Coeliac disease: Lack of consensus regarding definitions of coeliac disease

Real-life Performance of Multiplex Celiac Antibody Test in the Diagnosis of Pediatric Celiac Disease

OBJECTIVE

Tissue-transglutaminase antibodies (TGA) may be used to diagnose celiac disease (CD) without biopsy in selected cases. We aimed to investigate real-life performance of a CD serology automated analyzer (Bioplex2200), and to explore the correlation between TGA levels and intestinal biopsies in children.

METHODS

A retrospective review was performed in 2 pediatric gastroenterological centers, between November 1, 2018 and April 1, 2020 and included patients with both TGA serology testing and duodenal biopsies. Retrieved data included patients' demographics, medical background, TGA levels, and biopsy results.

RESULTS

Overall, 538 children were evaluated, 256 with positive TGA (68.4% girls, median age 6.4 years), and 282 with negative TGA (53.9% girls, median age 13.4 years). Among patients with positive TGA, intestinal biopsies confirmed CD in 219 (85.5%). Overall, positive serology with normal histology was found in 14.5% of the cohort, with 52%; 21.6%; 21.1%; and 4.2% in TGA ranges of 1 to 3 times upper limit of normal (ULN); 3 to 5 ULN; 5 to 10 ULN; and above 10 times ULN, respectively, P < 0.001. Area under the receiver-operating characteristic curve (AUC) was 0.963 (95% CI 0.947-0.980). Among patients with positive TGA, 216 (84.4%) had positive anti-endomysial antibodies. In this sub-group, the overall diagnostic performance was inferior, with AUC of 0.737 (95% CI 0.834-0.839).

CONCLUSIONS

The Multiplex TGA assay had a very high diagnostic accuracy in real-life. Among patients with positive TGA, adding EMA did not improve the diagnostic performance of the test. False-positive rates differed between different ranges of TGA and were low with TGA above 10 times ULN.

The role of histopathology in the diagnosis and management of coeliac disease and other malabsorptive conditions

Most absorption of nutrients takes place in the proximal small intestine, and the most common disorders leading to malabsorption are associated with a morphological abnormality in the duodenal mucosa that is appreciable in histological sections of biopsy specimens. Coeliac disease is the most well-known example, causing intraepithelial lymphocytosis, inflammation and villous atrophy in the duodenum. Remarkably similar inflammatory changes can be induced by other processes, including medications, e.g. angiotensin II receptor blockers and immune checkpoint inhibitors, immune dysregulation disorders, e.g. common variable immunodeficiency and autoimmune enteropathy, infections, collagenous sprue, and tropical sprue. However, there are often subtle histological differences from coeliac disease in the type of inflammatory infiltrate, the presence of crypt apoptosis, and the extent and type of inflammation beyond the duodenum. The clinical setting and serological investigation usually allow diagnostic separation, but some cases remain challenging. Histopathology is also important in assessing the response to treatment, such as the change in villous architecture caused by a gluten-free diet, or the response to cessation of a potentially causative medication. This review examines the practical role that histopathology of duodenal biopsy specimens plays in the assessment and management of inflammatory malabsorptive processes of the proximal small intestine, with a particular emphasis on coeliac disease.

The Role of Early Programming and Early Nutrition on the Development and Progression of Celiac Disease: A Review

Experimental and epidemiological evidence has shown that modifications of the intrauterine environment can have deleterious consequences for individuals, expressed as an increased risk of suffering non-communicable pathologies in adult life, which is known as the hypothesis of the early origin of diseases or fetal programming. On the other hand, changes in gene expression patterns through epigenetic modifications can be the basis for long-term maintenance of the effects of fetal programming. In this sense, epigenetics comprises the study of intrauterine disturbances, which develop diseases in the adult, including celiac disease (CD). In addition, early feeding practices could influence the risk of CD development, such as breastfeeding timing and duration and age of gluten introduction in the diet. Gluten acts as a trigger for CD in genetically predisposed subjects, although approximately 30% of the world population has HLA DQ2 or DQ8, the prevalence of the disease is only 1–3%. It is not known what factors act to modify the risk of disease in genetically at-risk subjects. Taking into account all these considerations, the aim of the current review is to elucidate the role of early programming and the effect of early nutrition on the development and progression of CD. It is logical that attention has been paid to gluten as a key element in preventing the disease. However, there is no strong evidence in favor of the protective factor of breastfeeding, timing of introduction of gluten during lactation, and the development of CD. Diet, genetic risk, microbiota, and environmental interaction are possible triggers of the change in tolerance to an immune response to gluten, but large-scale cohort studies are needed. Emerging scientific concepts, such as epigenetics, may help us establish the role of these factors.

