Rapid Immunochromatography on Fresh Intestinal Biopsy Is Highly Accurate in Detecting Intestinal Antitransglutaminase Antibodies.

ABSTRACT

INTRODUCTION: Intestinal antitransglutaminase antibodies (I-anti-TG2) are a specific marker of celiac disease (CeD). The aim of this study was to evaluate the diagnostic accuracy of a novel application of an immunochromatographic assay referred to as Rapid_AntiTG2 to detect I-anti-TG2 on intestinal biopsy lysate. METHODS: Consecutive pediatric patients referred to a single center for elective upper endoscopy were enrolled. Biopsies were taken from duodenal bulb and distal duodenum. For each sampling site, 2 biopsies were analyzed for standard histology, 1 biopsy was cultured to perform the reference standard assay for I-anti-TG2 detection (endomysium [EMA] biopsy), and 1 biopsy was mechanically lysed to perform Rapid_AntiTG2. The primary outcome was the diagnostic accuracy of Rapid_AntiTG2 on biopsy lysate compared with that of the gold standard (serology + histopathology) for CeD diagnosis. The secondary outcome was the agreement of Rapid_AntiTG2 with EMA biopsy. RESULTS: One hundred forty-eight patients were included. Of them, 79 were those with CeD (64 classical CeD, 2 seronegative CeD, and 13 potential CeD) and 69 were controls. Rapid_AntiTG2 on biopsy lysate had very high diagnostic accuracy (sensitivity 100%, specificity 97%, LR+ 34.1, LR- 0.01) in separating patients with CeD from controls. Diagnostic accuracy was unchanged in patients with potential and seronegative CeD. Rapid_AntiTG2 on biopsy lysate had almost perfect agreement with the EMA biopsy reference test (99% agreement, Cohen K 0.97). DISCUSSION: I-anti-TG2 can be detected with an immunochromatographic assay after simple mechanical lysis of fresh intestinal biopsy with very high diagnostic accuracy. The test is quick and easy to perform and can be widely available in any endoscopy unit. Its implementation would allow a better understanding of the prognostic value of I-anti-TG2 and help clinicians in cases of suspected CeD that are difficult to classify.