The main purpose of this study is to see how cells taken from the lining of the intestine behave in the laboratory with exposure to gluten and other substances that act on the immune system. The cells lining the intestine of a person with celiac disease should be different than a person without celiac disease. The study doctors would like to see how the cells react after coming in contact with gluten and if substances that act on the immune system can prevent gluten related inflammation. Examples of these substances include steroids. The cells should produce chemicals of their own in response to the gluten. These other chemicals will be measured and the results compared between those with:

• celiac disease that does not respond to a gluten-free diet (refractory celiac disease)
• celiac disease which is controlled by a gluten-free diet
• uncontrolled celiac disease (either newly diagnosed with celiac disease or not on a gluten-free diet
• gluten-sensitivity
• disorders other than celiac disease.

The primary purpose of this study is to determine the effect of in-vitro introduction of gluten on inflammatory response primarily Interferon-γ and other cytokines, such as IL-15, IL-18 and IL-21, in cultures obtained from small intestinal mucosal biopsy samples of subjects who underwent upper endoscopy.

Secondary goals include comparing the inflammatory response to immunosuppressants and cytokines after exposing the cultures obtained from small intestinal mucosal biopsies taken from RCD I subjects with intestinal mucosal biopsies taken from subjects with CeD controlled on a Gluten-Free Diet (GFD), uncontrolled CeD, Gluten sensitivity and Non-celiac Controls.

Inclusion Criteria:

• 18-75 years of age
• Undergoing a clinically indicated upper endoscopy

Exclusion Criteria:

• Anticoagulation or antiplatelet therapy
• Known active non-celiac intestinal inflammatory disorder

Subjects will be selected from patients undergoing a clinically indicated upper endoscopy at Beth Israel Deaconess Medical Center