The investigators will evaluate the use of an HLA-DQ2-gliadin tetramer for staining of gluten specific T cells in the diagnostics of uncertain celiac disease. Some patients have started on a gluten free diet without a diagnosis of celiac disease. Subsequent later investigation in special care is difficult as the patients often are reluctant to prolonged gluten challenge. The investigators use the HLA-DQ2-gliadin tetramers for detection of gluten specific T cells after a short gluten challenge. By this method the investigators search to discriminate between true celiac disease and clinical gluten intolerance without celiac disease, in a population of HLA-DQ2+ persons already on a gluten free diet without a formal diagnosis of celiac disease.