Nomenclature and diagnosis of seronegative coeliac disease and chronic non-coeliac enteropathies in adults: the Paris consensus

Clinical manifestations, diagnosis and long-term prognosis of adult autoimmune enteropathy: Experience from Peking Union Medical College Hospital

BACKGROUND

Autoimmune enteropathy (AIE) is a rare disease whose diagnosis and long-term prognosis remain challenging, especially for adult AIE patients.

AIM

To improve overall understanding of this disease's diagnosis and prognosis.

METHODS

We retrospectively analyzed the clinical, endoscopic and histopathological characteristics and prognoses of 16 adult AIE patients in our tertiary medical center between 2011 and 2023, whose diagnosis was based on the 2007 diagnostic criteria.

RESULTS

Diarrhea in AIE patients was characterized by secretory diarrhea. The common endoscopic manifestations were edema, villous blunting and mucosal hyperemia in the duodenum and ileum. Villous blunting (100%), deep crypt lymphocytic infiltration (67%), apoptotic bodies (50%), and mild intraepithelial lymphocytosis (69%) were observed in the duodenal biopsies. Moreover, there were other remarkable abnormalities, including reduced or absent goblet cells (duodenum 94%, ileum 62%), reduced or absent Paneth cells (duodenum 94%, ileum 69%) and neutrophil infiltration (duodenum 100%, ileum 69%). Our patients also fulfilled the 2018 diagnostic criteria but did not match the 2022 diagnostic criteria due to undetectable anti-enterocyte antibodies. All patients received glucocorticoid therapy as the initial medication, of which 14/16 patients achieved a clinical response in 5 (IQR: 3-20) days. Immunosuppressants were administered to 9 patients with indications of steroid dependence (6/9), steroid refractory status (2/9), or intensified maintenance medication (1/9). During the median of 20.5 months of follow-up, 2 patients died from multiple organ failure, and 1 was diagnosed with non-Hodgkin's lymphoma. The cumulative relapse-free survival rates were 62.5%, 55.6% and 37.0% at 6 months, 12 months and 48 months, respectively.

CONCLUSION

Certain histopathological findings, including a decrease or disappearance of goblet and Paneth cells in intestinal biopsies, might be potential diagnostic criteria for adult AIE. The long-term prognosis is still unsatisfactory despite corticosteroid and immunosuppressant medications, which highlights the need for early diagnosis and novel medications.

Flow cytometry for the assessment and monitoring of aberrant intraepithelial lymphocytes in non-responsive celiac disease and non-celiac enteropathies

BACKGROUND

Few data are available on flow cytometry (FC) for monitoring intraepithelial lymphocytes (IELs) in refractory celiac disease (RCD), non-responsive celiac disease (NRCD), and non-celiac enteropathies (NCEs).

AIMS

1) To investigate the significance of monitoring IELs immunophenotype with FC in patients with NRCD, RCD and NCEs; 2) to evaluate FC concordance with immunohistochemistry (IHC) and γ-TCR clonality analysis.

METHODS

Patients investigated between January-2012 and February-2023 were divided into two groups: 1)confirmed RCD or NRCD being investigated for persistent symptoms and suspected complications of celiac disease (CD); 2)NCEs lacking clinical/histological response. Clinical/molecular features and outcomes were retrospectively collected and analysed according to presence/absence of aberrant IELs on FC (cut-off≥20 % CD103+sCD3-CD8-iCD3+ IELs).

RESULTS

52 patients (18 RCD,21 NRCD,13 NCEs; 38F, 55±13 years; median follow-up 30 months, IQR 2-58) underwent 100 FC IELs determinations. 22/52 had ≥2 FC determinations and IEL phenotype remained unchanged over time in all them (κ=1.00). Aberrant IEL phenotype in CD was associated with increased mortality (HR 4.2, 95 % CI 1.5-11.9, p < 0.01). No patients with NCEs had an aberrant IEL phenotype at FC, although 3/13 developed lymphoma and 4/13 died. Concordance of FC was fair with both IHC (κ=0.40) and γ-TCR clonality analysis (κ=0.22).

CONCLUSION

FC is accurate for assessing and monitoring IEL phenotype and providing important prognostic information in celiac patients. Further study is needed on its role in NCEs.

