Towards an individual screening strategy for first-degree relatives of celiac patients.

Celiac disease (CD) is known to be more prevalent in first-degree relatives of patients. In this retrospective cohort study of 609 relatives between 1994 and 2016, we investigated the effect of sex, HLA type, and age at time of index celiac diagnosis. Pearson's chi-square test and Kaplan-Meier survival analysis were used as statistical analyses. CD screening was carried out for 427 relatives (70%), resulting in a prevalence of 15%. HLA typing in 335 relatives showed HLA-DQ2/DQ8 positivity in 87.5%. In 63% of children and all parents, celiac disease was diagnosed at first screening. It was diagnosed significantly more often in females, HLA-DQ2 homozygosity, and children (all p < 0.05). In children aged 0-1 year at time of index diagnosis, celiac disease was diagnosed after consecutive screening in 58%, after 3.9 ± 2.5 (max 10) years (p < 0.001).Conclusion: Future screening policies for relatives of celiac patients should include retesting, especially in HLA-positive relatives younger than 10 years of age. In addition, one-time celiac-specific antibody testing alone could be sufficient to rule out the disease in adolescent siblings and parents of newly diagnosed celiac patients. What is Known: • Celiac disease is more prevalent in first-degree relatives of celiac patients (risk 3-12%). • HLA-DQ2 homozygous sisters/daughters are at highest risk (25%). What is New: • If younger than 10 years of age, repeated testing is necessary in HLA-DQ2/DQ8-positive first-degree relatives when celiac disease is diagnosed in a family. • One-time celiac-specific antibody testing alone could be sufficient to rule out the disease in adolescent siblings and parents of newly diagnosed celiac patients.