of a single multisite reference center for rare endocrine growth and developmental disorders, over a period of 14 years. Patients with congenital hypothyroidism and adrenal hyperplasia were excluded as they are generally identified during neonatal screening. RESULTS: Median age at diagnosis depended on the disease: first year of life for GD, before the age of five years for ectopic NH and MAS, 8-10 years for IGHD, TS (11% diagnosed antenatally) and CAIS and 17.4 years for ICHH. One third of the patients were diagnosed before the age of five years. Diagnosis occurred in adulthood in 22% of cases for CAIS, 11.6% for TS, 8.8% for GD, 0.8% for ectopic NH, and 0.4% for IGHD. A male predominance (2/3) was observed for IGHD, ectopic NH, ICHH and GD. CONCLUSION: The early recognition of growth/developmental failure during childhood is essential, to reduce time-to-diagnosis and improve outcomes.

10 years of CEMARA database in the AnDDI-Rares network: a unique resource facilitating research and epidemiology in developmental disorders in France.

BACKGROUND: In France, the Ministry of Health has implemented a comprehensive program for rare diseases (RD) that includes an epidemiological program as well as the establishment of expert centers for the clinical care of patients with RD. Since 2007, most of these centers have entered the data for patients with developmental disorders into the CEMARA population-based registry, a national online data repository for all rare diseases. Through the CEMARA web portal, descriptive demographic data, clinical data, and the chronology of medical follow-up can be obtained for each center. We address the interest and ongoing challenges of this national data collection system 10 years after its implementation. METHODS: Since 2007, clinicians and researchers have reported the "minimum dataset (MDS)" for each patient presenting to their expert center. We retrospectively analyzed administrative data, demographic data, care organization and diagnoses. RESULTS: Over 10 years, 228,243 RD patients (including healthy carriers and family members for whom experts denied any suspicion of RD) have visited an expert center. Among them, 167,361 were patients affected by a RD (median age 11 years, 54% children, 46% adults, with a balanced sex ratio), and 60,882 were unaffected relatives (median age 37 years). The majority of patients (87%) were seen no more than once a year, and 52% of visits were for a diagnostic procedure. Among the 2,869 recorded rare disorders, 1,907 (66.5%) were recorded in less than 10 patients, 802 (28%) in 10 to 100 patients, 149 (5.2%) in 100 to 1,000 patients, and 11 (0.4%) in > 1,000 patients. Overall, 45.6% of individuals had no diagnosis and 6.7% had an uncertain diagnosis. Children were mainly referred by their pediatrician (46%; n = 55,755 among the 121,136 total children referrals) and adults by a medical specialist (34%; n = 14,053 among the 41,564 total adult referrals). Given the geographical coverage of the centers, the median distance from the patient's home was 25.1 km (IQR = 6.3 km-64.2 km). CONCLUSIONS: CEMARA provides unprecedented support for epidemiological, clinical and therapeutic studies in the field of RD. Researchers can benefit from the national scope of CEMARA data, but also focus on specific diseases or patient subgroups. While this endeavor has been a major collective effort among French RD experts to gather large-scale data into a single database, it provides tremendous potential to improve patient care.

CEMARA an information system for rare diseases.

Rare diseases cover a group of conditions characterized by a low prevalence, affecting less than 1 in 2,000 people; 5000 to 7000 rare diseases have been currently identified in Europe. Most diseases do not have any curative treatment. They represent thus an important public health concern. CEMARA is based on a n-tier architecture. Its main objective is to collect continuous and complete records of patients with rare diseases, and their follow-up through a web-based Information System, and to analyse the epidemiological patterns. In France, 41 out of 131 labelled Reference Centres (RC) are sharing CEMARA. Presently 56,593 cases have been registered by more than 850 health care professionals belonging to 171 clinical sites. The national demand of care was explored in relation with the offer of care in order to reach an improved match. Within 2 years, CEMARA stimulated sharing a common platform, a common ontology with Orphanet and initiating new cohorts of rare diseases for improving patient care and research.

Healthcare trajectory of children with rare bone disease attending pediatric emergency departments.

BACKGROUND: Children with rare bone diseases (RBDs), whether medically complex or not, raise multiple issues in emergency situations. The healthcare burden of children with RBD in emergency structures remains unknown. The objective of this study was to describe the place of the pediatric emergency department (PED) in the healthcare of children with RBD. METHODS: We performed a retrospective single-center cohort study at a French university hospital. We included all children under the age of 18 years with RBD who visited the PED in 2017. By cross-checking data from the hospital clinical data warehouse, we were able to trace the healthcare trajectories of the patients. The main outcome of interest was the incidence (IR) of a second healthcare visit (HCV) within 30 days of the index visit to the PED. The secondary outcomes were the IR of planned and unplanned second HCVs and the proportion of patients classified as having chronic medically complex (CMC) disease at the PED visit. RESULTS: The 141 visits to the PED were followed by 84 s HCVs, giving an IR of 0.60 [95% CI: 0.48-0.74]. These second HCVs were planned in 60 cases (IR = 0.43 [95% CI: 0.33-0.55]) and unplanned in 24 (IR = 0.17 [95% CI: 0.11-0.25]). Patients with CMC diseases accounted for 59 index visits (42%) and 43 s HCVs (51%). Multivariate analysis including CMC status as an independent variable, with adjustment for age, yielded an incidence rate ratio (IRR) of second HCVs of 1.51 [95% CI: 0.98-2.32]. The IRR of planned second HCVs was 1.20 [95% CI: 0.76-1.90] and that of unplanned second HCVs was 2.81 [95% CI: 1.20-6.58]. CONCLUSION: An index PED visit is often associated with further HCVs in patients with RBD. The IRR of unplanned second HCVs was high, highlighting the major burden of HCVs for patients with chronic and severe disease.

