Gluten Challenge In Coeliac Disease Research Articles

Kinetics of mucosal granulocyte activation after gluten challenge in coeliac disease

ObjectiveTo elucidate the dynamics of the rectal inflammatory response to rectal gluten challenge in coeliac disease by measuring inflammatory mediators released by activated neutrophils, eosinophils and mast cells/basophils. Material and methodsThe release of myeloperoxidase (MPO), eosinophilic cationic protein (ECP) and histamine was measured continuously during the early challenge period (3–6 h after gluten challenge) in coeliac patients (n=9) and healthy controls (n=5). A segmental perfusion technique was used to carry out this part of the study. Another method, the mucosal patch technique, was used to enable studies of the late challenge period (5–48 h after gluten challenge) in coeliac patients (n=10) and healthy controls (n=15). ResultsDuring the early challenge period the MPO levels began to increase as earlyas 3 h after challenge and increased progressively (p<0.001) during the next 3 h. A decline in MPO levels was seen 15 h after challenge and another phase of increasing levels at 24 h. The MPO values declined 48 h after challenge but still remained significantly increased (p<0.05). The ECP levels started to increase 4 h after challenge and increased progressively during the next 2 h (p<0.05). The ECP kinetics during the late challenge period was similar as for MPO but the relative increase in ECP was more modest. No increase in histamine was found except in one patient who had a transient, early increase of histamine (3–5 h after challenge). No signs of inflammatory reaction to gluten were seen in the controls. ConclusionsThere is a pronounced neutrophil activation in coeliac patients after rectal gluten challenge. This activation is apparent 4 h after challenge and remains for at least 48 h. A more modest eosinophil activation defined by ECP levels starts 1–2 h later and also remains for at least 48 h. The biphasic pattern of MPO and ECP after challenge suggests a biphasic inflammatory reaction.

Peripheral blood T cells induced by gluten challenge in coeliac disease target a specific molecular motif and express a gut-homing integrin

Peripheral blood T cells induced by gluten challenge in coeliac disease target a specific molecular motif and express a gut-homing integrin

Peripheral blood T cells induced by gluten challenge in coeliac disease target a specific molecular motif and express a gut-homing integrin

Peripheral blood T cells induced by gluten challenge in coeliac disease target a specific molecular motif and express a gut-homing integrin

In vivo gluten challenge in celiac disease.

In vivo gluten challenge has been used since the early 1950s to study the role of cereal fractions in celiac disease. While early studies relied on crude indicators of celiac toxicity, the advent of jejunal biopsy and sophisticated immunohistochemical techniques has allowed accurate studies to be performed. Studies to determine the nature of the cereal component that is toxic to patients with celiac disease have concentrated on wheat because of its nutritional importance. A number of in vitro studies indicated the presence of one or more celiac-activating epitopes with the N-terminus of the A-gliadin molecule. In vivo challenge with three synthetic peptides subsequently indicated the toxicity of a peptide corresponding to amino acids 31 to 49 of A-gliadin. In vivo gluten challenge is the gold standard for the assessment of celiac toxicity; however, jejunal biopsy is a relatively invasive procedure, thus, other methods have been investigated. Direct infusion of the rectum with gluten has been shown to result in an increase in mucosal intraepithelial lymphocytes, occurring only in celiac patients. This method has been used to study the celiac toxicity of gliadin subfractions. The in vitro technique of small intestinal biopsy organ culture is also a useful tool and appears to give the same results as in vivo challenge. The importance of tiny amounts of gliadin in the diet, such as that which occurs in wheat starch, has been studied by in vivo challenge; this technique has clarified the position of oats in the gluten-free diet. Several studies suggest that this cereal may be included in the diet of most adult celiac patients. Studies of the transport of gliadin across the enterocyte following ingestion or challenge suggest that gliadin may be metabolized by a different pathway in celiac disease. This could result in an abnormal presentation to the immune system, triggering a pathogenic rather than a tolerogenic response.

Immune reaction against the cytoskeleton in coeliac disease

BACKGROUNDThe cytoskeleton actin network of intestinal microvilli has been found to be rapidly impaired after gluten challenge in coeliac disease (CD). The aim of this study was to investigate the...

