Dermatitis herpetiformis (DH), or Duhring’s disease, is a chronic autoimmune blistering skin disease (AIBD). Despite its name it is not related to infection with herpes viruses; instead the clinical presentation of the skin resembles that of herpes infections (i.e., a papulovesicular rash that is often found on the extensor surfaces of elbows, knees, proximal forearms, scalp, buttocks). DH is closely associated with gluten-sensitive enteropathy: it may be the first symptom of celiac disease. At least three-quarters of patients with DH have some degree of enteropathy, but gastrointestinal and abdominal symptoms are usually absent. Conversely, only one quarter of patients with celiac disease develop DH. Because of its rareness and the vesicular appearance and pruritus DH can be mistaken for other, more common dermatological conditions (e.g., eczema, popular urticarial, scabies).

If DH remains undiagnosed in clinically active patients, those individuals may develop overt celiac disease, including the related complications (e.g., osteoporosis, anemia, small bowel lymphoma, all due to the underlying enteropathy). Diagnosis of DH may also increase identification of associated autoimmune disorders, including Hashimoto’s thyroiditis, rheumatoid arthritis, sarcoidosis, lupus erythematosus, Sjoegren’s syndrome, and pernicious anemia.
Investigations for diagnosis of DH may include skin biopsy, serological testing, HLA typing, and digestive studies. Gold standard for confirming a suspected DH diagnosis is a direct immunofluorescence (IF) microscopy of perilesional skin, showing granular deposition of IgA immunocomplexes just below the basement membrane. Multiple biopsies may be necessary to confirm DH by direct IF microscopy.  Indirect IF microscopy may be useful for detection of circulating IgA autoantibodies against endomysium, gliadin, reticulin, and transglutaminases. For the diagnosis of DH, commercially available ELISA kits are reported to have sensitivities of 47-95% and specificities of >90%. All of these serological tests may be good markers for DH, but comprehensive data on specificity and sensitivity of combinations of those have not been reported in the literature up to now.

Therefore, in this project we want to identify the serological test system(s) that is most suitable for the serological diagnosis of patients with DH and to improve the detection of autoantibodies in DH and celiac disease diagnostics.