Childhood celiac disease: response of treated patients to a small uniform daily dose of wheat gluten

A Clinician's Guide to Gluten Challenge

Gluten challenge is an essential clinical tool that involves reintroducing or increasing the amount of gluten in the diet to facilitate diagnostic testing in celiac disease (CD). Nevertheless, there is no consensus regarding the applications of gluten timing, dosing, and duration in children. This review aims to summarize the current evidence, discuss practical considerations, and proposes a clinical algorithm to help guide testing in pediatric patients. Childhood development, social circumstances, and long-term health concerns must be considered when identifying a candidate for gluten challenge. Based on previous studies, the authors suggest baseline serology followed by a minimum of 3-6 grams of gluten per day for over 12 weeks to optimize diagnostic accuracy for evaluation of CD. A formal provider check-in at 4-6 weeks is essential so the provider and family can adjust dosing or duration as needed. Increasing the dose of gluten further may improve diagnostic yield if tolerated, although in select cases a lower dose and shorter course (6-12 weeks) may be sufficient. There is consensus that mild elevations in celiac serology (<10 times the upper limit of normal) or symptoms, while supportive are not diagnostic for CD. Current North American Society for Pediatric Gastroenterology, Hepatology and Nutrition guidelines recommend histologic findings of intraepithelial lymphocytosis, crypt hyperplasia, and villous atrophy as the accurate and most appropriate endpoint for gluten challenge.

The clinical response to gluten challenge: a review of the literature

The aim of this review was to identify, evaluate and summarize all relevant studies reporting on the clinical response to gluten challenge by adult or pediatric patients with suspected or diagnosed coeliac disease (CD) on a gluten-free diet. We evaluated the effect of gluten challenge on changes in symptoms, intestinal mucosa histology, and serum antibodies. A systematic electronic search was performed for studies published as of 1966 using PubMed and Scopus databases. In the reviewed studies, doses ranged from 0.2 to 30 g/day of wheat gluten or comprised a gluten-containing diet. The onset of symptoms upon gluten intake varied largely from days to months and did not parallel serum antibody or histological changes. Within 3 months of gluten challenge, 70%-100% of pediatric CD patients became positive for AGA-IgA and EMA-IgA antibodies and 50%-70% for AGA-IgG. A limited number of trials suggest that no more than half of adult patients developed positive AGA-IgA, EMA-IgA, tTG-IgA or DGP-IgA/IgG titers. Approximately 50%-100% of pediatric and adult patients experienced mucosal relapse of gluten provocation within 3 months, which was preceded by increased mucosal intra-epithelial lymphocytes within several days of challenge. A 3-month high-dose gluten challenge should be suitable to diagnose the majority of CD patients. In some cases prolonged challenge may be needed to verify diagnosis. Combination testing for antibodies and mucosal histology may fasten the diagnosis.

Is gluten challenge really necessary for the diagnosis of coeliac disease in children younger than age 2 years?

OBJECTIVE

In the diagnosis of coeliac disease (CD), gluten challenge is recommended for children under the age of 2 years at initial biopsy. The aim of the study was to investigate the diagnostic yield of gluten challenge in this group of children.

PATIENTS AND METHODS

We included children aged 2 years or younger who were analysed for possible CD and who had villous atrophy at initial small bowel biopsy in the period 1993-2004. We subsequently identified all patients who underwent a complete gluten challenge.

RESULTS

We identified 333 children with possible CD. In 100 children (30%), a gluten challenge was performed, with the diagnosis being confirmed in 97. Retrospectively, in 2 of the 3 children without mucosal relapse, data available before gluten challenge did not justify the initial diagnosis of CD. In the third patient, transient gluten intolerance could not be excluded. At first biopsy, the 2 children without mucosal relapse had negative serological parameters, whereas the third patient had IgA antigliadin antibodies, but no IgA anti-endomysium antibodies (EMA). Indeed, all of the patients with EMA at diagnosis had a relapse at gluten challenge.

CONCLUSIONS

Routine gluten challenge in children younger than 2 years at initial diagnosis of CD has an extremely low diagnostic yield. We suggest that routine gluten challenge in this group of patients is not necessary when patients have villous atrophy in combination with EMA. Therefore, a revision of the current diagnostic criteria has to be considered.

Even small amounts of gluten cause relapse in children with celiac disease

BACKGROUND

Previously, a gluten challenge was customary to establish the diagnosis of celiac disease in children. There are no clear recommendations on how to perform this challenge or what markers to rely on for timing the biopsy after the challenge. The authors' aim was to monitor gluten intake, clinical symptoms, and antibody kinetics to evaluate the influence of gluten exposure during the challenge.

