G. Maiella

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.

Activation of NOD2-mediated Intestinal Pathway in a Pediatric Population with Crohn's Disease

Background: NOD2 is an intracellular protein involved in host recognition of specific bacterial molecules and is genetically associated with several inflammatory diseases, including Crohns disease (CD). NOD2 stimulation activates the transcription factor, NF‐κB, through RIP2, a caspase‐recruitment domain‐containing kinase. NOD2/RIP2 signaling also mediates the activation of antimicrobial peptides such as human α‐defensin 5 (HD‐5) and human α‐defensin 6 (HD‐6), both produced by Paneth cells. The present study is aimed at describing the downstream events triggered specifically by NOD2 induction in order to demonstrate that the protein, other than overexpressed, is also physiologically associated with RIP2 and Erbin in the bioptic intestinal inflamed specimens of children affected by CD. Methods: Fifteen children with CD and 10 children used as controls were entered in the study. Mucosal biopsy specimens were taken during endoscopy and mRNA and protein expressions were detected by using real‐time polymerase chain reaction and Western blot. Results: NOD2 is able to form an immunocomplex with the kinase RIP2. As compared to controls, in the inflamed mucosa of patients both mRNA and protein expression levels of RIP2 are increased, and its active phosphorylated form is overexpressed. Conclusions: In this study we provide for the first time ex vivo evidence of physiologically relevant protein interactions with NOD2, which are able to trigger the innate immune response in intestinal mucosal specimens of children with CD. (Inflamm Bowel Dis 2009)

The anti-deamidated gliadin peptide antibodies unmask celiac disease in small children with chronic diarrhoea

OBJECTIVES To assess the usefulness of a new class of antibodies, the anti-deamidated gliadin peptides, in the diagnostic approach to children less than 2 years with suspected celiac disease. PATIENTS AND METHODS We investigated 40 children (median age: 16.8 months; age range: 4-24 months), with symptoms and signs of chronic enteropathy and high serum levels of conventional anti-gliadin antibodies, but normal values of anti-transglutaminase and anti-endomysial antibodies; all underwent measurement of anti-deamidated gliadin peptides serum levels, upper gastrointestinal endoscopy with biopsies and HLA typing; 40 subjects served as controls. RESULTS In 29 patients (group A) serum levels of anti-deamidated gliadin peptides were normal and duodenal histology showed a spectrum of abnormalities ranging from mucosal inflammatory infiltrates to villous damage (in almost all cases compatible with Marsh 1-to-2 lesions). All improved on a cows and soy milk free diet containing gluten. In 11 patients (group B) there were high serum levels of anti-deamidated gliadin peptides and histology showed features suggestive of celiac disease (Marsh 2-to-3 lesions) in all; furthermore, human leucocyte antigen typing was consistent with a celiac disease genetic pattern in all. Group B patients significantly improved on a gluten free diet containing cows and soy milk proteins. None of the control group was anti-deamidated gliadin peptides positive. CONCLUSIONS In children younger than 2 years with signs of chronic enteropathy and normal values of classical serum markers of celiac disease, the latter can be predicted by high serum levels of anti-deamidated gliadin peptides.

PA29 PRESUMPTIVE SAFETY FOR CELIAC PATIENTS OF WHEAT BAKED GOODS RENDERED GLUTEN-FREE DURING SOURDOUGH FERMENTATION

After several interviews, this teenager admitted participation to an unusual dietary party with three peers, 4 days before admission. They ate a “soup” formed by gravel, wheat flour and water, for slimming purposes. The soup recipe had been found on an unidentified web site. After the party, one of the friends underwent emergency appendectomy for appendix occlusion caused by a gravel stone, another had been admitted for acute abdominal pain followed by passage of gravel stones in the stool while the third eliminated the stones in the stools without any complaint. Discussion: This case-report highlights the risks related to improper use of uncontrolled information found on the internet. There is a rising and widespread use of the web among children and adolescents. Recent studies showed that adolescents disclose personal information and may display risky behaviour. Sylvia wanted to loose weight even though her BMI was normal (18.7 = 25th percentile for age and gender). Concerns about weight, body shape and dieting are common among adolescent girls and may represent risk factors for eating disorders. One’s body image perception is influenced by several factors, including personal, parental and friends’ judgement, sociocultural environment and media pressures, that are believed to encourage the development of an unrealistically thin ideal of body shape. Independent of age and BMI, parental and media influences on adolescents are predictive of becoming highly concerned with weight and a constant dieter. Abdominal ultrasound is usually the first-line (and often the only) imaging investigation performed in the diagnostic process of children with AAP, to exclude appendicitis or other surgical conditions (e.g. intussusception). Abdominal ultrasound has however limitations (e.g. presence of excessive intestinal gas and operator dependence) and does not always identify ingested foreign bodies. In this patient, the intestinal stones were indeed detected only by a standard abdominal x-ray. Conclusions: Acute or recurrent abdominal pain is a frequent complaint in adolescents, particularly of those experiencing emotional and socio-familial difficulties. A careful interview can help to identify risky behaviours that could be responsible for this distressing disorder. As suggested by this case-report, the use of junk information retrieved by uncontrolled internet sources should be investigated. The deliberate ingestion of foreign bodies is a possible cause of AAP in teenagers.

