Condition category
Digestive System
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims

Crohn’s disease is chronic inflammatory condition of gastro-intestinal tract that affects 60,000 people in the UK. The etiology is unclear and there is no definite cure. 80% of patients with Crohn’s disease will undergo surgery in their lifetime. About 70-80% of them will have endoscopic recurrence within 1 year. Endoscopic recurrence correlates well with subsequent clinical recurrence. Effective post surgical therapy with drugs, diet or a combination of both may decrease recurrences and associated morbidity and
re-operation rates. Inspite of medical therapy, clinical recurrence rates are as high as 45% within the first year and increases progressively with time. In this study, we investigate the possibility of reducing recurrence rates in such patients using IgG4 based exclusion diets.
IgG4 based exclusion diets:
Hypersensitivity to certain food types has been studied as one of the contributing factors in Crohn’s disease. In this study, individual patients immune response to different food types (antigens) is measured using IgG4 antibody titers against 14 common foods types (cheddar cheese, egg white, egg yolk, rice, wheat, peanuts, soya, tomato, potato, milk, cheese, chicken, lamb, pork). Four food types with highest antibody titres (and hence most severe immune response) will then be excluded from the patient’s diet.
Our study aims to further the knowledge in potential role of IgG4 in Crohn’s disease by defining the source of IgG4 anti-food antibodies in patients with Crohn’s disease.

Who can participate?
Patients who undergo surgery for Crohn’s disease at St George’s hospital will be invited to participate in the study. They should be 16 years or over and should be able to provide informed consent. Those who agree to dietary restriction will be included in the study. Patients who are diagnosed with other autoimmune disorders and those who undergo surgery for isolated perianal Crohn’s disease will be excluded from the study.

What does the study involve?
Patients who consent to participate in the study will be randomly assigned to control group or intervention group. At recruitment, patients in the intervention group will be advised to exclude 4 types of food from their diet based on blood tests. The diet will need to be started 1 month of surgery and should be continued for 1 year from start of diet. Patients in control group will not have any dietary advice. They will be followed up or 1 year.
All patients who undergo surgery for Crohn’s disease are routinely followed up in clinic every 3 months. They also undergo colonoscopy at 1 year. Data for the research will be collected during these clinic visits and no additional visits or procedures will be necessary.
The data required for this research is predominantly collected from routine pre operative and post operative assessments done for all patients who undergo surgery for Crohn’s disease. Blood tests and BMI are checked routinely pre operatively and on follow ups. For purpose of research, an additional 10 ml of blood is collected for measuring IgG4 titres, at recruitment and every 3 months during follow ups. Information about patient’s relevant symptoms over the previous 24 hrs will also be collected pre operatively and on follow ups using a questionnaire. Mesenteric (part of intestine) samples collected will either be blood spilt during the procedure or collected from mesenteric veins which will be resected. This will add less than 5 minutes to the operative procedure.

What are the possible benefits and risks of participating?
We do not envisage any side effects. Dietary advice will be provided if necessary. Patients may be made aware of food hypersensitivities. As a result of blood testing dietary changes may be suggested to you, we hope to bring about symptomatic improvement and less frequent relapses. Patients will be provided with contact details for the research team to be contacted in reasonable hours for any clarifications.

Where is the study run from?
The entire study is based in St Georges Hospital.

When is the study starting and how long is it expected to run for?
We expect this study to run for 2 years. The study will end when we have recruited 50 patients and the last patient has completed 1 year follow up. We expect to start this study in March 2013 and end by April 2015.

Who is funding the study?
The study is funded by the Colorectal Surgery department of St Georges Hospital.

Who is the main contact?
Felix Nicholas

Trial website

Contact information



Primary contact

Prof Devinder Kumar


Contact details

3rd floor
St. James’ Wing
St George’s Hospital
SW17 0QT
United Kingdom
+44 (0)20 8725 5789

Additional identifiers

EudraCT number number

Protocol/serial number

version 11.2

Study information

Scientific title

Preventing postoperative relapse of Crohn's disease by using IgG4 guided exclusion diets: A randomised controlled trial


Study hypothesis

Exclusion of specific food types in diet determined by serum IgG4 levels helps prevent relapse in patients who undergo surgery for Crohn's disease.

