Point-of-care testing for celiac disease has a low sensitivity in endoscopy

BackgroundCeliac disease (CD) is a common but underdiagnosed condition. A rapid point-of-care test (POCT) could reduce lead times and missed diagnoses.ObjectiveTo assess the utility of an immunoglobulin (Ig) A tissue transglutaminase (TTG) antibody POCT in an endoscopic setting.DesignProspective observational study.SettingA single UK university hospital.PatientsPatients presenting with suspected CD, known CD, and routine endoscopy for upper GI symptoms.InterventionsAll patients were tested with POCT, serum TTG, endomysial antibody (EMA), and upper GI endoscopy with duodenal biopsies at the same visit.Main Outcome MeasurementsComparison was made with histology in all cases, with villous atrophy regarded as diagnostic of CD.ResultsA total of 576 patients (63.5% female, mean [± standard deviation] age 49.7 years [± 17.6 years]) were recruited. A total of 523 patients had no prior diagnosis of CD, and 53 patients had known CD coming for reassessment. A total of 117 patients were newly diagnosed with CD, and 82 were positively identified by the POCT. Sensitivity, specificity, positive predictive value, and negative predictive value were 70.1%, 96.6%, 85.4%, and 91.8%, respectively. In comparison, TTG and EMA both performed significantly better than the POCT. Sensitivity and specificity of TTG were 91.0% and 83.5%, respectively, and EMA were 83.8% and 97.5%, respectively. Of patients with known CD coming for reassessment, 26 had villous atrophy, and POCT results were positive in 16 (61.5%). There was poor agreement between POCT and standard serology.LimitationsHigh pre-test probability of CD.ConclusionThe performance of this POCT was disappointing compared with standard serology and cannot at present be recommended within the context of an endoscopy unit.