Prevalence and Significance of the Presence of Anti-transglutaminase and Anti-endomysium Antibodies in Patients with Early Inflammatory Joint Disease

Introduction: Celiac disease (CD) affects the small intestine, leading to a progressive disappearance of intestinal villi, and can be found in association with several other autoimmune and inflammatory conditions. The main objective of this study was to determine the prevalence and the clinical significance of anti-transglutaminase and anti-endomysium antibodies in patients diagnosed with early rheumatoid arthritis (RA) and spondyloarthritis (SpA).

Methods: We measured anti-transglutaminase and anti-endomysium antibodies in biobanked serum samples at inclusion in two French prospective multicenter cohorts of patients with suspected early rheumatoid arthritis (ESPOIR, n = 713) and spondyloarthritis (DESIR, n = 709). Results were compared with the clinical, laboratory, and radiographic findings obtained in patients during a 10-year follow-up period.

Results: In the DESIR cohort, anti-transglutaminase antibodies were evidenced at low levels (less than three times the upper limit of normal) in 2/709 (0.42%) patients and anti-endomysium antibodies in 0/709 (0%). In the ESPOIR cohort, anti-transglutaminase antibodies were evidenced in 6/713 (0.84%) patients and anti-endomysium antibodies in 1/713 (0.14%). Only the latter patient was confirmed to have celiac disease. Interestingly, this patient was ultimately diagnosed with Sjögren's disease, an autoimmune condition known to be associated with an increased risk of celiac disease.

Conclusion: The very low identified prevalence of anti-transglutaminase and anti-endomysium antibodies suggests a negligible risk of celiac disease in patients with early-stage RA or SpA, which are among the most common inflammatory rheumatic conditions. Consequently, routine screening for celiac disease via these antibodies in patients presenting with early inflammatory rheumatic conditions should not be performed except in case of clinical suspicion of celiac disease.