**5.2 Autoimmune atrophic gastritis (AAG)**

In the early stage of AAG, due to the reduced gastric acid secretion and intrinsic factors the clinician should focus on preventing the deficiency of B12, iron, and folate as the development of anemia could be prevented with supplementation of these nutritions. In case of the presence of pernicious anemia already, the clinician should consider B12 repletion, cyanocobalamin, and iron supplements to restore hemoglobin function. Also, clinician should note that AAG is usually associated with autoimmune diseases, such as autoimmune thyroid disease, type 1 diabetes mellitus, and Addison disease [146–156].

## **5.3 Celiac disease**

A lifelong strict GFD can be considered the only treatment for celiac disease [157]. For patients who have refractory type celiac disease, they might need a pharmacological intervention besides the strict GFD diet. The use of drugs that work on proteolytic destruction of gluten peptides, inhibition of intestinal permeability to prevent gluten absorption, inhibition of TG2, or modulation of the immune response to gluten to prevent T cell activation is a promising option [158, 159]. Currently, the most promising treatment is the vaccine Nexvax2, which is an adjuvant-free mixture of tripeptides immunodominant epitopes for gluten-specific CD4-positive T cells. However, it is still in the preliminary stages [160–162].
