The Contact Activation System and Ulcerative Colitis

The Contact Activation System and Ulcerative Colitis

The study aims to describe alterations in the contact activation system during active and inactive ulcerative colitis.

Contact activation system measures are compared in a cross sectional (healthy controls vs. active disease) and longitudinal (active diasese vs. inactive disease) fashion.

We include and follow up on 102 adults with active ulcerative colitis. Visits are week 0 (inclusion), 6, 12 and 26 (end of study). We obtain plasma and fecal samples at each visit. Whereas we obtain colonic tissue samples only at inclusion and end of study.

Registered data are:

• Demographics realate to UC and general wellbeing.
• Clinical parametres used for UC evaluation are PRO2, SCCAI, CRP, fecal calprotectin, Mayo endoscopic subscore and Nancy index.
• The contact activation system is characterised by FXII, prekallikrein, kallikrein generation, HK, cHK (specific to plasma kallikrein), cHK (specific to tissue kallikrein), C1 inhibitor and Kallistatin.
• Polymerized alpha-1-antitrypsin is characterised by the degree of polymerization and the capacity to activate the contact activation system.

Inclusion Criteria:

• Fulfill diagnostic criteria of ulcerative colitis
• SCCAI score ≥ 5
• Mayo Endoscopic Subscore ≥ 1
• Age ≥ 18 years
• Most understand written and oral information in Danish
• Informed consent must be given

Exclusion Criteria:

• Pregnancy

• Infection at inclusion

• Any existing disease at inclusion:

  • liver disease or defect in CAS
  • inflammatory rheumatologic or dermatologic disease
  • cardiovascular or renal disease
  • immunodeficiency or hematologic diseases
  • malignancies

• Medication with

  • Systemic corticosteroids at inclusion
  • ACE-inhibitor
  • Acetylsalicylic acid/NSAID
  • Warfarin, Phenprocoumon, NOAC and heparins