Diagnostic Delay of Celiac Disease in Childhood.

Importance: The extent and factors associated with risk of diagnostic delay in pediatric celiac disease (CD) are poorly understood. Objectives: To investigate the diagnostic delay of CD in childhood, and to assess factors associated with this delay. Design, Setting, and Participants: Multicenter, retrospective, cross-sectional study (2010-2019) of pediatric (aged 0-18 years) patients with CD from 13 pediatric tertiary referral centers in Italy. Data were analyzed from January to June 2023. Main Outcomes and Measures: The overall diagnostic delay (ie, the time lapse occurring from the first symptoms or clinical data indicative of CD and the definitive diagnosis), further split into preconsultation and postconsultation diagnostic delay, were described. Univariable and multivariable linear regression models for factors associated with diagnostic delay were fitted. Factors associated with extreme diagnostic delay (ie, 1.5 × 75th percentile) and misdiagnosis were assessed. Results: A total of 3171 patients with CD were included. The mean (SD) age was 6.2 (3.9) years; 2010 patients (63.4%) were female; and 10 patients (0.3%) were Asian, 41 (1.3%) were Northern African, and 3115 (98.3%) were White. The median (IQR) overall diagnostic delay was 5 (2-11) months, and preconsultation and postconsultation diagnostic delay were 2 (0-6) months and 1 (0-3) month, respectively. The median (IQR) extreme overall diagnostic delay (586 cases [18.5%]) was 11 (5-131) months, and the preconsultation and postconsultation delays were 6 (2-120) and 3 (1-131) months, respectively. Patients who had a first diagnosis when aged less than 3 years (650 patients [20.5%]) showed a shorter diagnostic delay, both overall (median [IQR], 4 [1-7] months for patients aged less than 3 years vs 5 [2-12] months for others) and postconsultation (median [IQR], 1 [0-2] month for patients aged less than 3 years vs 2 [0-4] months for others). A shorter delay was registered in male patients, both overall (median [IQR], 4 [1-10] months for male patients vs 5 [2-12] months for female patients) and preconsultation (median [IQR], 1 [0-6] month for male patients vs 2 [0-6] months for female patients). Family history of CD was associated with lower preconsultation delay (odds ratio [OR], 0.59; 95% CI, 0.47-0.74) and lower overall extreme diagnostic delay (OR, 0.75; 95% CI, 0.56-0.99). Neurological symptoms (78 patients [21.5%]; OR, 1.35; 95% CI, 1.03-1.78), gastroesophageal reflux (9 patients [28.1%]; OR, 1.87; 95% CI, 1.02-3.42), and failure to thrive (215 patients [22.6%]; OR, 1.62; 95% CI, 1.31-2.00) showed a more frequent extreme diagnostic delay. A previous misdiagnosis (124 patients [4.0%]) was more frequently associated with gastroesophageal reflux disease, diarrhea, bloating, abdominal pain, constipation, fatigue, osteopenia, and villous atrophy (Marsh 3 classification). Conclusions and Relevance: In this cross-sectional study of pediatric CD, the diagnostic delay was rather short. Some factors associated with risk for longer diagnostic delay and misdiagnosis emerged, and these should be addressed in future studies.

New and old criteria for diagnosing celiac disease: do they really differ? A retrospective observational study.

BACKGROUND: The aim of this study is to compare two groups of celiac patients: the first one, in which diagnosis was based on a "biopsy sparing" approach according to the 2012 ESPGHAN criteria, and the second one, based on the biopsy approach like the one of the 1991 Revised Criteria, in order to find relevant difference for sex, M/F ratio, age at diagnosis, clinical features at the onset, presence and prevalence of concomitant autoimmune disorders. METHODS: Our study involves 61 patients having the Celiac Disease (CD) onset from February 2013 to February 2020. The 32 patients who received diagnosis according "biopsy sparing" criteria were enrolled in group (1) The 29 patients who received diagnosis by duodenal biopsy were enrolled in group (2) Prevalence of comorbidities was analysed through chi-square test. RESULTS: In group 1 the prevalence of comorbidities such as Insulin-Dependent Diabetes Mellitus (IDDM) and thyroiditis was of 53%, while in group 2 it was only of 24%. Analysing the IDDM prevalence between the two groups we found a relevant difference. At the same time, the prevalence of thyroiditis was also significantly different. In group 1, male patients, in particular, would seem to have a higher incidence of CD related autoimmune disorders. CONCLUSIONS: An increased prevalence of IDDM, thyroiditis and juvenile idiopathic arthritis (JIA) in the first group would show that the "biopsy sparing" approach could expose patients to a greater length of disease activity that might be responsible for the onset of such comorbidities. Further studies should be carried out on more numerous samples of patients in order to confirm or not these data.

Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet.

BACKGROUND: The gluten-free diet (GFD) has limitations, and there is intense research in the development of adjuvant therapies. AIM: To examine the effects of orally administered Aspergillus niger prolyl endopeptidase protease (AN-PEP) on inadvertent gluten exposure and symptom prevention in adult celiac disease (CeD) patients following their usual GFD. METHODS: This was an exploratory, double-blind, randomized, placebo-controlled trial that enrolled CeD patients on a long-term GFD. After a 4-wk run-in period, patients were randomized to 4 wk of two AN-PEP capsules (GliadinX; AVI Research, LLC, United States) at each of three meals per day or placebo. Outcome endpoints were: (1) Average weekly stool gluten immunogenic peptides (GIP) between the run-in and end of treatments and between AN-PEP and placebo; (2) celiac symptom index (CSI); (3) CeD-specific serology; and (4) quality of life. Stool samples were collected for GIP testing by ELISA every Tuesday and Friday during run-ins and treatments. RESULTS: Forty patients were randomized for the intention-to-treat analysis, and three were excluded from the per-protocol assessment. Overall, 628/640 (98.1%) stool samples were collected. GIP was undetectable (< 0.08 µg/g) in 65.6% of samples, and no differences between treatment arms were detected. Only 0.5% of samples had GIP concentrations sufficiently high (> 0.32 µg/g) to potentially cause mucosal damage. Median GIP concentration in the AN-PEP arm was 44.7% lower than in the run-in period. One-third of patients exhibiting GIP > 0.08 µg/g during run-in had lower or undetectable GIP after AN-PEP treatment. Compared with the run- in period, the proportion of symptomatic patients (CSI > 38) in the AN-PEP arm was significantly lower (P < 0.03). AN-PEP did not result in changes in specific serologies. CONCLUSION: This exploratory study conducted in a real-life setting revealed high adherence to the GFD. The AN-PEP treatment did not significantly reduce the overall GIP stool concentration. However, given the observation of a significantly lower prevalence of patients with severe symptoms in the AN-PEP arm, further clinical research is warranted.

Monitoring coeliac disease in 2024, time to change practice?

PURPOSE OF REVIEW: Persistent villous atrophy is associated with morbidity in coeliac disease and most commonly due to ongoing gluten ingestion. Current methods for assessing gluten exposure and persisting villous atrophy include dietary questionnaires and repeat duodenal biopsy, which have limited accuracy or are invasive. This review discusses adjunctive and/or novel tests that could be used to overcome these challenges. RECENT FINDINGS: Small bowel capsule endoscopy is well tolerated and helps to evaluate for persisting villous atrophy and importantly, complications associated with coeliac disease. Testing for urinary and/or stool gluten immunogenic peptides may help identify recent gluten exposure, but further studies are still warranted to evaluate the accuracy and applicability of this approach. Measuring spikes in circulating Interleukin-2 following gluten challenge has shown promise for coeliac disease diagnosis, and thus may serve as a useful confirmatory test in those with persisting symptoms but provides no information on mucosal inflammation. No specific gut microbial signature has been identified in coeliac disease; however, studies have shown a reduced microbial diversity in active disease, which with future refinement may prove clinically useful. SUMMARY: There is no evidence to support alternative methods for assessing persisting villous atrophy in coeliac disease over performing an up-to-date duodenal biopsy. Monitoring for adherence to a gluten-free diet remains clinically challenging and should be a priority for future research.

Path Towards Biopsy-Free Diagnosis of Celiac Disease in Pediatric Patients.

