Background: Coeliac disease (CD) is an autoimmune disease of the small intestine caused by gluten ingestion in genetically predisposed subjects. It can occur isolated or in combination with other autoimmune diseases. Autoimmune Addison's disease is frequently associated with other organ-specific autoimmune diseases. We have investigated the prevalence of CD among a large cohort of patients with autoimmune Addison's disease.
Methods: Seventy-six patients (44 women) with Addison's disease, 52% of whom had polyendocrine failure, were recruited from a registry of organ-specific autoimmune diseases in Norway. All sera were analysed for antibodies against gliadin (AGA), endomysium (EMA) and tissue transglutaminase (tTG). Patients with positive EMA and/or anti-tTG were offered endoscopy. The human leucocyte antigen (HLA) class II genotypes were determined.
Results: Five patients had antibodies against both endomysium and tissue transglutaminase. In these five patients, CD was verified by biopsy. One patient had known CD prior to the study. All six patients with CD carried the CD-associated HLA haplotype DR3-DQ2. The total prevalence of CD was 7.9%.
Conclusion: CD is frequently associated with Addison's disease. The risk of developing CD seems to be higher than can be explained by the common DR3-DQ2 association alone. It is often asymptomatic or associated with unspecific symptoms. Addison patients should be screened for the presence of CD on a regular basis.