Diagnostic accuracy and applicability of intestinal auto-antibodies in the wide clinical spectrum of coeliac disease

BACKGROUND

Intestinal coeliac auto-antibodies are the marker of coeliac disease (CD). Since the determination of these antibodies is still not widely available, we used immunoassays to identify the most suitable technology for revealing intestinal auto-antibodies in the wide clinical spectrum of CD.

METHODS

Intestinal auto-antibodies have been prospectively investigated in CD suspected children using two immunoassays: intestinal-deposits of IgA anti-tissue transglutaminase antibodies (anti-tTG) and biopsy-culture IgA anti-endomysium (AEA). Intestinal IgM antibodies have been determined in IgA-deficient subjects.

FINDINGS

Two-hundred and twenty-one suspected CD patients were enrolled. Intestinal antibodies were tested positive for both assays in classical CD patients (n = 178) with villous atrophy and positive serum-CD antibodies, potential CD patients (n = 16) with normal intestinal mucosa and positive serum-CD antibodies, and pre-potential CD patients (n = 14) with normal intestinal mucosa and negative serum-CD antibodies. In 13/221 with normal intestinal mucosa, negative CD-serum antibodies and negative intestinal antibodies CD has been excluded. All classical, 14/16 potential and 11/14 pre-potential CD patients on gluten-free diet (GFD) improved their symptoms. In 9/11 pre-potential patients intestinal antibodies disappeared on GFD. Both assays were negative in 69/71 control subjects. The two assays showed high diagnostic sensitivity (100%) and specificity (99%).

INTERPRETATION

Intestinal CD-antibodies make prompt diagnosis in the wide clinical spectrum of CD reducing the delay in diagnosis and treatment, especially in pre-potential CD patients. The easy handling biopsy culture assay is an effective diagnostic tool which should be carried out by any gastroenterology unit to recognize all CD clinical manifestations.

FUNDING

Interreg Central-Europe, IRCCS "Burlo Garofolo".

Gluten-Induced Extra-Intestinal Manifestations in Potential Celiac Disease-Celiac Trait

Celiac disease patients may suffer from a number of extra-intestinal diseases related to long-term gluten ingestion. The diagnosis of celiac disease is based on the presence of a manifest small intestinal mucosal lesion. Individuals with a normal biopsy but an increased risk of developing celiac disease are referred to as potential celiac disease patients. However, these patients are not treated. This review highlights that patients with normal biopsies may suffer from the same extra-intestinal gluten-induced complications before the disease manifests at the intestinal level. We discuss diagnostic markers revealing true potential celiac disease. The evidence-based medical literature shows that these potential patients, who are “excluded” for celiac disease would in fact benefit from gluten-free diets. The question is why wait for an end-stage disease to occur when it can be prevented? We utilize research on dermatitis herpetiformis, which is a model disease in which a gluten-induced entity erupts in the skin irrespective of the state of the small intestinal mucosal morphology. Furthermore, gluten ataxia can be categorized as its own entity. The other extra-intestinal manifestations occurring in celiac disease are also found at the latent disease stage. Consequently, patients with celiac traits should be identified and treated.

Will the Real Coeliac Disease Please Stand Up? Coeliac Disease Prevalence in the German LIFE Child Study

OBJECTIVES

Assessing the seroprevalence and the prevalence of definite coeliac disease (CD) in the German LIFE Child Health study cohort including immunoglobulin A (IgA) antibodies against tissue transglutaminase (IgA-TTG) in addition to IgG antibodies against deamidated gliadin peptides (IgG-DGP) and human leukocyte antigen (HLA)-DQ2/8 genotyping.

METHODS

Samples from children and adolescents were first screened for IgA-TTG and IgG-DGP. If IgA-TTG was above 0.5 times the upper limit of normal and/or IgG-DGP was positive, IgA antibodies against endomysium (IgA-EmA) were measured, and HLA was genotyped. In patients with only IgG-DGP positivity, total IgA was assayed. Subjects with suspicious results were followed up serologically and, in case of repeatedly positive antibody results, invited for a personal interview. Further diagnostic data were obtained independent from our study.