BACKGROUND: Laboratory testing for celiac disease in pediatric patients integrates serology, genetic susceptibility and duodenal biopsy examination. The 2023 American College of Gastroenterology guidelines recommend a biopsy-free approach in pediatric patients utilizing tissue transglutaminase antibody titers >10 times upper limit of normal and subsequent endomysial antibody seropositivity as sufficient for diagnosis. The objective of this study is to assess the diagnostic accuracy of biopsy-free approach at our pediatric hospital. METHODS: We conducted a retrospective study involving pediatric patients who underwent biopsy for diagnostic confirmation of celiac disease between May 2019 and May 2023. For these patients, the tissue transglutaminase and endomysial antibody test results were retrieved and performance of biopsy-free approach was assessed using the duodenal histology as the gold standard for celiac disease diagnosis. RESULTS: Tissue transglutaminase antibody titers >10 times upper limit of normal alone demonstrated a positive predictive value of 99% for identifying celiac disease in children. Although endomysial antibody testing is underutilized at our center, its inclusion further improved the predictability to 100 %. CONCLUSION: Positive predictive value of tissue transglutaminase antibody titers >10 times upper limit of normal is sufficiently high for celiac disease diagnosis in children and may allow for deferral of duodenal biopsy at diagnosis.

Prevalence and Predictors of Celiac Disease in Children With Constipation.

OBJECTIVE: To determine the prevalence of celiac disease and its predictors in children with constipation. METHODS: A hospital-based cross-sectional comparative study was conducted between November, 2018 to April, 2020. Children aged 1-12 years were screened for the presence of constipation as per ROME IV criteria and designated as cases. Age and sex matched healthy children with normal bowel habits were enrolled as comparison group. Participants underwent a detailed history and examination, and were screened for celiac disease by estimating serum anti-tissue transglutaminase IgA antibody levels (tTG-IgA). Upper gastrointestinal endoscopy and duodenal biopsy were performed in all participants who tested positive on screening (serum tTG-IgA ≥ 20 U/mL). The prevalence of celiac disease and associated factors were compared between the two groups. RESULTS: A total of 460 children (230 in each group) with mean (SD) age 64.08 (37.12) months were enrolled. Twenty-one (4.6%) children screened positive for anti tTG antibodies, among these 15 (75%) children had biopsy features suggestive of celiac disease (Marsh grade III). Children with constipation had significantly higher prevalence of celiac disease (5.65% vs 0.87%, P = 0.004) compared to children without constipation. Wasting and stunting were significantly associated with celiac disease in constipated children (P < 0.001). CONCLUSION: Children with constipation and associated growth failure have a high prevalence of celiac disease.

[Chronic diarrhoea: when is it celiac disease and when not?] / Chronische Durchfälle: Wann ist es eine Zöliakie und wann nicht?

Patients who come to clinical consultation for chronic diarrhoea (i.e., diarrhoea lasting for more than four weeks) may suffer from a wide range of clinical conditions. The possible diagnoses range from a misunderstanding of what can be considered normal and what pathological in terms of daily bowel movements, to a severe malabsorption syndrome. Since the list of possible causes of chronic diarrhoea can be puzzling, the physician's approach needs to be systematic and structured in order to allow the correct diagnosis and treatment. This article proposes an algorithm for the diagnosis of chronic diarrhoea and discusses in detail the key clinical aspects of celiac disease, which is considered a paradigmatic disease as regards chronic malabsorptive diarrhoea.

Universal screening for early detection of chronic autoimmune, metabolic and cardiovascular diseases in the general population using capillary blood (UNISCREEN): low-risk interventional, single-centre, pilot study protocol.

INTRODUCTION: Chronic autoimmune (type 1 diabetes and coeliac disease) and metabolic/cardiovascular (type 2 diabetes, dyslipidaemia, hypertension) diseases are highly prevalent across all age ranges representing a major public health burden. Universal screening for prediction/early identification of these conditions is a potential tool for reducing their impact on the general population. The aim of this study is to assess whether universal screening using capillary blood sampling is feasible at a population-based level. METHODS AND ANALYSIS: This is a low-risk interventional, single-centre, pilot study for a population-based screening programme denominated UNISCREEN. Participants are volunteers aged 1-100 who reside in the town of Cantalupo (Milan, Italy) undergoing: (1) interview collecting demographics, anthropometrics and medical history; (2) capillary blood collection for measurement of type 1 diabetes and coeliac disease-specific autoantibodies and immediate measurement of glucose, glycated haemoglobin and lipid panel by point-of-care devices; (3) venous blood sampling to confirm autoantibody-positivity; (4) blood pressure measurement; (5) fulfilment of a feasibility and acceptability questionnaire. The outcomes are the assessment of feasibility and acceptability of capillary blood screening, the prevalence of presymptomatic type 1 diabetes and undiagnosed coeliac disease, distribution of glucose categories, lipid panel and estimate of cardiovascular risk in the study population. With approximately 3000 inhabitants, the screened population is expected to encompass at least half of its size, approaching nearly 1500 individuals. ETHICS AND DISSEMINATION: This protocol and the informed consent forms have been reviewed and approved by the San Raffaele Hospital Ethics Committee (approval number: 131/INT/2022). Written informed consent is obtained from all study participants or their parents if aged <18. Results will be published in scientific journals and presented at meetings. CONCLUSIONS: If proven feasible and acceptable, this universal screening model would pave the way for larger-scale programmes, providing an opportunity for the implementation of innovative public health programmes in the general population. TRIAL REGISTRATION NUMBER: NCT05841719.

