Significance of Ficolin 2 in the Determination of Serological Activity in Chronic Inflammatory Bowel Disease
Condition: Crohn Disease
MeSH terms: Crohn Disease; Intestinal Diseases; Inflammatory Bowel Diseases
Study type: Observational

Summary: 
      Background Determining disease activity in IBD is sometimes difficult and, to be accurate,
      requires endoscopy. The serum marker CRP has not proven sufficiently valuable as a marker for
      IBD specific inflammation. As an alternative, so far fecal calprotectin appears to be more
      reliable and has shown a certain value as predictive marker. Our preliminary data now show,
      that the serum concentrations of ficolin-2 are significantly higher in CD patients with a HBI
      >3. Ficolin-2 is a lectin and acute phase protein produced in the liver and, like MBL, can
      activate the lectin pathway of complement. Unlike MBL, deficiency for ficolin-2 was not
      detected in our patient cohort, nor could we find functional deficiencies for ficolin-2
      (paper submitted).

      Study Aims The study is aimed to substantiate the data from our pilot study which shows that
      ficolin-2 is significantly increased in CD patients during inflammation. Therefore, the study
      will measure ficolin-2 concentrations in a sufficiently large patient group to obtain enough
      statistical power and to compare these results with the endoscopic disease score (SES-CD) and
      CRP and calprotectin values. Statistical analysis of the data will show us if ficolin-2 is a
      reliable and easy to obtain new marker for active inflammation in CD.

      Study Design Based on a power analysis 112 CD patients and 112 UC patients need to be
      analyzed. They will be recruited from Bern, Basel and Lausanne. Only patients with routine
      endoscopy will be included in the study and will be scored by SES-CD. Blood samples will be
      collected at the day of endoscopy. Stool sample will be collected within the same week of
      endoscopy. Calprotectin and CRP concentrations will be determined by routine diagnostics,
      ficolin-2 concentrations will be determined by ELISA in our laboratory. Finally, all data
      will be statistically analyzed.
    

Detailed description: 
      Background

      Background Like mannan-binding lectin (MBL), ficolins are important soluble receptors for
      microbial associated molecular patterns leading to the activation of the lectin pathway
      complement. Ficolins are structurally related to MBL, but due to their different carbohydrate
      recognition domain represent an own family of lectins (1). The single polypeptide chains of
      ficolins form trimers and the trimers finally form higher order structures (tetramers up to
      hexamers) which constitute the functional protein. Humans have three ficolins: Ficolin-1
      (M-ficolin), -2 (L-ficolin) and -3 (H-ficolin), whereas ficolin-2 and -3 are present in the
      serum, ficolin-1 is found on the surface of monocytes. Both, ficolin-2 and -3 are produced in
      the liver with an additional source for ficolin-3 in the lung. Like MBL, ficolins have to
      assemble with the MBL-associated serin proteases (MASPs) in order to activate the complement
      pathway (1). In our study on a possible role for the influence of the complement system in
      the development of CD-associated anti-Saccharomyces cerevisiae antibodies (ASCAs), we noticed
      that chronic inflammatory bowel disease (CIBD) patients, specifically Crohn's disease (CD)
      patients, exhibited high serum ficolin 2 concentrations.

      Our research group is interested in the interaction of the innate immune system with
      microorganisms of the intestinal flora, focusing on possible defects in innate immune
      mechanisms. We have more than ten years experience in the field, with a special focus on ASCA
      and MBL. We have been able to continuously publish our work about these theories.

      Our earlier and present studies on the role of MBL and the lectin pathway of complement in CD
      led to the finding of increased ficolin-2 concentration in the sera of CD patients. Moreover,
      we found that CD patients with a Harvey-Bradshaw index >3 had significantly higher ficolin 2
      concentrations than those with a Harvey-Bradshaw index of ≤ 3.

      Study Hypotheses

      The following hypotheses are to be tested:

        1. The ficolin 2 concentration is higher in Crohn's patients with active disease than in CD
           patients in remission.

        2. Ficolin 2 correlates with endoscopic activity.

        3. Ficolin 2 correlates with calprotectin.

      Objective

      The findings from the first part of the study are to be confirmed in a prospective and more
      detailed study with a larger patient cohort, testing our (new) working hypothesis that
      ficolin 2 represents a serum marker for disease activity in CD.

      Since it is currently difficult to reliably determine disease activity in CD patients using
      serum and stool markers without simultaneous endoscopic examination, another specific and
      easy to obtain disease marker which correlates well with disease activity would be highly
      welcome. Particularly because the current standard marker, to monitor disease activity
      (faecal calprotectin), is much less accepted than testing for parameters in the blood.

      Therefore, the study aims at answering the question of whether ficolin 2 is present in
      greater concentrations in the blood of Crohn's patients with active inflammation compared to
      CD patients in remission or to ulcerative colitis (UC) patients.

      Methods

      For the purposes of the study, the endoscopic activity index will be recorded using the
      SES-CD (simplified endoscopic score for CD) for Crohn's patients and the Mayo score for
      colitis patients.

      Approximately 5 ml blood will be taken to prepare serum. (5.5 ml or 4.9 ml S Monovette or 4.7
      ml or 4.9 ml serum gel Monovette).

      A second test tube of blood will be taken for CRP determination. In order to measure
      calprotectin, the patient will be asked to provide a stool sample shortly before or shortly
      after the endoscopic examination (within one week).

      Serum ficolin values are measured by enzyme-linked immune sorbent assay (ELISA) in the
      laboratory at the Department of Clinical Research, University of Bern; all other values are
      determined in routine diagnostic laboratories.
    

Intervention name(s): Endoscopy; Endoscopy
Intervention type(s): Other; Other
Intervention description(s): Only patients undergoing endoscopy for clinical reasons will be included in the study, i.e. no endoscopies will be performed solely for study reasons. For the purposes of our study, endoscopy serves to determine the degree of inflammation and no additional biopsies are taken. Blood for CRP and ficolin-2 analysis will be taken through the Venflon® installed for endoscopy.; Only patients undergoing endoscopy for clinical reasons will be included in the study, i.e. no endoscopies will be performed solely for study reasons. For the purposes of our study, endoscopy serves to determine the degree of inflammation and no additional biopsies are taken. Blood for CRP and ficolin-2 analysis will be taken through the Venflon® installed for endoscopy.
Observational model: Case-Only
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        All CD and UC patients undergoing endoscopy for clinical reasons at one of the involved
        clinical centers.
      
Biospecimen description: 
      Serum Stool
    
Keywords: Inflammatory bowel diseases; Crohn disease; Ficolin-2; C-Reactive Protein; Calprotectin; Inflammatory markers; SES-CD