Margherita Bonamico

The gluten-free diet: a nutritional risk factor for adolescents with celiac disease?

BACKGROUND The gluten-free diet is the standard therapy for patients affected by celiac disease, although compliance with the diet is not optimal in adolescents or adults. Moreover, the gluten-free diet may induce nutritional imbalances. METHODS Alimentary habits and diet composition were examined in 47 adolescents with celiac disease and 47 healthy aged-matched control subjects. All subjects compiled a 3-day alimentary record that allowed determination of their energy intakes: the macronutrient composition of their diets; and their iron, calcium, and fiber intakes. To evaluate compliance with the gluten-free diet, immunoglobulin A antigliadin and antiendomysium antibodies were assessed in all with celiac disease. RESULTS The analysis of the records and the results of antibody levels showed that 25 subjects strictly followed dietetic prescriptions (group 1A), whereas 22 patients consumed gluten-containing food (group 1B). Those with celiac disease and control subjects (group 2) consumed a normocaloric diet. Lipid and protein consumption was high, however, and the consumption of carbohydrates low. Moreover, dietary levels of calcium, fiber, and especially in girls, iron, were low. These nutritional imbalances were significantly more evident in group 1A than in group 1B, as a consequence of poor alimentary choices. Moreover, in group 1A overweight and obesity were more frequent (72%) than in group 1B (51%) and in the control subjects (47%). CONCLUSIONS In people with celiac disease, adherence to a strict gluten-free diet worsens the already nutritionally unbalanced diet of adolescents, increasing elevated protein and lipid consumption. In the follow-up of patients with celiac disease, considerable effort has yet to be made to improve compliance with a gluten-free diet, and especially to control the nutritional balance of the diet in compliant patients.

Patchy villous atrophy of the duodenum in childhood celiac disease.

Objectives Patchy villous atrophy of the duodenal mucosa has been described in adults with untreated celiac disease (CD) but not in children. The authors evaluated the presence and the distribution of villous atrophy in children with celiac disease to see whether this histologic pattern exists in children. Methods We studied 95 children at diagnosis (Group 1) and seven during gluten challenge (Group 2). We measured anti-endomysium antibodies (EMA) by immunofluorescence on monkey esophagus, antihuman-tissue transglutaminase autoantibodies (anti-tTG Abs) by radioimmunoprecipitation, and HLA-DQ2/DQ8 heterodimers by polymerase chain reaction using specific primers. During upper intestinal endoscopy, at least five duodenal biopsy samples were obtained, one from the duodenal bulb and four from the distal duodenum. Results Thirteen of 95 (13.7%) patients in Group 1 and in 3 of 7 (42.9%) in Group 2 had patchy villous atrophy of the duodenum. In all 16 patients, villous atrophy of the bulb was present. In four children from Group 1, villous atrophy was observed only in the bulb samples. EMA, anti-tTG Abs, and HLA-DQ2/DQ8 heterodimers were present in all patients. Fourteen of 16 had symptomatic CD, and two were silent, detected during screening in subjects at risk for CD. Conclusions This is the first study demonstrating that children with CD may have patchy villous atrophy of the duodenum. The bulb mucosa may be the only duodenal area involved, both at diagnosis and after gluten challenge. Therefore, multiple endoscopic biopsies should always be performed, not only in the distal duodenum, but also in the bulb.

Genetic contribution of the HLA region to the familial clustering of coeliac disease

In order to assess the effect of the HLA region on familiality of coeliac disease (CD), we carried out a study on 121 CD index cases and 325 first degree relatives. The transmission disequilibrium test confirmed the importance of the HLA‐DR3 haplotype in CD susceptibility. However, the different distortion found in affected children inheriting maternal or paternal DR3 alleles suggested that the sex of the parent might influence the risk conferred by this haplotype. The increase in risk to siblings of affected individuals relative to the risk in the general population (λs) and the contribution of the HLA genes to this clustering (λsHLA) have also been estimated. Non‐overlapping data from the literature have been collected and combined with our sample to extend such analysis. Then, the percentage contribution of the HLA region to the development of CD among siblings was 36·2%. This result confirms that the HLA genotypes are an important genetic background to CD development but shows that additional susceptibility factors remain to be identified.

Prevalence and clinical picture of celiac disease in italian down syndrome patients: a multicenter study.

