Statement of the Prolamin Working Group on the Determination of Gluten in Fermented Foods Containing Partially Hydrolyzed Gluten

On August 12, 2020, the U.S. Food and Drug Administration (FDA) has finalized a rule related to gluten-free labeling for foods containing fermented, hydrolyzed ingredients. The FDA believes that there is no scientifically valid analytical method effective for determining gluten in fermented or hydrolyzed foods. In the absence of an analytical method, the FDA has decided to evaluate gluten-free claims on these foods based only on evidence that the food or ingredient used is gluten-free before fermentation or hydrolysis. For example, barley-based beers from which gluten is removed during brewing using special filtration, adsorption and/or enzymatic treatment are therefore excluded from bearing a gluten-free label

Persistent changes in circulating and intestinal γδ T cell subsets, invariant natural killer T cells and mucosal-associated invariant T cells in children and adults with coeliac disease.

Coeliac disease is a chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically predisposed individuals. The only current therapy is a lifelong gluten free diet. While much work has focused on the gliadin-specific adaptive immune response in coeliac disease, little is understood about the involvement of the innate immune system. Here we used multi-colour flow cytometry to determine the number and frequency of γδ T cells (Vδ1, Vδ2 and Vδ3 subsets), natural killer cells, CD56(+) T cells, invariant NKT cells, and mucosal associated invariant T cells, in blood and duodenum from adults and children with coeliac disease and healthy matched controls. All circulating innate lymphocyte populations were significantly decreased in adult, but not paediatric coeliac donors, when compared with healthy controls. Within the normal small intestine, we noted that Vδ3 cells were the most abundant γδ T cell type in the adult epithelium and lamina propria, and in the paediatric lamina propria. In contrast, patients with coeliac disease showed skewing toward a predominant Vδ1 profile, observed for both adult and paediatric coeliac disease cohorts, particularly within the gut epithelium. This was concurrent with decreases in all other gut lymphocyte subsets, suggesting a specific involvement of Vδ1 cells in coeliac disease pathogenesis. Further analysis showed that γδ T cells isolated from the coeliac gut display an activated, effector memory phenotype, and retain the ability to rapidly respond to in vitro stimulation. A profound loss of CD56 expression in all lymphocyte populations was noted in the coeliac gut. These findings demonstrate a sustained aberrant innate lymphocyte profile in coeliac disease patients of all ages, persisting even after elimination of gluten from the diet. This may lead to impaired immunity, and could potentially account for the increased incidence of autoimmune co-morbidity

CD56 expression is profoundly downregulated in the coeliac gut, but not blood, both in percentage of cell expression, and expression intensity.

<p>CD56 expression was analysed on non-T cells, non-γδ T cells, and Vδ1 T cells in terms of frequency (A) and mean fluorescence intensity (B). Flow cytometry plots are also shown for representative control and coeliac donors (C). For simplicity, data is shown for a paediatric population only, but similar trends were noted in the adult cohort. *P <0.05, **P<0.01, ***P<0.001, error bars show standard error of the mean.</p

γδ T cells from the coeliac small intestine display a functional “effector memory” phenotype.

<p>(A) Differential expression of CD45RA and CD27 by γδ T cells was used to analyse naïve (CD45RA+/CD27+), central memory (TCM; CD45RA-/CD27+), effector memory (TEM; CD45RA-/CD27-) and terminally differentiated (TEMRA; CD45RA+/CD27-) subsets in the blood, small intestinal epithelium and lamina propria from paediatric patients. (B) Expression of IFN-γ by unstimulated and stimulated epithelial γδ T cells, control n=5, coeliac n=4. *P <0.05, **P<0.01, ***P<0.001, error bars show standard error of the mean.</p

Innate lymphocyte subsets are altered in the intestinal epithelium and lamina propria of both paediatric and adult coeliac donors, compared with controls.