Intraepithelial Lymphogram in the Diagnosis of Celiac Disease in Adult Patients: A Validation Cohort

BACKGROUND

Celiac disease is a gluten-related pathology, highly prevalent and heterogeneous in its clinical presentation, which leads to delays in diagnosis and misdiagnosis. The analysis of duodenal intraepithelial lymphocytes (IELs) by flow cytometry (lymphogram) is emerging as a discriminative tool in the diagnosis of various forms of celiac disease (CD).

AIMS

The aim of this study was to validate IEL lymphogram performance in the largest adult series to our knowledge, in support of its use as a diagnostic tool and as a biomarker of the dynamic celiac process.

METHODS

This was a retrospective study including 768 adult patients (217 with active CD, 195 on a gluten-free diet, 15 potential CD patients, and 411 non-celiac controls). The IEL subset cut-off values were established to calculate the diagnostic accuracy of the lymphogram.

RESULTS

A complete celiac lymphogram profile (≥14% increase in T cell receptor [TCR]γδ IELs and simultaneous ≤4% decrease in surface-negative CD3 [sCD3-] IELs) was strongly associated with active and potential forms in over 80% of the confirmed patients with CD, whereas the remaining patients with CD had partial lymphogram profiles (≥14% increase in TCRγδ or ≤4% decrease in sCD3- IELs), with lower diagnostic certainty. None of these patients had a non-celiac lymphogram. Quantifying the TCRγδ versus sCD3- imbalance as a ratio (≥5) is a discriminative index to discard or suspect CD at diagnosis.

CONCLUSIONS

We have validated the IEL lymphogram's diagnostic efficiency (79% sensitivity, 98% specificity), with an LR+ accuracy of 36.2. As expected, the increase in TCRγδ IELs is a reliable marker for celiac enteropathy, while changes in sCD3- IEL levels throughout the dynamic CD process are useful biomarkers of mucosal lesions.

Predictors of Subsequent Celiac Disease Seropositivity in Patients Diagnosed with Duodenal Villus Atrophy on Upper Endoscopy

BACKGROUND

The diagnosis of celiac disease (CD) is based on positive IgA autoantibodies to tissue transglutaminase (TTG IgA) and confirmatory histopathology demonstrating duodenal villus atrophy (VA). Diagnostic challenges can occur when VA is found on duodenal biopsies in patients without prior CD serologies.

AIMS

To characterize the predictors of CD seropositivity in patients with VA on biopsy without prior CD serologies.

METHODS

We performed a retrospective cohort study of patients found to have duodenal VA on histopathology from 2010 to 2020 who did not have prior CD serologies measured and who had them checked after their biopsy. Patients with known or suspected CD prior to their duodenal biopsy were excluded.

RESULTS

Of 162 patients with VA and no prior CD serologies, 50 (31%) subsequently had an elevated TTG IgA consistent with CD. Patients with an elevated TTG IgA were more likely to be non-Hispanic (76% vs. 42%; p < 0.001), white (74% vs. 62%; p = 0.025), and younger (ages 18-39, 26% vs. 12%; p = 0.002) compared to those with a negative TTG IgA. By contrast, these patients were less likely to present in middle adulthood (ages 40-59, 6% vs. 29%; p =  0.002). The most common identified etiologies of seronegative VA were Crohn's disease (13%), seronegative CD (8.9%), H. pylori infection (6.3%), tropical sprue (5.4%), and olmesartan-related enteropathy (3.6%).

CONCLUSION

Age and ethnicity may be helpful when stratifying the likelihood of CD in the absence of supporting serologies. A majority of patients (69%) diagnosed with VA without prior CD serologies have negative serologies, consistent with seronegative CD or the spectrum of non-celiac enteropathies for which further evaluation is needed.

Systematic review: Clinical phenotypes, histopathological features and prognosis of enteropathy due to angiotensin II receptor blockers

BACKGROUND

Although enteropathy due to angiotensin II receptor blockers (ARBs) has been known for over 10 years, clinicians' awareness of this condition is still low.

AIMS

To systematically review the literature about clinical phenotypes, distribution of mucosal changes throughout the gastrointestinal tract and prognosis of enteropathy due to ARBs.

METHODS

According to PRISMA guidelines, we searched PubMed and Embase for relevant articles up to November 6, 2023. We included full-text papers, letters, case reports and case series describing enteropathy due to ARBs. Patients were classified into subgroups based on endoscopic and histological findings of different regions of the gastrointestinal tract. The protocol was registered with Open Science Framework (https://doi.org/10.17605/OSF.IO/TK67C).

