Coeliac disease case finding and diet monitoring by point‐of‐care testing

Abstract

Background : Immunoglobulin A class transglutaminase autoantibodies are highly predictive markers of active coeliac disease, a disorder difficult to recognize solely on clinical grounds. Aims : To develop and evaluate a simple rapid test for point‐of‐care detection of coeliac autoantibodies. Methods : The novel whole blood test utilizes the patient's endogenous transglutaminase in red blood cells for detection of transglutaminase‐specific immunoglobulin A antibodies present in the blood sample, with normal plasma immunoglobulin A detection as positive test control. We evaluated 284 patients under suspicion of coeliac disease and undergoing jejunal biopsy, and 263 coeliac patients on a gluten‐free diet, 383 being tested prospectively in a point‐of‐care setting. Results were compared with histology, conventional serum autoantibody results and dietary adherence. Results : The rapid test showed 97% sensitivity and 97% specificity for untreated coeliac disease, and identified all immunoglobulin A‐deficient samples. Point‐of‐care testing found new coeliac cases as efficiently as antibody tests in laboratory. Coeliac autoantibodies were detected onsite in 21% of treated patients, while endomysial and transglutaminase antibodies were positive in 20% and 19%, respectively. The positivity rate correlated with dietary lapses and decreased on intensified dietary advice given upon positive point‐of‐care test results. Conclusions : Point‐of‐care testing was accurate in finding new coeliac cases and helped to identify and decrease dietary non‐compliance.