METHODS

Twenty-five children under investigation for suspected celiac disease were challenged. One child was excluded because blood samples, food records, or biopsy was lacking. Median age at the postchallenge biopsy was 3.8 (2.7-8.8) years. The families kept daily records of the children's gluten intake and of symptoms that occurred. Blood samples were taken monthly for analysis of antigliadin and endomysium antibodies and total immunoglobulin A (IgA). A third biopsy was performed when clinical symptoms suggested a relapse.

RESULTS

All 24 children showed deterioration of the mucosa or elevated antibodies during gluten challenge. Median duration of the challenge was 13 (5-51) weeks, and mean gluten intake was 1.7 (0.2-4.3) g/d and 0.1 (0.02-0.26) g/kg daily.

CONCLUSIONS

Gluten intake during the challenge varied widely, and the parents were unable to give their children the recommended amount. Despite the small amounts given, all children showed signs of relapse at a clinical, laboratory, or histologic level. Much smaller amounts of gluten than previously suggested seem sufficient to cause relapse during gluten challenge in children.

Dose dependent effects of protracted ingestion of small amounts of gliadin in coeliac disease children: a clinical and jejunal morphometric study

This study aimed to investigate the effects of chronic ingestion of small amounts of gliadin on children with coeliac disease. A four week challenge was performed on 20 children who had been on a gluten free diet for mean (SD) 14 (3) months. They were given a daily dose of either 100 mg (group A, n = 10, mean age 4 (2) years) or 500 mg of gliadin (group B, mean age 5 (3) years). The effects of the gliadin were monitored by morphometric study of the jejunal mucosa, intestinal permeability test with cellobiose/mannitol, and serum antigliadin antibody test. After the challenge, group A patients showed a significant increase in the mean intraepithelial lymphocyte count (before challenge 11 (3), afterwards 19 (6)) and a decrease in the villous height/crypt depth ratio (beforehand 1.5 (0.1), afterwards 1.3 (0.2)), while the intestinal permeability test remained normal and the IgA-antigliadin antibody increased in four of 10 children. After the challenge group B showed more pronounced histological changes, an increase in the mean urinary cellobiose/mannitol % (beforehand 0.028 (0.020), afterwards 0.058 (0.028)), and IgA-antigliadin antibody positivity in six of eight subjects. The discriminant analysis function showed that the pretreatment group, group A after challenge, and group B after challenge were correctly classified in 90% of cases by functions based on the individual intraepithelial lymphocyte count and the villous height/crypt depth ratio. This study shows that chronic ingestion of small amounts of gluten causes dose-dependent damage to the small intestinal mucosa in children with coeliac disease. The predictive value of laboratory tests, such as the antigliadin antibody test and the intestinal permeability test seems to be lower in treated patients than in those with active coeliac disease.

Low gluten diet in the treatment of adult coeliac disease: effect on jejunal morphology and serum anti-gluten antibodies

Treatment of patients with coeliac disease with a low gluten containing diet (LGD) remains controversial. We have studied jejunal morphology and antigluten (AG) antibody titres by ELISA in patients on a LGD of 2.5-5 g/day for three to 14 months (median six months) and compared results with patients on a strict gluten free diet (GFD) for six to 27 months (median 13 months). We found no significant difference in villous height or crypt depth (eight LGD v 10 GFD patients) or serum AG-IgA, -IgG, and IgM titres (13 LGD v 12 GFD patients). there was however, a significant increase (p less than 0.05) in intra-epithelial lymphocytes in those patients on a LGD. We conclude that adult coeliac patients can tolerate a LGD without gross morphological change and without initiating significant AG antibody responses.

Gluten-sensitive enteropathy in childhood

Genetic and environmental factors (breast feeding, probably viral infections) play a role in the expression of the disease. Prevalence of GSE in childhood did not substantially decrease in the last 15 years in all European countries, where GSE is still more common in infantile age and presents frequently gastrointestinal symptoms. A decrease has been reported in childhood in several United Kingdom areas and in Finland, where the clinical presentation is changing, shifting upward with age and coming closer to the adult type of the disease. The following clinical problems have been reported in the recent literature: enamel hypoplasia; monosymptomatic short stature; arthritis and other immunologic diseases; association with diabetes, atopy, Iga deficiency, and probably Down's syndrome. Delay in puberty and other peculiar problems of the disease have been described in adolescents. Tests assessing the permeability of the small intestine and the blood levels of antigliadin antibodies have recently gained success as noninvasive tools for the diagnosis of the GSE. The gluten should be withdrawn from the diet and the challenge with gluten should be performed not before 12 months of gluten-free diet with an accurate timing of the biopsy on the basis of the antigliadin and antireticulin antibodies, to avoid clinical and growth damage. Celiac children do require a permanent gluten-free (and not poor) diet. In reality, too many celiac adolescents are off-diet.

