Coeliac disease is a chronic immune-mediated enteropathy triggered by gluten intake, which affects the small intestine in genetically susceptible individuals (HLA-DQ2 and/or HLA-DQ8). This disease, which occurs in both children and adults, is among the most common genetically determined disorders in Western countries. It is characterized by the presence of very varied and often nonspecific clinical manifestations (primarily digestive symptoms and signs of intestinal malabsorption), as well as the presence of specific antibodies (tissue transglutaminase and endomysium) and enteropathy. Currently, the only treatment for coeliac disease is a strict gluten-free diet for life. The main objective of the NATURCEL (NATURal history, epidemiological, clinical, diagnostic and therapeutic aspects of CoELiac disease and noncoeliac enteropathies) registry is to collect selected variables on different aspects of the disease (epidemiological, clinical, genetic, immunological, etc.) for a subsequent shared analysis for scientific and translational purposes.
La enfermedad celíaca es una enteropatía crónica inmunomediada desencadenada por la ingesta de gluten, que afecta al intestino delgado en individuos genéticamente susceptibles (HLA-DQ2 y/o HLA-DQ8). Esta entidad, que ocurre tanto en niños como en adultos, es una de las enfermedades genéticamente determinadas más comunes en los países occidentales. Se caracteriza por un amplio espectro de manifestaciones clínicas, habitualmente inespecíficas, en el que predominan los síntomas digestivos y los signos de malabsorción intestinal, así como la presencia de anticuerpos específicos (transglutaminasa tisular y endomisio) y enteropatía. Actualmente, el único tratamiento para la enfermedad celíaca es una dieta sin gluten estricta durante toda la vida. El objetivo principal del registro NATURCEL (estudio de la historia NATURal, aspectos epidemiológicos, clínicos, diagnósticos y terapéuticos de la enfermedad CELíaca y las enteropatías no celíacas) es obtener variables seleccionadas sobre diferentes aspectos de la enfermedad (epidemiológicos, clínicos, genéticos, inmunológicos, etc.), para un análisis conjunto posterior con finalidad científica y traslacional.
Coeliac disease (CD) is a chronic immune-mediated enteropathy triggered by the ingestion of gluten in genetically susceptible individuals carrying HLA-DQ2 and/or HLA-DQ8 haplotypes. CD is the most common genetically determined chronic intestinal disease and is characterized by a wide spectrum of clinical manifestations, as well as the presence of specific antibodies (tissue transglutaminase and endomysium) and enteropathy.1–5 The prevalence of CD varies across regions and is influenced by genetic predispositions and dietary habits (type and amount of cereal consumption). The estimated global seroprevalence is 1.4%, while the prevalence confirmed by biopsy is 0.7%.6 In Catalonia (Spain), population-based studies have shown that the CD seroprevalence has remained stable over the past two decades at approximately 0.5%,7,8 whereas the prevalence of clinically diagnosed CD in primary care is considerably lower, at 0.2%.9 This gap is particularly notable in adults (0.18%) compared with children (0.32%), with a female-to-male ratio of approximately 2:1.9,10
To date, the only effective treatment for CD is a strict, lifelong gluten-free diet (GFD). Adequate adherence to the diet is crucial for preventing comorbidities and long-term complications.11 Dietary adherence among patients with CD is typically assessed through expert nutritionist interviews, patient self-reports and/or structured questionnaires such as the Coeliac Dietary Adherence Test (CDAT)12 (validated in Spanish)13 or the Biagi score.14 More recently, an objective approach consisting of the detection of gluten immunogenic peptides (GIPs) in faeces or urine has been introduced, enabling direct measurement of gluten intake within the past few days.15 The incorporation and standardization of these evaluation methods in follow-up protocols is essential to ensure effective therapeutic management.
Despite the growing recognition of CD and other gluten-related disorders, significant challenges remain in the diagnosis and management of atypical forms—such as seronegative coeliac disease or low-grade coeliac enteropathy—where noncoeliac enteropathies that mimic certain features of CD further complicate clinical decision-making. Further research is needed to validate and integrate novel diagnostic tools into standardized clinical algorithms. These include flow cytometry analysis of duodenal intraepithelial lymphocyte subpopulations (TCRγδ+ and CD3−),16–26 peripheral blood-activated gut-homing CD8+ T cells27,28; cytokine expression profiling (IL-2, IL-8, IL-10, TNF-α, IFN-γ, etc.) in peripheral blood or duodenal biopsies29–31; and whole-blood assays measuring IL-2 release (WBAIL-2) for the detection of gluten-specific T cells,32 among other emerging diagnostic tools.
