Mucosal cytokine response after short-term gluten challenge in celiac disease and non-celiac gluten sensitivity

OBJECTIVES

In celiac disease (CD), gluten induces both adaptive and innate immune responses. Non-celiac gluten sensitivity (NCGS) is another form of gluten intolerance where the immune response is less characterized. The aim of our study was to explore and compare the early mucosal immunological events in CD and NCGS.

METHODS

We challenged 30 HLA-DQ2(+) NCGS and 15 CD patients, all on a gluten-free diet, with four slices of gluten-containing bread daily for 3 days. Duodenal biopsy specimens were collected before and after challenge. The specimens were examined for cytokine mRNA by quantitative reverse transcriptase-PCR and for MxA-expression and CD3(+) intraepithelial lymphocytes (IELs) by immunohistochemistry and compared with specimens from untreated CD patients and disease controls.

RESULTS

In CD patients, tumor necrosis factor alpha (P=0.02) and interleukin 8 (P=0.002) mRNA increased after in vivo gluten challenge. The interferon gamma (IFN-γ) level of treated CD patients was high both before and after challenge and did not increase significantly (P=0.06). Four IFN-γ-related genes increased significantly. Treated and untreated CD patients had comparable levels of IFN-γ. Increased expression of MxA in treated CD patients after challenge suggested that IFN-α was activated on gluten challenge. In NCGS patients only IFN-γ increased significantly (P=0.03). mRNA for heat shock protein (Hsp) 27 or Hsp70 did not change in any of the groups. Importantly, we found that the density of IELs was higher in NCGS patients compared with disease controls, independent of challenge, although lower than the level for treated CD patients.

CONCLUSIONS

CD patients mounted a concomitant innate and adaptive immune response to gluten challenge. NCGS patients had increased density of intraepithelial CD3(+) T cells before challenge compared with disease controls and increased IFN-γ mRNA after challenge. Our results warrant further search for the pathogenic mechanisms for NCGS.

Absence of somatization in non-coeliac gluten sensitivity

OBJECTIVE

In contrast to coeliac disease (CD), the mechanism behind non-coeliac gluten sensitivity (NCGS) is unclear. The aims of the study were to measure the presence of somatization, personality traits, anxiety, depression, and health-related quality of life in NCGS individuals compared with CD patients and healthy controls, and to compare the response to gluten challenge between NCGS and CD patients.

MATERIAL AND METHODS

We examined 22 CD patients and 31 HLA-DQ2+ NCGS patients without CD, all on a gluten-free diet. All but five CD patients were challenged orally for 3 days with gluten; symptom registration was performed during challenge. A comparison group of 40 healthy controls was included. Patients and healthy controls completed questionnaires regarding anxiety, depression, neuroticism and lie, hostility and aggression, alexithymia and health locus of control, physical complaints, and health-related quality of life.

RESULTS

The NCGS patients reported more abdominal (p = 0.01) and non-abdominal (p < 0.01) symptoms after gluten challenge than CD patients. There were no significant differences between CD and NCGS patients regarding personality traits, level of somatization, quality of life, anxiety, and depressive symptoms. The somatization level was low in CD and NCGS groups. Symptom increase after gluten challenge was not related to personality in NCGS patients.

CONCLUSIONS

NCGS patients did not exhibit a tendency for general somatization. Personality and quality of life did not differ between NCGS and CD patients, and were mostly at the same level as in healthy controls. NCGS patients reported more symptoms than CD patients after gluten challenge.

Rapid accumulation of CD14+CD11c+ dendritic cells in gut mucosa of celiac disease after in vivo gluten challenge

BACKGROUND

Of antigen-presenting cells (APCs) expressing HLA-DQ molecules in the celiac disease (CD) lesion, CD11c(+) dendritic cells (DCs) co-expressing the monocyte marker CD14 are increased, whereas other DC subsets (CD1c(+) or CD103(+)) and CD163(+)CD11c(-) macrophages are all decreased. It is unclear whether these changes result from chronic inflammation or whether they represent early events in the gluten response. We have addressed this in a model of in vivo gluten challenge.

METHODS

Treated HLA-DQ2(+) CD patients (n = 12) and HLA-DQ2(+) gluten-sensitive control subjects (n = 12) on a gluten-free diet (GFD) were orally challenged with gluten for three days. Duodenal biopsies obtained before and after gluten challenge were subjected to immunohistochemistry. Single cell digests of duodenal biopsies from healthy controls (n = 4), treated CD (n = 3) and untreated CD (n = 3) patients were analyzed by flow cytometry.