Supposed coeliac disease during childhood and its presentation 14-38 years later

Thirty-five subjects treated with a gluten-free diet for a chronic gastrointestinal disorder (no biopsy performed) in early childhood were re-examined 14-38 (median, 28) years later. Twenty-one accepted jejunal biopsy at re-examination. None of those studied were on a gluten-free diet at the time of the study. Ten of 21 biopsy specimens were abnormal--6 with flat mucosa and very low disaccharidase levels, indicating coeliac disease, and 4 with low disaccharidase activity but morphologically normal mucosa. Three of the six subjects with flat mucosa showed a slight fat and lactose malabsorption, but their clinical condition did not suggest serious intestinal disease. Ingestion of gluten throughout most of childhood did not appear to affect growth, as evaluated by final height. Jejunal biopsy is recommended in all patients with gastrointestinal symptoms that are not otherwise explainable if their medical history shows a period of gluten-free diet for a chronic gastrointestinal disorder in childhood.

Studies of intestinal lymphoid tissue. VI--Proliferative response of small intestinal epithelial lymphocytes distinguishes gluten- from non-gluten-induced enteropathy

Several diseases of the small intestine, including gluten-sensitivity, present with malabsorption and a "flat" mucosa. Determination of the mitotic index of epithelial lymphocytes provides a simple, objective method of assessing, and thus of predicting, whether a flat mucosa is due to gluten-sensitivity (index greater than 0.2%), or not (index less than 0.2%). The use of this index in circumstances especially likely to cause diagnostic confusion--for example, intestinal lymphoma; Crohn's jejunitis of immunodeficiency--is illustrated in this paper. Of seven cases, five (two primary lymphoma, three immunodeficiency) had been treated with a gluten-free diet without benefit; a mitotic index performed on the initial biopsy in each of these patients could have predicted from the outset that none was gluten-sensitive. Of the remaining two cases, determination of the mitotic index on the biopsy initially obtained from a man with severe hypogammaglobulinaemia would have indicated that he was also gluten-sensitive. Empirical use of a gluten-free diet was avoided in the other patient (with flat small intestinal mucosa and low mitotic index) in whom the diagnosis was ultimately shown to be due to Crohn's disease of jejunum.

Transient gastro-intestinal disorders during infancy and early childhood. A follow-up study with special reference to coeliac disease

In a reappraisal study of coeliac disease (CD) 38 children and adolescents were studied: 20 (group A) had a previous diagnosis of CD from early childhood but had been lost to follow-up, 18 (group B) had in infancy or early childhood been hospitalized for more than 1 month for different gastro-intestinal symptoms without receiving a diagnosis of CD. In the present study the patients had a clinical examination and Hb, serum IgA and folate were analysed. These investigations did not prove helpful in selecting coeliac cases. Intestinal biopsy revealed CD in 8 patients in group A and in 6 patients in group B. Thus the frequency of CD was almost the same in the two groups. All 14 patients with CD had very few complaints, when a careful medical history was taken before biopsy. The present study shows the importance of performing intestinal biopsy on liberal indications on patients with an infancy or early childhood history of malabsorption-related symptoms. Among these patients many coeliacs are likely to be found.

Reintroduction of gluten in adults and children with treated coeliac disease

Twenty-eight patients, thought to have coeliac disease and on gluten free diets, were put on a normal diet to confirm their diagnoses. Nineteen had been diagnosed in adult life (ACD) and nine in childhood (CCD). Patients were assessed on jejunal, morphological, and symptomatic parameters. Eighteen patients with ACD relapsed within seven weeks. Nine patients with CCD relapsed at variable times but five took longer than seven weeks, the longest period beint 10 months. Seven patients had no symptoms despite morphological deterioration during challenge and one patient, with ACD, did not relapse and was HLA B8 negative. This patient with ACD had subtotal villous atrophy on two jejunal biopsies and later showed morphological improvement on a gluten free diet. There was no correlation between the relapse time and time spent on a gluten free diet.