<p>Scatterplots showing percentages of small intestinal innate lymphocyte subsets in (A) epithelium, and (B) lamina propria for paediatric (n=34 controls, n=19 UCD) and adult coeliac (n=7 controls, n=8 TCD, n=6 UCD) donors and matched control subjects. All subsets are expressed as a percentage of the total T cell population. TCD = treated coeliac donors (on gluten free diet), UCD = untreated coeliac donors (diet contains gluten). Dotplots show flow cytometry data from gut epithelial cells (C), and lamina propria cells (D) for representative control and coeliac donors, where Vα7.2 ⁺ /CD161⁺ populations describe MAIT cells. *P <0.05, **P<0.01, ***P<0.001, error bars show standard error of the mean.</p

Genetically distinct subsets within ANCA-associated vasculitis

BACKGROUND Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a severe condition encompassing two major syndromes: granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis) and microscopic polyangiitis. Its cause is unknown, and there is debate about whether it is a single disease entity and what role ANCA plays in its pathogenesis. We investigated its genetic basis. METHODS A genomewide association study was performed in a discovery cohort of 1233 U. K. patients with ANCA-associated vasculitis and 5884 controls and was replicated in 1454 Northern European case patients and 1666 controls. Quality control, population stratification, and statistical analyses were performed according to standard criteria. RESULTS We found both major-histocompatibility-complex (MHC) and non-MHC associations with ANCA-associated vasculitis and also that granulomatosis with polyangiitis and microscopic polyangiitis were genetically distinct. The strongest genetic associations were with the antigenic specificity of ANCA, not with the clinical syndrome. Anti-proteinase 3 ANCA was associated with HLA-DP and the genes encoding alpha(1)-antitrypsin (SERPINA1) and proteinase 3 (PRTN3) (P = 6.2x10(-89), P = 5.6x10(-12), and P = 2.6x10(-7), respectively). Anti-myeloperoxidase ANCA was associated with HLA-DQ (P = 2.1x10(-8)). CONCLUSIONS This study confirms that the pathogenesis of ANCA-associated vasculitis has a genetic component, shows genetic distinctions between granulomatosis with polyangiitis and microscopic polyangiitis that are associated with ANCA specificity, and suggests that the response against the autoantigen proteinase 3 is a central pathogenic feature of proteinase 3 ANCA-associated vasculitis. These data provide preliminary support for the concept that proteinase 3 ANCA-associated vasculitis and myeloperoxidase ANCA-associated vasculitis are distinct autoimmune syndromes. (Funded by the British Heart Foundation and others.

Initial presenting manifestations in 16,486 patients with inborn errors of immunity include infections and noninfectious manifestations

Background: Inborn errors of immunity (IEI) are rare diseases, which makes diagnosis a challenge. A better description of the initial presenting manifestations should improve awareness and avoid diagnostic delay. Although increased infection susceptibility is a well-known initial IEI manifestation, less is known about the frequency of other presenting manifestations. Objective: We sought to analyze age-related initial presenting manifestations of IEI including different IEI disease cohorts. Methods: We analyzed data on 16,486 patients of the European Society for Immunodeficiencies Registry. Patients with autoinflammatory diseases were excluded because of the limited number registered. Results: Overall, 68% of patients initially presented with infections only, 9% with immune dysregulation only, and 9% with a combination of both. Syndromic features were the presenting feature in 12%, 4% had laboratory abnormalities only, 1.5% were diagnosed because of family history only, and 0.8% presented with malignancy. Two-third of patients with IEI presented before the age of 6 years, but a quarter of patients developed initial symptoms only as adults. Immune dysregulation was most frequently recognized as an initial IEI manifestation between age 6 and 25 years, with male predominance until age 10 years, shifting to female predominance after age 40 years. Infections were most prevalent as a first manifestation in patients presenting after age 30 years. Conclusions: An exclusive focus on infection-centered warning signs would have missed around 25% of patients with IEI who initially present with other manifestations. (J Allergy Clin Immunol 2021;148:1332-41.