The SPINK gene family and celiac disease susceptibility

The gene family of serine protease inhibitors of the Kazal type (SPINK) are functional and positional candidate genes for celiac disease (CD). Our aim was to assess the gut mucosal gene expression and genetic association of SPINK1, -2, -4, and -5 in the Dutch CD population. Gene expression was determined for all four SPINK genes by quantitative reverse-transcription polymerase chain reaction in duodenal biopsy samples from untreated (n = 15) and diet-treated patients (n = 31) and controls (n = 16). Genetic association of the four SPINK genes was tested within a total of 18 haplotype tagging SNPs, one coding SNP, 310 patients, and 180 controls. The SPINK4 study cohort was further expanded to include 479 CD cases and 540 controls. SPINK4 DNA sequence analysis was performed on six members of a multigeneration CD family to detect possible point mutations or deletions. SPINK4 showed differential gene expression, which was at its highest in untreated patients and dropped sharply upon commencement of a gluten-free diet. Genetic association tests for all four SPINK genes were negative, including SPINK4 in the extended case/control cohort. No SPINK4 mutations or deletions were observed in the multigeneration CD family with linkage to chromosome 9p21-13 nor was the coding SNP disease-specific. SPINK4 exhibits CD pathology-related differential gene expression, likely derived from altered goblet cell activity. All of the four SPINK genes tested do not contribute to the genetic risk for CD in the Dutch population

Gas-phase infrared spectrum of the coronene cation

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Autoantibodies and histogenesis of celiac disease

OBJECTIVE: Autoantibodies are used as markers for celiac disease (CD) identifying patients with mucosal lesions. The purpose of this study was to evaluate the sensitivity and role of the autoantibodies such as IgA antiendomysium (EMA), IgA antigliadin (AGA) and the IgA antitissue transglutaminase (tTGA) in histogenesis of celiac disease. METHODS: Seventy-nine cases including 30 untreated celiacs, 5 celiacs on gluten-free diet (GFD), 41 first degree relatives and 3 non-relatives suspected for CD were investigated. Three untreated celiacs with IgA deficiency were excluded from this study group. IgA antibodies to tTGA were determined by ELISA, as described before. Twelve of 41 relatives and 2 cases of non relatives suspected with positive serology underwent a small intestinal biopsy. Results were correlated with the degrees of abnormality of the intestinal mucosa in patients with CD. Intestinal biopsies obtained from study population were evaluated for histological quantification. RESULTS: Celiacs and suspected cases with positive EMA/AGA and or tTGA showed shorter villi (p < 0.007) and/or a higher number of intraepithelial lymphocytes (IEL) (p < 0.035). The sensitivity of serology (EMA, AGA, tTGA) in patients with Marsh IIIc was 100%. However, in patients with Marsh IIIa the sensitivity for EMA, AGA, and tTGA was 40%, 50% and 20% respectively. CONCLUSIONS: The appearance of antibodies is related to the degree of mucosal infiltration by IELs. Although tTGA, like EMA provide a highly sensitive parameter for the detection of celiacs with severe mucosal damage, it appears to be less sensitive (even less than AGA) in celiac patients with milder histopathological abnormalities. However, it should be recognized that the substantial part of the celiac population present with these milder forms of mucosal abnormalities. Using tTGA as a single test in screening may result in missing up to 60-70% of celiacs with mild mucosal abnormalities. Combination with other screening tests (at least with AGA) is essential and strongly recommende

Accuracy of serologic tests and HLA-DQ typing for diagnosing celiac disease

BACKGROUND: Estimates of the diagnostic performance of serologic testing and HLA-DQ typing for detecting celiac disease have mainly come from case-control studies. OBJECTIVE: To define the performance of serologic testing and HLA-DQ typing prospectively. DESIGN: Prospective cohort study. SETTING: University hospital. PATIENTS: Patients referred for small-bowel biopsy for the diagnosis of celiac disease. INTERVENTIONS: Celiac serologic testing (antigliadin antibodies [AGA], antitransglutaminase antibodies [TGA], and antiendomysium antibodies [EMA]) and HLA-DQ typing. MEASUREMENTS: Diagnostic performance of serologic testing and HLA-DQ typing compared with a reference standard of abnormal histologic findings and clinical resolution after a gluten-free diet. RESULTS: Sixteen of 463 participants had celiac disease (prevalence, 3.46% [95% CI, 1.99% to 5.55%]). A positive result on both TGA and EMA testing had a sensitivity of 81% (CI, 54% to 95.9%), specificity of 99.3% (CI, 98.0% to 99.9%), and negative predictive value of 99.3% (CI, 98.0% to 99.9%). Testing positive for either HLA-DQ type maximized sensitivity (100% [CI, 79% to 100%]) and negative predictive value (100% [CI, 98.6% to 100%]), whereas testing negative for both minimized the negative likelihood ratio (0.00 [CI, 0.00 to 0.40]) and posttest probability (0% [CI, 0% to 1.4%]). The addition of HLA-DQ typing to TGA and EMA testing, and the addition of serologic testing to HLA-DQ typing, did not change test performance compared with either testing strategy alone. LIMITATION: Few cases of celiac disease precluded meaningful comparisons of testing strategies. CONCLUSIONS: In a patient population referred for symptoms and signs of celiac disease with a prevalence of celiac disease of 3.46%, TGA and EMA testing were the most sensitive serum antibody tests and a negative HLA-DQ type excluded the diagnosis. However, the addition of HLA-DQ typing to TGA and EMA testing, and the addition of serologic testing to HLA-DQ typing, provided the same measures of test performance as either testing strategy alone

Laboratory infrared spectroscopy of cationic polycyclic aromatic hydrocarbon molecules

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