RESULTS

We included 94 articles reporting 183 cases (101 female, mean age at diagnosis 69 ± 10 years). The clinical picture at diagnosis was characterised by severe diarrhoea (97%) and weight loss (84%, median -13 kg), leading to hospital admission in 167 (95%) patients. Olmesartan (90%) was most frequently implicated. Villous atrophy (VA) was reported in 164/183 (89%) patients. One hundred and nine had only VA, 12 had pan-gastrointestinal involvement, 23 had VA and gastric involvement and 19 had VA and colon involvement (predominantly microscopic colitis). Outcomes were reported for 178/183 (97%) patients, who all recovered clinically on ARBs withdrawal. Histological recovery occurred in all 96 patients with VA at baseline who underwent follow-up duodenal biopsy.

CONCLUSIONS

Enteropathy due to ARBs is characterised by severe malabsorption often requiring hospital admission and can involve the entire gastrointestinal tract. Clinician awareness can lead to prompt diagnosis and excellent prognosis.

Diagnosis of Seronegative and Ultrashort Celiac Disease

In its conventional form, celiac disease (CeD) is characterized by both positive serology and flat villi in the duodenum, and is well known by gastroenterologists and general practitioners. The aim of this review was to shed light on 2 neglected and not yet well-defined celiac phenotypes, that is, seronegative and ultrashort CeD. Seronegative CeD can be suspected in the presence of flat villi, positive HLA-DQ2 and/or HLA-DQ8, and the absence of CeD antibodies. After ruling out other seronegative enteropathies, the diagnosis can be confirmed by both clinical and histologic improvements after 1 year of a gluten-free diet. Ultrashort CeD is characterized by the finding of flat villi in the duodenal bulb in the absence of mucosal damage in the distal duodenum and with serologic positivity. Data on the prevalence, clinical manifestations, histologic lesions, genetic features, and outcome of seronegative and ultrashort CeD are inconclusive due to the few studies available and the small number of patients diagnosed. Some additional diagnostic tools have been developed recently, such as assessing intestinal transglutaminase 2 deposits, flow cytometry technique, microRNA detection, or proteomic analysis, and they seem to be useful in the identification of complex cases. Further cooperative studies are highly desirable to improve the knowledge of these 2 still-obscure variants of CeD.

Myths and Facts about Food Intolerance: A Narrative Review

Most adverse reactions to food are patient self-reported and not based on validated tests but nevertheless lead to dietary restrictions, with patients believing that these restrictions will improve their symptoms and quality of life. We aimed to clarify the myths and reality of common food intolerances, giving clinicians a guide on diagnosing and treating these cases. We performed a narrative review of the latest evidence on the widespread food intolerances reported by our patients, giving indications on the clinical presentations, possible tests, and dietary suggestions, and underlining the myths and reality. While lactose intolerance and hereditary fructose intolerance are based on well-defined mechanisms and have validated diagnostic tests, non-coeliac gluten sensitivity and fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) intolerance are mainly based on patients' reports. Others, like non-hereditary fructose, sorbitol, and histamine intolerance, still need more evidence and often cause unnecessary dietary restrictions. Finally, the main outcome of the present review is that the medical community should work to reduce the spread of unvalidated tests, the leading cause of the problematic management of our patients.

Refractory celiac disease and its mimickers: a review on pathogenesis, clinical-pathological features and therapeutic challenges

Refractory celiac disease (RCD) and enteropathy-associated T-cell lymphoma (EATL) are rare, yet severe complications of celiac disease (CD). Over the last decades, several studies have addressed the biology and clinical-pathological features of such conditions, highlighting unique disease patterns and recurrent genetic events. Current classification proposals identify two forms of RCD, namely: (i) type 1 RCD (RCD-I), characterized by phenotypically normal intra-epithelial lymphocytes (IELs); and (ii) type 2 RCD (RCD-II), featuring phenotypically aberrant IELs. While RCD-I likely represents a gluten-independent dysimmune reaction against small bowel epithelial cells, RCD-II is better considered an in situ aggressive T-cell lymphoma, with high rates of progression to overt EATL. The diagnosis of RCD and EATL is often challenging, due to misleading clinical-pathological features and to significant overlap with several CD-unrelated gastro-intestinal disorders. Similarly, the treatment of RCD and EATL is an unmet clinical need for both gastroenterologists and hematologists. Moving from such premises, this review aims to provide a comprehensive view of RCD and EATL, specifically considering their pathogenesis and the many still open issues concerning their diagnosis and clinical management.

