Prediction Models for Celiac Disease Development in Children From High-Risk Families: Data From the PreventCD Cohort

BACKGROUND & AIMS

Screening for celiac disease (CD) is recommended in children with affected first-degree relatives (FDR). However, the frequency of screening and at what age remain unknown. The aims of this study were to detect variables influencing the risk of CD development and develop and validate clinical prediction models to provide individualized screening advice.

METHODS

We analyzed prospective data from the 10 years of follow-up of the PreventCD-birth cohort involving 944 genetically predisposed children with CD-FDR. Variables significantly influencing the CD risk were combined to determine a risk score. Landmark analyses were performed at different ages. Prediction models were created using multivariable Cox proportional hazards regression analyses, backward elimination, and Harrell's c-index for discrimination. Validation was done using data from the independent NeoCel cohort.

RESULTS

In March 2019, the median follow-up was 8.3 years (22 days-12.0 years); 135/944 children developed CD (mean age, 4.3 years [range, 1.1-11.4]). CD developed significantly more often in girls (P = .005) and in Human Leukocyte Antigen (HLA)-DQ2 homozygous individuals (8-year cumulative incidence rate of 35.4% vs maximum of the other HLA-risk groups 18.2% [P < .001]). The effect of homozygosity DR3-DQ2/DR7-DQ2 on CD development was only present in girls (interaction P = .04). The prediction models showed good fit in the validation cohort (Cox regression 0.81 [0.54]). To calculate a personalized risk of CD development and provide screening advice, we designed the Prediction application https://hputter.shinyapps.io/preventcd/.

CONCLUSION

Children with CD-FDR develop CD early in life, and their risk depends on gender, age and HLA-DQ, which are all factors that are important for sound screening advice. These children should be screened early in life, including HLA-DQ2/8-typing, and if genetically predisposed to CD, they should get further personalized screening advice using our Prediction application.

TRIAL REGISTRATION NUMBER

ISRCTN74582487 (https://www.isrctn.com/search?q=ISRCTN74582487).

Gamma-gliadin specific celiac disease antibodies recognize p31-43 and p57-68 alpha gliadin peptides in deamidation related manner as a result of cross-reaction

Celiac disease (CeD) is a T-cell-dependent enteropathy with autoimmune features where tissue transglutaminase (TG2)-mediated posttranslational modification of gliadin peptides has a decisive role in the pathomechanism. The humoral immune response is reported to target mainly TG2-deamidated γ-gliadin peptides. However, α-gliadin peptides, like p57-68, playing a crucial role in the T-cell response, and p31-43, a major trigger of innate responses, also contain B-cell gliadin epitopes and γ-gliadin like motifs. We aimed to identify if there are anti-gliadin-specific antibodies in CeD patients targeting the p31-43 and p57-68 peptides and to examine whether deamidation of these peptides could increase their antigenicity. We explored TG2-mediated deamidation of the p31-43 and p57-68 peptides, and investigated serum antibody reactivity toward the native and deamidated α and γ-gliadin peptides in children with confirmed CeD and in prospectively followed infants at increased risk for developing CeD. We affinity-purified antibody populations utilizing different single peptide gliadin antigens and tested their binding preferences for cross-reactivity in real-time interaction assays based on bio-layer interferometry. Our results demonstrate that there is serum reactivity toward p31-43 and p57-68 peptides, which is due to cross-reactive γ-gliadin specific antibodies. These γ-gliadin specific antibodies represent the first appearing antibody population in infancy and they dominate the serum reactivity of CeD patients even later on and without preference for deamidation. However, for the homologous epitope sequences in α-gliadins shorter than the core QPEQPFP heptapeptide, deamidation facilitates antibody recognition. These findings reveal the presence of cross-reactive antibodies in CeD patients recognizing the disease-relevant α-gliadins.