RESULTS

We screened 2363 children's blood samples collected from 2011 to 2015. The seroprevalence, that is, IgA-TTG and/or IgA-EmA positivity or IgG-DGP positivity with IgA <0.05 g/L, was 1.57% (95% confidence interval [CI95%] 1.14-2.15). The prevalence of suspected CD, that is, seroprevalence and compatible HLA genotype with hitherto unknown mucosal damage, was 1.35% (CI95% 0.96-1.91). Definite CD, that is, seropositivity accompanied by positive intestinal biopsy or IgA-TTG ≥ 10 × upper limit of normal, was found in 0.42% (CI95% 0.22-0.80). Seven children claimed to have CD. The HLA haplotype, however, matched in only 4 of them resulting in an overall CD prevalence of at least 0.59% (CI95% 0.34-1.02). Thirteen unclear cases remained; therefore, the prevalence may even be higher.

CONCLUSIONS

The prevalence of definite CD in a population-representative German cohort is higher than previously described. HLA-DQ typing is helpful to identify false-positive IgA-TTG patients negative for IgA-EmA and/or IgG-DGP under screening conditions and unmasks possible misdiagnoses of CD.

Distinct and Synergistic Contributions of Epithelial Stress and Adaptive Immunity to Functions of Intraepithelial Killer Cells and Active Celiac Disease

BACKGROUND & AIMS

The mechanisms of tissue destruction during progression of celiac disease are poorly defined. It is not clear how tissue stress and adaptive immunity contribute to the activation of intraepithelial cytotoxic T cells and the development of villous atrophy. We analyzed epithelial cells and intraepithelial cytotoxic T cells in family members of patients with celiac disease, who were without any signs of adaptive antigluten immunity, and in potential celiac disease patients, who have antibodies against tissue transglutaminase 2 in the absence of villous atrophy.

METHODS

We collected blood and intestinal biopsy specimens from 268 patients at tertiary medical centers in the United States and Italy from 2004 to 2012. All subjects had normal small intestinal histology. Study groups included healthy individuals with no family history of celiac disease or antibodies against tissue transglutaminase 2 (controls), healthy family members of patients with celiac disease, and potential celiac disease patients. Intraepithelial cytotoxic T cells were isolated and levels of inhibitory and activating natural killer (NK) cells were measured by flow cytometry. Levels of heat shock protein (HSP) and interleukin 15 were measured by immunohistochemistry, and ultrastructural alterations in intestinal epithelial cells (IECs) were assessed by electron microscopy.

RESULTS

IECs from subjects with a family history of celiac disease, but not from subjects who already had immunity to gluten, expressed higher levels of HS27, HSP70, and interleukin-15 than controls; their IECs also had ultrastructural alterations. Intraepithelial cytotoxic T cells from relatives of patients with celiac disease expressed higher levels of activating NK receptors than cells from controls, although at lower levels than patients with active celiac disease, and without loss of inhibitory receptors for NK cells. Intraepithelial cytotoxic T cells from potential celiac disease patients failed to up-regulate activating NK receptors.

CONCLUSIONS

A significant subset of healthy family members of patients with celiac disease with normal intestinal architecture had epithelial alterations, detectable by immunohistochemistry and electron microscopy. The adaptive immune response to gluten appears to act in synergy with epithelial stress to allow intraepithelial cytotoxic T cells to kill epithelial cells and induce villous atrophy in patients with active celiac disease.