CEMARA: a Web dynamic application within a N-tier architecture for rare diseases.

Rare diseases include a group of conditions characterized by a prevalence lower than 5 per 10,000 in the community. In France, any rare disease affects less than 30,000 patients and often much less. Three to 4% of children and 6% of the population in Europe are affected. It is a true public health stake since most diseases do not have any curative treatment. In France, the Ministry of Health has initiated a National Rare Diseases Plan. Twenty five out of 132 labelled Reference Centres (RC) decided to share a common Information System named CEMARA. It is dedicated to collect continuous and complete records of all patients presenting with a rare disease, and their follow-up. The main objective of CEMARA is to contribute to the missions of the RC regarding the registration and description of their activities, coordination of the network of their correspondents, organization of the follow-up of rare diseases, and analysis of the epidemiological patterns. A description of CEMARA is provided as well as its cooperation with Orphanet and Genatlas, and a presentation of 11803 current records collected by more than 300 health care professionals belonging to more than 70 sites.

Federating patients identities: the case of rare diseases.

BACKGROUND: Patient information in rare disease registries is generally collected from numerous data sources, necessitating the data to be federated. In addition, data for research purposes must be de-identified. Transforming nominative data into de-identified data is thus a key issue, while minimizing the number of identity duplicates. We propose a method enabling patient identity federation and rare disease data de-identification while preserving the pertinence of the provided data. RESULTS: We developed a rare disease patient identifier. The IdMR generation process is a three-phased algorithm involving a hash function to irreversibly de-identify nominative patient data, including those of foetuses. This process minimizes collision risks and reduces variability for the purpose of identity federation. The IdMR was generated for 360,000 patients of the CEMARA database. It allowed identity federation of 1771 duplicated files. No collisions were introduced. CONCLUSION: We examined and discussed the risks of collisions and the creation of duplicates as well as the risks of patient re-identification. We discussed our choice of nominative input information in light of that used by other patient identification solutions. The IdMR is a patient identifier that enables identity federation and file linkage. The simplicity of the algorithm and the universality and stability of the input data make it a good candidate for European cross-border rare disease projects.

Management of rare diseases of the Head, Neck and Teeth: results of a French population-based prospective 8-year study.

BACKGROUND: In the last ten years, national rare disease networks have been established in France, including national centres of expertise and regional ones, with storage of patient data in a bioinformatics tool. The aim was to contribute to the development and evaluation of health strategies to improve the management of patients with rare diseases. The objective of this study has been to provide the first national-level data concerning rare diseases of the head, neck and teeth and to assess the balance between demand and supply of care in France. METHODS: Centres of expertise for rare diseases record a minimum data set on their clinical cases, using a list of rare Head, Neck and Teeth diseases established in 2006. The present analysis focuses on 2008 to 2015 data based on the Orphanet nomenclature. Each rare disease RD "case" was defined by status "affected" and by the degree of diagnostic certainty, encoded as: confirmed, probable or non-classifiable. Analysed parameters, presented with their 95% confidence intervals using a Poisson model, were the following: time and age at diagnosis, proportions of crude and standardized RD prevalence by age, gender and geographical site. The criteria studied were the proportions of patients in Paris Region and the "included cases geography", in which these proportions were projected onto the other French Regions, adjusting for local populations. RESULTS: In Paris Region, estimated prevalence of these diseases was 5.58 per 10,000 inhabitants (95% CI 4.3-7.1). At December 31st 2015, 11,342 patients were referenced in total in France, of whom 7294 were in Paris Region. More than 580 individual clinical entities (ORPHA code) were identified with their respective frequencies. Most abnormalities were diagnosed antenatally. Nearly 80% of patients recorded come to Paris hospitals to obtain either diagnosis, care or follow up. We observed that the rarer the disease, the more patients were referred to Paris hospitals. CONCLUSIONS: A health network covering a range of aspects of the rare diseases problematic from diagnostics to research has been developed in France. Despite this, there is still a noticeable imbalance between health care supply and demand in this area.

Prevalence of fibrodysplasia ossificans progressiva (FOP) in France: an estimate based on a record linkage of two national databases.

