Inoculating Celiac Disease Patients With the Human Hookworm Necator Americanus: Evaluating Immunity and Gluten-sensitivity
Primary Purpose
Celiac Disease
Status
Completed
Phase
Phase 2
Locations
Australia
Study Type
Interventional
Intervention
Necator americanus
Sham inoculation
Sponsored by
![Princess Alexandra Hospital, Brisbane, Australia](https://trials-media.s3.amazonaws.com/orgs/princess-alexandra-hospital-brisbane-australia.jpeg)
About this trial
This is an interventional treatment trial for Celiac Disease focused on measuring Celiac disease, Parasitic infections, necator americanus, Immunity
Eligibility Criteria
Inclusion Criteria:
- Diagnosis of celiac disease
- Positive tTG (IgA)or positive anti IgA gliadin or anti-endomysial antibody test.
- Marsh score ≥3 on small bowel biopsy (subtotal villous atrophy)
- Clinical, biochemical or histological improvement on gluten free diet.
- Compliance with a gluten-free diet for 6 months lead-in.
- Lifestyle & travel history indicative of a low risk for helminthic infection.
- Good general health not on immunomodifying agents.
- Ability to complete study
- Understand study & risks
- Social supports
- Workplace flexibility
- Normal tTG at enrollment (<10 dependent on serology)
- A HLA-DQ2 phenotype
- Negative fecal test for intestinal helminthes.
- Negative serological test for anti-strongyloides antibodies
Exclusion Criteria:
- Children (age < 18)
- Immunomodulating medication in 6 months pre-enrollment
- Oral or intramuscular/intravascular steroids
- Regular weekly use of aspirin
- Regular weekly use of NSAID
- Regular weekly use of COXII inhibitors
- Regular weekly use of statin medications
- Clinical history indicating a likely need to use an immune suppressive agent during the course of the study.
- Unmanaged risk of pregnancy
- Past history of infection with helminthes (other than a past history of infection with the pinworm, Enterobius vermicularis)
- History of insulin dependent diabetes mellitus or Addison's disease
- History of anaphylaxis or severe allergic reactions
- Having received a vaccine within the preceding 30 days
- Positive strongyloides serology
- Iron deficiency anemia
Sites / Locations
- Queensland Institute of Medical Research
- Princess Alexandra Hospital
- Logan Hospital
Arms of the Study
Arm 1
Arm 2
Arm Type
Active Comparator
Placebo Comparator
Arm Label
I
II
Arm Description
Arm I will be inoculated with the human hookworm necator americanus at weeks 0 and 12.
Arm II participants will receive and identical sham-inoculums comprising a diluted amount of 0.2ml McIlhenny & Co Tabasco Pepper Sauce®
Outcomes
Primary Outcome Measures
Duodenal histology (Marsh classification) and rectal histology
Secondary Outcome Measures
Peripheral blood mononuclear cells and mucosal lymphocytes will be grown ex vivo and challenged with gluten antigen immunodominant peptide. Cell proliferation and cytokine profiles will also be measured.
Full Information
NCT ID
NCT00671138
First Posted
May 1, 2008
Last Updated
January 31, 2016
Sponsor
Princess Alexandra Hospital, Brisbane, Australia
Collaborators
The Broad Foundation, Townsville Hospital, James Cook University, Queensland, Australia, Walter and Eliza Hall Institute of Medical Research, Queensland Institute of Medical Research
1. Study Identification
Unique Protocol Identification Number
NCT00671138
Brief Title
Inoculating Celiac Disease Patients With the Human Hookworm Necator Americanus: Evaluating Immunity and Gluten-sensitivity
Official Title
A Phase 2a, Randomized, Double Blinded, Placebo Controlled, Study Evaluating Immunity and Gluten-sensitivity by Inoculating Celiac Disease Patients With the Human Hookworm Necator Americanus.
Study Type
Interventional
2. Study Status
Record Verification Date
January 2016
Overall Recruitment Status
Completed
Study Start Date
October 2007 (undefined)
Primary Completion Date
December 2008 (Actual)
Study Completion Date
September 2009 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Princess Alexandra Hospital, Brisbane, Australia
Collaborators
The Broad Foundation, Townsville Hospital, James Cook University, Queensland, Australia, Walter and Eliza Hall Institute of Medical Research, Queensland Institute of Medical Research
4. Oversight
Data Monitoring Committee
Yes
5. Study Description
Brief Summary
The disappearance of intestinal parasites from humans in developed countries may be responsible for the upsurge in many diseases including Celiac Disease, Crohn's, ulcerative colitis, asthma and hay fever. A parasite's survival relies on its ability to interfere with the host's immune response. The mechanisms employed to do this are similar to those required by a person to regulate against the so-called autoimmune disorders, diseases in which the system turns on itself. The investigators suspect that when parasites are excluded from the environment, some individuals become sufficiently self-reactive to develop an autoimmune disease. American researchers have successfully treated patients with Crohn's and ulcerative colitis using a pig whipworm (Trichuris suis). The investigators have undertaken a similar preliminary study using a human hookworm in Crohn's patients.