Histopathological evaluation of duodenal biopsy in the PreventCD project. An observational interobserver agreement study

Aim of the current study was to evaluate the inter-observer agreement between pathologists in the diagnosis of celiac disease (CD), in the qualified context of a multicenter study. Biopsies from the "PreventCD" study, a multinational- prospective- randomized study in children with at least one-first-degree relative with CD and positive for HLA-DQ2/HLA-DQ8. Ninety-eight biopsies were evaluated. Considering diagnostic samples with villous atrophy (VA), the agreement was satisfactory (κ = 0.84), but much less when assessing the severity of these lesions. The use of the recently proposed Corazza-Villanacci classification showed a moderately higher level of agreement (κ = 0.39) than using the Marsh-Oberhuber system (κ = 0.31). 57.1% of cases were considered correctly oriented. A number of >4 samples per patient was statistically associated to a better agreement; orientation did not impact on κ values. Agreement results in this study appear more satisfactory than in previous papers and this is justified by the involvement of centers with experience in CD diagnosis and by the well-controlled setting. Despite this, the reproducibility was far from optimal with a poor agreement in grading the severity of VA. Our results stress the need of a minimum of four samples to be assessed by the pathologist.

Accuracy in Diagnosis of Celiac Disease Without Biopsies in Clinical Practice

BACKGROUND & AIMS

The guidelines of the European Society of Pediatric Gastroenterology, Hepatology, and Nutrition allow for diagnosis of celiac disease without biopsies in children with symptoms and levels of immunoglobulin A against tissue-transglutaminase (TGA-IgA) 10-fold or more the upper limit of normal (ULN), confirmed by detection of endomysium antibodies (EMA) and positivity for HLA-DQ2/DQ8. We performed a large, international prospective study to validate this approach.

METHODS

We collected data from consecutive pediatric patients (18 years or younger) on a gluten-containing diet who tested positive for TGA-IgA from November 2011 through May 2014, seen at 33 pediatric gastroenterology units in 21 countries. Local centers recorded symptoms; measurements of total IgA, TGA, and EMA; and histopathology findings from duodenal biopsies. Children were considered to have malabsorption if they had chronic diarrhea, weight loss (or insufficient gain), growth failure, or anemia. We directly compared central findings from 16 antibody tests (8 for TGA-IgA, 1 for TGA-IgG, 6 for IgG against deamidated gliadin peptides, and 1 for EMA, from 5 different manufacturers), 2 HLA-DQ2/DQ8 tests from 2 manufacturers, and histopathology findings from the reference pathologist. Final diagnoses were based on local and central results. If all local and central results were concordant for celiac disease, cases were classified as proven celiac disease. Patients with only a low level of TGA-IgA (threefold or less the ULN) but no other results indicating celiac disease were classified as no celiac disease. Central histo-morphometry analyses were performed on all other biopsies and cases were carefully reviewed in a blinded manner. Inconclusive cases were regarded as not having celiac disease for calculation of diagnostic accuracy. The primary aim was to determine whether the nonbiopsy approach identifies children with celiac disease with a positive predictive value (PPV) above 99% in clinical practice. Secondary aims included comparing performance of different serological tests and to determine whether the suggested criteria can be simplified.

RESULTS

Of 803 children recruited for the study, 96 were excluded due to incomplete data, low level of IgA, or poor-quality biopsies. In the remaining 707 children (65.1% girls; median age, 6.2 years), 645 were diagnosed with celiac disease, 46 were found not to have celiac disease, and 16 had inconclusive results. Findings from local laboratories of TGA-IgA 10-fold or more the ULN, a positive result from the test for EMA, and any symptom identified children with celiac disease (n = 399) with a PPV of 99.75 (95% confidence interval [CI], 98.61-99.99); the PPV was 100.00 (95% CI, 98.68-100.00) when only malabsorption symptoms were used instead of any symptom (n = 278). Inclusion of HLA analyses did not increase accuracy. Findings from central laboratories differed greatly for patients with lower levels of antibodies, but when levels of TGA-IgA were 10-fold or more the ULN, PPVs ranged from 99.63 (95% CI, 98.67-99.96) to 100.00 (95% CI, 99.23-100.00).

CONCLUSIONS

Children can be accurately diagnosed with celiac disease without biopsy analysis. Diagnosis based on level of TGA-IgA 10-fold or more the ULN, a positive result from the EMA tests in a second blood sample, and the presence of at least 1 symptom could avoid risks and costs of endoscopy for more than half the children with celiac disease worldwide. HLA analysis is not required for accurate diagnosis. Clinical Trial Registration no: DRKS00003555.