Why NATURCEL is novel and necessaryA review of the literature shows that, to our knowledge, only one registry with characteristics comparable to NATURCEL currently exists in Europe: the Swedish National Coeliac Disease Register, a nationwide paediatric registry (https://researchdata.se/en/catalogue/dataset/ext0139-1).33 Other large general-purpose population cohorts, such as the Norwegian HUNT4 study,34 include individuals with CD, but these are not a disease-specific registry, as they were not exclusively designed for CD nor structured as multicentre clinical registries. In Spain, there are also precedents such as REPAC (2006–2007), REPAC-2 (2011–2017),35 and REPAC-3 (2018–present), collectively known as the Spanish National Registry of Paediatric Coeliac Patients,36 representing three time-limited multicentre national registries. Likewise, several European paediatric cohorts monitor autoimmunity or follow genetically at-risk children as part of longitudinal research on environmental triggers and disease development.37 However, these initiatives are restricted to childhood, lack continuous recruitment, and are not clinical registries aimed at long-term follow-up.
To date, no registry specifically dedicated to CD in adults has been established in Spain, and no prospective, continuous, multicentre registry covering both adults and children exists worldwide. This stands in contrast to other digestive disorders (such as inflammatory bowel disease,38Helicobacter pylori infection,39 or eosinophilic oesophagitis40) for which robust national and international registries have been available for years. Given the high prevalence and growing clinical complexity of CD, this absence represents a major unmet need.
To address these gaps and to promote standardized, high-quality multicentre research, the NATURCEL Registry (NATURal history, epidemiological, clinical, diagnostic, and therapeutic aspects of CoELiac disease and noncoeliac enteropathies) was established in Spain in June 2025. NATURCEL provides a comprehensive, harmonised, and prospectively maintained framework for data collection across healthcare institutions involved in the diagnosis, management, and research of CD and noncoeliac enteropathies.
NATURCEL differs substantially from previously reported initiatives in several key aspects. It includes both adults and children, thereby overcoming the inherent limitations of paediatric -only registries. Unlike time-limited projects such as REPAC-1 and REPAC-2, NATURCEL is conceived as a continuous, prospective, longitudinal registry with no predefined end date. It is multicentre and multidisciplinary, integrating centres from primary care, gastroenterology, paediatrics, pathology, biochemistry, immunology, dietetics and nutrition, which enables truly comprehensive and standardized data collection. Importantly, it is the first registry worldwide designed to encompass both CD and noncoeliac enteropathies, allowing comparative analyses across conditions with overlapping clinical, serological, and histological features.
In addition, NATURCEL incorporates harmonised clinical, serological, histological, and genetic variables to ensure methodological consistency nationwide. Finally, international expansion is planned through collaboration with centres worldwide with recognized expertise in CD, positioning NATURCEL to become the first international multicentre registry with continuous recruitment of both coeliac and noncoeliac enteropathy patients.
By addressing the major limitations of previous registries—restricted to paediatrics, limited duration, specific geographic location, and narrow disease scope—NATURCEL aims to become a cutting-edge platform for translational research, epidemiological surveillance, clinical quality improvement, and ultimately, a driver of innovation in the field of coeliac and enteropathy research.
Design of the NATURCEL registryThe NATURCEL registry is a prospective, multicentre, descriptive registry initiated by the Research Group ‘Intestinal Immunity and Coeliac Disease’ of the Centre for Biomedical Research Network in Liver and Digestive Diseases (CIBEREHD, research group CB17/04/00040, principal investigator: Dr. Maria Esteve, www.ciberehd.org/grupos/grupo-de-investigacion?id=16148), which is based at Hospital Universitari Mútua Terrassa. This group and institution act as the lead promoter of the registry and specialize in the study of the pathophysiology and immunology of CD. The project is endorsed by the Spanish Association of Gastroenterology (Asociación Española de Gastroenterología, AEG) and was developed in collaboration with Hospital Universitari de Bellvitge, Hospital Clínic de Barcelona, Hospital Universitari Arnau de Vilanova, Hospital Universitari Germans Trias i Pujol and the Primary Care Centre Florida Sud. The creation of this collaborative initiative involves multiple health care specialties, including primary care, gastroenterology, paediatrics, dietetics and nutrition, pathology, and immunology. In addition, the registry plans to integrate a biobank of biological samples in the near future, which will be centralized and managed by the Biobank Clínic-IDIBAPS, a certified facility and collaborator of the CIBEREHD consortium. A central component of the project is the REDCap database, which ensures secure, structured, and scalable data management. This article presents the rationale, design, implementation, and expected impact of the NATURCEL registry. The main benefits of participation in the multicentre NATURCEL registry for patients, patient associations, scientific societies, and society/governments are summarized in Fig. 1.