Atrioventricular block associated with Crohn's relapsing colitis in a 12‐year‐old child

To the Editor: Inflammatory bowel diseases (IBDs) are associated with extraintestinal manifestations. Many systems or organs, i.e., eye, skin, liver, bone, and joints are frequently involved in IBD, but cardiac involvement is considered rare. Myopericarditis, worsening of congestive heart failure, sinusal symptomatic bradycardia, and heart block have been described in IBD patients as side effects of infliximab (chimeric monoclonal antibody to tumor necrosis factor-a). Cardiac conduction disturbances associated with IBD, in the absence of infliximab treatment, have been described in only a few case reports regarding adult patients with ulcerative colitis. Cardiac conduction system disturbance in children with Crohn’s disease (CD), not treated with infliximab, have not been reported yet. We describe the case of a 12-year-old child with CD involving the terminal ileum. There was no past history of cardiac disease and no evidence of myocardial ischemia or recent viral infection. The patient was treated with nutritional therapy (Modulen) and with azathioprine, but he was not treated with any anti-TNFa drugs. CD had been in remission for 6 months when the child developed bloody diarrhea without any systemic symptoms. He was hospitalized for relapse of CD. Colonoscopy showed active pancolitis. Laboratory data showed hemoglobin 11.8 mg/dL, white cells 9340 (neutrophils 79.4%), erythrocyte sedimentation rate (ESR) (31 mm/h), and D-dimer (782 mg/dL). Serology for cytomegalovirus, Epstein–Barr virus, and Mantoux test were negative. Fecal exam was positive for Clostridium difficile and antiSaccharomyces cerevisiae antibodies (ASCA) were high (160; normal value < 14). ECG showed first-degree atrioventricular block which was absent in previous electrocardiogram (ECG) (Fig. 1) and it was confirmed by 24-hour ECG monitoring. To assess autonomic system balance, heart rate variability (HRV), by short computed ECG monitoring (10 minutes), was recorded. Low LF/HF ratio (0.36), which is a sign of increased parasympathetic tone, was shown. Treatment with intravenous methylprednisone for 2 days was started. After 48 hours the bloody diarrhea cleared. Subsequently, oral therapy was carried out for several weeks. The azathioprine therapy was later replaced with methotrexate 20 mg/week intramuscularly, salazopyrin 2 cp 3 times a day, and folic acid. Metronidazole for C. difficile infection was also administered. On 3-month follow-up both outpatient review of bowel habits and colonoscopy were normal. Hematochemical parameters returned to normal range (hemoglobin 12.4 mg/dL, white cell 5000, ESR 8 mm/h). The LF/HF ratio returned to normal values (1.48). Monitoring ECG for 5 hours confirmed the persistence of atrioventricular block (PR mean 0.21 sec; normal value for age: 0.09–0.18 sec). To today, atrioventricular block is still present. We describe the case of a child with first-degree atrioventricular block associated with CD. This heart block, absent in previous ECG, appeared during the relapse of colitis and did not disappear at termination of relapse and is still present after 12 months. The excess of vagal activity, observed during relapse of disease, seems not have been implicated in the origin of atrioventricular block because of its persistence after vagal reequilibrium. Atrioventricular block in CD has been associated with infliximab therapy, but our patient had not been treated with this drug. Azathioprine and aminosalycilates seem to play a role in the etiology of pericarditis, but not in cardiac conduction disturbances. In conclusion, in our case both autonomic imbalance and drug therapy do not seem to be implicated in atrioventricular block, so it might be that the inflammatory state of relapsing colitis has caused damage to the cardiac conduction system cells. Microvascular endothelial dysfunction has been found in IBD patients. We speculate that some ischemic microdamage in the cardiac conduction system of our FIGURE 1. ECG recorded in Lead II before (A) and during (B) relapse of CD. ECG in B shows atrioventricular block.

381 Conventional AGA Positivity in Children Under Two Years of Age: Celiac Disease or Food Allergy? the Role of Anti-Deamidated Gliadin Peptide Antibodies

Background: Chronic gastrointestinal symptoms in children aged less than two years often represent a clinical challenge for paediatricians, since discriminating between coeliac disease (CD) and food allergy (FA) in this age group might be quite tricky, as classical serum markers for CD, except anti-gliadin antibodies (AGA), are not uncommonly negative. Objective: The aim of our study was to assess the role of aDGP as diagnostic tool differentiating between CD and FA in children aging less than 24 months with high levels of serum AGA, when EmA and anti-tTG are negative. Methods: We investigated 40 children (median age: 16,8 months; age range: 4-24 months), with chronic gastrointestinal symptoms suggesting either CD or FA and with high serum levels of conventional AGA, with normal values of serum IgA, anti-transglutaminase (anti-tTG) and anti-endomysial (EmA) antibodies and without sensitization to the most common food antigens. All of them underwent measurement of serum levels of aDGP (IgA and IgG) and upper gastrointestinal endoscopy with duodenal biopsies; 40 controls were ageand sex-matched to these patients in order to clarify the aDGP specificity. Results: 29 patients (group A) had normal levels of aDGP; their histological features were compatible with Marsh I to III lesions and mimicked CD. However, all of them markedly improved on a cows milk, soy and egg free diet containing gluten. After three months, these food antigens were reintroduced; subsequently, the vast majority of children (93,1%) belonging to group A experienced a clinical relapse and the return to the previous oligoantigenic diet was once more beneficial. On the other hand, 11 patients (group B) had high serum levels of aDGP (IgG positivity in all of them; IgA positivity in 9), whereas histology showed the same lesions of group A. HLA typing was obtained; haplotypes carried by children of group B were consistent with CD genetic pattern. Moreover, they significantly improved on a gluten free diet containing cows milk, soy and egg. None of the control group (group C) was aDGP positive. Conclusions: Our data indicate that serum IgG aDGP may be of pivotal usefulness in identifying celiac patients under two years of age with chronic gastrointestinal symptoms and only conventional AGA positivity, distinguishing them from FA. Although the great clinical improvement with GFD in group B, gluten challenge will be permorfed to confirm CD diagnosis.