Similar Responses of Intestinal T Cells From Untreated Children and Adults With Celiac Disease to Deamidated Gluten Epitopes

BACKGROUND & AIMS

Celiac disease is a chronic small intestinal inflammatory disorder mediated by an immune response to gluten peptides in genetically susceptible individuals. Celiac disease is often diagnosed in early childhood, but some patients receive a diagnosis late in life. It is uncertain whether pediatric celiac disease is distinct from adult celiac disease. It has been proposed that gluten-reactive T cells in children recognize deamidated and native gluten epitopes, whereas T cells from adults only recognize deamidated gluten peptides. We studied the repertoire of gluten epitopes recognized by T cells from children and adults.

METHODS

We examined T-cell responses against gluten by generating T-cell lines and T-cell clones from intestinal biopsies of adults and children and tested proliferative response to various gluten peptides. We analyzed T cells from 14 children (2-5 years old) at high risk for celiac disease who were followed for celiac disease development. We also analyzed T cells from 6 adults (26-55 years old) with untreated celiac disease. All children and adults were positive for HLA-DQ2.5. Biopsies were incubated with gluten digested with chymotrypsin (modified or unmodified by the enzyme transglutaminase 2) or the peptic-tryptic digest of gliadin (in native and deamidated forms) before T-cell collection.

RESULTS

Levels of T-cell responses were higher to deamidated gluten than to native gluten in children and adults. T cells from children and adults each reacted to multiple gluten epitopes. Several T-cell clones were cross-reactive, especially clones that recognized epitopes from γ-and ω-gliadin. About half of the generated T-cell clones from children and adults reacted to unknown epitopes.

CONCLUSIONS

T-cell responses to different gluten peptides appear to be similar between adults and children at the time of diagnosis of celiac disease.

The role of gluten consumption at an early age in celiac disease development: a further analysis of the prospective PreventCD cohort study

Background: We previously found that the introduction of small quantities of gluten at 4-6 mo of age did not reduce the risk of celiac disease (CD) in a group of high-risk children. However, the consumption of high amounts of gluten early in life has been suggested to increase CD risk.Objective: The aim of this study was to evaluate this hypothesis by using data from the previous study of the PreventCD trial (www.preventcd.com).Design: Gluten intake was prospectively quantified by using specific food records between 11 and 36 mo of age in 715 children positive for the human leukocyte antigen (HLA)-DQ2 and/or HLA-DQ8 from 5 European countries. According to the PreventCD protocol, infants received 100 mg immunologically active gluten/d or placebo from 4 to 6 mo of age, with a stepwise and fixed gluten increase until age 10 mo and unrestricted intake thereafter. The primary outcome of the present study was the impact of the amount of gluten consumed from age 10 mo onward on CD development.Results: Mean daily gluten intakes from 10 mo onward were significantly different between countries for children at all ages (P < 0.001) but not between children who developed CD and those who did not within the same country (P > 0.05). The variables country, sex, intervention group, and gluten consumption pattern did not show significant associations with CD development risk (HRs not significant). In addition, the interaction between HLA risk group and gluten consumption pattern showed no significant risk on CD development, except for the DQ2.2/DQ7 haplotype (HR: 5.81; 95% CI: 1.18, 28.74; P = 0.031).Conclusions: Gluten consumption patterns as well as the amount of gluten consumed at 11-36 mo of age do not influence CD development for most related HLA genotypes in children with a genetic risk. This study reports the gluten consumption pattern in children at risk of CD from different European countries. This trial was registered at www.controlled-trials.com as ISRCTN74582487.

Randomized feeding intervention in infants at high risk for celiac disease

BACKGROUND

A window of opportunity has been suggested for reducing the risk of celiac disease by introducing gluten to infants at 4 to 6 months of age.

METHODS

We performed a multicenter, randomized, double-blind, placebo-controlled dietary-intervention study involving 944 children who were positive for HLA-DQ2 or HLA-DQ8 and had at least one first-degree relative with celiac disease. From 16 to 24 weeks of age, 475 participants received 100 mg of immunologically active gluten daily, and 469 received placebo. Anti-transglutaminase type 2 and antigliadin antibodies were periodically measured. The primary outcome was the frequency of biopsy-confirmed celiac disease at 3 years of age.

