Advanced Technology in Food Production

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ATFP: Human Consumption of Plant Foods Produced Using Genetic Engineering (GE) Technologies (2015)

Citation:

Nakajima O, Koyano S, Akiyama H, Sawada J, Teshima R. Confirmation of a lack of IgE binding to Cry3Bb1 from genetically modified (GM) crops. Regul Toxicol Pharmacol. 2010; 56 (3): 306-311.

PubMed ID: 19818822
 
Study Design:
Non-Randomized Crossover Trial
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
This study was designed to assess the binding characteristics to recombinant Cry3Bb1 of IgE antibodies in serum samples of allergy patients.
 
Inclusion Criteria:
  • Commercially available serum samples from a total of 13 corn allergy patients in the US. They were all reactive to multiple food allergens.
  • Serum samples were obtained from 55 Japanese patients with food allergies who exhibited signs of allergy clinically and were positive for allergen-specific IgE
  • Sera from three healthy donors (specific-IgE-negative) in Japan were used as controls
  • Informed consent had been obtained from all of the food allergy patients and healthy donors.
Exclusion Criteria:
Not reported.
Description of Study Protocol:

Recruitment

  • Commercially available serum samples from a total of 13 corn allergy patients in the US. They were all reactive to multiple food allergens.
  • Serum samples were obtained from 55 Japanese patients with food allergies who exhibited signs of allergy clinically and were positive for allergen-specific IgE
  • Sera from three healthy donors (specific-IgE-negative) in Japan were used as controls.

Design

Non-randomized crossover trial.

Blinding Used

Implied with measurements.

Intervention

Not applicable.

Statistical Analysis

Mean and SD, intervariability and intra-assay variability were reported.

Data Collection Summary:

Timing of Measurements
Measurements made in selected patients.

Dependent Variables
Binding characteristics to recombinant Cry3Bb1 of IgE antibodies.

Independent Variables

  • MON863 corn and stack varieties contain Cry3Bb1 protein
  • Commercially available serum samples from corn allergy patients in the United States (reactive to multiple food allergens), Japanese patients with food allergies who exhibited signs of allergy clinically and were positive for allergen-specific IgE and three healthy donors (specific-IgE-negative) in Japan were used as controls.
Description of Actual Data Sample:

Initial N
71 serum samples from the following:

  • 13 corn allergy patients in the United States
  • 55 Japanese allergy patients
  • Three healthy donors (specific-IgE-negative) in Japan were used as controls.

Attrition (Final N)
As above.

Age
Not described.

Ethnicity
Not described.

Other Relevant Demographics
Not reported.

Anthropometrics
Not reported.

Location
United States and Japan.

Summary of Results:
Key Findings
  • Two samples from the Japanese allergy patients were suspected of being positive, but Western blotting analysis with purified Cry3Bb1 indicated that the binding between IgE and Cry3Bb1 was non-specific
  • Ultimately, no specific binding between IgE and recombinant Cry3Bb1 was detected
  • Next, all proteins extracted from MON863 corn and non-GM corn were probed with IgE antibodies in serum samples from the corn allergy patients by Western blotting, but the staining patterns of MON863 and non-GM corn were similar, meaning that unintended allergic reactions to MON863 are
    unlikely to occur
  • No IgE antibodies that were specific for recombinant Cry3Bb1 were found in any of the serum of the patients in either group
  • Serum P1 and serum P2, which were positive for corn-specific IgE (13.8 IU and 13.9 IU per ml, respectively) from American patients
  • Comparison with the results of the analysis of the non-GM corn extract showed that no new proteins were detected by the analysis of the MON863 extract
  • No protein in the corn extracts was detected near 75kDa
  • No proteins were recognized when serum from the healthy control was tested
  • When serum samples P1 and P2 were diluted 40-fold, the IgE did not react with any protein in the corn extracts. When serum sample P1 was diluted four-fold, the IgE bound to a 17-kDa protein
  • When serum sample P2 was diluted four-fold, the IgE reacted with an 11-kDa protein and a 17-kDa protein
  • A strong band was detected near 17kDa and was thought to be recognized by serum P1 and serum P2 in lanes five, seven, 12 and 14
  • Many proteins in the 10kDa to 15kDa range were detected in lanes one and eight and it was impossible to identify the 11-kDa protein recognized by serum sample P2 as the protein detected by CBB staining
  • The staining patterns of MON863 and non-GM corn were similar, meaning that unintended allergic reactions to MON863 are unlikely to occur.
Author Conclusion:
  • Our study provides additional information that confirms the predicted lack of IgE-binding to Cry3Bb1 in people with existing food allergies
  • IgE antibodies from corn allergy patients and patients with various food allergies did not bind specifically to recombinant Cry3Bb1
  • The IgE antibodies from the corn allergy patients yielded the same binding profiles in relation to extracts of MON863 and of non-GM corn
  • MON863 is as safe as non-GM corn from the standpoint of no specific binding between IgE antibodies and recombinant Cry3Bb1
  • The results of this study support the findings of the existing safety assessment and provide additional information regarding the safety of GM corn containing Cry3Bb1.
Funding Source:
Government: Ministry of Health, Labour and Welfare of Japan and by a grant from the Food Safety Commission of Japan.
Reviewer Comments:
  • Study does not provided details on study population characteristics, study duration and exposure to GM corn containing Cry3Bb1 of the population and subjects demographics
  • Study does not provided details on whether subjects serum samples are from a controlled clinical trial or from hospital samples
  • Study details are required including inclusion and exclusion criteria
  • Samples were analyzed but no details on their baseline values
  • Statistical analysis was not reported to show comparison: Small sample size
  • Some of these subjects had diagnosed food allergies, asthma, dust allergies, etc. other than corn: Difficult to draw conclusions
  • It is not a representative sample
  • Independent blind comparison with an appropriate reference standard details are not provided
  • Further longer and repeated exposure studies are warranted.
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) N/A
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) N/A
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? No
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? No
  2.2. Were criteria applied equally to all study groups? ???
  2.3. Were health, demographics, and other characteristics of subjects described? No
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? ???
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? ???
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? N/A
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? ???
  8.1. Were statistical analyses adequately described and the results reported appropriately? No
  8.2. Were correct statistical tests used and assumptions of test not violated? ???
  8.3. Were statistics reported with levels of significance and/or confidence intervals? No
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes