Ulcerative Colitis (UC) 

UC is a chronic immune-mediated condition that affects the colon and rectum, leading to periods of flares and remission.

 

Overview

UC is a major form of chronic inflammatory bowel disease, alongside Crohn’s disease. 1 It typically follows a relapsing‑remitting course and is characterized by inflammation that is confined to the colon, starting in the rectum and potentially extending to the entire colon with inflammation typically restricted to the mucosal layer.

Clinical presentation by extent:

  • Proctitis – inflammation limited to the rectum
  • Left‑sided colitis – extending up to the splenic flexure
  • Pancolitis – involvement of the entire colon

Patients commonly experience bloody diarrhea, abdominal pain, and fever during periods of active disease. 2 Chronic inflammation often begins early in life and can significantly impair quality of life. 3

 

Epidemiology in Switzerland

  • Prevalence: Approximately 0.2% of the Swiss population is affected by UC, contributing to an overall IBD prevalence of about 0.4% (≈1 in 250 inhabitants). 4
  • Incidence: The annual incidence of UC is approximately 2.4 new cases per 100,000 Swiss inhabitants, based on population-based data from the Canton of Vaud. 5
  • Age of onset: UC can occur at any age, but most commonly presents in young adults. The peak age of onset is between 30 and 40 years, with a smaller second peak occurring later in adulthood 6.
  • Gender distribution: Men and women are affected almost equally 6.

 

Pathogenesis

The exact cause of UC is not yet fully understood. However, it is assumed that several factors are involved, including genetic predisposition, changes in the gut microbiome, and various environmental factors. Impaired epithelial barrier function allows increased exposure to luminal antigens, triggering an amplified mucosal immune response. This dysregulated interplay between the innate and adaptive immune systems results in a chronic, uncontrolled inflammation. 7

The extent of UC, which often has a relapsing course, can range from the rectum (proctitis) to involvement of the entire colon (pancolitis). Typical symptoms include bloody diarrhea, abdominal pain, urgent need to defecate, nausea, as well as fever, weight loss, and anemia. 7, 8

 

Diagnosis

For the diagnosis of UC, a combination of medical history, clinical examination, and typical sonographic, endoscopic, histological, and laboratory findings is required. 7, 8

 

Therapy

The choice of therapy is based on several factors, including:

  • Symptom severity
  • Disease extent (proctitis, left-sided colitis, pancolitis)
  • Course and duration of disease
  • Presence of extraintestinal manifestations and comorbidities
  • Previous treatments

Importantly, patient preference should be incorporated into the decision-making process to ensure personalized care. 8

 

The following drug classes are available for the treatment of ulcerative colitis: 8

  • Corticosteroids
  • 5-Aminosalicylates
  • Conventional immunosuppressants such as thiopurines and methotrexate
  • Biologics
    • Integrin antagonists
    • TNFα antagonists
    • IL-12/23 antagonist
    • IL-23 antagonists
  • Small molecules
    • JAK inhibitors
    • Sphingosine-1 receptor modulators

Integrin Antagonist 

Learn more about the mode of action of the integrin antagonist:

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VV-MEDMAT-133544

References

  • 1. Podolsky DK et al. Inflammatory Bowel Disease. New England Journal of Medicine. 2002;347:417-429​.

  • 2. Ordás I, Eckmann L, Talamini M, Baumgart DC, Sandborn WJ. Ulcerative colitis.Lancet. 2012;380(9853):1606-1619. 

  • 3. Ng SC et al. Worldwide incidence and prevalence of inflammatory bowel disease in the 21st century: a systematic review of population-based studies. Lancet. 2017;390:2769–2778.

  • 4. Schoepfer A et al. Epidemiologie und sozioökonomische Aspekte der chronisch entzündlichen Darmerkrankungen in der Schweiz.Therapeutische Umschau. 2019; 75(5):255-259.

  • 5. Pittet V, Juillerat P et al. Inflammatory bowel disease incidence trends in the Canton of Vaud, Switzerland, 1991-2005: a population-based cohort study. Eur J Gastroenterol Hepatol. 2010;22(10):1170-1176.

  • 6. Magro F et al. ECCO Guidelines on Ulcerative Colitis. Journal of Crohn’s and Colitis. 2017;11(6):649–670.

  • 7. Roda G et al. Crohn’s Disease. Nature Reviews Disease Primers. 2020;6(1):22.  

  • 8. Raine T et al. ECCO Guidelines on Therapeutics in Ulcerative Colitis: Medical Treatment. Journal of Crohn's and Colitis. 2022;16(1):2-17.