IMMUNE REACTION AGAINST CYTOSKELETON IN COELIAC DISEASE

28 Background The cytoskeleton actin network of intestinal microvilli has been found to be rapidly impaired after gluten challenge in coeliac disease (CD). The aim of this study was to investigate the presence in both children and adults of an immune reaction towards cytoskeleton structures such as actin filaments. Patients and Methods Eighty-one CD patients (51 children and 30 adults) were studied at our outpatient clinics from 1996 to 1998 by indirect immunofluorescence (IF), ELISA and Western-blotting for anti-actin (AAA) and other non-organ specific autoantibodies before and after a gluten-free diet (GFD). Sixteen patients with autoimmune hepatitis type 1 (AH-1), 10 with Crohn's disease and 60 healthy subjects were studied as controls. Findings Sixty-one out eighty-five CD patients, of whom 31/34 were adults (91%) and 30/51 children (58%), were positive for IgA AAA and/or IgG AAA. IgA AAA were strongly correlated with the most severe forms of intestinal villous atrophy (p<0.0001; RR: 58.7). After GFD, AAA became undetectable within five months. CD was associated with AH-1 in 2/16 patients. Interpretation We describe an immune reaction against the cytoskeleton, besides the one against the extracellular matrix in both children and adults with CD. Since AAA are strongly associated with the most severe degrees of villous atrophy, they could represent a useful serological marker of intestinal villous atrophy in CD.

Rectal epithelial gamma/delta T-lymphocyte responses to local gluten challenge in coeliac disease.

The proportion of intra-epithelial lymphocytes (IEL) that utilize the gamma/delta form of the T-cell receptor (TCR) is increased in coeliac disease, but their function remains unexplained. The response of intra-epithelial lymphocytes to rectal gluten challenge in coeliac and control subjects was studied after a rectal challenge of 2 g of Frazer's fraction III. A marked rise in CD3+ IEL occurred after challenge in the coeliac patients, peaking at 6 h and returning to normal by 48 h, with no significant changes in the gamma/delta TCR+ IEL. The IEL did not significantly change after gluten challenge in the controls. Acute gluten challenge induces infiltration of the rectal mucosa by T cells in coeliac patients, which is not accompanied acutely by increased numbers of gamma/delta TCR+ IEL. This study supports the hypothesis that alpha/beta TCR+ T cells may be of importance in the early response of coeliac patients to local gluten challenge.

Intestinal permeability after single dose gluten challenge in coeliac disease.

The changes of intestinal permeability before and after a gluten load were studied. The study group comprised 27 patients with coeliac disease (mean age 12.3 years) and 19 healthy controls matched by sex and age. Intestinal permeability was studied by measuring the urinary excretion of two sugars, lactulose and L-rhamnose, before and six hours after the ingestion of five palatable biscuits made with 50 g of gluten powder. The patients with coeliac disease had been on a gluten free diet during the previous two years. After the gluten load lactulose and L-rhamnose urinary excretion changed significantly in patients, and a significant increase in the lactulose: L-rhamnose ratio was also observed. No significant changes were observed in the controls. In view of the modification of the three biopsies diagnostic protocol made by the European Society for Paediatric Gastroenterology and Nutrition, permeability tests associated with single gluten challenges may be an added contribution to the accuracy of the diagnosis in childhood.

Postpubertal gluten challenge in coeliac disease.

Altogether 38 postpubertal children with coeliac disease were rebiopsied. Mucosal abnormality in nine (24%) of them indicated poor adherence to the diet. Gluten challenge with a diet containing a normal amount of gluten was performed in those 29 patients with a normal mucosa. During challenge, rebiopsy was done when reticulin antibodies turned positive (mean 0.6 years, range 0.2-2.0) or at the end of the two year study. Histologically a clear relapse into coeliac disease was seen in all 23 patients who were positive for reticulin antibodies. At this time gliadin antibodies were positive in all but two. Sixteen (70%) of those who relapsed were completely asymptomatic. Three girls and one boy did not relapse within two years, indicating the possible recovery from coeliac disease to be 11%. All four had undergone gluten challenge earlier in childhood, after initial diagnosis and mucosal recovery, and this had resulted in mucosal relapse. To establish definite postpubertal recovery from coeliac disease in cases with normal mucosa at two years from challenge, further follow up studies of reticulin antibodies and later rebiopsy are needed. The reticulin antibody test seems to be suitable for prediction of mucosal relapse in coeliac disease.