RESULTS

In treated CD patients, the gluten challenge increased the density of CD14(+)CD11c(+) DCs, whereas the density of CD103(+)CD11c(+) DCs and CD163(+)CD11c(-) macrophages decreased, and the density of CD1c(+)CD11c(+) DCs remained unchanged. Most CD14(+)CD11c(+) DCs co-expressed CCR2. The density of neutrophils also increased in the challenged mucosa, but in most patients no architectural changes or increase of CD3(+) intraepithelial lymphocytes (IELs) were found. In control tissue no significant changes were observed.

CONCLUSIONS

Rapid accumulation of CD14(+)CD11c(+) DCs is specific to CD and precedes changes in mucosal architecture, indicating that this DC subset may be directly involved in the immunopathology of the disease. The expression of CCR2 and CD14 on the accumulating CD11c(+) DCs indicates that these cells are newly recruited monocytes.

Assessing possible celiac disease by an HLA-DQ2-gliadin Tetramer Test

OBJECTIVES

Investigation of uncertain celiac disease (CD) in patients already on a gluten-free diet (GFD) is difficult. We evaluated HLA-DQ2-gliadin tetramers for detection of gluten-specific T cells in peripheral blood and histological changes in the duodenum after a short gluten challenge as a diagnostic tool.

METHODS

HLA-DQ2+ individuals on a GFD for at least 4 weeks were investigated; 35 with uncertain diagnosis, 13 CD patients, and 2 disease controls. All participants had a challenge with four slices of gluten-containing white bread, daily for 3 days (d1-d3). An esophagogastroduodenoscopy with biopsy sampling was done on d0 and d4. Biopsies were scored according to revised Marsh criteria. Peripheral blood CD4+ T cells were isolated, stained with HLA-DQ2-gliadin peptide tetramers, and analyzed by flow cytometry on d0 and d6.

RESULTS

After challenge, a positive tetramer test was seen in 11/13 CD patients. Four of these subjects also showed typical histological changes on challenge. Of the 35 patients with uncertain diagnosis, 3 were diagnosed with CD. Two of these three patients had both positive tetramer staining and histological changes in biopsies after challenge.

CONCLUSIONS

Tetramer staining for gluten-specific T cells is a sensitive method in detecting an immune response in CD patients after a short gluten challenge. The prevalence of CD in the group with self-prescribed GFD was about 10%.

[Cancer risk in coeliac disease]

BACKGROUND

Coeliac disease is a common disease which seems to be considered less harmful now than previously. An association between coeliac disease and some types of cancer is well known. It is thus important to evaluate the seriousness of the condition and give patients advice and proper follow-up.

MATERIAL AND METHODS

The article is based upon literature retrieved through a non-systematic search of PubMed. There are no Norwegian, but several European studies on the topic. Study design and patient selection varies.

RESULTS

Most studies show increased cancer risk and mortality, especially for B-and T-cell lymphoma also outside the gut. The risk of breast and lung cancer is decreased. The studies show that the risk of mortality and cancer development is most pronounced the first three years after coeliac disease is diagnosed. The mortality of patients with coeliac disease during this period is nearly doubled in relation to a control population. There does not seem to be an increased cancer risk when the disease is diagnosed during childhood. Adherance to a gluten-free diet is at least partly protective.

INTERPRETATION

Coeliac disease causes a certain increased risk of cancer and early death. It is not an innocent condition. This strengthens the arguments for coeliac patients to adhere to a gluten free diet.

Tetramer visualization of gut-homing gluten-specific T cells in the peripheral blood of celiac disease patients

Tetramers of MHC-peptide complexes are used for detection and characterization of antigen-specific T cell responses, but they require knowledge about both antigenic peptide and the MHC restriction element. The successful application of these reagents in human diseases involving CD4+ T cells is limited. Celiac disease, an intestinal inflammation driven by mucosal CD4+ T cells recognizing wheat gluten peptides in the context of disease-associated HLA-DQ molecules, is an ideal model to test the potential clinical use of these reagents. We investigated whether gluten-specific T cells can be detected in the peripheral blood of celiac disease patients using DQ2 tetramers. Nine DQ2+ patients and six control individuals on a gluten-free diet were recruited to the study. Participants consumed 160 g of gluten-containing bread daily for 3 days. After bread-challenge, gluten-specific T cells were detectable in the peripheral blood of celiac patients but not controls both directly by tetramer staining and indirectly by enzyme-linked immunospot. These T cells expressed the beta(7) integrin indicative of gut-homing properties. Most of the cells had a memory phenotype, but many other phenotypic markers showed a heterogeneous pattern. Tetramer staining of gluten-specific T cells has the potential to be used for diagnosis of celiac disease.