Benefits of participation in the multicentre NATURCEL registry. The figure summarizes the main advantages for different stakeholders: patients, patient associations, scientific societies, and society/governments. Participation fosters scientific knowledge, collaboration, methodological quality, policy impact, health care efficiency, and improved patient outcomes. Abbreviations: NATURCEL: Registry for investigation of the natural history, epidemiological, clinical, diagnostic, and therapeutic aspects of coeliac disease and noncoeliac enteropathies.
All individuals diagnosed with CD and other gluten-related disorders will be included according to the criteria established by the European Society for the Study of CD for Adults (2025),1 the Paris Consensus Criteria for the Diagnosis of Seronegative CD2 and the 2020 ESPGHAN Criteria for the Diagnosis of CD in Childhood.3Table 1 summarizes the clinical presentations and definitions of CD considered in the NATURCEL registry, providing a standardized framework for patient classification and data collection. Table 2 presents the proposed criteria for CD diagnosis based on the modified Catassi and Fasano criteria,5 offering a practical framework based on a combination of clinical, serological, genetic, and histological data and response to a GFD.
Clinical presentations and definitions of coeliac disease as proposed in the NATURCEL registry.
| Clinical presentations and definitions1,4 | |
|---|---|
| Classic coeliac disease | • More common in children and very rare in adults.• Symptoms and signs of malabsorption (diarrhoea, steatorrhea, weight loss, iron deficiency anaemia, growth delay). |
| Nonclassic coeliac disease | • More frequent in adulthood, usually monosymptomatic or oligosymptomatic.• Selective malabsorption of micronutrients is common (iron, calcium, vitamin D, etc.).• Gastrointestinal symptoms: abdominal pain, bloating, gastroesophageal reflux disease, vomiting, regurgitation, irritable bowel syndrome–like symptoms, distension, etc.• Extraintestinal signs and symptoms: iron deficiency anaemia, bone mass loss, mild increase in liver enzymes, fertility disorders, etc. |
| Asymptomatic or subclinical coeliac disease | • No detectable symptoms despite characteristic intestinal lesions.• Usually diagnosed through screening (general population or at-risk groups).• Symptoms (e.g., fatigue) are often recognized retrospectively due to their improvement on a GFD. |
| Potential coeliac disease | • Refers to patients with a normal intestinal biopsy (Marsh 0, <25 IELs) but at increased risk of developing coeliac disease due to the presence of specific molecular or cellular markers:° Positive serological tests° Increased γδ T cells in the duodenum° Positive tissue transglutaminase 2 staining• Some authors also include first-degree relatives with permissive genetics under “potential coeliac disease.” Others consider Marsh 1 lesions as potential coeliac disease. |
| Nonresponsive coeliac disease | • Persistence of clinical symptoms and/or signs of malabsorption despite adherence to a GFD for 12 months. Four possible scenarios:1. Persistent villous atrophy due to gluten ingestion (voluntary, inadvertent, or cross-contamination).2. Persistence of symptoms despite complete serological and histological response. Other concomitant disorders should be considered: functional gastrointestinal disorders, fructose+sorbitol intolerance, lactose intolerance, microscopic colitis, bile acid malabsorption, etc.3. Slow responders (mucosal healing beyond 2 years).4. Refractory coeliac disease type 1 or 2. |
| Refractory coeliac disease | • Persistence or recurrence of symptoms or signs of malabsorption and villous atrophy despite a strict GFD for >12 months, after excluding other causes of villous atrophy. Subclassified into:° RCD type I: duodenal IELs show a normal phenotype with polyclonal TCR rearrangement.° RCD type II: duodenal IELs show an aberrant phenotype with loss of surface markers (CD3, CD4, CD8) but preserved cytoplasmic CD3 expression. TCR rearrangement is usually oligoclonal or monoclonal. |
Abbreviations: RCD: refractory coeliac disease; IEL: intraepithelial lymphocyte; TCR: T-cell receptor; GFD: gluten-free diet.