BACKGROUND: Fibrodysplasia ossificans progressiva (FOP) is a rare, severely disabling, and life-shortening genetic disorder that causes the formation of heterotopic bone within soft connective tissue. Previous studies found that the FOP prevalence was about one in every two million lives. The aim of this study is to estimate the FOP prevalence in France by probabilistic record-linkage of 2 national databases: 1) the PMSI (Programme de médicalisation des systèmes d'information), an administrative database that records all hospitalization activities in France and 2) CEMARA, a registry database developed by the French Centres of Reference for Rare Diseases. RESULTS: Using a capture-recapture methodology to adjust the crude number of patients identified in both data sources, 89 FOP patients were identified, which results in a prevalence of 1.36 per million inhabitants (CI95% = [1.10; 1.68]). FOP patients' mean age was 25 years, only 14.9% were above 40 years, and 53% of them were males. The first symptoms - beside toe malformations- occurred after birth for 97.3% of them. Mean age at identified symptoms was 7 years and above 18 years for only 6.9% of patients. Mean age at diagnosis was 10 years, and above 18 years for 14.9% of the patients. FOP patients were distributed across France. CONCLUSIONS: Despite the challenge of ascertaining patients with rare diseases, we report a much higher prevalence of FOP in France than in previous studies elsewhere. We suggest that efforts to identify patients and confirm the diagnosis of FOP should be reinforced and extended at both national and European level.

Prognostic Factors From an Epidemiologic Evaluation of Fibrous Dysplasia of Bone in a Modern Cohort: The FRANCEDYS Study.

Fibrous dysplasia of bone (FD) is a rare genetic but sporadic bone disease that can be responsible for bone pain, fracture, and bone deformity. The prognosis may be difficult to establish because of the wide spectrum of disease severity. We have analyzed the data from the French National Reference center for FD. We have established a database from standardized medical records. We have made descriptive statistics of the various forms of FD and examined the prognostic factors by multivariable logistic regression analysis, with a parsimonious stepwise method. The primary outcome was a clinically relevant composite index combining bone pain (visual analogic scale >3) and/or incident fracture. In our modern cohort of 372 patients, the median age at diagnosis was 23 years. The revealing symptom (at a median age of 18 years) was bone pain in 44% of patients and a fracture in 9%, but the diagnosis was fortuitous in 25% of cases. Monostotic forms represented 58% of patients and polyostotic forms 42%. The femur was the most commonly affected bone (44% of patients), followed by the skull (38%). Twelve percent of patients had McCune-Albright syndrome (MAS). With a median duration of follow-up of 7 years among 211 patients, we observed an incidence of fracture of 17% and 51% of patients had no bone pain at the end of follow-up (with or without bisphosphonate therapy). In univariate analysis, younger age at diagnosis, renal phosphate wasting, a polyostotic form, prevalent fracture, and bisphosphonate use were significant predictors. In the multivariate model, the polyostotic form and bisphosphonate use remained significant predictors. In conclusion, in a national referral center for FD, one patient on follow-up out of six had incident fracture. A polyostotic form was the main risk factor of a poorer outcome. © 2016 American Society for Bone and Mineral Research.

A methodology for a minimum data set for rare diseases to support national centers of excellence for healthcare and research.

BACKGROUND: Although rare disease patients make up approximately 6-8% of all patients in Europe, it is often difficult to find the necessary expertise for diagnosis and care and the patient numbers needed for rare disease research. The second French National Plan for Rare Diseases highlighted the necessity for better care coordination and epidemiology for rare diseases. A clinical data standard for normalization and exchange of rare disease patient data was proposed. The original methodology used to build the French national minimum data set (F-MDS-RD) common to the 131 expert rare disease centers is presented. METHODS: To encourage consensus at a national level for homogeneous data collection at the point of care for rare disease patients, we first identified four national expert groups. We reviewed the scientific literature for rare disease common data elements (CDEs) in order to build the first version of the F-MDS-RD. The French rare disease expert centers validated the data elements (DEs). The resulting F-MDS-RD was reviewed and approved by the National Plan Strategic Committee. It was then represented in an HL7 electronic format to maximize interoperability with electronic health records. RESULTS: The F-MDS-RD is composed of 58 DEs in six categories: patient, family history, encounter, condition, medication, and questionnaire. It is HL7 compatible and can use various ontologies for diagnosis or sign encoding. The F-MDS-RD was aligned with other CDE initiatives for rare diseases, thus facilitating potential interconnections between rare disease registries. CONCLUSIONS: The French F-MDS-RD was defined through national consensus. It can foster better care coordination and facilitate determining rare disease patients' eligibility for research studies, trials, or cohorts. Since other countries will need to develop their own standards for rare disease data collection, they might benefit from the methods presented here.

Patient information, consents and privacy protection scheme for an information system dedicated to pervasive developmental disorders.

Patients explicit and unambiguous information, patients consents and privacy protection are reviewed in this article, in the frame of the deployment of the information system TEDIS dedicated to autism spectrum disorders. The role of the Delegate to the Protection of Data is essential at this stage. We developed a privacy protection scheme based on storing encrypted patients personal data on the server database and decrypting it on the Web browser. It tries to respond to the end-users request to manage nominative data in a human readable form and to meet with privacy protection framework.