Fabio Massimo Magliocca

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.

Fecal Lactate and Ulcerative Colitis

Impaired metabolism of short-chain fatty acids, as well as a modified fecal ionogram, have been reported in ulcerative colitis. Fecal water samples from 62 patients with ulcerative colitis were analyzed in the present investigation to evaluate changes in SCFAs and lactic acid in relation to activity and severity of disease. Short-chain fatty acid levels were high in quiescent and mild disease (162.6 +/- 63.6 and 147.8 +/- 63.2 mM/L, respectively), but significantly decreased in the severe form (64.7 +/- 46.9 mM/L). Lactate showed a progressive increase from mild colitis (3.0 +/- 1.8 mM/L) to severe colitis (21.4 +/- 18.6 mM/L). It thus appears that mild colitis displayed a fecal pattern characterized by normal pH and bicarbonate, slightly impaired electrolyte handling, high short-chain fatty acid values, and only moderately increased lactate. Severe colitis, on the other hand, was characterized by low fecal pH, bicarbonate, and potassium, high sodium and chloride, low short-chain fatty acid levels, and very high lactate levels. A critical lowering of intraluminal pH, which shifts bacterial metabolism from short-chain fatty acid to lactate production, may be responsible for the intraluminal pooling of lactate.

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.

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.

Serologic and genetic markers of celiac disease: A sequential study in the screening of first degree relatives

Objectives: The prevalence of celiac disease (CD) among the relatives and the complications of an undiagnosed CD prompted us to identify a useful disease screening strategy. Methods: We studied 441 first degree relatives of 208 CD patients by immunoglobulin (Ig)A antiendomysium antibodies (EMA) and radioimmunoprecipitation assay (RIA) IgA antitransglutaminase autoantibodies (TGAA). Of these, 364 were typed for human leukocyte antigen-DRB1, -DQA1, and -DQB1 genes by the polymerase chain reaction sequence specific primers method. It was suggested to the autoantibody-positive subjects that they should undergo intestinal biopsy. Results: TGAA were positive in 46 of 439 relatives, EMA in 38; intestinal lesions related to CD were present in 40 subjects. We also found two immunodeficient fathers with duodenal villous atrophy. In three serology-positive subjects, permission for intestinal biopsy was refused; for another three serology-positive cases, duodenal mucosa was normal. Thus, the strict CD prevalence resulted 9.5%, the enlarged prevalence 10.9%. The DQ2/DQ8 heterodimers were carried in 231 of 364 subjects and in 38 of 40 biopsy-proven celiac patients. Three DQ2-positive parents became positive to the serology during a long-lasting follow-up. Conclusions: On the basis of a carefully conducted study, CD prevalence in our series was seen as very high. These data suggest an accurate algorithm to select candidates for intestinal biopsy among CD high-risk subjects. First, an evaluation of the sensitive RIA TGAA and of total IgA (in IgA deficiency RIA IgG anti-tissue transglutaminase assay) should be performed. Then, an evaluation of the TGAA and the genetic study would be advisable 2 to 3 years later in negative subjects. Those carrying the DQ2/DQ8 heterodimers should continue the serologic follow-up; the others need a clinical follow-up.

First salivary screening of celiac disease by detection of anti-transglutaminase autoantibody radioimmunoassay in 5000 Italian primary schoolchildren.

Objective: The high prevalence of celiac disease (CD) prompted us to evaluate a new, noninvasive disease screening strategy. The aim was to identify CD in 6- to 8-year-old children for a timely diagnosis, start gluten-free diet (GFD) in compliant subjects, achieve the growth target, and prevent CD complications. Methods: Five thousand subjects were invited to participate in the study. Four thousand forty-eight saliva samples were tested for anti-tissue transglutaminase (tTG) immunoglobulin (Ig)A using a fluid-phase radioimmunoprecipitation method. Positive children were tested for serum radioimmunoassay tTG IgA, enzyme-linked immunosorbent assay tTG IgA, and anti-endomysium IgA. Children confirmed as positive by serum assays underwent endoscopy with duodenal biopsies and, at the diagnosis of CD, were suggested to start GFD. Results: Consent was obtained from 4242 parents (84.8%) for the screening to be performed, and adequate saliva samples were collected from 4048 children (95.4%). Thirty-two children were found to be salivary tTG IgA positive and 9 with borderline autoantibody levels. Thirty-one of the 32 and 3 of the 9 subjects were also serum positive. Twenty-eight children showed villous atrophy when undergoing intestinal biopsy, whereas 1 had Marsh 1 lesions; 3 children were suggested to start GFD without performing endoscopy. CD prevalence in the population investigated (including 19 CD known cases) was 1.16%. The ratio between screening-detected patients and those diagnosed before the screening was 3:2. The ratio between symptomatic and asymptomatic patients was 1:1.6. Conclusions: We demonstrated that it is possible to perform a powerful, simple, well-accepted, and sensitive CD screening using saliva. Until now, the compliance with GFD in children with CD has been optimal.