Celiac disease: an immune dysregulation syndrome

Celiac disease is a chronic immune-mediated condition that develops in genetically predisposed individuals. It is characterized by the presence of circulating auto-antibodies in addition to an enteropathy and at times, other extra-intestinal manifestations triggered by exposure to the gliadin fraction of gluten, a family of proteins found in wheat, barley, and rye. There seems to be a rise in reported adverse reactions to gluten, an entity currently termed non-celiac gluten (or perhaps more accurately, wheat) sensitivity, where neither the enteropathy nor the auto-antibodies are present. Celiac disease has protean extra-intestinal manifestations, and an accurate diagnosis should be sought in people suffering from seemingly unrelated complaints, such as fatigue, anorexia, delayed puberty, short stature, decreased bone density, unusual skin rashes, unexplained iron deficiency, and infertility. The presence of an enteropathy, in conjunction with the positive serology, is considered the diagnostic gold standard for making the diagnosis of celiac disease. It is important to stress that the elimination of gluten, even in asymptomatic patients, brings about health benefits, particularly in relation to bone health, as well as a decrease in the incidence of small bowel malignancy, especially lymphoma. Better understanding of the pathophysiology of celiac disease and the molecular mechanisms involved in antigen recognition and processing has provided the impetus for the development of pharmacologic agents that might block the recognition of gluten and its conversion to a toxic antigenic target. Inhibition of tight junction dysregulation could also prevent or minimize the damage triggered by gluten. Work on genetically modified wheat cultivars has progressed, and the possibility of a vaccine to block the immune mediated trigger is being actively investigated. Education and guidance by a knowledgeable nutritionist or registered dietitian can go a long way in minimizing the stress and facilitating the acceptance of the diet and the life-style changes that it represents.

Potential celiac children: 9-year follow-up on a gluten-containing diet

OBJECTIVES

Potential celiac disease (CD) is defined by the presence of serum anti-tissue-transglutaminase (anti-TG2) antibodies and normal duodenal mucosa. The major clinical problem is the management of asymptomatic patients and how to predict the development of villous atrophy. This prospective longitudinal cohort study describes the natural history of potential CD up to 9 years and explores risk factors associated with the development of mucosal damage.

METHODS

Two hundred and ten potential CD children were eligible for the study; 175/210 asymptomatic children were left on a gluten-containing diet. Antibodies and clinical symptoms were checked every 6 months, and a small bowel biopsy was taken every 2 years to evaluate histological, immunohistochemical, and anti-TG2 deposits. Patients were genotyped for HLA and a set of non-HLA CD-associated genes.

RESULTS

Forty-three percent of patients showed persistently elevated anti-TG2 level, 20% became negative during follow-up, and 37% showed a fluctuant anti-TG2 course with transiently negative values. At 3 years of follow-up, 86% of cases remained potential; 73 and 67% still had normal duodenal architecture at 6 and 9 years, respectively. Male sex, slight mucosal inflammation at time 0, and a peculiar genetic profile delineate a cohort of individuals who were prone to develop mucosal damage during time.

CONCLUSIONS

A sizeable proportion of asymptomatic potential celiac patients showed fluctuation or negativization of antibody production, and many of these, with persistently positive anti-TG2, did not develop mucosal damage after 9 years of follow-up. Celiac population is a multivariate aggregate of individuals with different genetic and phenotypic profiles. Caution is required before prescribing a gluten-free diet for life to asymptomatic individuals with potential CD.

Screening for celiac disease, by endomysial antibodies, in patients with unexplained articular manifestations

Celiac disease (CD) is an autoimmune systemic disease characterized by not only gastrointestinal but also extraintestinal manifestations. The aim of our study was to do a serological screening for CD, by IgA endomysial antibodies (EmA), in patients with unexplained articular manifestations. Two hundred and eleven patients suffering from arthritis or arthralgia without evident cause were studied. EmA were determined by indirect immunofluorescence on human umbilical cord. Two thousand and five hundred blood donors served as control group. Out of 211 patients, 5 had EmA (2.37 %). The frequency of EmA in our patients was significantly higher than in the control group (2.37 vs. 0.28 %, p < 0.01). All patients with positive EmA were female. EmA were significantly more frequent in female patients than in female healthy subjects (3 vs. 0.4 %, p < 0.01). Medical records revealed: diarrhea (one patient), short size (one patient), anemia (three patients), weight loss (two patients) spontaneous abortion (three patients), secondary amenorrhea (one patient), early menopause (one patient) and early baby death (one patient). Biochemical analysis showed decreased level of calcium (one patient), vitamin D (one patient) and cholesterol (one patient). Unexplained liver cytolysis was observed in two patients. Radiological examination showed demineralization of two hands in one patient. Bone osteodensitometry done in one patient out of five revealed lumbar osteopenia. The articular manifestations of the five patients did not respond to corticosteroid treatment. CD must be considered among the differential diagnosis in a patient with arthritis or arthralgia.

