We wish to study the absolute numbers, ratio and phenotype of CD27+IgE+ and CD27-IgE+ memory-B-cells in blood of atopic children who suffer from proven IgE-mediated asthma/hay fever, atopic dermatitis or food allergy and compare these with healthy…
ID
Source
Brief title
Condition
- Allergic conditions
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
From each patient, the absolute B- and T-cell numbers in blood (cells per
milliliter of blood) will be determined, as well as the relative frequencies of
naïve and IgM+, IgG+, IgA+ and IgE+ memory B-cells. Total and allergen-specific
serum IgE levels will be determined. These parameters will be compared between
patients with food allergy, patients with asthma, patients with hay fever and
healthy controls. Finally, we will study the correlation of IgE+ memory-B-cell
numbers with serum IgE levels and the IgE allergen-specificity.
Secondary outcome
Relate the changes in the B-cell compartment and serum IgE levels to changes in
T-cell subsets, eosinophils, basophils and mast cells in blood. Since the
anatomical location differs between asthma/hay fever, atopic dermatitis and
food allergy, we hypothesize that distinct B cells are involved.
Background summary
Immunoglobulin E (IgE) antibodies mediate the onset of a wide range of allergic
disorders through their recognition of allergens. IgE is on of the five
antibody isotypes produced by terminally differentiated B-cells. The commitment
of a B-cell to isotype class switch to an IgE-producing cell is a tightly
regulated process. In healthy individuals, IgE-producing B-cells are very
infrequent and therefore hardly detectable. We recently identified two distinct
IgE+ memory B-cell populations in blood of healthy donors: CD27+IgE+ and
CD27-IgE- B-cells. CD27-IgE- B-cells are derived from T-cell dependent
responses and CD27+IgE+ from T-cell independent responses. Studies on these
distinct IgE+ populations can provide new insights into the processes
underlying allergic reactions
Study objective
We wish to study the absolute numbers, ratio and phenotype of CD27+IgE+ and
CD27-IgE+ memory-B-cells in blood of atopic children who suffer from proven
IgE-mediated asthma/hay fever, atopic dermatitis or food allergy and compare
these with healthy non-atopic children. Furthermore, these B-cell numbers will
be correlated to allergen-specific and total serum IgE levels. Finally,
patients will be grouped based on their IgE allergen-specificity (food or
inhalant) and IgE+ B-cell numbers will be compared between these groups of
patients.
Study design
We will study different immune cells in blood of patients between 6-18 years of
age with proven asthma/hayfever, atopic dermatitis and foodallergy and in blood
of age-matched healthy controls. With a newly developed flow cytometric
approach we can for the first time study abnormalities in IgE+ B cells of
allergic patients and compare these values with non-allergic healthy age
matched controls. We will relate our findings in the IgE+ B cell compartment
with other immune cells involved in allergic reactions, i.e. other B-cell
subsets, T-cells and eosinophils.
The study will be cross-sectional, observational with 1x collection of blood.
Already obtained values of healthy non-allergic children and young adults will
be used as age-matched controls.
Study burden and risks
We will plan one visit for the patient to the outpatient clinic (if possible
this will be scheduled at a regular follow-up visit) to draw 1 blood sample of
7ml heparinized blood. The total burden will thus be one venipuncture, and
occasionally one extra clinic visit. There are no additional health risks,
because there is no intervention.
Dr. Molewaterplein 50
Rotterdam 3015GE
NL
Dr. Molewaterplein 50
Rotterdam 3015GE
NL
Listed location countries
Age
Inclusion criteria
* children from 6-18 yrs old with asthma/rhinitis, atopic dermatitis or food allergy
* Atopy with proven allergen (RAST class >1.4 or specific IgE serum levels > 0.7 IU/L or positive skin prick test with HEP index > 0.21)
* Positive doubleblind food provocation test or convincing history of recent adverse response to food intake
* Informed written consent
Exclusion criteria
- Patients < 6 yrs old
- Children who are receiving immunosuppressive therapy
- Children with substantial co-morbidity of immune-related diseases, especially immunodeficiencies or autoimmune disease (e.g. diabetes)
- Children receiving anti-IgE antibody treatment (e.g. with Xolair)
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL39649.078.12 |