A tissue transglutaminase (tTG) IgA and/or IgG test is used as part of an evaluation for certain autoimmune conditions, most notably coeliac disease. Coeliac disease tests are used to screen for and help diagnose coeliac disease and a few other gluten-sensitive conditions (such as dermatitis herpetiformis, a condition that causes an itchy, burning, blistering rash on the skin).
IgE has an essential role in type I hypersensitivity, which manifests various allergic diseases, such as allergic asthma, most types of sinusitis, allergic rhinitis, food allergies and specific types of chronic urticaria and atopic dermatitis. IgE also plays a pivotal role in responses to allergens, such as: anaphylactic drugs, bee stings and antigen preparations used in desensitization immunotherapy.