Background and Aims The study investigates the practical utility of whole-blood gene expression profiling to diagnose inflammatory bowel diseases [IBDs]. Methods The discovery cohorts included 102 and 51 paediatric IBD patients and controls, and 95 and 46 adult IBD patients and controls, respectively. The replication cohorts included 447 and 76 paediatric IBD patients and controls, and 271 and 108 adult IBD patients and controls, respectively. In the discovery phase, RNA samples extracted from whole peripheral blood were analysed using RNA-Seq, and the predictive values of selected biomarkers were validated using quantitative polymerase chain reaction [qPCR]. Results In all, 15 differentially expressed transcripts [adjusted p ≤0.05] were selected from the discovery sequencing datasets. The receiver operating characteristic curves and area under the curve [ROC-AUC] in replication analyses showed high discriminative power [AUC range, 0.91–0.98] for 11 mRNAs in paediatric patients with active IBD. By contrast, the AUC-ROC values ranged from 0.63 to 0.75 in comparison among inactive paediatric IBDs and active/inactive adult IBDs, indicating a lack of discriminative power. The best multi-mRNA diagnostic classifier showed moderate discriminative power [AUC = 0.81] for paediatric inactive IBD, but was not able to discriminate active or inactive adult IBD patients from controls. The AUC-ROC values did not confirm an ability of the mRNAs abundances to discriminate between active ulcerative colitis and active Crohn’s disease in paediatric or adult populations. Conclusions This study identifies and validates blood transcriptional biomarkers that could be used in clinical settings as diagnostic predictors of IBD clinical activity in paediatric, but not adult, IBD patients.

Most inflammatory bowel diseases (IBDs) are classic complex disorders represented by common alleles. Here we aimed to define the genetic architecture of pediatric and adult-onset IBDs for the Polish population. A total of 1495 patients were recruited, including 761 patients with Crohn’s disease (CD; 424 pediatric), 734 patients with ulcerative colitis (UC; 390 pediatric), and 934 healthy controls. Allelotyping employed a pooled-DNA genome-wide association study (GWAS) and was validated by individual genotyping. Whole exome sequencing (WES) was performed on 44 IBD patients diagnosed before 6 years of age, 45 patients diagnosed after 40 years of age, and 18 healthy controls. Altogether, out of 88 selected SNPs, 31 SNPs were replicated for association with IBD. A novel BRD2 (rs1049526) association reached significance of P = 5.2 × 10−11 and odds ratio (OR) = 2.43. Twenty SNPs were shared between pediatric and adult patients; 1 and 7 were unique to adult-onset and pediatric-onset IBD, respectively. WES identified numerous rare and potentially deleterious variants in IBD-associated or innate immunity-associated genes. Deleterious alleles in both groups were over-represented among rare variants in affected children. Our GWAS revealed differences in the polygenic architecture of pediatric- and adult-onset IBD. A significant accumulation of rare and deleterious variants in affected children suggests a contribution by yet unexplained genetic components.

Aim: This Polish study estimated the prevalence of the Helicobacter pylori infection in symptomatic children aged 3-18 and investigated its association with gastrointestinal complaints.Methods: We prospectively enrolled 1984 children (54% female) with a mean age of 9.5 AE 4.1 years, from Silesia, Poland, for the Good Diagnosis Treatment Life screening programme from 2009 to 2016. They underwent a 13 C-isotope-labelled urea breath test (UBT) to assess their Helicobacter pylori status, making this the biggest Polish study to use this approach. Further analysis included parental-reported gastrointestinal symptoms and standard deviation scores (SDS) of anthropometric measurements.Results: The Helicobacter pylori infection was identified in 220 (11%) children (48% female) and was independent of age and sex. The frequency of symptoms did not differ between Helicobacter positive and negative children (all p > 0.05). Children with a positive UBT result had a lower body mass SDS (À0.41 AE 0.98 versus À0.26 AE 1.01, p = 0.04) and height SDS (À0.45 AE 1.34 versus À0.23 AE 1.27, p = 0.02), but similar body mass index SDS.Conclusion: We found a low prevalence of Helicobacter pylori in symptomatic children, and positive UBT results were not associated with symptoms that suggested Helicobacter pylori infections. Our findings support the 2017 European and North American guidelines for Helicobacter infections in children.

Low bone mineral density often complicates IBD in children. QUS is not an appropriate method for the assessment of bone status in children. Nutritional status seems to have a greater impact on bone status than corticosteroids therapy.

SummaryPersistent presence of ATP4A autoantibodies (ATP4AA) directed towards parietal cells is typical for atrophic body gastritis (ABG), an autoimmune disease associated with type 1 diabetes. We assessed whether Helicobacter pylori (Hp) infection might be associated with positivity for ATP4AA in children with type 1 diabetes. Sera were collected from 70 (38Ǩ) type 1 diabetes children [aged 13·2 ± 4·5 years, age at diagnosis 8·8 ± 4·3 years, diabetes duration 4·5 ± 3·8 years, mean HbA1c 7·8 ± 1·6% (62 ± 17·5 mmol/mol)] seen at the regional diabetes clinic in Katowice, Poland. Patients were tested concurrently for Hp infection by means of a 13C urea breath test. ATP4AA were measured using a novel radioimmunoprecipitation assay developed at the Barbara Davies Center for Childhood Diabetes, University of Colorado. ATP4AA were present in 21 [30%, 95% confidence interval (CI) = 19-41%] and Hp infection was detected in 23 (33%, 95% CI = 22-44%) children.There was no statistically significant association between ATP4AA presence and Hp status. ATP4AA presence was not associated with current age, age at type 1 diabetes diagnosis, diabetes duration or current HbA1c. ATP4AA were more prevalent in females [42% (26-58%)] than males [16% (3-28%)], P = 0·016. ATP4A are found in nearly one-third of children with type 1 diabetes and more common among females. In this cross-sectional analysis, Hp infection was not associated with autoimmunity against parietal cells.