Clinical Impact of Gastrointestinal Multiplex PCR Panels on Relapse Prediction in Ulcerative Colitis: A Prospective One-Year Follow-up Study

Background: This study aimed to evaluate the effect of the gastrointestinal system multiplex PCR panel (GISP) on the relapse-free survival of ulcerative colitis (UC) both active and in remission patients. Methods: In this prospective single-center study, adult patients with ulcerative colitis were followed for one year. Baseline disease activity was assessed using the Partial Mayo Score (PMS). Gastrointestinal multiplex PCR panel testing was performed, and the association between PCR positivity and relapse-free survival was analyzed using survival models. Results: At baseline 74.1% of patients were in remission and 25.9% were in the active period. At least one causative agent was detected in 39.7% of stool samples evaluated by GISP. The most common agents were Enteropathogenic E. coli (EPEC) (52.2%), Campylobacter spp. (13.8%), and Enteroaggregative E. coli (EAEC) (11.6%). There was no difference between patients in baseline remission and relapse groups regarding agent positivity. A relapse developed in 38.5% of the patients within one year follow-up. There was no difference between relapse-free survival in GISP positive and negative patients. In patients who were active at baseline, the relapse-free period was shorter. As a result of the study, the most critical factor affecting the relapse-free period was the partial Mayo score (PMS), which we used to determine the activity status of the disease at baseline. Conclusion: According to the results of the study, GISP positivity did not affect relapse-free survival. The role of GISP in UC patients' follow-up and predicting clinical outcomes of patients in relapse or remission was limited.