Celiac disease is a genetically determined disorder of the small intestine, occurring due to an immune response to ingested gluten-containing food. The resulting damage to the small intestinal mucosa hampers nutrient absorption, and is characterized by diarrhea, abdominal pain, and a variety of extra-intestinal manifestations. Invasive and costly methods such as endoscopic biopsy are currently used to diagnose celiac disease. Detection of the disease by histopathologic analysis of biopsies can be challenging due to suboptimal sampling. Video capsule images were obtained from celiac patients and controls for comparison and classification. This study exploits the use of DAISY descriptors to project two-dimensional images onto one-dimensional vectors. Shannon entropy is then used to extract features, after which a particle swarm optimization algorithm coupled with normalization is employed to select the 30 best features for classification. Statistical measures of this paradigm were tabulated. The accuracy, positive predictive value, sensitivity and specificity obtained in distinguishing celiac versus control video capsule images were 89.82%, 89.17%, 94.35% and 83.20% respectively, using the 10-fold cross-validation technique. When employing manual methods rather than the automated means described in this study, technical limitations and inconclusive results may hamper diagnosis. Our findings suggest that the computer-aided detection system presented herein can render diagnostic information, and thus may provide clinicians with an important tool to validate a diagnosis of celiac disease.
Coeliac disease (CD) is an inflammatory disorder of the small intestine. It includes aberrant adaptive immunity with presentation of CD toxic gluten peptides by HLA-DQ2 or DQ8 molecules to gluten-sensitive T cells. A ω-gliadin/C-hordein peptide (QPFPQPEQPFPW) and a rye-derived secalin peptide (QPFPQPQQPIPQ) were proposed to be toxic in CD, as they yielded positive responses when assessed with peripheral blood T-cell clones derived from individuals with CD. We sought to assess the immunogenicity of the candidate peptides using gluten-sensitive T-cell lines obtained from CD small intestinal biopsies. We also sought to investigate the potential cross-reactivity of wheat gluten-sensitive T-cell lines with peptic-tryptic digested barley hordein (PTH) and rye secalin (PTS). Synthesised candidate peptides were deamidated with tissue transglutaminase (tTG). Gluten-sensitive T-cell lines were generated by culturing small intestinal biopsies from CD patients with peptic-tryptic gluten (PTG), PTH or PTS, along with autologous PBMCs for antigen presentation. The stimulation indices were determined by measuring the relative cellular proliferation via incorporation of (3) H-thymidine. The majority of T-cell lines reacted to the peptides studied. There was also cross-reactivity between wheat gluten-sensitive T-cell lines and the hordein, gliadin and secalin peptides. PTH, PTS, barley hordein and rye secalin-derived CD antigen-sensitive T-cell lines showed positive stimulation with PTG. ω-gliadin/C-hordein peptide and rye-derived peptide are immunogenic to gluten-sensitive T-cell lines and potentially present in wheat, rye and barley. Additional CD toxic peptides may be shared.