Clinical outcomes and risk factors of secondary extraintestinal manifestation in ulcerative colitis: results of a multicenter and long-term follow-up retrospective study.

Background: Extraintestinal manifestations (EIM) are common in ulcerative colitis (UC). In Shanghai, China, data on the incidence rate and risk factors of EIM in UC patients remain scarce. Methods: The study population consisted of UC patients who were identified from a prospectively maintained, institutional review board-approved database at our institutes from June 1986 to December 2018. The demographic and clinical characteristics of the study participants were analyzed. The study included secondary EIM in UC patients and follow-up, while primary EIM was excluded. The diagnosis of EIM was based on clinical, radiological, endoscopic, and immunologic examination and histological findings. Results: In total, 271 eligible patients were included in the current study, with a median follow-up time of 13.0 years (interquartile range, 9.0-17.0), and including 31 cases (11.4%) that developed EIM. EIM was associated with clinical outcomes in UC patients and the following factors were identified as contributing factors for the development of EIM: a disease duration of >5 years (odds ratio (OR), 3.721; 95% confidence interval (CI) [1.209-11.456]), age at diagnosis >40 years (OR, 2.924, 95% CI [1.165-7.340]), refractory clinical symptoms (OR, 4.119; 95% CI [1.758-9.650]), and moderate or severe anemia (OR, 2.592; 95% CI [1.047-6.413]). Conclusion: In this study, approximately 11.4% UC patients go on to develop at least one EIM. Clinicians should prioritize early control of the disease and treatment of anemia in UC in order to prevent the development of EIM and improve disease prognosis.