Haldor Topsoe unveils new ammonia catalyst

Abstract

Celiac disease (CD) is defined as a chronic immune-mediated enteropathy precipitated by exposure to dietary gluten (storage proteins of wheat, rye, barley, and oats) in genetically predisposed individuals. Recent epidemiologic data suggest a prevalence of approximately 1% in most Western countries. The genetic predisposition includes human leukocyte antigen (HLA) DQ2 and DQ8 genes as major factors and a number of non-HLA genes. In addition to gluten, other environmental triggers such as pathogenic microorganisms, timing of gluten introduction, and breastfeeding may be important for disease development. CD is classically characterized by small intestinal villous atrophy, crypt hyperplasia, and increased lymphocyte infiltration. The clinical features of CD include both intestinal symptoms, such as diarrhea or steatorrhea, as well as extraintestinal symptoms, such as bone pain or osteoporosis. CD is frequently associated with autoimmune diseases, such as type 1 diabetes, and neurological and psychiatric complaints, such as schizophrenia. Further gluten-related disorders are dermatitis herpetiformis, gluten ataxia, wheat-dependent exercise-induced anaphylaxis, non-celiac gluten sensitivity, and irritable bowel syndrome. The diagnostic scheme of CD is usually based on symptoms typical of CD, testing of serum antibodies, and histological judgment of small intestinal biopsies. The complex pathomechanism of CD consists of incomplete digestion of gluten, para- and transcellular passage of gluten peptides through the epithelium, and immune responses in the lamina propria. The adaptive immunity includes the deamidation and transamidation of gluten peptides by tissue transglutaminase, their binding to HLA-DQ molecules, their presentation to T cells, and the subsequent delivery of damaging cytokines and chemokines. Additionally, antibodies against gluten peptides and autoantibodies against transglutaminase are produced by B cells. The adaptive immunity is accompanied by the innate immunity characterized by the production of interleukin 15 and the expansion of intraepithelial lymphocytes.