Persistent villous atrophy predicts development of complications and mortality in adult patients with coeliac disease: a multicentre longitudinal cohort study and development of a score to identify high-risk patients

OBJECTIVE

Persistent villous atrophy (pVA) in coeliac disease (CD) despite a gluten-free diet (GFD) has unclear meaning. We aimed to (i) study the relationship between pVA and long-term outcomes and (ii) develop a score to identify patients at risk of pVA.

DESIGN

This is a multicentre retrospective-prospective study consisting of a study cohort (cohort 1) and an external validation cohort (cohort 2) of patients with biopsy-proven CD diagnosed between 2000 and 2021. Cohort 1 was used to (i) compare long-term outcomes between patients with and without pVA (Marsh ≥3a) at follow-up biopsy and (ii) to develop a score to evaluate the risk of pVA, which was validated in cohort 2.

RESULTS

Of 2211 patients, 694 (31%) underwent follow-up duodenal biopsy and were included in the study cohort (491F, 44±16 years). 157/694 (23%) had pVA. Risk of complications (HR 9.53, 95% CI 4.77 to 19.04, p<0.001) and mortality (HR 2.93, 95% CI 1.43 to 6.02, p<0.01) were increased in patients with pVA. A 5-point score was developed and externally validated (receiver operating characteristic area under the curve 0.78, 95% CI 0.68 to 0.89) to stratify patients by risk of pVA: low (0-1 points, 5% pVA), intermediate (2 points, 16% pVA) and high (3-5 points, 73% pVA). Predictors for pVA used in the score were age at diagnosis ≥45 years (OR 2.01, 95% CI 1.21 to 3.34, p<0.01), classical pattern of CD (OR 2.14, 95% CI 1.28 to 3.58, p<0.01), lack of clinical response to GFD (OR 2.40, 95% CI 1.43 to 4.01, p<0.001) and poor GFD adherence (OR 48.9, 95% CI 26.1 to 91.8, p<0.001).

CONCLUSIONS

Risk of complications and mortality were increased in patients with pVA. We developed a score to identify patients at risk of pVA and in need of histological reassessment and closer follow-up.

Localised intestinal Kaposi sarcoma in a patient with non-coeliac seronegative villous atrophy

Seronegative villous atrophy (SNVA) is a diagnostic challenge for gastroenterologists, which is defined by villous atrophy and negative coeliac serology. Non-coeliac forms of SNVA, such as autoimmune enteropathy, can be life-threatening leading to intractable diarrhoea and severe malabsorption that require systemic immunosuppression. When all known causes have been excluded, it is termed idiopathic villous atrophy (IVA). We present a case of non-coeliac SNVA complicated by Kaposi sarcoma (KS). A previously well HIV-negative man in his 30s presented with a 4-month history of watery diarrhoea and 25 kg weight loss. After prolonged investigation, he was diagnosed with non-coeliac SNVA without an identified aetiology that would be consistent with IVA. Clinical recovery was achieved with parenteral nutrition for type II intestinal failure and immunosuppression using high-dose corticosteroids. On subsequent gastroscopy, he was diagnosed with localised intestinal KS prompting cessation of all immunosuppression but remained in clinical remission.

The Gluten-Free Diet for Celiac Disease: Critical Insights to Better Understand Clinical Outcomes

The gluten-free diet (GFD) remains a complex paradigm in managing celiac disease (CeD) in children and adults, and there are many reasons why GFD adherence should be strict to improve outcomes. However, this is a challenging task for patients, since they need to have access to quality healthcare resources that facilitate optimal GFD adherence. Understanding the strengths and weaknesses of the GFD, tackling coexisting nutritional deficiencies, and dealing with complex situations, such as seronegative CeD or non-responsive CeD, all require the involvement of a multidisciplinary team. The short- and long-term follow-up of CeD patients should preferably be performed by a combined Gastroenterology and Nutrition service with well-defined quality standards and the multidisciplinary involvement of physicians, nurses, dietitians, and psychologists. Nutritional advice and counseling by an experienced dietitian can reduce the costs associated with long-term follow-up of CeD patients. Likewise, psychological interventions may be essential in specific scenarios where implementing and sustaining a lifelong GFD can cause a significant psychological burden for patients. This manuscript aims to provide guidelines to improve clinical practice in the follow-up and monitoring of CeD patients and provide information on the nutritional risks of an ill-advised GFD. Clinicians, biochemists, food technologists, dietitians, and psychologists with a global view of the disease have been involved in its writing.