The Celiac Iceberg: Characterization of the Disease in Primary Schoolchildren

Objective: Celiac disease (CD) has a prevalence of 0.55% to 1% in Italy. Identifying CD in schoolchildren to characterize CD iceberg and evaluate the effect of diagnosis in screening-detected children. Methods: A total of 7377 5- to 8-year-old children were invited to participate. A total of 5733 salivary samples were collected and tested for anti-transglutaminase antibodies (tTGAb), using a fluid-phase radioimmunoassay. Salivary tTGAb-positive children were analyzed for serum antibodies (anti-endomysium antibodies, radioimmunoassay, and enzyme-linked immunosorbent assay tTGAb). Positive children underwent endoscopy and then started gluten-free diet (GFD) and periodical follow-up. Results: Forty-six subjects were found salivary tTGAb–positive and 16 border-line. Forty-five of 46 and 5 of 15 of them were also serum antibody–positive. Forty-two children showed duodenal villous atrophy and 1 had only type 1 lesions. Three children started GFD without performing endoscopy. CD prevalence (including 23 previously diagnosed children with CD) was 1.2%. Considering all 65 celiacs in our sample, a silent CD was found in 64%, typical in 28%, atypical in 7%, and potential in 1%. All patients showed strict adherence to GFD, weight and stature increase, and well-being improvement. Eighty-five percent and all but 2 screening-detected children with CD had Italian parents. Conclusions: Our sample size, representative of primary schoolchildren of our region, demonstrated that CD prevalence is growing in Italy, with a modified clinical spectrum and iceberg deepness.

Evaluation of Stool Antigen Test, PCR on ORAL Samples and Serology for the Noninvasive Detection of Helicobacter pylori Infection in Children

Background.  Endoscopy represents the gold standard for the diagnosis of Helicobacter pylori infection. We evaluated three noninvasive tests in a group of children: the immunoassay for detection of H. pylori stool antigen, the polimerase chain reaction for identification of bacterial DNA on the oral cavity and the serum specific antibodies.

HLA-DQB1*02 dose effect on RIA anti-tissue transglutaminase autoantibody levels and clinicopathological expressivity of celiac disease.

Objectives: Celiac disease is an autoimmune enteropathy caused by gluten ingestion in genetically susceptible individuals. Anti-transglutaminase autoantibody (tTGAb) assay is useful to detect candidates undergoing intestinal biopsy. Our aim was to investigate whether the DQB1*02 allele could influence tTGAb titers and the clinicopathological expressivity of the disease. Methods: A total of 124 patients with celiac disease, tested for RIA tTGAb at diagnosis, were typed for HLA-DRB1, -DQA1, and -DQB1 genes and divided according to the number of DQB1*02 alleles: group 1, homozygous; group 2, heterozygous; group 3, negative. Results: The mean of tTGAb indexes was significantly higher in group 1 patients than in group 2 (P < 0.02) and group 3 patients (P < 0.01). Patients with at least 1 DQB1*02 allele showed more often a typical CD and diffuse histological lesions than did patients in the other groups. Conclusions: The study demonstrates that tTGAb titers are HLA-DQB1*02 dose dependent, with significantly higher levels in homozygous individuals. Moreover, individuals with at least 1 HLA-DQB1*02 allele tend to have a more expressed clinical and histological form of celiac disease.

Duodenal bulb in celiac adults: The "whether biopsying" dilemma

Background: Celiac disease (CD)-related lesions were described in duodenal bulb of celiac patients. Goal: Our aim was to evaluate the morphology of bulb mucosa in adult celiac patients and in controls to evaluate its usefulness for CD diagnosis. Study: We studied 43 celiac patients (10 male, median age: 35.2 y) at diagnosis and 43 gastroenterological controls (10 male, median age: 37.8 y), submitted to upper endoscopy for gastroenterological complaints. Histologic lesions were assayed by an experienced pathologist according to the Marsh modified classification. Antiendomysium antibodies and antitransglutaminase antibodies-tTGAb (ELISA and/or RIA) have been tested. In selected patients, DNA was typed for DRB1, DQA1, and DQB1 genes by sequence-specific primer polymerase chain reaction. Results: In all celiac patients lesions were present in the bulb mucosa. One female with thyroiditis, who had a CD daughter, showed lesions only in the duodenal bulb. Patchy villous atrophy was found in another patient. All celiacs were antiendomysium and/or tTGAb positive. DQ2 heterodimer was present in 5 CD patients. The gastroenterological controls showed normal mucosa in the duodenum. Conclusions: This study demonstrates that CD-related histologic lesions are present in duodenal bulb of adult patients. Moreover, the normal aspect of this mucosa in gastroenterological controls implies the high negative predictive value of this finding. Therefore, we suggest taking at least 1 biopsy on the bulb area and 1 from the distal duodenum for CD diagnosis, in all the patients submitted to upper endoscopy, to avoid missed or delayed diagnosis.