Abstract Celiac disease (CD) is frequently diagnosed in patients with type 1 diabetes (T1D), and T1D patients can exhibit Abs against tissue transglutaminase, the auto-antigen in CD. Thus, gliadin, the trigger in CD, has been suggested to have a role in T1D pathogenesis. The objective of this study was to investigate whether gliadin contributes to enteropathy and insulitis in NOD-DQ8 mice, an animal model that does not spontaneously develop T1D. Gliadin-sensitized NOD-DQ8 mice developed moderate enteropathy, intraepithelial lymphocytosis, and barrier dysfunction, but not insulitis. Administration of anti-CD25 mAbs before gliadin-sensitization induced partial depletion of CD25+Foxp3+ T cells and led to severe insulitis, but did not exacerbate mucosal dysfunction. CD4+ T cells isolated from pancreatic lymph nodes of mice that developed insulitis showed increased proliferation and proinflammatory cytokines after incubation with gliadin but not with BSA. CD4+ T cells isolated from nonsensitized controls did not response to gliadin or BSA. In conclusion, gliadin sensitization induced moderate enteropathy in NOD-DQ8 mice. However, insulitis development required gliadin-sensitization and partial systemic depletion of CD25+Foxp3+ T cells. This humanized murine model provides a mechanistic link to explain how the mucosal intolerance to a dietary protein can lead to insulitis in the presence of partial regulatory T cell deficiency.
Spontaneous lupus-like syndrome in HLA-DQ2 transgenic mice with a mixed genetic background
To investigate the role of HLA-DQ2 in the pathogenesis of associated immune disorders, we generated transgenic mice that expressed HLA-DQ2 in the absence of endogenous murine class II molecules (AE 0 DQ2). These AE 0 DQ2 mice with a mixed genetic background spontaneously developed skin lesions on their ears, whereas control AE 0 DQ6 genotype control mice (also with a mixed genetic background) did not. The skin lesions were characterized by deep subepidermal blistering with hydropic degeneration and lymphoid infiltration in the subepidermal area as determined by histopathology. Immunofluorescence analysis revealed thick band-like granular deposition of IgG, IgM, and a thin band of IgA deposition along the basement membrane. AE 0 DQ2 mice also developed significant and progressive hematuria and proteinuria as compared with the AE 0 DQ6 mice (p < 0.05). Histopathology showed immune complex deposits in the glomeruli of AE 0 DQ2 mice. Immunofluorescence analysis showed progressive mesangial and capillary wall deposition of IgA, IgM, IgG and C1q in the kidney. With electron microscopy, the deposits showed a ‘fingerprint’ substructure; and tubuloreticular structures were identified within endothelial cells. Conversely, these changes were not observed in AE 0 DQ6 mice. Serum anti-double stranded (ds)DNA IgM and IgG levels were also significantly elevated among AE 0 DQ2 mice compared with AE 0 DQ6 mice (p < 0.001). In conclusion, AE 0 DQ2 mice spontaneously develop an autoimmune lupus-like syndrome and are useful model for this disease. It remains to be determined whether genetic admixture played a role in the development of this systemic lupus erythematosus-like syndrome in HLA-DQ2 transgenic mice. Lupus (2010) 19, 815—829.
Induction of Antigen-Specific Tolerance by Oral Administration of Lactococcus lactis Delivered Immunodominant DQ8-Restricted Gliadin Peptide in Sensitized Nonobese Diabetic Ab° Dq8 Transgenic Mice
Abstract Active delivery of recombinant autoantigens or allergens at the intestinal mucosa by genetically modified Lactococcus lactis (LL) provides a novel therapeutic approach for the induction of tolerance. Celiac disease is associated with either HLA-DQ2- or HLA-DQ8-restricted responses to specific antigenic epitopes of gliadin, and may be treated by induction of Ag-specific tolerance. We investigated whether oral administration of LL-delivered DQ8-specific gliadin epitope induces Ag-specific tolerance. LL was engineered to secrete a deamidated DQ8 gliadin epitope (LL-eDQ8d) and the induction of Ag-specific tolerance was studied in NOD AB° DQ8 transgenic mice. Tolerance was assessed by delayed-type hypersensitivity reaction, cytokine measurements, eDQ8d-specific proliferation, and regulatory T cell analysis. Oral administration of LL-eDQ8d induced suppression of local and systemic DQ8-restricted T cell responses in NOD AB° DQ8 transgenic mice. Treatment resulted in an Ag-specific decrease of the proliferative capacity of inguinal lymph node (ILN) cells and lamina propria cells. Production of IL-10 and TGF-β and a significant induction of Foxp3+ regulatory T cells were associated with the eDQ8d-specific suppression induced by LL-eDQ8d. These data provide support for the development of effective therapeutic approaches for gluten-sensitive disorders using orally administered Ag-secreting LL. Such treatments may be effective even in the setting of established hypersensitivity.
