Serologic antibodies in relation to outcome in postoperative Crohn's disease

Background and Aim: Disease recurs frequently after Crohn's disease resection. The role of serological antimicrobial antibodies in predicting recurrence or as a marker of recurrence has not been well defined. Methods: A total of 169 patients (523 samples) were prospectively studied, with testing peri‐operatively, and 6, 12 and 18 months postoperatively. Colonoscopy was performed at 18 months postoperatively. Serologic antibody presence (perinuclear anti‐neutrophil cytoplasmic antibody [pANCA], anti‐Saccharomyces cerevisiae antibodies [ASCA] IgA/IgG, anti‐OmpC, anti‐CBir1, anti‐A4‐Fla2, anti‐Fla‐X) and titer were tested. Quartile sum score (range 6–24), logistic regression analysis, and correlation with phenotype, smoking status, and endoscopic outcome were assessed. Results: Patients with ≥ 2 previous resections were more likely to be anti‐OmpC positive (94% vs55%, ≥ 2 vs < 2, P = 0.001). Recurrence at 18 months was associated with anti‐Fla‐X positivity at baseline (49% vs 29%; positive vs negative, P = 0.033) and 12 months (52% vs 31%, P = 0.04). Patients positive (n = 28) for all four antibacterial antibodies (anti‐CBir1, anti‐OmpC, anti‐A4‐Fla2, and anti‐Fla‐X) at baseline were more likely to experience recurrence at 18 months than patients negative (n = 32) for all four antibodies (82% vs 18%, P = 0.034; odds ratio 6.4, 95% confidence interval 1.16–34.9). The baseline quartile sum score for all six antimicrobial antibodies was higher in patients with severe recurrence (Rutgeert's i3‐i4) at 18 months, adjusted for clinical risk factors (odds ratio 1.16, 95% confidence interval 1.01–1.34, P = 0.039). Smoking affected antibody status. Conclusions: Anti‐Fla‐X and presence of all anti‐bacterial antibodies identifies patients at higher risk of early postoperative Crohn's disease recurrence. Serologic screening pre‐operatively may help identify patients at increased risk of recurrence.