Status of vitamins and minerals in children with screening-identified celiac disease: A case-control study.

OBJECTIVES: Micronutrient deficiencies characterize classical "late-diagnosed" celiac disease (CeD). This study aimed to identify the prevalence of micronutrient deficiencies among children with "early-diagnosed" screening-identified CeD to determine the clinical value of routine testing for deficiencies in those patients. METHODS: A case-control study was conducted on screening-identified CeD patients diagnosed during a mass screening study (84 patients, mean age 11.3 ± 2.6 years). The controls (443 children, mean age 10.8 ± 2.5 years) were negative for celiac disease serological screening. Hemoglobin, serum levels of iron, ferritin, folate, vitamin B12, vitamin A, vitamin E, 25-OH vitamin D, zinc, and selenium were measured. RESULTS: The mean serum levels of hemoglobin, iron, ferritin, vitamin D, zinc, copper, and selenium were significantly lower in CeD patients than in healthy controls (hemoglobin 12.56 vs. 13.02 g/dL [p = 0.04]; iron 10.61 vs. 17.6 µmol/L [p < 0.001], ferritin 25.7 vs. 48.3 µg/L [p < 0.001], vitamin D 29.1 vs. 37.5 nmol/L, zinc 11.9 vs. 21.7 µmol/L, copper 18.9 vs. 32.5 µmol/L, selenium 1.04 vs. 1.36 µmol/L; p < 0.001). Patients with celiac and severe intestinal damage (Marsh IIIb and IIIc) had significantly lower serum ferritin and vitamin A levels than patients with mild intestinal damage (Marsh II and IIIa) (ferritin 15 vs. 22 µg/L, p < 0.025; vitamin A 0.85 vs. 1.35 µmol/L, p = 0.007). CONCLUSION: Micronutrient deficiencies are still detectable in "early-diagnosed" screening-identified CeD cases, a clinically relevant result that strongly supports efforts for screening and early diagnosis of CeD.

A Dedicated Celiac Disease Program Improves Celiac Quality Care Metrics and Short-Term Outcomes in Real Life.

BACKGROUND AND AIMS: Dedicated multidisciplinary programs in gastroenterology are emerging with the goal to improve care. There is little information about the effects of a celiac disease program on disease-related quality care metrics and outcomes. We aimed to compare quality care metrics, symptom resolution, and serological response among patients diagnosed and treated in a celiac disease program with a standard of care cohort. METHODS: We performed a retrospective cohort study with adult celiac disease patients. We divided patients into two groups: celiac disease patients treated in our program and those treated by gastroenterologists not affiliated with the program (standard of care). We abstracted data from electronical medical records and compared frequency at which guideline-driven quality care metrics were obtained, assessed symptom resolution, and serological response based on IgA anti-tissue transglutaminase levels. RESULTS: We included 340 patients, 120 in the celiac disease program (89 women) and 220 (166 women) in the standard of care. Frequency of quality care metrics implementation in program patients was significantly greater for all variables (p < 0.0005). Diarrhea resolved in 38/46 (82.6%) in the CD program and 63/98 (64.2%) in the standard of care after starting a gluten-free diet (p = .025); bloating also resolved significantly more often in the former (26/34) than the latter (31/58; p = 0.03). Otherwise, there were no significant differences in resolution of clinical symptoms or serological response. CONCLUSION: A celiac disease program improves celiac-related quality care metrics and may improve outcomes such as diarrhea resolution compared to standard of care.

Prevalence of coeliac disease in patients with systemic lupus erythematosus: a systematic review and meta-analysis.

