Comparative risk of incident Clostridioides difficile infection with vedolizumab versus anti‑TNF in ulcerative colitis: A retrospective cohort study.

BACKGROUND

The comparative risk of Clostridioides difficile infection (CDI) between vedolizumab (VDZ) and anti-TNF in ulcerative colitis (UC) is unclear.

AIMS: To compare incidence densities (IDs) and risks of CDI and C. difficile nucleic acid positivity between UC receiving VDZ versus anti-TNF.

METHODS

We retrospectively enrolled patients receiving VDZ or anti-TNF (Nov 2020-Oct 2024) with negative baseline C. difficile tests. IDs and incidence density ratios (IDRs) were calculated. Hazard ratios (HRs) were estimated using marginal structural Cox models.

RESULTS

Of 214 patients, 156 received VDZ (202 PY) and 58 anti-TNF (53 PY). CDI occurred in 22 on VDZ (10.89/100 PY) and 8 on anti-TNF (15.09/100 PY), IDR = 0.71 (p = 0.427). C. difficile positivity occurred in 33 on VDZ (16.34/100 PY) and 8 on anti-TNF (15.09/100 PY), IDR = 1.07 (p = 0.841). Adjusted HRs for CDI and positivity were 0.95 (95 % CI: 0.41-2.22, p = 0.907) and 1.40 (95 % CI: 0.62-3.19, p = 0.417), respectively. Sensitivity analysis in biologic-naïve patients gave consistent results.

CONCLUSION

No statistically significant differences in CDI or C. difficile positivity risk were detected between VDZ and anti‑TNF in UC. Wide confidence intervals preclude definitive conclusions, and the observed signals require validation in larger prospective cohorts.