Patient Care - Allergy & Immunology - October 2007 - (Page 8)

I Celiac disease celiac disease, and HLA DQ8 present the T cells in the intestine with gluten peptides that trigger an immune response, thus conferring susceptibility to the disease. Elimination of the environmental component, gluten, leads to a resolution of clinical symptoms and the histologic inflammatory response. The inflammatory response occurs in the lamina propria and epithelium of the intestine. Ingested gluten crosslinks with tissue transglutaminase released in the lamina propria, leading to the deamidation of the gluten peptides. Recognizing the Express Stop Elderly patients diagnosed with celiac disease often present with vague complaints such as fatigue, bone pain, pyrexia, and arthralgia that can be attributed to other comorbid conditions. deamidated peptides—bound to HLA-DQ2 and HLA-DQ8 molecules—CD4 T cells become stimulated. These activated cells in turn activate other lymphocytes to generate cytokines such as interferon-gamma and interleukin-4, which damage the villi, resulting in enteropathy. The infiltration of intraepithelial lymphocytes is CD8 T-cell dependent and does not relate to the activation process of CD4 T cells in the lamina propria. Although the exact mechanism and pathogenic role of these lymphocytes are not known, certain restricted gene rearrangements in these CD8 T cells are thought to be responsible for refractory celiac disease and enteropathic T-cell lymphoma. Clinical presentation and criteria Celiac disease manifests as symptomatic, asymptomatic, or latent disease. Symptomatic, or classic, disease is characterized by diarrhea, abdominal pain, weight loss, flatulence, and nutritional deficiencies and is seen in 20% to 30% of patients with celiac disease. Patients with asymptomatic or clinically silent disease have either no symptoms, mild complaints such as fatigue or malaise, or nonspecific lab abnormalities such as unexplained anemia, folate deficiency, elevated serum transaminase levels, and osteopenia. Clinically silent disease—accounting for 70% to 80% of celiac cases—may manifest with only non-GI symptoms such as gait ataxia, epilepsy, peripheral neuropathy, aphthous stomatitis, or arthritis.4-6 Both classic and clinically silent celiac disease are associated with substantial morbidity arising from weight loss, metabolic bone disease, and anemia. The term latent celiac disease describes either current or past disease in a patient who has normal mucosa. It is now thought that the severity of latent disease can be estimated by the concentration of a detectable serum antibody. Refractory celiac disease—believed to be the first step to enteropathic T-cell lymphoma—is characterized by intractable diarrhea, villous atrophy, and failure to respond to a gluten-free diet.7 Elderly patients diagnosed with celiac disease often present with vague complaints such as fatigue, bone pain, pyrexia, and arthralgia that can be attributed to other comorbid conditions. Only a clinical suspicion and heightened awareness can improve the rate of diagnosis in this population. Given that 1 in 4 patients diagnosed with celiac disease is 60 or older, an improved rate of diagnosis in the elderly is critical, especially since the incidence of associated malignancies such as lymphoma, small bowel carcinomas, and oropharyngeal cancers is high.8 Celiac disease is associated with autoimmune diseases and dermatologic conditions such as dermatitis herpetiformis (see Table 1, page 9). The autoimmune disorders include type 1 diabetes, autoimmune myocarditis, neuropathy, and primary biliary cirrhosis. Although diabetes does not improve with a gluten-free diet, autoimmune neuropathy and myocarditis do. Celiac disease is associated with an increased risk for GI and lymphoproliferative can- 8 PATIENT CARE ALLERGY & IMMUNOLOGY www.patientcareonline.com http://www.patientcareonline.com

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Patient Care - Allergy & Immunology - October 2007 Research Digest Contents Medicine in the News When to Suspect Celiac Disease and How to Proceed From There Averting Angioedema’s Potentially Dire Consequences Is There a Role for Leukotriene Receptor Antagonists in Treating Allergic rhinitis? Clinical Clips Dermatology Case Challenge Classified Advertising

Patient Care - Allergy & Immunology - October 2007

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