BACKGROUND: There is some evidence of a higher prevalence of coeliac disease (CD) among patients with SLE than in the general population. However, the prevalence estimates vary substantially. OBJECTIVE: To investigate the prevalence of CD among patients with SLE through systematic review and meta-analysis. METHODS: We performed searches in the databases of Medline, Embase, Cochrane and Web of Science Core Collection between 1 January 1990 and 9 July 2023. A total of 2053 publications were rendered in the searches, of which 68 were reviewed in full text and 14 included in the analyses. Primary analysis estimated the pooled prevalence of biopsy-verified CD in patients with SLE. In the secondary analysis, the prevalence of serological markers indicative of CD was investigated. The quality of studies was appraised using the Joanna Briggs Institute Critical Appraisal Tool. We conducted meta-regression analyses to investigate associations between the prevalence of CD in individuals with SLE and publication year, study population size, CD prevalence in the general population, proportion of females and quality assessment score. RESULTS: A total of 14 studies met the inclusion criteria, of which 11 were included in the primary analysis of biopsy-verified CD. Among 1238 patients with SLE, 14 had CD. The weighted pooled prevalence of CD was 0.7% (95% CI 0.0 to 1.8). The weighted pooled prevalence of CD serological markers in 1063 patients with SLE was 3.7% (95% CI 1.4 to 6.7). In meta-regression analyses, no associations between CD prevalence and study characteristics, demographics and quality assessment scores were found. CONCLUSIONS: In this meta-analysis, we found a weighted pooled prevalence of biopsy-verified CD in patients with SLE comparable with the prevalence in the general population. Our findings do not support routine screening for CD in patients with SLE. However, individual screening could be considered in cases of clinical suspicion and additional risk factors for CD. PROSPERO REGISTRATION NUMBER: CRD42022339594.

Prevalence of celiac-related antibodies and its impact on metabolic control in Egyptian children with type 1 diabetes mellitus.

OBJECTIVE: The simultaneous presence of celiac disease and type 1 diabetes (T1DM) is coupled with more hazards of comorbidities and complications. This current study aimed to screen for celiac disease in Egyptian children with type 1 diabetes and evaluate its impact on glycemic control. METHODS: A cross-sectional study was verified with 200 Egyptian children diagnosed with T1DM and having a diabetic duration of less than five years. Testing for anti-tissue transglutaminase IgA (tTG-IgA), anti-tissue transglutaminase IgG (tTG-IgG), anti-Endomysial IgA (EMA), and Hb A1c levels were done. RESULTS: The serological screening revealed that 11 cases (5.5%) tested positive; 8 children with T1DM (4.0%) showed tTG-IgA antibodies ≥ 10 times the upper limit of normal (ULN) with at least one symptom; and 3 cases (1.5%) had levels between 20 and 50 IU/ml (considering a cut-off point of 10 U/ML for positive results). Intestinal biopsy was performed for these three cases, with one case detected to have subtotal villous atrophy, resulting in an overall prevalence of celiac disease in T1DM as 4.5%. Children with positive screening exhibited a higher insulin dose, a higher HbA1c, an increased frequency of hypoglycemic attacks, and recurrent DKA compared to negative cases. A negative correlation was detected between tTG-IgA antibodies with height Z score and hemoglobin level, while a positive correlation was found between tTG-IgA antibodies and HbA1c level. CONCLUSION: Undiagnosed celiac disease in children with T1DM negatively impacted metabolic control and affected their general health.

Prevalence and Predictive Factors for Celiac Disease in Children With Type 1 Diabetes: Whom and When to Screen? A Nationwide Longitudinal Cohort Study of Swedish Children.

OBJECTIVE: To examine the prevalence and predictive factors for celiac disease (CD) after a diagnosis of type 1 diabetes (T1D) in children and adolescents, to improve the current screening guidelines. RESEARCH DESIGN AND METHODS: The association between sex, age at T1D diagnosis, HLA, and diabetes autoantibodies, and a diagnosis of CD was examined in 5,295 children with T1D from the Better Diabetes Diagnosis study in Sweden. RESULTS: The prevalence of biopsy-proven CD was 9.8%, of which 58.2% already had a CD diagnosis before or at T1D onset. Almost all, 95.9%, were diagnosed with CD within 5 years after the T1D diagnosis. Younger age at the T1D diagnosis and being homozygote for DQ2 increased the risk of CD after T1D, but neither sex nor diabetes-related autoantibodies were associated with the risk. CONCLUSIONS: Age at and time after diabetes diagnosis should be considered in screening guidelines for CD in children with T1D.

Validation of red flags in the workup of children with long-term abdominal pain - A retrospective study.

