Abstract Background Clinicians often face difficulties differentiating Crohn’s disease (CD) and ulcerative colitis (UC) in patients with nonspecific endoscopic and histological findings, resulting in the diagnosis of unspecified inflammatory bowel diseases (IBD-U). Data suggest that IgG antibodies against integrin αvβ6 (V6 Ab) are associated to UC but not CD. Recent studies suggest that measuring V6 Ab serum levels may be valuable for differential diagnostic purposes. The primary objective of the study was to assess the sensitivity and specificity of V6 Ab serum level measurement in our IBD population. Furthermore, we assessed the correlation between disease characteristics, activity and V6 Ab serum levels in UC patients. Methods Consecutive IBD patients with an established diagnosis undergoing control colonoscopy in a tertiary IBD centre were included. Baseline demographic data, current treatment, disease extent, clinical, biomarker, endoscopic and histologic disease activity were recorded. V6 Ab serum levels were measured with the Anti-Integrin αvβ6 ELISA Kit (RUO). Patients’ informed consent was obtained. Results A total of 40 IBD patients, including 10 CD and 30 UC patients (15 with clinical activity and 15 in clinical remission) were enrolled. V6 Ab serum levels were significantly higher in UC than CD (p = 0.039). ROC-analysis found 1.33 U/ml to be the best cut-off level (p = 0.0432; AUC: 0.7074) with 100% sensitivity and 50% specificity and a a positive predictive value of 85.7% and a negative predictive value of 100% to differentiate between UC and CD. No significant correlation was found between V6 Ab serum levels and CRP (p = 0.057), faecal calprotectin (p = 0.77), endoscopic activity (p = 0.624) or disease extent (p = 0.624) in UC patients. Conclusion Our study supports the value of V6 Ab serum level measurement as a differential diagnostic tool in IBD patients, however optimal cut-off values are yet to be determined. Our data do not support its use in disease activity monitoring and disease phenotype or course prediction. Conflict of interest: Angyal, Dorottya: No conflict of interest Balogh, Fruzsina: No conflict of interest Gonczi, Lorant: No conflict of interest Lontai, Livia: No conflict of interest Kosa, Janos: No conflict of interest Garam, Nora: No conflict of interest Lakatos, Péter Laszlo: No conflict of interest Ilias, Akos: No conflict of interest
Angyal et al. (Thu,) studied this question.