Anti-integrin αvβ6 antibody as a biomarker for diagnosing ulcerative colitis: a nationwide multicenter validation study.

Background: A serum biomarker for diagnosing ulcerative colitis (UC) remains to be established. Although we recently reported an anti-integrin αvβ6 antibody (V6 Ab) for diagnosing UC with high sensitivity and specificity, no large-scale validation study exists. This study aimed to validate the diagnostic value of V6 Ab for UC using a nationwide multicenter cohort study.

Methods: We measured V6 Ab titers in patients definitively diagnosed with UC, Crohn's disease (CD), or other gastrointestinal disorders (OGDs). The primary outcome was the diagnostic value of V6 Ab. Secondary outcomes were factors associated with false-negative results in patients with UC and false-positive results in patients without UC and the heterogeneity of the diagnostic value of V6 Ab among the participating facilities.

Results: We enrolled 1241, 796, and 206 patients with UC, CD, and OGD, respectively, from 28 Japanese high-volume referral centers. The diagnostic sensitivity of V6 Ab for UC was 87.7%, and its specificities for CD and OGDs were 82.0% and 87.4%, respectively. Multivariable logistic regression analysis showed that false-negative results were associated with older age at the time of sample collection, current smokers, lower partial Mayo score, and not receiving advanced therapies in patients with UC, and false-positive results were associated with colonic CD in patients with CD. No factor was associated with false-positive results in patients with OGDs. There were no significant differences in the diagnostic value of V6 Ab among the centers.

Conclusions: The diagnostic value of V6 Ab for UC was validated in the large-scale nationwide multicenter study.