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The aim of the study was to determine the correlation between duodenal mucosal biopsies and tissue transglutaminase immunoglobulin A (tTG-IgA) levels in pediatric patients with biopsy-confirmed celiac disease (CD) and eosinophilic gastrointestinal disorders (EGID) who have had repeat duodenal biopsies after initiating a gluten-free diet., Methods: A retrospective chart review was performed of children with CD and EGID seen at the Children's Hospital of Philadelphia between 2003 and 2018. Data collected included duodenal biopsy pathology, celiac serology including tTG-IgA, and symptom reports. Duodenal healing was defined as normal villous architecture and no intraepithelial lymphocytes. These data were compared with tTG-IgA level. Data were analyzed with Fisher exact test and t test methods., Results: Thirty-nine patients had normal IgA and diagnoses of both CD and EGID. At second biopsy, 44% (17/39) of patients showed no histologic evidence of active CD and 36% (14/39) of patients had negative tTG-IgA values. Sixty percent (9/15) of patients with no evidence of CD on biopsy had abnormal tTG-IgA levels, and 57% (8/14) of patients with normal tTG-IgA levels had evidence of active disease on biopsy., Conclusions: The data show that an abnormal tTG-IgA drawn after initiation of a gluten-free diet is not correlated with duodenal mucosal injury in pediatric patients with CD and EGID. This suggests that serologic surveillance with tTG-IgA is not sufficient to monitor CD intestinal healing in this patient cohort. Persistent elevations of tTG-IgA in CD patients with normal duodenal biopsies should prompt investigation into other potential causes., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 The Author(s). Published by Wolters Kluwer on behalf of European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Objectives: TSLP has been shown to be associated with eosinophilic esophagitis (EoE). Specifically, children with EoE often have the nucleotides AA or AG instead of GG at the single nucleotide polymorphism position RS3806932. Presently, the phenotypic characteristics in EoE children with the TSLP EoE risk allele are unknown., Methods: A retrospective analysis was performed of all children with EoE who had TSLP genotyping at The Children's Hospital of Philadelphia from 2008-2014. EoE food allergen triggers, presence of atopic features, IgE mediated food allergy and skin prick testing results were reviewed. The number and type of EoE food allergen triggers were compared with genotype using chi-square analysis. Primary cell cultures from EoE patients with or without the risk allele were stimulated with ovalbumin and TSLP secretion was measured by ELISA., Results: Fifty three of 309 patients were found to have no copies of the TSLP risk allele, whereas 256 patients were found to have one or more copies of the risk allele. There was an increase in the number of patients with three or more EoE food allergens among those who were either homozygous or heterozygous for the risk allele compared to those without the risk allele (P < 0.0001). This was independent of their atopic background. Primary cultures from patients homozygous for the risk allele had greater TSLP secretion than those isolated from heterozygous patients., Conclusions: The TSLP risk allele is associated with having multiple EoE food allergen triggers. This novel EoE genotypic-phenotypic correlation may guide future treatment for those with the TSLP risk allele.

Compression wood is a type of reaction wood formed on the underside of softwood stems when they are tilted from the vertical and on the underside of branches. Its quantification is still a matter of some scientific debate. We developed a new technique that has the potential to do this based on the higher proportions of (1→4)-β-d-galactans that occur in tracheid cell walls of compression wood. Wood was milled, partially delignified, and the non-cellulosic polysaccharides, including the (1→4)-β-d-galactans, extracted with 6 M sodium hydroxide. After neutralizing, the solution was serially diluted, and the (1→4)-β-d-galactans determined by an immuno-dot assay using the monoclonal antibody LM5, which specifically recognizes this polysaccharide. Spots were quantified using a dilution series of a commercially available (1→4)-β-d-galactan from lupin seeds. Using this method, compression and opposite woods from radiata pine (Pinus radiata) were easily distinguished based on the amounts of (1→4)-β-d-galactans extracted. The non-cellulosic polysaccharides in the milled wood samples were also hydrolysed using 2 M trifluoroacetic acid followed by the separation and quantification of the released neutral monosaccharides by high performance anion exchange chromatography. This confirmed that the compression woods contained higher proportions of galactose-containing polysaccharides than the opposite woods.

CD4 T cell responses are crucial to prevent and control viral infection; however, virus-specific CD4 T cell activity is considered to be rapidly lost during many persistent viral infections. This is largely caused by the fact that during viral persistence CD4 T cells do not produce the classical Th1 cytokines associated with control of acute viral infections. Considering that CD4 T cell help is critical for both CD8 T cell and B cell functions, it is unclear how CD4 T cells can lose responsiveness but continue to sustain long-term control of persistent viral replication. We now demonstrate that CD4 T cell function is not extinguished as a result of viral persistence. Instead, viral persistence and prolonged T cell receptor stimulation progressively redirects CD4 T cell development away from the Th1 response induced during an acute infection toward T follicular helper cells. Importantly, this sustained CD4 T cell functionality is critical to maintain immunity and ultimately aid in the control of persistent viral infection.