Children with celiac disease are nearly three times as likely to develop JIA relative to the general population. Adults with celiac disease are nearly two times as likely to be diagnosed with RA.
"I hope that our study can ultimately change clinical practice by lowering the threshold to evaluate celiac disease patients for inflammatory joint diseases," John B. Doyle, MD, a gastroenterology fellow at Columbia University Irving Medical Center in New York City, told Medscape Medical News.
"Inflammatory joint diseases, such as JIA and RA, are notoriously difficult to diagnose given their variable presentations," he said. "But if JIA or RA can be identified sooner by physicians, patients will ultimately benefit by starting disease-modifying therapy earlier in their disease course."
The study was published online in The American Journal of Gastroenterology.
Celiac disease, which is an immune-mediated disorder, has been linked to numerous autoimmune diseases, including type 1 diabetes, autoimmune thyroid disease, lupus, and inflammatory bowel disease (IBD), Doyle noted. However, a definitive epidemiologic association between celiac disease and inflammatory joint diseases such as JIA or RA hasn't been established.
Doyle and colleagues conducted a nationwide population-based, retrospective matched cohort study using the Epidemiology Strengthened by Histopathology Reports in Sweden. They identified 24,014 patients diagnosed with biopsy-proven celiac disease between 2004 and 2017.
With these data, each patient was matched to five reference individuals in the general population by age, sex, calendar year, and geographic region, for a total of 117,397 people without a previous diagnosis of celiac disease. The researchers calculated the incidence and estimated the relative risk for JIA in patients younger than 18 years and RA in patients aged 18 years or older.
For those younger than 18 years, the incidence rate of JIA was 5.9 per 10,000 person-years among the 9415 patients with celiac disease vs 2.2 per 10,000 person-years in the general population, over a follow-up of 7 years. Those with celiac disease were 2.7 times as likely to develop JIA.
The association between celiac disease and JIA remained similar after adjustment for education, Nordic country of birth, type 1 diabetes, autoimmune thyroid disease, lupus, and IBD. The incidence rate of JIA among patients with celiac disease was higher in both females and males, and across all age groups studied.
When 6703 children with celiac disease were compared with their 9089 siblings without celiac disease, the higher risk for JIA in patients with celiac disease fell slightly short of statistical significance.
For those aged 18 years or older, the incidence rate of RA was 8.4 per 10,000 person-years among the 14,599 patients with celiac disease vs 5.1 per 10,000 person-years in the general population, over a follow-up of 8.8 years. Those with celiac disease were 1.7 times as likely to develop RA.
As with the younger cohort, the association between celiac disease and RA in the adult group remained similar after adjustment for education, Nordic country of birth, type 1 diabetes, autoimmune thyroid disease, lupus, and IBD. Although both men and women with celiac disease had higher rates of RA, the risk was higher among those in whom disease was diagnosed at age 18-59 years compared with those who received a diagnosis at age 60 years or older.
When 9578 adults with celiac disease were compared with their 17,067 siblings without celiac disease, the risk for RA remained higher in patients with celiac disease.
This suggests "that the association between celiac disease and RA is unlikely to be explained by environmental factors alone," Doyle said.
Notably, the primary analysis excluded patients diagnosed with JIA or RA before their celiac disease diagnosis. In additional analyses, however, significant associations emerged.
Among children with celiac disease, 0.5% had a previous diagnosis of JIA, compared with 0.1% of matched comparators. Those with celiac disease were 3.5 times more likely to have a JIA diagnosis.
Among adults with celiac disease, 0.9% had a previous diagnosis of RA, compared with 0.6% of matched comparators. Those with celiac disease were 1.4 times more likely to have a RA diagnosis.
"We found that diagnoses of these types of arthritis were more common before a diagnosis of celiac disease compared to the general population," Benjamin Lebwohl, MD, director of clinical research at the Celiac Disease Center at Columbia University, told Medscape Medical News.
"This suggests that undiagnosed and untreated celiac disease might be contributing to these others autoimmune conditions," he said.
Doyle and Lebwohl emphasized the practical implications for clinicians caring for patients with celiac disease. Among patients with celiac disease and inflammatory joint symptoms, clinicians should have a low threshold to evaluate for JIA or RA, they said.
"Particularly in pediatrics, we are trained to screen patients with JIA for celiac disease, but this study points to the possible bidirectional association and the importance of maintaining a clinical suspicion for JIA and RA among established celiac disease patients," Marisa Stahl, MD, assistant professor of pediatrics and associate program director of the pediatric gastroenterology, hepatology, and nutrition fellowship training program at the University of Colorado School of Medicine in Aurora, told Medscape Medical News.
Stahl, who wasn't involved with this study, also conducts research at the Colorado Center for Celiac Disease. She and colleagues are focused on understanding the genetic and environmental factors that lead to the development of celiac disease and other autoimmune diseases.
Given the clear association between celiac disease and other autoimmune diseases, Stahl agreed that clinicians should have a low threshold for screening, with "additional workup for other autoimmune diseases once an autoimmune diagnosis is established."
The study was supported by Karolinska Institutet and the Swedish Research Council. Lebwohl coordinates a study on behalf of the Swedish IBD quality register, which has received funding from Janssen. The other authors declared no conflicts of interest. Stahl reported no relevant disclosures.
Am J Gastroenterol. Published October 28, 2022. Abstract
Carolyn Crist is a health and medical journalist who reports on the latest studies for Medscape, MDedge, and WebMD.
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Cite this: Celiac Disease Linked to Higher Risk for Rheumatoid Arthritis, Juvenile Idiopathic Arthritis - Medscape - Nov 17, 2022.