Computer-Based Diagnosis of Celiac Disease by Quantitative Processing of Duodenal Endoscopy Images

Celiac disease (CD) is a lifelong chronic autoimmune systemic disease that primarily affects the small bowel of genetically susceptible individuals. The diagnostics of adult CD currently rely on specific serology and the histological assessment of duodenal mucosa on samples taken by upper digestive endoscopy. Because of several pitfalls associated with duodenal biopsy sampling and histopathology, and considering the pediatric no-biopsy diagnostic criteria, a biopsy-avoiding strategy has been proposed for adult CD diagnosis also. Several endoscopic changes have been reported in the duodenum of CD patients, as markers of villous atrophy (VA), with good correlation with serology. In this setting, an opportunity lies in the automated detection of these endoscopic markers, during routine endoscopy examinations, as potential case-finding of unsuspected CD. We collected duodenal endoscopy images from 18 CD newly diagnosed CD patients and 16 non-CD controls and applied machine learning (ML) and deep learning (DL) algorithms on image patches for the detection of VA. Using histology as standard, high diagnostic accuracy was seen for all algorithms tested, with the layered convolutional neural network (CNN) having the best performance, with 99.67% sensitivity and 98.07% positive predictive value. In this pilot study, we provide an accurate algorithm for automated detection of mucosal changes associated with VA in CD patients, compared to normally appearing non-atrophic mucosa in non-CD controls, using histology as a reference.

Computer-Based Diagnosis of Celiac Disease by Quantitative Processing of Duodenal Endoscopy Images

Celiac disease (CD) is a lifelong chronic autoimmune systemic disease that primarily affects the small bowel of genetically susceptible individuals. The diagnostics of adult CD currently rely on specific serology and the histological assessment of duodenal mucosa on samples taken by upper digestive endoscopy. Because of several pitfalls associated with duodenal biopsy sampling and histopathology, and considering the pediatric no-biopsy diagnostic criteria, a biopsy-avoiding strategy has been proposed for adult CD diagnosis also. Several endoscopic changes have been reported in the duodenum of CD patients, as markers of villous atrophy (VA), with good correlation with serology. In this setting, an opportunity lies in the automated detection of these endoscopic markers, during routine endoscopy examinations, as potential case-finding of unsuspected CD. We collected duodenal endoscopy images from 18 CD newly diagnosed CD patients and 16 non-CD controls and applied machine learning (ML) and deep learning (DL) algorithms on image patches for the detection of VA. Using histology as standard, high diagnostic accuracy was seen for all algorithms tested, with the layered convolutional neural network (CNN) having the best performance, with 99.67% sensitivity and 98.07% positive predictive value. In this pilot study, we provide an accurate algorithm for automated detection of mucosal changes associated with VA in CD patients, compared to normally appearing non-atrophic mucosa in non-CD controls, using histology as a reference.

A Combination Therapy in a Rare Case of Adult-Onset Autoimmune Enteropathy

Autoimmune enteropathy (AIE) is a differential diagnosis of incurable chronic diarrhea, malnutrition, and weight loss. This type of diarrhea is associated with protein enteropathy that usually affects the small intestine. The diagnosis of AIE is based on chronic diarrhea, malabsorption, specific histological result, antibodies against enterocytes, and excluding similar conditions. In this case, a 28-year-old female presented with diarrhea, lower limb edema, weight loss, and electrolyte imbalances. Endoscopic examination demonstrated duodenal villous atrophy, while duodenal biopsies revealed villous blunting, scattered intraepithelial lymphocytes, and crypt hyperplasia in the lamina propria. The patient was treated with immunosuppressive treatment including methylprednisolone and azathioprine, achieving clinical remission.

Updates in the diagnosis and management of coeliac disease

Coeliac disease is a common autoimmune disorder induced by ingesting gluten, the protein component of wheat, barley, and rye. It is estimated that one-in-hundred people worldwide have coeliac disease, of whom the majority remain undiagnosed. Coeliac disease is characterized by a wide range of gastrointestinal and extraintestinal symptoms but can also present asymptomatically. Diagnosing coeliac disease depends on the concordance of clinical, serological and histopathological data. However, the diagnosis can be challenging and frequently overlooked. Undiagnosed coeliac disease is associated with an increased risk of complications and detrimental effects on quality of life. Early diagnosis and treatment of coeliac disease are necessary to reduce the risk of long-term complications.