Chronic diarrhea of childhood and the misuse of elimination diets

A prospective study was undertaken of 108 children referred for outpatient evaluation of chronic recurrent diarrhea. The majority of the children did not have a serious underlying disorder. Elimination diets (milk free, egg free, wheat free) were widely prescribed for the treatment of chronic diarrhea and were given for longer intervals than originally recommended. Elimination diets sometimes resulted in inadequate caloric intake and failure to thrive. Wheat (gluten)-free diets were prescribed for over one month in 59% of children without a specific diagnosis being made. These findings indicate that elimination diets are frequently misused, and prolonged adherence to elimination diets may result in nutritional damage. The indiscriminate use of wheat-free diets for the treatment of chronic diarrhea may be masking the diagnosis of celiac disease and may account for the low incidence of this disorder in the United States.

Variability of gluten intolerance in treated childhood coeliac disease

Fifty children consecutively attending a clinic for coeliac disease co-operated in a trial; 10 found to have flat mucosa were excluded. Forty children of mean age 9.8 years, whose duodenal or jejunal mucosa had returned to normal or near normal appearance after a mean of 5.8 years on gluten-free diets, were put back on normal diets. In 37, mucosal occurred in a mean of 16.9 months (four to 74 months). Four of the 37 had serial biopsies, in which mucosal enzymes (particularly lactase) fell and interepithelial lymphocyte counts rose before the mucosal morphology was regarded as definitely 'coeliac'. Three children had normal mucosal appearance after 58 to 73 months on normal diets, one of whom showed temporary mucosal abnormalities, another having occasionally low enzymes, in both suggesting underlying gluten sensitivity. Lactase suppression and raised IEL counts appear to be sensitive indicators of gluten intolerance. In our experience, a diagnosis of coeliac disease based on severe mucosal damage and a satisfactory response to a gluten-free but milk-containing diet implies a very strong likelihood of permanent or prolonged gluten intolerance, but with a striking variability in its expression.

Gluten challenge in treated coeliac disease

Thirty-two children with a past diagnosis of coeliac disease were reinvestigated by means of gluten challenge. They had received a gluten-free diet for a mean period of 6-5 years (range 0-25-11-0) before gluten challenge, and had a mean age of 9-9 years (range 3-0-15-3) at the onset of challenge. Small intestinal biopsies were performed before and after the gluten challenge (at least 10 g natural gluten per day for 3 months in the majority) and, as judged by light microscopy and morphometric techniques, coeliac disease was confirmed in 25 (78%) of the 32 patients; challenge was continued in the remaining 7 for a total period of 2 years when biopsies were repeated in 6 children and all were normal. Serum and RBC folate, serum iron, Hb level, and clinical symptoms were unpredictable variables in identifying children who developed gluten-induced enteropathies. The social and emotional effects of gluten challenge are discussed. The results highlight the importance of gluten challenge and intestinal biopsy in the diagnosis of coeliac disease and strongly suggest that a normal biopsy after a 3-month gluten challenge (as described above) excludes coeliac disease.

The 15 g D-xylose absorption test: its application to the study of coeliac disease

The absorption of xylose following an oral load of 15 g D-xylose has been studied by serial blood levels in 17 untreated adult coeliac patients, 21 treated coeliac patients, and 30 non-coeliac patients. A statistically significant difference in xylose blood levels was found between untreated coeliac and non-coeliac patients at all the times studied, but a complete separation between these two groups occurred only at the 75 minute stage. The reproducibility of absorption was assessed by repeating the test in 16 subjects. The 95% confidence limits of the standard error of estimate are narrowest at 75 and 90 minutes.

Standardised approach to gluten challenge in diagnosing childhood coeliac disease

Thirty-five children, in whom coeliac disease had been diagnosed on inadequate grounds and who had been on a gluten-free diet for one to 10 years, were challenged with gluten in accordance with a standardised procedure. All children were admitted to hospital for 48 hours for general assessment, two one-hour blood xylose tests, and the introduction of gluten. Thirty children underwent a pre-challenge peroral jejunal mucosal biopsy; the specimens were either normal or showed slight non-specific abnormalities. Gluten powder 20 g/day was given in addition to an otherwise gluten-free diet. The children were reassessed as outpatients every two weeks, when a one-hour blood xylose test was performed. Repeat biopsy was performed when xylose absorption fell or after three months. Seventeen children had abnormal post-challenge biopsy appearances compatible with coeliac disease in relapse; 14 of these children completed their challenge within eight weeks. Seventeen children had completely normal biopsy appearances at the end of three months and were returned to a normal diet. One to two years later eight underwent repeat biopsies, which showed nothing abnormal. In only one child, the oldest in the series, were the histological findings equivocal. In the 17 children in whom coeliac disease was confirmed the duration of gluten challenge was not related to age, duration of gluten-free diet, histological findings on the pre-challenge biopsy, or HLA status.