AIM: To evaluate red flags as an instrument to distinguish other medical conditions from Functional Gastrointestinal Disorders (FGID) in children with long-term abdominal pain. METHODS: In a retrospective follow-up, data were collected from 317 children who were referred for medical assessment due to long-term abdominal pain between the years 2011 and 2012 at three Swedish paediatric open clinic units in Sweden. Throughout the review of medical records, any documented red flags at the primary consultation and finally set diagnosis after 1 year were noted for all cases. RESULTS: A non-FGID disease was diagnosed in 32 cases (10.1%). The sensitivity of red flags to predict inflammatory bowel disease (IBD) was 100% and the specificity 64.1%. The sensitivity of red flags to predict celiac disease was 45.5% and the specificity 63.7%. The sensitivity of red flags to predict any non-FGID disease was 59.4%, and the specificity was 65.6%. CONCLUSION: The use of red flags is a sensitive instrument to identify patients with IBD but less applicable when identifying celiac disease and other organic diseases. Specificity is generally low and future biomarkers for assessing children with long-term abdominal pain is needed.

Reduced expression of Ankyrin-G and E-cadherin in duodenal mucosal biopsy of subjects with celiac disease.

Confirmatory diagnosis of celiac disease (CD) include histopathology of duodenal biopsy and tissue trans-glutaminase-IgA. Identification of tissue-specific histological markers is warranted to improve the diagnosis. A genetic study in CD identified the association of ankyrin-G that connects E-cadherin with ß2-spectrin in epithelial cells of the duodenal tissue. We attempted to investigate the differential expression of ankyrin-G, E-cadherin and ß2-spectrin in duodenal biopsy of CD subjects compared to non-CD controls. Duodenal tissue was collected from 83 study participants, of which 50 were CD, and 33 were non-CD controls. Whole RNA was isolated from 32 CD and 23 non-CD controls from available tissues, and differential mRNA expression was measured using real-time PCR. Tissue sections from 18 CD cases and 10 non-CD controls were immunostained using monoclonal antibodies. Tissue immunohistochemistry were evaluated for differential expression and pattern of expression. RT-PCR revealed significantly reduced expression of ankyrin-G (fold change=0.63; p=0.03) and E-cadherin (fold change=0.50; p=0.02) among CD subjects compared to non-CD controls. Tissue immunohistochemistry confirmed the reduced expression of ankyrin-G and E-cadherin in CD. Differential expression is grossly limited within the outer columnar epithelial cell layer. Expression fold change of E-cadherin was seen to partially correlate with the serum tTG level (r=0.4; p=0.04). In CD, reduced expression of two key cytoskeletal proteins (ankyrin-G and E-cadherin) in duodenum mucosa was observed, which indicates its implication in disease biology and could be tested as a tissue-specific biomarker for CD. Functional studies may unravel the specific contribution of these proteins in CD pathophysiology.

CD, or not CD, that is the question: a digital interobserver agreement study in coeliac disease.

OBJECTIVE: Coeliac disease (CD) diagnosis generally depends on histological examination of duodenal biopsies. We present the first study analysing the concordance in examination of duodenal biopsies using digitised whole-slide images (WSIs). We further investigate whether the inclusion of immunoglobulin A tissue transglutaminase (IgA tTG) and haemoglobin (Hb) data improves the interobserver agreement of diagnosis. DESIGN: We undertook a large study of the concordance in histological examination of duodenal biopsies using digitised WSIs in an entirely virtual reporting setting. Our study was organised in two phases: in phase 1, 13 pathologists independently classified 100 duodenal biopsies (40 normal; 40 CD; 20 indeterminate enteropathy) in the absence of any clinical or laboratory data. In phase 2, the same pathologists examined the (re-anonymised) WSIs with the inclusion of IgA tTG and Hb data. RESULTS: We found the mean probability of two observers agreeing in the absence of additional data to be 0.73 (±0.08) with a corresponding Cohen's kappa of 0.59 (±0.11). We further showed that the inclusion of additional data increased the concordance to 0.80 (±0.06) with a Cohen's kappa coefficient of 0.67 (±0.09). CONCLUSION: We showed that the addition of serological data significantly improves the quality of CD diagnosis. However, the limited interobserver agreement in CD diagnosis using digitised WSIs, even after the inclusion of IgA tTG and Hb data, indicates the importance of interpreting duodenal biopsy in the appropriate clinical context. It further highlights the unmet need for an objective means of reproducible duodenal biopsy diagnosis, such as the automated analysis of WSIs using artificial intelligence.