Using a small group of healthy people with celiac disease, the investigators will test if a human hookworm, Necator americanus, inhibits immune responsiveness to gluten. Celiac disease is a very common autoimmune-like disease (1% of Americans are affected although only a minority are aware they have the condition). In this condition, an individual becomes reactive to gluten, a protein in foods derived from wheat, barley, oats and rye.
What makes celiac disease such a good model for Crohn's disease is that similar immune changes are common to both, but in celiac disease the people are usually well, are not taking powerful immune suppressive drugs and the provocative antigens (the molecules that engage the immune system and provoke the disease) are known and can be excluded or introduced. As well as being of direct benefit to people with celiac disease, this study may give direction as to the potential of this parasite to manage inflammatory bowel disease.
People with proven celiac disease who live in Brisbane, a modern Australian city, will be invited to participate. Enrollment will require that the candidate has been avoiding gluten for six months.
The study is a blinded study (where the researchers and study subjects do not know who has gotten the parasites) aimed at comparing the disease activity and immunity after a controlled breach of the gluten-free diet in individuals with celiac disease, before and after hookworm infection. The disease severity and the immune system of celiac subjects before and after being inoculated with N. americanus will be examined using conventional and experimental investigations. This group's immunity will be compared to that of a group of matched, celiac control subjects (not infected with hookworm), before and after eating four pieces of standard white bread each day for three to five days. Twenty people, ten subjects per arm, will be recruited. Ten larvae initially, then five more after twelve weeks will be placed on the skin under a light dressing for thirty minutes.
The investigators aim to test whether the hookworm infection will change the immune processes and suppress gluten sensitivity in people with celiac disease. Outcomes to be measured will be those that reflect the activity of celiac disease.
Detailed Description
Background and aims: A number of lines of evidence suggest that the disappearance of helminths from human populations in developed countries may be responsible for the upsurge in autoimmune diseases, the so-called hygiene hypothesis. Using a small cohort of healthy subjects with quiescent celiac disease, our aim is to test if the ubiquitous hookworm (HW) of humans, Necator americanus, inhibits immune responsiveness to a gluten challenge (GC). As well as being of potential benefit to people with gluten intolerance, this study will provide the opportunity to undertake detailed investigation at the mucosal level of the host-parasite interaction, and the underlying immune response, and by extension, the potential of nematode infection to modulate the inflammatory response in IBD. Unlike experimental helminth infections in either animals genetically predisposed to colitis or in clinical IBD (where a range of complicating cofactors are present), this study addresses what happens in healthy humans who do not have a background of helminth exposure, and who are not currently compromised by either inflammation or immunosuppressive drugs.
Methods: Twenty healthy adults with well-documented celiac disease (DQ2 phenotype) compliant with a gluten-free (GF) diet for ≥ 6 months (based on history and a normal tissue transglutaminase [tTG]) will be recruited and randomly assigned to two groups of ten. Ten will be inoculated with hookworm (HW) larvae and 10 will serve as uninfected controls. Study subjects and Investigators will be blinded to allow comparison of disease activity and immune profiles. HW larvae will be cultured from feces supplied by a volunteer donor, previously infected for this purpose. Conventional endoscopy and biopsy will be performed twice per subject, before and after oral and rectal GCs (2x50g slices of wheat bread twice daily for 3-5 days and 6g of gluten in a 40ml slurry instilled into the rectum per endoscope, respectively). Rectal biopsy will be undertaken 4 hr and duodenal biopsy collected six days following GC; blood will be collected before and after acquiring hookworm infection and on day six following GC. Thus, four data sets will be accrued for comparison: ten GF celiac-subjects before HW infection; 10 GF celiac-s after HW infection; ten GC celiac-s before HW infection; and 10 GC celiac-s after HW infection.
Safety: A large body of observational data documenting the safety of experimental hookworm infection is available, both from our own and studies by others. Two of our researchers have maintained infections including occasional "top-up" inoculations for three years without ill effects.