Oats and barley toxicity in coeliac patients

The effect of addition of oats and barley to the glutenfree diets of a group of patients with coeliac disease has been studied using the oral 5 g xylose excretion test to assess small bowel function before and after these supplementations.

Both oats and barley were found to be potentially harmful to coeliac patients although the toxic effect of barley was more readily produced than that of oats.

On the basis of their results, the authors recommend the exclusion of both barley and oats, in addition to wheat and rye, from the coeliac diet. In view of the well recognized risk of the development of malignancy, such a diet should be followed particularly rigorously in those patients with a persistence of symptoms and of marked villous atrophy.

Confirming persistence of gluten intolerance in children diagnosed as having coeliac disease in infancy

In young infants the clinical and investigative features of coeliac disease (CD) may be mimicked by other conditions such as cow's milk intolerance or secondary disaccharidase deficiency. It is therefore especially important to confirm a diagnosis of CD by later gluten challenge in such infants. Sixteen children in whom the diagnosis of CD had been made before the age of 12 months had an oral gluten challenge, after being treated with a gluten-free diet for periods of one month to 5 years. In 15 we showed intestinal xylose malabsorption by the one-hour blood xylose level within 1-28 days of starting ingestion of gluten. One child, with a persistently normal one-hour blood xylose test after gluten challenge for 3 months, had normal absorption and normal jejunal histology after 18 months on a gluten-containing diet; she is considered not to have CD. The one-hour blood xylose test before and after gluten challenge can help to confirm the diagnosis in coeliac patients diagnosed in infancy.

Symposium on pathology of the gastrointestinal tract-Part II. Small intestinal biopsy

A practical approach to the interpretation of peroral small intestinal biopsy specimens is presented. Biopsy technique and tissure handling are described. Interpretation of normal and abnormal biopsy specimens is discussed. A practical classification of abnormal small intestinal biopsies is presented and illustrated.

Limitations of xylose tolerance test as a screening procedure in childhood coeliac disease

The usefulness of the xylose tolerance test as a screening procedure for coeliac disease has been reassessed in 54 children with suspected coeliac disease. 5- and 24-hour urinary excretion rates of xylose were of no value in discriminating between patients with and without coeliac disease; similarly, the 3-hour blood xylose concentration was nondiscriminatory. Three (15-8%) patients with subtotal villous atrophy and 8 (61-5%) with partial villous atrophy due to coeliac disease had one-hour blood xylose values which fell within the normal range. The effect of withdrawal or reintroduction of dietary gluten on sequential one-hour blood xylose levels was variable and generally unhelpful in predicting those patients who developed gluten-induced mucosal changes. The results of the present study emphasize the serious limitations of the xylose tolerance test as a screening procedure in childhood coeliac disease. It is recommended that the use of the urinary xylose test should be abandoned in the paediatric population. A normal one-hour blood xylose value does not exclude a diagnosis of coeliac disease even in young children who have never received a gluten-free diet. A clinical suspicion of coeliac disease remains the most important single factor in deciding whether to preform a jejunal biopsy.

Coeliac disease during the teenage period: the value of serial serum folate estimations

A group of teenage coeliac patients has been followed at three monthly intervals in the Outpatient Department to assess their progress and also to monitor their ability to maintain a gluten-free diet. After a follow-up period of four to six years a detailed reassessment was carried out in hospital on 10 patients, only five of whom had persevered with a gluten-free diet. The jejunal mucosal histology of those patients who did not persist with a gluten-free diet remained ;flat' although these patients appeared to have remitted clinically. Those subjects who did persist with a gluten-free regime had a normal or near normal mucosal histology. It was difficult on the basis of clinical, haematological, or biochemical criteria to separate the two groups. The best single assessment of whether these patients were maintaining a gluten-free diet was serial serum folate estimations. It is often extremely difficult to say whether teenage coeliac patients are keeping to their diet unless repeated jejunal biopsies are obtained, and this study suggests that serial serum folate estimations can act as a reasonable criterion of whether subjects are maintaining a gluten-free regime.