Modified Catassi and Fasano diagnostic criteria for coeliac disease (2025).
| Modified Catassi and Fasano diagnostic criteria for coeliac disease5 |
|---|
| At least 4 out of 5 criteria (or 3 out of 4 if HLA-DQ2/DQ8 testing is not available): |
| 1. Typical symptoms of coeliac disease |
| 2. High-titre IgA class coeliac-specific antibodies |
| 3. Determination of HLA-DQ2 and/or DQ8a |
| 4. Enteropathy compatible with coeliac disease on intestinal biopsyb |
| 5. Response to a gluten-free dietc |
Note: A family history of coeliac disease adds further evidence for the diagnosis.
Includes Marsh–Oberhuber type 1–3 lesions associated with low or high titres of coeliac-specific antibodies, and/or with subepithelial IgA deposits and/or an increased percentage of duodenal TCR γδ+ lymphocytes.17
Additionally, patients with noncoeliac enteropathies identified during the diagnostic work-up for suspected CD will also be included.
Data collection and study variablesStudy data will be collected and managed using the REDCap electronic data capture tool hosted at Asociación Española de Gastroenterología (AEG; www.aegastro.es).41,42 REDCap (Research Electronic Data Capture) is a secure, web-based software platform designed to support data for research studies, providing (1) an intuitive interface for validated data capture; (2) auditing of trials for tracking data manipulation and export procedures; (3) automated export procedures for seamless data downloads to common statistical packages; and (4) procedures for data integration and interoperability with external sources.
Overall, the collected variables are grouped into the following categories: demographic data, medical history, clinical symptoms and signs, serological tests, genetics, endoscopy and pathology, densitometry, follow-up and treatment, and GIP detection and diagnosis. Table 3 provides a detailed list of these variables. For each case to be considered valid, a set of core variables—marked with an asterisk (*) in the platform—must be completed. These include informed consent, sex, age, clinical symptoms and signs, serological tests, endoscopy and duodenal biopsy results and final diagnosis. Additional study-specific variables can be included for research projects conducted by one or more participating centres. The NATURCEL registry will be available in Catalan, Spanish, and English to facilitate data entry in both clinical and research settings and enable efficient export of data and text for the preparation of scientific manuscripts in English while also encouraging participation from research groups nationally and internationally.
Main variables included in the NATURCEL registry classified by data category.
| Demographic data | Medical history | Clinical signs | Serological tests | Genetics | Endoscopy and pathological anatomy | Densitometry | Gluten immunogenic peptides | Follow-up and treatment | Diagnosis |
|---|---|---|---|---|---|---|---|---|---|
| Date of inclusionYear of birthSexGenderHospitalInformed consentDate of follow-up completionReason for follow-up completion | Smoking statusAlcohol consumptionAssociated diseases and comorbiditiesFamily historyMedication | Date of symptoms onsetPrincipal symptomDigestive signsMalabsorption of micronutrients and other analytical alterationsExtradigestive signs | Date of testType of test: basal/follow-upDiet at the test: GCD/GFDIgA deficiencySerological test performedResultValueUnitsKit | Date of genetic studyGenetic markers of CD | Date of endoscopyType of test: basal/follow-upDiet at the endoscopy: GCD/GFDExamination resultsH. pylori and presence of parasites (e.g., giardiasis)Marsh (Oberhuber) classificationIntraepithelial lymphocytes countingCD lymphogramRefractory CD lymphogram | Date of testType of test: basal/follow-upT scoreZ scoreTrabecular bone score (TBS)Fractures | Date of sample collectionType of sample: faeces/urineDetermination methodResultValue | Date of GFD startGFD adherenceMethod of GFD adherence evaluationClinical responsePersistence of symptomsSerological responseHistological responsePersistence of duodenal atrophyH. pylori eradicationPneumococcal vaccination | Date of diagnosisDiagnosis classification: CD, non-CD atrophy, non-CD lymphocytic enteritis, normal intestinal mucosa, other enteropathies |
Abbreviations: CD: coeliac disease; GFD: gluten-free diet; GCD: gluten-containing diet.