Outcome Measures: These will include: subject symptom diary, full blood analysis, C-reactive protein, total and specific IgE and serum tryptase activity. The duodenal (Marsh classification) and rectal histology will be graded by a single pathologist. Goblet cells and mucosal T cells will be stained to aid quantification of responses. Peripheral blood mononuclear cells (PBMCs) and mucosal lymphocytes from intestinal biopsies will be grown ex vivo and challenged with gluten antigen immunodominant peptide (alpha-gliadin 57-73 Q65E, QLQPFPQPELPYPQPQS). Cell proliferation and cytokine profiles in response to HW and gluten antigens will be measured from PBMCs and intestinal biopsies. Varying the timing of the inoculations may provide worthwhile direction on the importance of the Th2 response only if there is a profound difference between newly established (Th2-dominant) versus mature (Th-neutral) parasite infections, as suggested by our earlier work with experimental human infections. Levels of transcription of genes of interest will be assessed using quantitative real time PCR and microarrays.
Outcomes: The null hypothesis is that Necator americanus does not change the immune process sufficiently to suppress gluten sensitivity in people with celiac disease. The measured outcomes reflect the activity of celiac disease, including the severity of mucosal inflammation, and the character and intensity of the immune processes. This study though is as much about IBD. Celiac disease is not IBD, but this model of IBD affords a previously unexplored opportunity to test quasi autoimmune responses in the duodenum and rectum to a specific antigen, one that can be introduced or excluded on demand. The immune profiling will focus on the characteristics that drive inflammation in IBD providing a clear insight as to the potential of helminths in Crohn's disease and ulcerative colitis.
Extension Study; Control patients invited to enroll in an extension of the study; each to be inoculated, challenged and investigated as per the original hookworm cohort (as above).
Low dose gluten challenge Study: This trial extension seeks to establish if hookworm infection might improve tolerance to small amounts of gluten in patients with celiac disease. The study is open. It utilises celiac patients already infected with hookworm and in whom the blood and mucosal baseline characteristics have been carefully documented. The gluten exposure will apply doses that have been demonstrated by others in a trial setting to be safe and well-tolerated. Effectiveness of hookworm infection to mitigate gluten intolerance will be measured by the quantifiable changes that occur in biopsies previously taken (pre-challenge) compared with tissue collected post-challenge.Histology will be performed as previously described. Biopsies are to be fixed in neutral buffered formalin, processed and carefully orientated and embedded in paraffin wax. Sections (3 μm) will be stained with haematoxylin and eosin (H&E) and immunostained with anti-CD8 (or anti-CD3 depending on availability) antibodies (Novocastra Laboratories Ltd). The intraepithelial lymphocytes (IELs) per 100 nucleated enterocytes (100NE) will be counted at 24 randomly selected sites between the villous tip and the base of the crypt (Vh/Cd) in each biopsy. Individual and collective outcomes on tissue collected after hookworm infection, but whilst on a gluten free diet, will be compared with those from tissue collected after the pasta challenge.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Celiac Disease
Keywords
Celiac disease, Parasitic infections, necator americanus, Immunity
7. Study Design
Primary Purpose
Treatment
Study Phase
Phase 2
Interventional Study Model
Parallel Assignment
Masking
ParticipantCare ProviderInvestigatorOutcomes Assessor
Allocation
Randomized
Enrollment
20 (Actual)
8. Arms, Groups, and Interventions
Arm Title
I
Arm Type
Active Comparator
Arm Description
Arm I will be inoculated with the human hookworm necator americanus at weeks 0 and 12.
Arm Title
II
Arm Type
Placebo Comparator
Arm Description
Arm II participants will receive and identical sham-inoculums comprising a diluted amount of 0.2ml McIlhenny & Co Tabasco Pepper Sauce®
Intervention Type
Biological
Intervention Name(s)
Necator americanus
Intervention Description
10 necator americanus larvae will be inoculated at week 0 with a further 5 larvae inoculated at week 12
Intervention Type
Other
Intervention Name(s)
Sham inoculation
Intervention Description
A diluted amount of McIlhenny & Co Tabasco Pepper Sauce will be applied via a gauze dressing at weeks 0 and 12.
Primary Outcome Measure Information:
Title
Duodenal histology (Marsh classification) and rectal histology
Time Frame
21 weeks
Secondary Outcome Measure Information:
Title
Peripheral blood mononuclear cells and mucosal lymphocytes will be grown ex vivo and challenged with gluten antigen immunodominant peptide. Cell proliferation and cytokine profiles will also be measured.
Time Frame
21 weeks
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
Diagnosis of celiac disease
Positive tTG (IgA)or positive anti IgA gliadin or anti-endomysial antibody test.
