Clinical Trial Details
— Status: Recruiting
Administrative data
| NCT number |
NCT02786914 |
| Other study ID # |
235/14 |
| Secondary ID |
|
| Status |
Recruiting |
| Phase |
N/A
|
| First received |
May 5, 2016 |
| Last updated |
January 15, 2018 |
| Start date |
April 2016 |
| Est. completion date |
April 2020 |
Study information
| Verified date |
January 2018 |
| Source |
Assaf-Harofeh Medical Center |
| Contact |
Arnon Elizur |
| Phone |
+97289779820 |
| Email |
elizura[@]gmail.com |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Patients with suspected tree-nut or sesame allergy based on sensitization on skin-prick tests
(SPT), will be assessed for allergy using component analysis and basophil activation test
(BAT) and entered into oral immunotherapy (OIT). Component analysis and BAT will be repeated
after completion of OIT. Patients with tree-nut or sesame allergy treated with the standard
of care of elimination diet will serve as controls
Description:
Patients will be recruited from the pool of patients referred to the investigators center for
evaluation of food allergy. For each tree-nut (walnut, pecan, cashew, pistachio, hazelnut or
almond) evaluated, 30 patients (ages 4-45 years old), with allergy to at least one tree-nut
will be recruited from the database pool referred to above. Skin prick tests (SPT) using
standardized 10 mg/ml tree-nut extracts, and BAT will be performed for all suspected
allergens. Sera will be taken and sent to ThermoFisher for IgE and IgG4 binding analysis to
purified components. Open OFCs will be performed for each tree-nut, unless clinically
contraindicated. The results of the OFC will form the basis to determine the sensitivity and
specificity of the component testing. Similarly, 40 patients with suspected sesame allergy
will be administered SPT and component analysis for sesame, with correlations to OFC.
The investigators will also utilize BAT to directly test whether the identified purified
components are sufficient to elicit reactivity. This objective can be met by either utilizing
saved patient sera on naive basophils or directly on a subsequently obtained blood sample
from the patient. For patients enrolling in OIT (secondary objective), sera will also be
taken after completion of the therapeutic regimen, and IgE as well as IgG4 binding to the
same components will be assessed and compared to pre-OIT results.
4.2 STATISTICAL ANALYSIS AND METHODS
4.3 Patients will be grouped by OFC their allergy status result for each tree-nut (patients
with a documented IgE-mediated reaction in the previous year or a positive OFC vs. patients
with regular consumption of the index food or a negative OFC). Descriptive statistics
(proportions for categorical variables, means or medians and standard deviations or
inter-quartile range for continuous variables) will be reported for all key participant
variables, including baseline and demographic characteristics, SPT, BAT and component testing
results.
For the primary objective, the sensitivity and specificity of the diagnostic tests (wheal for
SPT, and CD63 induction for BAT) and IgE/IgG4 binding to the purified components in
predicting OFC results allergy will be compared by receiver operating characteristic (ROC)
analysis. To this end, the investigators will evaluate molecular allergens singly or in
groups for their predictive utilities.
For the secondary objective, OFC positive patients with documented allergy who undergo OIT
for tree-nuts (n=15 for each tree-nut) or sesame (n=15) will be grouped according to OIT
outcome. Paired t-tests comparing IgE and IgG4 binding of specific molecular allergens in
individual patients before and after treatment will be performed. Additionally, the pre-OIT
IgE and IgG4 profiles against particular molecular allergens will be compared between OIT
outcome groups by t-test. 10 control patients treated with the standard of care of
elimination diet will be compared.
Power analysis: Using the Pearson Chi-square test for two proportions, with the assumption
that 75% of all OFC+ to tree-nuts will be positive to at least one specific component, in
order to detect a result with a P-value of <0.05, 15 positive and 15 negative sera for each
tree-nut would yield a power of 0.816. Based on the investigators experience with
immunoreactivity as assessed by western blot, in fact the investigators would expect that
much more than 75% of OFC+ patients would show IgE reactivity against at least one component.
Thus, the investigators feel that a total of thirty sera for each tree-nut should suffice for
the analysis.
Total number of patients: 180 patients to be evaluated for tree-nut allergy and 40 for sesame
allergy.