AbstractCeliac disease is a common systemic disorder that can have multiple hematologic manifestations. Patients with celiac disease may present to hematologists for evaluation of various hematologic problems prior to receiving a diagnosis of celiac disease. Anemia secondary to malabsorption of iron, folic acid, and/or vitamin B12 is a common complication of celiac disease and many patients have anemia at the time of diagnosis. Celiac disease may also be associated with thrombocytosis, thrombocytopenia, leukopenia, venous thromboembolism, hyposplenism, and IgA deficiency. Patients with celiac disease are at increased risk of being diagnosed with lymphoma, especially of the T-cell type. The risk is highest for enteropathy-type T-cell lymphoma (ETL) and B-cell lymphoma of the gut, but extraintestinal lymphomas can also be seen. ETL is an aggressive disease with poor prognosis, but strict adherence to a gluten-free diet may prevent its occurrence.
Supraesophageal Reflux: Validation of a Symptom Questionnaire
OBJECTIVESTo develop and validate a questionnaire for supraesophageal manifestations of reflux (SER) that will facilitate its study in clinical and research settings.STUDY DESIGNThe Supraesophageal Reflux Questionnaire (SERQ) and previously validated Reflux Symptom Index (RSI) were subjected to multiple types of validity testing, including content validity, concurrent validity, reproducibility, and predictive validity.RESULTSThe concurrent validity and reproducibility of both instruments was good to excellent for most items tested. The predictive validity of the SERQ was superior to the RSI when it included the covariates of history of sinusitis, use of over‐the‐counter antacid medications, age, gender, and body mass index.CONCLUSIONSThe SERQ will serve as both a useful clinical and research tool by offering not only SER symptom information, like the RSI, but also information about the patient's medical history and medication usage that will facilitate use of the SERQ in research protocols.EBM rating: B‐2b
The Role of Defective Mismatch Repair in Small Bowel Adenocarcinoma in Celiac Disease
Abstract Celiac disease is associated with an increased risk of small bowel adenocarcinoma. The aims of this study were to investigate the molecular basis, assess outcomes, and identify clinicopathologic characteristics of small bowel adenocarcinoma in celiac disease. Retrospective case control cohort study of all celiac disease patients treated at our institution for small bowel adenocarcinoma and matched control patients with sporadic small bowel adenocarcinoma from July 1960 to November 2002. Mismatch repair (MMR) status was accessed by testing tissue for microsatellite instability (MSI) and for hMLH1 and hMSH2 protein expression. Over a 40-year time period, 18 patients with small bowel adenocarcinoma and celiac disease were treated at the Mayo Clinic. One celiac disease patient was excluded. High-frequency MSI (MSI-H) was identified in 8 of 11 (73%) and 2 of 22 (9%) available small bowel adenocarcinoma specimens in the celiac disease and control groups, respectively. In the celiac disease group, MSI-H was associated with loss of hMLH1 and hMSH2 in 6 and 1 specimens, respectively. Loss of hMLH1 occurred in both control tumors. Stage was associated with celiac disease status (P = 0.018), and 78% of controls were stage III or IV compared with 47% of celiac disease patients. Overall, survival was better (P = 0.025) in the celiac disease group compared with stage-matched controls. Celiac disease patients with small bowel adenocarcinoma had a high incidence defective MMR (73%) compared with controls and had better survival compared with stage-matched controls. In addition, celiac disease patients presented more frequently with early-stage small bowel adenocarcinoma. The better survival and earlier presentation of small bowel adenocarcinoma in celiac disease appears to be biologically associated with defective MMR.