Celiac disease and chronic liver disease: is there a relationship?

Celiac disease is a multisystem disease, and the liver is affected in a subset of patients. We herein present a case series of 25 patients with celiac disease who had evidence of cirrhosis of the liver. We retrospectively reviewed the case records of patients with celiac disease having concomitant cirrhosis. The diagnosis of celiac disease was made on the basis of the modified European Society of Pediatric Gastroenterology, Hepatology, and Nutrition criteria. Of 25 patients (nine males; mean age 28.8 ± 16.6 years) with celiac disease and cirrhosis, 17 patients presented predominantly with cirrhosis, while 8 presented primarily with celiac disease. Five patients had known cause of cirrhosis (autoimmune hepatitis, three; PBC, one; hepatic venous outflow tract obstruction, one); the remaining 20 were cryptogenic. Gluten-free diet led to improvement in diarrhea and anemia and to a better control of ascites and other features of liver failure. Some patients with cryptogenic cirrhosis have coexistent celiac disease, and they show response to gluten-free diet. Patients with cryptogenic cirrhosis should be screened for celiac disease.

Non-Celiac Gluten sensitivity: the new frontier of gluten related disorders

Non Celiac Gluten sensitivity (NCGS) was originally described in the 1980s and recently a “re-discovered” disorder characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing food, in subjects that are not affected with either celiac disease (CD) or wheat allergy (WA). Although NCGS frequency is still unclear, epidemiological data have been generated that can help establishing the magnitude of the problem. Clinical studies further defined the identity of NCGS and its implications in human disease. An overlap between the irritable bowel syndrome (IBS) and NCGS has been detected, requiring even more stringent diagnostic criteria. Several studies suggested a relationship between NCGS and neuropsychiatric disorders, particularly autism and schizophrenia. The first case reports of NCGS in children have been described. Lack of biomarkers is still a major limitation of clinical studies, making it difficult to differentiate NCGS from other gluten related disorders. Recent studies raised the possibility that, beside gluten, wheat amylase-trypsin inhibitors and low-fermentable, poorly-absorbed, short-chain carbohydrates can contribute to symptoms (at least those related to IBS) experienced by NCGS patients. In this paper we report the major advances and current trends on NCGS.

Fingertip rapid point-of-care test in adult case-finding in coeliac disease

BACKGROUND

Coeliac disease (CD), due to its protean clinical manifestation, is still very under diagnosed in adults and delays in diagnosis may take years and even decades. Simple tools to find cases in primary care may help to identify patients for further diagnostic tests. We have evaluated the usefulness of an on site rapid fingertip whole blood point-of-care test (POCT) for such a purpose.

METHODS

As CD is known to run within families, we tested 148 healthy relatives of 70 Romanian index cases with biopsy-proven CD (87% of all first-degree family members, median age 36 years) for the presence of circulating autoantibodies. In addition to performing the POCT (which measures blood erythrocyte self-TG2-autoantibody complexes) on site, blood was drawn for later evaluations of serum IgA-class endomysial antibodies (EMA). EMA-positive sera were further tested for transglutaminase 2 antibodies (TG2-IgA). All serological parameters were analyzed blindly in a centralized laboratory that had no knowledge of the on site POCT result. Endoscopic small intestinal biopsies was recommended for all POCT- or EMA-test positive subjects.

RESULTS

In on site testing the POCT was positive in 12/148 first-degree relatives (8%) and all these subjects were also serum EMA-positive. A positive EMA test was found only in one other subject. All remaining 135 healthy first-degree relatives were negative for both POCT and EMA. Four subjects positive for both POCT and EMA were negative for TG2-IgA. Ten out of thirteen of the antibody-positive subjects agreed to undergo endoscopy. The POCT was found to be positive in 8/9 first-degree relatives having coeliac-type mucosal lesions of grade Marsh 2 (n = 3) or Marsh 3 (n = 6). The three POCT-positive subjects not agreeing to undergo endoscopy were also both EMA- and TG2-IgA-positive.

CONCLUSION

The fingertip whole blood rapid POCT might fulfill the unmet need for a simple and cheap case-finding biomarker for early detection and presumptive diagnosis of CD. Confirmatory studies are warranted in adult case-finding in specialized outpatient clinics and in primary care.