Background A multicenter research study of Down syndrome patients was carried out to estimate the prevalence of celiac disease in patients with Down syndrome and to show clinical characteristics and laboratory data of Down syndrome patients. Methods The authors studied 1,202 Down syndrome patients. Fifty-five celiac disease patients (group 1) were compared with 55 immunoglobulin A antigliadin–positive antiendomysium antibodies–negative patients (group 2) and with 57 immunoglobulin A antigliadin–negative antiendomysium antibodies–negative patients (group 3). Results Celiac disease was diagnosed in 55 of 1,202 Down syndrome patients (4.6%). In group 1, weight and height percentiles were shifted to the left, whereas these parameters were normally distributed in groups 2 and 3. In celiac patients, diarrhea, vomiting, failure to thrive, anorexia, constipation, and abdominal distension were higher than in the other two groups. Low levels of hemoglobinemia, serum iron, and calcium were observed more frequently in group 1. The diagnosis of celiac disease was made after a mean period of 3.8 years from the initiation of symptoms. Sixty-nine percent of patients showed a classic presentation, 11% had atypical symptoms, and 20% had silent celiac disease. Autoimmune disorders were more frequent (30.9%) in group 1 than in the other two groups examined (15%;P < 0.05). Conclusions This study reconfirms a high prevalence of celiac disease in Down syndrome. However, the diagnostic delay, the detection of atypical symptoms or silent form in one third of the cases, and the increased incidence of autoimmune disorders suggest the need for the screening of celiac disease in all Down syndrome patients.

Importance of gluten in the induction of endocrine autoantibodies and organ dysfunction in adolescent celiac patients

OBJECTIVE:It is well known that a high number of celiac patients may develop autoantibodies against endocrine glands, but it has not yet been clarified if this increased autoimmune response and the impaired organ function that can develop may be related to the presence or absence of gluten in the diet. The aim of the present study was to evaluate the effect of gluten on the autoimmunity and function of the endocrine glands in adolescent celiac patients.METHODS:To clarify this aspect we investigated 44 patients (28 females), aged 11–20 yr (15.21 ± 2.7 yr): 25 (mean age, 15.1 ± 2.2 yr) on a gluten-free diet (treated patients) and 19 (mean age 15.4 ± 2.9 yr) with a diet containing gluten (untreated patients). Forty adolescent subjects, aged 14–19 yr (mean age, 14.9 ± 2.7 yr), of whom 20 were females, were studied as controls. Antibodies against the thyroid, adrenal, and pancreas were evaluated. Thyroid-stimulating hormone FT3, FT4, T3, T4, dehydroepiandrosterone sulphate, 17-OH progesterone, and cortisol, analyzed basally and 60 min after intravenous ACTH stimulation, were assayed to evaluate thyroid and adrenal function. The fasting glycemia level was used to evaluate the endocrine pancreas function. An ultrasonogram of the thyroid gland was performed on all patients. HLA class II typing for DR3 and DQB1 was performed in 32 of 44 patients.RESULTS:Seven of 44 (15.9%) patients were positive for antibodies against peroxidase. Six of 44 (13.6%) were positive for antibodies against thyreoglobulin and four of them also showed positive antibodies against peroxidase. Therefore, in nine of 44 at least one antibody directed against thyroid tissue was positive. Seven of 44 (15.9%) were positive for antibodies against islet cell, one of 44 (2.3%) positive for antibodies against glutamic acid decarboxilase, one of 44 (2.3%) positive for antibodies against insulin, and none for antibodies against islet cell- 512bdc. In 15 of 44 (34%) at least one antibody against an endocrine tissue was positive. The genotype DR3 was found in 21 of 32 (65.6%) celiac patients (10 in the untreated and 11 in the treated group, respectively) and the genotype DQB1*02 (DQ2) was found in 30 of 32 (93.8%) patients (16 in the treated and 14 in the untreated group, respectively). DHA-S values were significantly lower in the untreated (30.5 ± 28.5 μg/dl) than in the treated group (61.3 ± 59.4 μg/dl, p < 0.05), and both showing significantly (p < 0.01) lower levels with respect to the controls (161 ± 52 μg/dl). One patient showed diabetes, another one clinical hypothyroidism (thyroid-stimulating hormone > 6), and two patients showed preclinical hypothyroidism. Interestingly, at least one antibody was positive in 10 of 19 untreated patients (52.6%) but only in five of 25 treated patients (20%), with a significantly different distribution (p < 0.001) between the two groups and without differences in the HLA genotype. The ultrasonographic evaluation of the thyroid resulted in a pathological score in six patients of the 44 examined (13.6%), suggesting the presence of thyropathy.CONCLUSIONS:The main results of this study are the high incidence of thyroid and pancreatic antibodies, and the possible role of gluten in the induction of the antibodies as well as, in few cases, the consequent organ dysfunction.