Sex and gender aspects are particularly relevant in CD. Female patients more often present with atypical or extraintestinal symptoms such as anaemia, osteoporosis, fertility disorders, or fatigue. These manifestations are frequently attributed to functional or psychosomatic conditions, leading to diagnostic delays compared with men.43–45 Such delays represent a clear example of gender bias in medicine, where women's symptoms may be underestimated, misattributed, or insufficiently investigated.43–46
This diagnostic gap has important consequences: undiagnosed CD in women has been associated with infertility, recurrent miscarriages, menstrual disorders, severe nutritional deficiencies, and greater psychological impact, including anxiety, depression, and reduced quality of life.46–48 Moreover, the clinical response to a GFD also appears to be poorer in women, possibly because of differences in symptom perception and reporting, further reflecting gender-related disparities in care.49 The gender of health care professionals may also influence diagnostic practices; studies suggest that female gastroenterologists and endoscopists are more likely to follow biopsy guidelines, directly affecting diagnostic accuracy.50,51
To address these challenges, the NATURCEL registry will systematically collect both sex (biological) and gender (sociocultural) variables, ensuring that analyses can be stratified and interpreted through a gender-sensitive lens. Data will include reproductive and hormonal status when applicable, as well as psychosocial and lifestyle factors. This approach, aligned with the SAGER guidelines52 and the ProGéneros Decalogue,53 aims to reduce diagnostic inequities and generate knowledge that contributes to more precise, equitable, and inclusive health care for patients with CD.
Scientific oversight, governance, and organizational rolesThe governance of the NATURCEL registry will be overseen by the Scientific Committee, the Scientific Secretariat, the Registry Coordinator, and the Advisory Committee. The roles and responsibilities of each of these bodies are described below.
The Scientific Committee of the NATURCEL registry is composed of four researchers who are specialists in gastroenterology or paediatrics, with a specific focus on CD and a recognized scientific career. At least one of them must be a researcher from the promoter group. The role of the Scientific Committee is to ensure the scientific quality, integrity, and relevance of research and publications by evaluating proposals, reviewing content, and advising on the scientific policy of the NATURCEL registry. The member list will be published on the NATURCEL project website.
The Scientific Secretariat will be responsible for managing the projects and ensuring the correct maintenance of the REDCap database. Furthermore, they will provide support and management for the Scientific Committee and the Advisory Committee; and assist in the organization of meetings, managing publications and communication channels among stakeholders, the public, and the press. The Scientific Secretariat is in charge of the Standard Operating Procedure (SOP) NATURCEL registry.
The Advisory Committee will be composed of national and international experts in CD, who may be consulted by the Scientific Committee to evaluate and provide feedback on proposed research projects. Its role is to provide independent expert guidance, insights, and recommendations to the Scientific Committee. The list of members will be published on the NATURCEL project website.
Finally, the Coordinator of the NATURCEL registry will be appointed by the Scientific Committee and will also serve as a member of it. The Coordinator's main responsibilities, together with the Scientific Secretariat, will be the supervision and maintenance of the registry and the transfer of data and biological samples in the future. In addition, the coordinator will ensure the strict compliance with the regulations established in the SOP regarding the application and approval of projects and the supervision of the drafting of the articles derived from the NATURCEL registry. In accordance with the responsibility in the registry, the coordinator will be considered a coauthor of all the manuscripts derived from NATURCEL.
Procedures and scientific use of the NATURCEL registryTo participate in the NATURCEL project and benefit from both its scientific output and local applicability, interested centres must obtain approval from their local Clinical Research Ethics Committee and sign a collaboration agreement with the registry's promoter group. After that, the Scientific Secretariat provides the site's principal investigator and its team with passwords to access the registry. Each patient must sign the relevant informed consent form before data entry.
To request the use of data from the NATURCEL registry for a research study, investigators must have included at least 100 patients in the registry. For the approval of the projects, the Scientific Committee will request their review by at least two members of the Advisory Committee, whose list will be published on the NATURCEL project website. A favourable report from the Scientific Committee and both reviewers is required, and minor or major revisions of the project may be requested. The purpose of this review is to improve the quality of the projects, enhance the relevance of the information provided and facilitate publication in high-impact journals.
