Introduction: Understanding of celiac disease has changed with the advent of serological markers (antigliadin IgA, anti-endomysial IgA and anti-transglutaminase IgA antibodies) and with the identification of major susceptibility genes (HLA-DQA1*05-DQB1*02). Reports of the efficacy of these diagnostic tests have varied, depending on the methodology used and the population investigated.
Objectives: To determine the clinical utility of genetic and serological markers in the diagnosis of celiac disease, their relationship with histological lesions and their changes during treatment, in order to establish an optimal diagnostic algorithm in our environment.
Patients and methods: We performed a retrospective study of 590 patients from the health area of Badajoz referred to the Immunology Laboratory for screening or follow-up of celiac disease. The results of intestinal histology, serological markers (antigliadin IgA, anti-endomysial IgA and anti-transglutaminase IgA antibodies), and genomic typing (HLA-DQA1*05-DQB1*02) were analyzed.
Results: The sensitivity and specificity of serological tests were greater than 90 %, with a negative predictive value of 98-100 %. HLA-DQA1*05-DQB1*02 was detected in 97 % of celiac patients, with a very high negative predictive value (99 %). On biopsy, 95 % of the patients with some grade of intestinal lesion were positive for antigliadin and/or anti-endomysial antibodies.
Conclusion: To avoid missed diagnoses, the diagnostic algorithm of celiac disease should include at least two serological markers (antigliadin antibodies and anti-endomysial and/or anti-transglutaminase antibodies) and IgA quantification. Genomic typing should be carried out if one or more markers are positive or if the subject belongs to any of the risk groups. The physician should decide on the advisability of intestinal biopsy on the basis of the patient's clinical and immunological history.