Adult-Onset Autoimmune Enteropathy: A Case Report

Small bowel villous atrophy is most often caused by celiac disease in the Western world, but other diseases should be explored in patients without positive serology. Adult-onset autoimmune enteropathy (AIE) is a rare cause of villous atrophy first known in children with T-cell dysregulation but also seen in adults with autoimmune predispositions. Here, an 82-year-old woman with autoimmune thyroiditis was admitted with weight loss and watery diarrhoea not responding to diet change. Endoscopy revealed villous atrophy both in the duodenum and in the ileum, but no positive celiac serology. A diagnosis of autoimmune enteropathy was made based on chronic diarrhoea not responding to diet change, autoimmune predisposition, villous atrophy, typical histological findings, and no evidence of immunodeficiency or medications causing villous atrophy. The patient was treated to good effect with corticosteroids but needed total parenteral nutrition while admitted. AIE should be considered in villous atrophy without positive celiac serology.

Clinical profile of patients with seronegative celiac disease

Aim

This study aimed to determine the clinical profile of patients with seronegative celiac disease (SNCD).

Background

Celiac disease (CD) is mainly diagnosed based on positive serology and duodenal mucosal atrophy, but some patients have negative serology. Their diagnosis has some limitations; delays in diagnosis are likely accompanied by a poor prognosis and a high risk of developing complications of CD.

Methods

In this retrospective study, 1115 patients were evaluated for CD with mucosal atrophy between 2010 to 2020. SNCD diagnosis requires genetic CD predisposition and improvement of both clinical symptoms and regrowth of duodenal villi after 12 months of a gluten-free diet (GFD) for all patients with IgA deficiency, other IgG-based serology for diagnosis of celiac was done and if these antibodies were negative, consider them as possible SNCD. If they had positive DQ2-DQ8 and improvement of clinical symptoms and mucosal atrophy after 12 months of GFD were confirmed SNCD.

Results

Of the 1115 study subjects, 27 had SNCD, 1088 had SPCD with a mean age of 29.7±15.7 years (1 to 76 years) in seropositive celiac disease (SPCD) subjects and 37.1±16.3 years (6 to 63 years) in SNCD participants and 19 female patients with SNCD were presented. The BMI of SNCD and SPCD patients were reported 23.9 and 21.4, respectively. In addition, SPCD subjects were more likely but not statistically significant to have a positive family history. Villous atrophy was shown in 100% SNCD and 95.6% SPCD cases. Scalloping and fissuring in duodenal biopsies were reported in 60% of SNCD and 84.5% of SPCD patients. There was some other cause of seronegative villous atrophy including 3 patients with Crohns disease, 2 with common variable immunodeficiency, 2 drug and one patient with peptic duodenitis. Anemia, neurological symptoms, and liver function tests (LFT) abnormality were common extra intestinal manifestations in SNCD individuals. Levels of Thyroid peroxidase (TPO), TSH were measured, it had been detected that SNCD cases had a higher rate of co-occurrence with thyroid diseases also SPCD cases showed a higher rate of co-occurrence with diabetes.

Conclusion

Among patients with celiac disease 2.4% are SNCD. SNCD are older than SPCD at the time of diagnosis and have higher BMI. Most common of cause of seronegative enteropathy also is SNCD followed by inflammatory bowel disease (IBD) common variable immunodeficiency (CVID), medication use, and duodenitis, in this area.

DQA1*0102 DQB1*0602 haplotype distinguishes coeliac disease and its complications from gluten unrelated enteropathies

BACKGROUND

Duodenal villous atrophy is due not only to coeliac disease and its complications but also to other rare enteropathies unrelated to gluten consumption, defined as noncoeliac enteropathies. The diagnosis of noncoeliac enteropathies remains challenging, and HLA typing has been widely used to exclude coeliac disease if DQ2 and DQ8 alleles are absent. However, the frequency of the various HLA alleles in noncoeliac enteropathies is still unknown.

AIMS

To describe the HLA genetic profile of patients affected by noncoeliac enteropathies who have been evaluated at our centres between 2000 and 2021, and to investigate the diagnostic role of HLA typing.