Additionally, upon completion of the approved projects, a draft of any resulting manuscripts and conference presentations must be submitted to all principal investigators from participating centres, as well as to the members of the Scientific Committee, the Scientific Secretariat, and the Coordinator. This process also ensures compliance with authorship policies and verifies the correct inclusion of citations, funding statements and acknowledgements. Fig. 2 illustrates the stepwise process for patient inclusion in the NATURCEL registry, as well as the procedures for study approval, data analysis, and publication applicable to the participating centres.
Algorithm illustrating the inclusion of patients in the multicentre NATURCEL registry and the process for requesting access to registry data. The left panel outlines the patient inclusion workflow: contact with the Scientific Secretariat, approval by the Clinical Research Ethics Committee, access to the database, and case entry. The right panel summarizes the data utilization process: submission of study proposals, compliance verification, approval by the Scientific Committee, data transfer, analysis, manuscript drafting, verification of authorship policy and citations, final review, and publication. Abbreviations: NATURCEL: Natural history, epidemiological, clinical, diagnostic, and therapeutic aspects of Coeliac disease and noncoeliac enteropathies registry; SOP: Standard Operating Procedure; GDPR: General Data Protection Regulation; AEG-REDCap: Research Electronic Data Capture platform hosted by the Spanish Association of Gastroenterology (Asociación Española de Gastroenterología).
The contribution of each participating centre to the NATURCEL registry must be appropriately acknowledged through authorship in the resulting scientific output. To this end, the authorship policy aims to include the maximum number of researchers possible, ensuring fair representation across participating centres. For each study, the principal investigator will propose the list of authors, which must be reviewed and approved by the Scientific Committee prior to submission—this applies to both journal publications and conference presentations. The order of authorship will be based on each contributor's relative involvement in the project, including patient inclusion, provision of biological samples (if applicable), study design, data analysis, and manuscript drafting. The Scientific Secretariat will maintain an up-to-date contact list of principal investigators and collaborators at each centre, along with records of patient recruitment by study. In all scientific outputs, the final author will be followed by the phrase “on behalf of the NATURCEL registry”. Further details can be found in the corresponding SOP.
Ethical and regulatory frameworkThe NATURCEL registry has been approved by a Clinical Research Ethics Committee in accordance with current legislation (Biomedical Research Law 14/2007) (Hospital Universitari MútuaTerrassa; Code: P/25-076//; date: May 16, 2025) and has been registered with ClinicalTrials.gov (NCT07070596). The registry will be constructed in accordance with the principles established in the Declaration of Helsinki (latest version: Helsinki, Finland, October 2024) and the Good Clinical Practice guidelines. In relation to the study data, we will follow the provisions of Law 5/1992 (Article 11.8, RD 561/1993), the European Data Protection Directive (95/46/EC), the General Data Protection Regulation (GDPR, Regulation (EU) 2016/679), the Organic Law 3/2018, of 5 December, on the Protection of Personal Data and Guarantee of Digital Rights (LOPDGDD), and Law 14/2007 on Biomedical Research.
All the data collected in the registry will be used exclusively for scientific research purposes. The principal investigators are committed to disseminating the scientific findings derived from the registry. Researchers involved in the project will ensure strict confidentiality to protect the personal and family privacy of all participants (Article 16.4, RD 561/1993). Furthermore, all necessary technical and organizational measures will be implemented to prevent unauthorized access to the data.
FundingThis registry is supported by a combination of public and private funding sources, including scientific societies, patient associations, and competitive research grants. Additional resources required for the ongoing maintenance and updating of the registry, as well as for supporting the Scientific Secretariat, may be obtained through funding from the pharmaceutical and food industries. Such funding will be accepted only under strict conditions, as described in the corresponding SOP. Interested parties may request this information from the Scientific Secretariat. Financial contributions from pharmaceutical and food companies will be entirely altruistic and specifically designated to support research in the field of CD and other enteropathies. Any financial contribution or involvement from industry must be explicitly disclosed in scientific publications, conference abstracts, public presentations, and other dissemination materials derived from the corresponding projects, in accordance with current regulations on scientific integrity, transparency, and conflicts of interest.
ConclusionsThe NATURCEL registry provides a standardized, multicentre, prospective data repository for CD, gluten-related disorders and noncoeliac enteropathies. Its collaborative framework and rigorous methodology support a wide range of scientific goals, including epidemiological surveillance, refinement of diagnostic and therapeutic strategies, and outcome assessment.
