Celiac disease is an autoimmune based, chronic inflammatory condition of the gi tract. People with celiac have a dysfunctional immune system response to the protein gluten that leads inflammation and damage of small intestinal mucosa. When the gluten, which is commonly found in grains like wheat, oats, brain, barley is consumed, antibodies and antigens signal the immune system to attack. Overtime this attack on the digestive tract can lead to decreased absorption of nutrients, diarrhea, gi upset, and other less common symptoms such as anemia and malnutrition. About 1% of population worldwide have celiac disease and only 5-10% of those with the condition are aware of having it. The incidence of Celiac is on the rise and is thought to have tripled over past 50 years. This may be explained partly due to higher awareness of the condition and better diagnosis methods, but could also be due to an increase in other risk factors associated with CD such as diabetes. Celiac disease results from interplay of both genetic and environmental factors. CD usually develops early in life, but in many patients symptoms may not appear till later in life. It occurs twice as often in females than males because the HLA gene loci DQ2/DQ8 are more frequently found in females than in male patients.Prevalence is higher in individuals suffering from anemia, diabetes, and other autoimmune diseases.

Celiac disease can present as an intestinal or extra-intestinal condition and in some cases may even be asymptomatic. Many cases go undiagnosed due to the failure to present any symptoms. Typical symptoms of celiac disease: Diarrhea Weight loss Gastric Upset Abdominal Pain Weakness and fatigue Atypical symptoms are often related to decreased absorption of nutrients or autoimmune responses and include Anemia Osteoporosis Dermatitis herpetiformis Autoimmune thyroiditis Clinical manifestation of Celiac depends on multitude of factors such as genetics, environmental factors, age, gender, and the extent of small intestinal inflammation. Refractory Celiac Disease (RCD) is defined by persisting malabsorption and villous atrophy after about one year of strict Gluten free diet. RCD is also more frequent in women than men. RCD can be type 1 or type 2 depending upon the presence of normal intraepithelial lymphocytes, or abnormal intraepithelial lymphocytes respectively.

Celiac disease in an autoimmune process in which the body makes antigens and antibodies in the presence of gliadin, the alcohol-soluble fraction of gluten. When gluten is consumed, the body mistakes its own gi tract cells for invader cells and antigens signal the immune system. Antibodies then attack the lining of the small intestine, most specifically the villi, which are the small finger like projections located on the surface of the lining. Overtime this attack on the digestive tract can lead to decreased absorption of nutrients, diarrhea, gi upset, and other less common symptoms such as anemia. Environmental Factors Among the environmental factors, gluten is the most common contributor in the development of Celiac disease. Gluten is present in grains like wheat, rye, oat, and barely and is rich in amino acids proline and glutamine. These residues are resistant to degradation by small intestinal proteases. Therefore, gluten protein is not digested completely and partial digestion leads to creation of multiple peptides. These peptides are generated by the action of enzyme tissue transglutaminase (tTG) which causes deamidation of gluten. The peptides are then presented by HLA DQ2 and HLA DQ8 molecules to T-cells. Both gluten as well as autoantigen tTG induce autoimmune response. In CD patients, gluten consumption leads to the production of tTG antibodies by B cells in small intestinal mucosa that can be detected in the serum.

Diagnosis of celiac disease is based on clinical manifestations, blood work, and imaging. The Gold Standard Histology or biopsy of the proximal small intestinal mucosa is the gold standard for detection of CD. Celiac disease biopsies will show changes in the tissues of gi tract such as mucosal villous atrophy with crypt hyperplasia and/or increased intra-epithelial lymphocytosis. Blood Tests Presence of serum antibodies to deamidated gliadin, endomysium or tissue transglutaminase. Anti-tTG antibody: The IgA tTG antibody is the preferred test for screening patients of all ages. Anti-deamidated gliadin peptide (DGP) antibody: Immunoglobulin G (IgG)–based DGP antibody is slightly more sensitive than the IgG-based tTG antibody. Anti- endomysial antibody: The specificity of these antibodies is higher compared to tTG antibody test. Presence of predisposing genetic factors, including human leukocyte antigen markers, HLA DQ2 and HLA DQ8. Intraepithelial lymphocytes, mainly for diagnosis of RCD.

Despite our current understanding of celiac disease, a gluten free diet is the only current treatment proven effective for CD and does not guarantee full relief from CD in many patients. Moreover, patients on a gluten free diet may develop refractory CD. Thus, there is an urgent need to look for other effective treatment options. Some of the promising treatment involves probiotics and drugs that are aimed at modifying gluten and enhancing tight junctions, but more research is needed.