RESULTS

Celiac disease was confirmed by means of biopsies in 77 children. To avoid underestimation of the frequency of celiac disease, 3 additional children who received a diagnosis of celiac disease according to the 2012 European Society for Pediatric Gastroenterology, Hepatology, and Nutrition diagnostic criteria (without having undergone biopsies) were included in the analyses (80 children; median age, 2.8 years; 59% were girls). The cumulative incidence of celiac disease among patients 3 years of age was 5.2% (95% confidence interval [CI], 3.6 to 6.8), with similar rates in the gluten group and the placebo group (5.9% [95% CI, 3.7 to 8.1] and 4.5% [95% CI, 2.5 to 6.5], respectively; hazard ratio in the gluten group, 1.23; 95% CI, 0.79 to 1.91). Rates of elevated levels of anti-transglutaminase type 2 and antigliadin antibodies were also similar in the two study groups (7.0% [95% CI, 4.7 to 9.4] in the gluten group and 5.7% [95% CI, 3.5 to 7.9] in the placebo group; hazard ratio, 1.14; 95% CI, 0.76 to 1.73). Breast-feeding, regardless of whether it was exclusive or whether it was ongoing during gluten introduction, did not significantly influence the development of celiac disease or the effect of the intervention.

CONCLUSIONS

As compared with placebo, the introduction of small quantities of gluten at 16 to 24 weeks of age did not reduce the risk of celiac disease by 3 years of age in this group of high-risk children. (Funded by the European Commission and others; PreventCD Current Controlled Trials number, ISRCTN74582487.).

Equilibrium binding model of bile salt-mediated chiral micellar electrokinetic capillary chromatography

Optimum concentration of bile salts in chiral separations depends on both the aggregation properties of the surfactant and the stability of the analyte-micelle complexes. An equilibrium model is proposed in which these two effects are treated separately. First the aggregation constants should be determined under the experimental conditions of the chiral MEKC analysis. With these data, the equilibrium concentrations of bile salt aggregates can be calculated at any total surfactant concentration. Using the Offord equation to approximate the mobilities of the enantiomer-bile salt complexes, a model function has been derived to fit the experimental mobilities. The method yields the binding constants of the enantiomers to each aggregate present. Those species are assumed to be important in the chiral recognition process, which have significantly different stability constants for the enantiomers. The method is demonstrated by the chiral separation of R- and S-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate with sodium taurodeoxycholate. Based on the calculated binding constants, tetrameric aggregates are assumed to be the discriminating species, while no significant difference in enantiomer binding to dimers was found.

Auditory brainstem potentials in uraemia

Evoked response audiometry was carried out to assess the viability of the auditory pathway in haemodialysed patients. The latency of the waves III and V and I-V interpeak latencies were significantly longer in the renal patients compared to the control group. The I-V interpeak latency was longer in 8 of our 13 patients than the upper limit (4.38 ms) in our laboratory. The possible cause for the central auditory dysfunction may be multifactorial, including the effect of metastatic calcifications, repeated occurrence of disequilibrium syndrome, or some small, molecular, toxic, metabolic substance. The significance of the different factors may vary among different haemodialysis centres.

Metabolites of gentamicin-producing Micromonospora species I. Isolation and identification of metabolites

From the cultural broth of a Micromonospora species 25 aminocyclitol antibiotics were isolated by repeated ion-exchange chromatographic processes. The main components of the metabolites were identified as gentamicin C1, C2, and C1a. The other previously reported gentamicin type antibiotics and some other degradation products including gentamicin A, B, B1, X2, sisomicin, garamine, gentamines etc., were identified by chemical, PMR, and mass spectroscopic studies. Besides these, seven new gentamicin type antibiotics were isolated and characterized.

Effect of experimental removal of molars on gastric and submaxillary salivary secretion in the rat

The absence of molars decreased HCl acid content of the stomach and histamine concentration in the gastric wall. Dry and wet weight of the submaxillary gland did not change, but the rate of secretion decreased significantly in rats without molars. A decrease in the number of afferent impulses from the oral cavity is believed to be a cause of diminished secretion.

Effect of removal of molars on weight increase and food intake in albino rats

Experimental extraction of molars, which rendered mastication impossible, reduced the rate of growth of young albino rats in comparison with controls. When free choice between granular and solid food was allowed, the rats with inhibited mastication preferred the food of granular consistency. A significant depression of growth rate in the rats deprived of chewing ability was noted, even when compared with pair-fed control rats that had received the same amount of food.