With the planned integration of a biobank, NATURCEL is expected to facilitate translational research and strengthen evidence-based practices. As it evolves, the registry is expected to play a pivotal role in standardizing and optimizing diagnostic algorithms, patient management, and informing clinical guidelines in gastroenterology.
Author contributionsThe initial project was drafted by Dr. Albert Martín and Dr. Maria Esteve from Hospital Universitari Mútua Terrassa, with collaborative review by Dr. Beatriz Arau, Dr. Carme Ferrer, Dra. Carme Loras and Dr. Roger Garcia-Puig from the same institution. The REDCap database was designed by Emma Sudrià (Fundació Docència i Recerca Mútua Terrassa). Methodological advice in immunology was provided by Dr. Anna Carrasco (Hospital Universitari Mútua Terrassa) and Mireia Fonolleda (Immunology Department, Catlab). A review of variables related to nutrition, diet, and adherence to a gluten-free diet was conducted by dietitian Montse Ibarra (Hospital Universitari Mútua Terrassa). The assessment of the project's applicability in the primary care setting was carried out by Dr. Iván Villar-Balboa (Primary Care Centre Florida Sud). Methodological support, design, and management of sample preservation for the development of a biobank of patients with CD and noncoeliac enteropathies were provided by Dr. Azucena Salas (August Pi i Sunyer Biomedical Research Institute—IDIBAPS, Hospital Clínic, Barcelona). Dr. Sebastià Videla (Clinical Pharmacology Department, Hospital Universitari Germans Trias i Pujol) provided expert methodological advice on the design and development of clinical research procedures related to this registry. External review of the database and methodological validation of the variable collection system were carried out by Dr. Gemma Ibáñez (Hospital Universitari de Bellvitge), Dr. Sabela Carballal (Hospital Clínic de Barcelona), and Dr. Montserrat Planella (Hospital Universitari Arnau de Vilanova). All the authors reviewed and approved the final version of the protocol.
Conflicts of interestA. Martín-Cardona has received financial support for conference attendance, scientific educational activities, and research support from AbbVie, Biogen, Faes Farma, Ferring, Janssen, MSD, Pfizer, Takeda, Dr. Falk Pharma, Lilly, Tillotts, and Grupo Juste.
B. Arau has received financial support for conference attendance and scientific educational activities from Ferring, AbbVie, Faes Farma, Ferring, Jannsen, MSD, Pfizer, Takeda, Dr. Falk Pharma, and Tillotts.
R. Garcia-Puig has received financial support for conference attendance, scientific educational activities, and research support from Abbott, Ferrer, Italfarmaco, Dr. Falk Pharma, Mead Johnson Nutrition, Nestlé Nutrition, Nutribén, Ordesa, and Sanofi.
M. Ibarra has received financial support for conference attendance, scientific educational activities, and research support from Nestlé S.A., Abbott Laboratories, Fresenius SE & Co. KGaA and Nutrisens.
M Planella has received financial support for conference attendance and scientific educational activities from Ferring, AbbVie, Jannsen, MSD, Pfizer, Takeda, Laboratorios Rubió and Casen Recordati.
A. Salas has received grants from Takeda, Roche, Nestle, Pfizer, Genentech, AbbVie, GSK, Scipher Medicine, Alimentiv, Inc, Boehringer Ingelheim and Agomab; received consulting or talking fees from Lilly, Johnson & Johnson, Genentech, GSK, Pfizer, Galapagos, AdBio Partners, HotSpot Therapeutics, Alimentiv, Nestle, GoodGut and Agomab.
Carme Loras has received a speaking and consultant fee from Boston Scientific, and consultant fee for FujiFilm.
M. Esteve has received financial support for conference attendance and research support from Abbvie, Faes Farma, Ferring, Janssen, Pfizer, Takeda, and Tillotts.
The remaining authors report no conflicts of interest.
This project is dedicated to the memory of Dr. Fernando Fernández Bañares, who left us too soon. Dr. Fernández Bañares played a pivotal role in the conception of the local CD registry at the Hospital Universitari MútuaTerrassa. We are confident that he would have been deeply enthusiastic to see his efforts expanded into a prospective multicentre registry such as the present one. His contributions to science and his dedication to the study of CD and microscopic colitis were very relevant and left a significant mark in the field. He was a great doctor, an excellent researcher and an exemplary mentor.