Duodenal bulb biopsies in celiac disease: a multicenter study

Objectives: Celiac disease (CD)–related lesions have been reported in duodenal bulb biopsies, sometimes the bulb mucosa being the only one affected. The aim was to verify in a significant series whether histological lesions are always present in the bulb of celiac patients, what is the prevalence of lesions when isolated to the bulb, and if similar lesions are present in nonceliac subjects. Methods: We studied 665 children with CD (241 males, range 9 months–15 years, 8 months), at diagnosis on a gluten-containing diet, and 348 age- and sex-matched gastroenterological controls submitted to upper endoscopy for gastroenterological complaints. During endoscopy, multiple biopsies (1 bulb and 4 distal duodenum samples) were taken. Anti-endomysium antibodies were evaluated by immunofluorescence method, anti–human tissue–transglutaminase antibodies by an enzyme-linked immunosorbent assay or radioimmunoassay. Human leukocyte antigen-DRB1, -DQA1, and -DQB1 genes were typed by polymerase chain reaction sequence–specific primers repeat method. Results: In all of the patients with CD, histological lesions were present in the bulb sample; in 16 of them, the lesions were present only in the bulb. Patchy villous atrophy was found in 20 children. All of the patients with CD were anti-endomysium and/or anti-transglutaminase positive. The controls showed neither autoantibody positivity nor mucosal changes compatible with CD. Conclusions: This study demonstrated that CD-related histological lesions are always present in the bulb; sometimes this specific site is the only one affected. Therefore, we suggest taking 2 biopsies from the bulb and 2 from the distal duodenum for CD diagnosis.

HLA-DQ and risk gradient for celiac disease.

Celiac disease (CD) is a rare example of multifactorial disorder in which a genetic test is of great clinical relevance, as the disease rarely develops in the absence of specific HLA alleles. We typed DR-DQ genes in 437 Italian children with celiac disease, 834 first-degree relatives, and 551 controls. Of patients, 91% carried DQ2 and/or DQ8 heterodimers, 6% only had beta2 chain, 2% was alpha5 positive, and four were DQ2/DQ8/beta2/alpha5 negative. Only the presence of alpha5 resulted negatively associated to disease (p = 2 x 10(-4)), whereas we confirmed the effect of the beta half of DQ2 dimer on CD predisposition (p = 4 x 10(-12)). Considering 1:100 disease prevalence, we obtained a risk gradient ranging from 1:7 for DQ2 and DQ8 individuals down to 1:2518 for subjects lacking all predisposing factors. The DQB1*02 and DQB1*0302 concurrence (p = 9 x 10(-4)), besides the DQB1*02/*02 homozygosity, had an additional role in disease genetic determination. The CD prevalence rose to 17.6% in sisters, 10.8% in brothers, and 3.4% in parents. In the three groups, the subjects carrying high-risk HLA molecules were 57%, 71%, and 58%; among them, 29%, 15%, and 6% respectively had CD. Those siblings and parents with no susceptible factors were not affected. These findings indicate the impact of the HLA test for CD in clinical practice.

Radioimmunoassay to detect antitransglutaminase autoantibodies is the most sensitive and specific screening method for celiac disease

