Associated disorders in celiac disease

Sammanfattning: Background: Celiac disease (CD) is an autoimmune disorder that affects genetically susceptible individuals and is induced by dietary gluten. Treatment consists of a lifelong gluten-free diet. CD is common and affects about 1% of the general population. The classic symptoms include diarrhea and malabsorption, but many patients have only mild symptoms or no symptoms at all. The proportion of individuals presenting with atypical symptoms or discovered only when investigating an associated condition of CD is increasing.Aims: The aim of this thesis was to investigate the risk of possible associated disorders through Swedish population-based registers. The objective was to gain more information on the consequences of having CD and to identify high risk groups where screening may be considered.Materials and methods: We used the Swedish hospital discharge register to examine the risk of liver disease, autoimmune heart disease, Addison’s disease and thyroid disorders in a cohort of about 14,000 individuals with CD and an age and sex matched reference population of 70,000 individuals. In the last study we used all regional pathology registers and the cancer registry to examine the risk of hematopoietic cancer, including lymphoma in three different cohorts: I) 28,810 individuals with CD; II) 12,681 individuals with small intestinal mucosal inflammation but without villous atrophy; and III) 3552 individuals with latent CD (a positive serology test for CD with a normal small intestinal biopsy).Results: CD is statistically significantly associated with an increased risk of liver disease, Addison’s disease, thyroid disease and lymphoma. We also found an increased risk of lymphoma in individuals with small intestinal mucosal inflammation. There was no statistically significant association between autoimmune heart disease or leukemia and CD. Latent CD was not associated with any hematopoietic cancers.Conclusion: This thesis found a positive association between CD and a number of autoimmune and inflammatory disorders. Clinicians need to have a high awareness of this association and to test for these conditions when symptoms appear.