Ethics approval

Not provided at time of registration

Study design

Randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

Not specified

Trial type


Patient information sheet

Not available in web format, please use contact Felix Nicholas on to request a patient information sheet


Crohn's disease


This will be a randomised controlled study. Patients will be enrolled for the study preoperatively. Patients will be invited to participate at the first available opportunity following the decision to perform surgery. The discussion could be held in the hospital wards in case of urgent surgeries and outpatient clinics for those undergoing elective procedure. Results from routine pre operative checks including BMI, CRP levels, Hemoglobin level, WBC count, platelet count, prealbumin, Albumin levels and faecal calprotectin levels will be collected. An additional 10 ml of blood will be collected at the same venepuncture for IgG4 titers. The sample will be centrifuged and stored at -40o C and processed in batches of four. IgG4 levels against 14 common food antigens will be checked using fluoroenzymeimmunoassay. Modified CDAI questionnaire will also be completed at enrolment. They will be randomized into intervention group and control (normal diet) group by simple randomization.

Four food antigens (and hence food types) against which each patient had the highest titres will be identified. Patients in the intervention group will be apprised of the IgG4 titres prior to discharge and appropriate written advice on food to be excluded will be given. Exclusion diet will be commenced 1 month after surgery. Patients in control group will continue to have normal diet. No changes to their drug maintenance regimen will be made.

As a routine, all postoperative patients with Crohn's disease are followed up in the clinic every 3 months. On each routine follow up, they undergo clinical examination including BMI and laboratory tests. Laboratory tests include Hemoglobin levels, WBC count, platelet count, albumin levels, pre albumin levels, CRP levels, liver function tests, renal function tests and faecal calprotectin levels. In addition, they undergo colonoscopy at one year. For the purpose of the study, results from the routine assessments including BMI, Hemoglobin, CRP levels, Platelet, WBC count, Albumin levels and faecal calprotectin will be collected on each follow up for 1 year (4 visits). Modified CDAI questionnaire will also be completed at each visit. A further 10 ml of blood will be collected for IgG4 titres on each visit. Their compliance to diet will be confirmed. Our team will perform majority of the colonoscopies for patients included in the study and Rutgeerts score will be recorded. In such cases where patients in our study are booked into a different endoscopy list, the appropriate endoscopist will be contacted prior to the procedure and apprised of this study. A member of the research team will be present personally during the procedure to ensure Rutgeerts score is recorded

In summary, patients in intervention group will be advised to exclude four food types for period of 1 year. Their follow up is similar to that of all patients following surgery for Crohn's disease irrespective of participation in the study. We will collect additional 10 ml of blood at recruitment and 4 follow up visits.

Intervention type



Not Applicable

Drug names

Primary outcome measures

1. Relapse over a 1 year period defined by Rutgeerts endoscopic severity score of i2, i3 or i4
2. Crohn's Disease Activity Index (CDAI) >150 or CDAI increase of more than 100 over baseline
3. Need for therapy to induce remission

Secondary outcome measures

Improvement in quality of life as measured by Short Inflammatory Bowel Disease Questionnaire (SIBDQ)

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Patients with histological diagnosis of Crohn's disease
2. Patients who needed surgery for Crohn's disease
3. Patients who agreed to dietary therapy for a minimum of 1 year or until relapse
4. Patients aged 16 and over
5. Patients capable of providing informed consent

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Severe disease unrelated to Crohn's disease like chronic renal failure or chronic liver disease or immunological disorders
2. Disease localised perineum
3. Other inflammatory conditions of bowel including Ulcerative colitis

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

3rd floor, St. James’ Wing
SW17 0QT
United Kingdom

Sponsor information


St George's University of London (UK)

Sponsor details

c/o Lisa Clutterback
Clinical Research Governance Officer
Joint Research and Enterprise Office (JREO)
Cranmer Terrace
SW17 0RE
United Kingdom
+44 (0)20 8725 0892

Sponsor type




Funder type

Hospital/treatment centre

Funder name

The Colorectal Research Fund at St George's Hospital (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes