Celiac.com 07/27/2015 - First-degree relatives of individuals with celiac disease are at increased risk for this disorder, but little is known about their risk for other autoimmune diseases.
The research team included Louise Emilsson, Cisca Wijmenga, Joseph A. Murray, and Jonas F. Ludvigsson. They are variously affiliated with the Primary Care Research Unit, Vårdcentralen Värmlands Nysäter, Värmland County, Sweden, the Department of Health Management and Health Economy, Institute of Health and Society, University of Oslo, Oslo, Norway, the Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands, the Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden, and with the Department of Pediatrics, Örebro University Hospital, Örebro, Sweden.
The team found individuals with celiac disease by searching computerized duodenal and jejunal biopsies, collected from 1969 through 2008, at 28 pathology departments in Sweden.
The team found 29,096 patients with celiac disease based on biopsy reports of villous atrophy of Marsh grade 3 or higher and matched individuals with celiac disease with up to 5 of 144,522 non-celiac control patients based on sex, age, county, and calendar year.
Through Swedish health care registries, the team identified all first-degree relatives (fathers, mothers, siblings, and offspring) and spouses of 84,648 individuals with celiac disease, and 430,942 control subjects. The team used Cox regression analysis to calculate hazard ratios (HRs) for non-celiac autoimmune disease, such as Crohn’s disease, type 1 diabetes mellitus, hypothyroidism, hyperthyroidism, psoriasis, rheumatoid arthritis, sarcoidosis, systemic lupus erythematosus, or ulcerative colitis, within these groups.
Cox analysis showed that during the follow-up period averaging just under 11 years, nearly 3333, or 4%, of the first-degree relatives of patients with celiac disease, and 12,860 relatives of controls (3.0%), had an autoimmune disease other than celiac disease.
First-degree relatives of people with celiac disease had an increased risk of non-celiac autoimmune disease, compared with controls (HR, 1.28; 95% confidence interval, 1.23–1.33), as did spouses (HR, 1.20; 95% confidence interval, 1.06–1.35).
Risk estimates for non-celiac autoimmune disease did not differ between first-degree relatives and spouses of individuals with celiac disease (interaction test: P = .11). Hazard Ratios for non-celiac autoimmune disease were highest in the first 2 years of follow-up evaluation.
First-degree relatives and spouses of individuals with celiac disease have a significantly higher risk of non-celiac autoimmune disease.
In addition to genetic factors, environmental factors and better awareness, testing and diagnosis might influence rates of autoimmune disorders in first-degree relatives of individuals with celiac disease.