Marsh score ≥3 on small bowel biopsy (subtotal villous atrophy)
Clinical, biochemical or histological improvement on gluten free diet.
Compliance with a gluten-free diet for 6 months lead-in.
Lifestyle & travel history indicative of a low risk for helminthic infection.
Good general health not on immunomodifying agents.
Ability to complete study
Understand study & risks
Social supports
Workplace flexibility
Normal tTG at enrollment (<10 dependent on serology)
A HLA-DQ2 phenotype
Negative fecal test for intestinal helminthes.
Negative serological test for anti-strongyloides antibodies
Exclusion Criteria:
Children (age < 18)
Immunomodulating medication in 6 months pre-enrollment
Oral or intramuscular/intravascular steroids
Regular weekly use of aspirin
Regular weekly use of NSAID
Regular weekly use of COXII inhibitors
Regular weekly use of statin medications
Clinical history indicating a likely need to use an immune suppressive agent during the course of the study.
Unmanaged risk of pregnancy
Past history of infection with helminthes (other than a past history of infection with the pinworm, Enterobius vermicularis)
History of insulin dependent diabetes mellitus or Addison's disease
History of anaphylaxis or severe allergic reactions
Having received a vaccine within the preceding 30 days
Positive strongyloides serology
Iron deficiency anemia
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
John T Croese, FRACP MD
Organizational Affiliation
The Townsville Hospital
Official's Role
Principal Investigator
First Name & Middle Initial & Last Name & Degree
A James M Daveson, MBBS
Organizational Affiliation
Princess Alexandra Hospital
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Alex Loukas, BSc Hon, PhD (UQ)
Organizational Affiliation
Queensland Institute of Medical Research
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
James McCarthy, MBBS FRACP PhD
Organizational Affiliation
Queensland Institute of Medical Research
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Robert Anderson, MB ChB BMedSc PhD FRACP
Organizational Affiliation
Walter & Eliza Hall Institute of Immunology
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Graeme Macdonald, MBBS FRACP PhD
Organizational Affiliation
Princess Alexandra Hospital
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Soraya Gaze, BSc PhD
Organizational Affiliation
Queensland Institute of Medical Research
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Rick Speares, MBBS PhD
Organizational Affiliation
Anton Breinl Centre for Public Health and Tropical Medicine, James Cook University, Townsville
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Andrew Clouston, MBBS (Qld) PhD (Qld) FRCPA
Organizational Affiliation
Envoi Pathology
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Andrew Pascoe, B. Pharm, B.Sc, MBBS, FRACP
Organizational Affiliation
Princess Alexandra Hospital
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Geoffrey Cobert, BSc PhD
Organizational Affiliation
Queensland Institute of Medical Research
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Dianne Jones, RN RM BAppSc
Organizational Affiliation
Princess Alexandra Hospital
Official's Role
Study Director
First Name & Middle Initial & Last Name & Degree
Sharon Cooke, RN
Organizational Affiliation
The Townsville Hospital
Official's Role
Study Director
Facility Information:
Facility Name
Queensland Institute of Medical Research
City
Brisbane
State/Province
Queensland
ZIP/Postal Code
4006
Country
Australia
Facility Name
Princess Alexandra Hospital
City
Brisbane
State/Province
Queensland
ZIP/Postal Code
4102
Country
Australia
Facility Name
Logan Hospital
City
Logan
State/Province
Queensland
ZIP/Postal Code
4131
Country
Australia
12. IPD Sharing Statement
Citations:
PubMed Identifier
24795483
Citation
Cantacessi C, Giacomin P, Croese J, Zakrzewski M, Sotillo J, McCann L, Nolan MJ, Mitreva M, Krause L, Loukas A. Impact of experimental hookworm infection on the human gut microbiota. J Infect Dis. 2014 Nov 1;210(9):1431-4. doi: 10.1093/infdis/jiu256. Epub 2014 May 3.
Results Reference
derived
PubMed Identifier
21408161
Citation
Daveson AJ, Jones DM, Gaze S, McSorley H, Clouston A, Pascoe A, Cooke S, Speare R, Macdonald GA, Anderson R, McCarthy JS, Loukas A, Croese J. Effect of hookworm infection on wheat challenge in celiac disease--a randomised double-blinded placebo controlled trial. PLoS One. 2011 Mar 8;6(3):e17366. doi: 10.1371/journal.pone.0017366.
Results Reference
derived
Links:
URL
http://www.broadmedical.org
Description
Broad Medical Research Program Website
Learn more about this trial
Inoculating Celiac Disease Patients With the Human Hookworm Necator Americanus: Evaluating Immunity and Gluten-sensitivity
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