METHODS

Genomic DNA was collected from 44 Italian and 19 British adult patients with noncoeliac enteropathies. Patient genotypes were compared with those of healthy Italian and British populations obtained from HLA bone marrow donors' banks. In addition, genotypes were also compared with those of patients with coeliac disease and complicated coeliac disease.

RESULTS

Both in the Italian and in the British group, the DQA1*0102 DQB1*0602 haplotype and related alleles occurred significantly more frequently in patients with noncoeliac enteropathies compared to coeliac disease and complicated coeliac disease.

CONCLUSIONS

Together with negative HLA-DQ2 and DQ8 haplotypes, the DQA1*0102 DQB1*0602 haplotype can be used to guide the differential diagnosis between coeliac disease and noncoeliac enteropathies.

The role of serology in the diagnosis of coeliac disease

Serology has significantly revolutionized the knowledge of celiac disease (CD), leading to the identification of unsuspected patients in at-risk CD groups, thereby increasing the number of CD diagnoses compared to the pre-screening era. Several markers for CD with a progressive diagnostic accuracy have been identified over the years, but only three of them, i.e. anti-tissue transglutaminase (anti-tTG), anti-endomysial (EmA) and anti-deamidated gliadin antibodies (DGP) are currently assessed in the daily clinical practice. A thorough review of the literature identified 44 original studies published between 1998 to 2022 for a total of 5098 pediatric and adult CD patients (without selective IgA deficiency) and 11930 disease controls. The results highlighted that anti-tTG IgA exhibited a higher sensitivity for CD (93.4%) than EmA IgA (92.8%), DGP IgG (81.8%) and DGP IgA (83.8%). The specificity of EmA IgA (99%) resulted to be higher than those of anti-tTG IgA (95.8%), DGP IgG (96.4%) and DGP IgA (92.1%). In patients with selective IgA deficiency, a condition closely related to CD, serological screening should include one of the three antibodies of IgG class, since anti-tTG, DGP and EmA have a very similar diagnostic accuracy in this clinical setting. According to age, there are two main diagnostic strategies for CD detection. In children, the revised ESPGHAN 2020 guidelines established that CD could be diagnosed in both symptomatic and asymptomatic children by high anti-tTG IgA titers (>10 times the cut-off) and EmA positivity with no need to obtain duodenal biopsy and HLA typing. In adult patients, although high tTG IgA titers (confirmed by EmA IgA positivity) correlate with villous atrophy, an intestinal biopsy is still considered mandatory for confirming CD diagnosis. Currently, a case finding approach in at-risk groups is preferred to mass screening for CD detection.

The differential diagnoses for severe enteropathy or severely damaged small intestinal mucosa

Aim

The aim of this study was to explore the aetiology of severe duodenal mucosal abnormality in consecutive patients who underwent gastroscopy and duodenal biopsy over the past 10 years.

Background

A range of differential diagnoses have been reported for severe duodenal architectural distortion.

Methods

Clinical and laboratory data of all the patients with severe duodenal architectural distortion diagnosed at MidCentral District Health Board (DHB), New Zealand were collected and statistically analysed. Ninety-five percent confidence intervals (CI) are shown.

Results

Between September 2009 and April 2019, 229 patients were diagnosed with severe enteropathy. The median patient age was 41 years (range 6-83 years). Two hundred and twenty-four of these patients (97.8%, 95.0-99.3%) were diagnosed with coeliac disease (CeD), with one of these patients having gluten induced T-cell lymphoma. From the remaining five patients, one had a diagnosis of tropical sprue and four did not have a clear aetiology. There were 180 patients from 191 (94.2%, 89.9-97.1%) with at least one positive coeliac marker, all with a diagnosis of CeD. Eleven patients (5.8% of 191, 2.9-10.1%) had negative markers for both tissue transglutaminase IgA (tTG-IgA) and IgA-endomysial antibodies (EMA-IgA) with six having a diagnosis of seronegative CeD.

Conclusion

Although the spectrum of histological changes in CeD may range from normal to a flat mucosa, severe duodenal architectural distortion seems to occur mainly in CeD. Idiopathic enteropathy was recorded as the second but by far less frequent presentation of severe enteropathy. This study highlights that infection and other aetiologies are rarely implicated in severe enteropathy, with one case (0.4%) of refractory CeD/T-cell lymphoma.