OBJECTIVE:The aim of this study was to establish the most sensitive and specific screening method for celiac disease. We tested three methods based on different principles, which all detect autoantibodies against the same antigen (tissue transglutaminase).METHODS:Sixty-two celiac children at the first biopsy (group 1), 78 celiac children on a gluten-free diet (group 2), 14 celiac children on a gluten-challenge (group 3), and 56 controls with a normal duodenal mucosa (group 4) were studied. The methods used were: 1) radioimmunoprecipitation assay using recombinant tissue transglutaminase (RIA); 2) commercial enzyme immunoassay using guinea pig tissue transglutaminase (ELISA); and 3) indirect immunofluorescence method for detection of antiendomysium antibodies (IF-EMA).RESULTS:RIA antitransglutaminase autoantibodies were detected in 100% of group 1, 43.6% of group 2, 100% of group 3, and none of the control subjects. ELISA antitransglutaminase autoantibodies were detected in 90.3% of group 1, 9% of group 2, 78.6% of group 3, and in none of the control subjects. IF-EMA were detected in 95.2% of group 1, 11.5% of group 2, 92.3% of group 3, and 1.8% of the controls.CONCLUSIONS:Our results demonstrate a very high sensitivity and specificity of the RIA method to detect antitransglutaminase autoantibodies in comparison to ELISA and IF-EMA assays. We can explain this finding with the use of human recombinant antigen and the increased capacity of the RIA method to detect low titers of autoantibodies. If our data are confirmed by studies on larger series, tissue transglutaminase RIA could be proposed as the best screening method for celiac patients.

A Report on the International Transglutaminase Autoantibody Workshop for Celiac Disease

OBJECTIVES:Measurement of transglutaminase autoantibodies (TGAA) is considered to be the most efficient single serologic test for celiac disease (CD) by the American Gastroenterological Association Institute. We hypothesized that a large international collaborative effort toward improving and standardizing TGAA measurement is both feasible and necessary. The primary aim of this workshop is to compare TGAA assays among various research and clinical laboratories to examine assay concordance and improve (and eventually standardize) the TGAA assay.METHODS:A total of 20 laboratories (5 commercial laboratories, 15 research and clinical laboratories) participated that included enzyme-linked immunosorbent assay (ELISA) and radiobinding assays. A total of 150 serum samples were distributed to each laboratory, with each laboratory receiving an equal aliquot that was coded and blinded, composed of 100 healthy control sera and 50 CD sera.RESULTS:Laboratory sensitivity ranged from 69% to 93% and specificity ranged from 96% to 100%. By receiver operator characteristic analysis, the area under the curve (C index) ranged from 0.9488 to 0.9904. When analyzing for linear correlation, r-squared was as high as 0.8882 but as low as 0.4244 for the celiac samples between different laboratories performing ELISA.CONCLUSIONS:This transglutaminase autoantibody workshop allows for larger-scale international participation for the purposes of improving and eventually standardizing the TGAA assay with subsequent workshops.

Autoimmune thyroid disease and celiac disease in children.

Background: Celiac disease (CD) may be associated with other immunologic disorders in adults and children. Previous studies linking CD and autoimmune thyroid disease in children have included very few patients with limited biochemical and immunologic screening tests. The aim of this multicenter study was to establish the prevalence of autoimmune thyroid involvement in a large series of pediatric patients with CD. Methods: Five hundred seventy‐three consecutive pediatric patients were enrolled from clinics in Torino, Bologna, Foggia, Rome (two clinics), Naples, and Bari. Three hundred forty‐three patients with CD were studied, 230 girls and 113 boys (median age, 8.5 years). Two hundred fifty‐six of the patients with CD (median age, 9 years) had been following a gluten‐free diet for 3 months to 16 years; 87 patients were untreated (median age, 6.2 years). The diagnosis of CD was made using the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) criteria. A control group of 230 subjects (median age, 8.3 years) was enrolled. Serum free triiodothyronine, free thyroxine, and thyroid‐stimulating hormone (TSH), antithyroperoxidase, antithyroglobulin, anti‐TSH receptor antibodies, and thyroid echographic pattern were considered. Results: Autoimmune thyroid disease was found in 90 of 343 (26.2%) patients with CD (62 on a gluten‐free diet) and in 20 (10%) of the control subjects (P = 0.001). Fifty‐four (15.7%) patients with CD and autoimmune markers had normal thyroid function (euthyroidism) as did 12 (6.0%) of the control subjects; hypothyroidism was observed in 28 (8.1%) patients with CD and in 7 (3.5%) of the control subjects. Hyperthyroidism was diagnosed in four patients with CD and in none of the control subjects with autoimmune markers. An abnormal echographic pattern was seen in 37 patients with CD (16.8%) and only in 1 (1.6%) of the control subjects (P = 0.002). Conclusions: The high frequency of autoimmune thyroid disease found among patients with CD, even those on a gluten‐free diet, may justify a thyroid status assessment at diagnosis and at follow‐up evaluation of children with CD. JPGN 37:63‐66, 2003.