ATFP: Human Consumption of Plant Foods Produced Using Genetic Engineering (GE) Technologies (2015)
Ladics GS, Bardina L, Cressman RF, Mattsson JL, Sampson HA. Lack of cross-reactivity between the Bacillus thuringiensis derived protein Cry1F in maize grain and dust mite Der p7 protein with human sera positive for Der p7-IgE. Regul Toxicol Pharmacol. 2006; 44 (2): 136-143.PubMed ID: 16406630
- Dust mite allergy based on clinical histories and skin prick testing
- Demonstrated Der p7-specific antibodies via immunoblot using subjects' sera.
- No history of dust mite allergy based on clinical histories and skin prick testing
- No demonstrated Der p7-specific antibodies via immunoblot using subjects' sera.
Not discussed; serum samples were provided by Dr. Tsai of Kuo-Tai Hospital, Tapei, Taiwan and Dr. High A Sampson of the United States.
Non-randomized crossover trial. The amino acid sequence of Cry1F protein (expressed by maize line 1507) was compared to a database of known allergens using criteria established by the ILSI-IFBC and FAO/WHO Expert Consultation of Allergenicity of Foods Derived from Biotechnology. The Cry1F protein did not show significant similarity or a match of eight contiguous identical amino acids with any allergen, but a single six contiguous amino acid match was identified between Cry1F and Der p7 protein of the dust mite. To investigate whether Cry1F was cross-reactive with Der p7, sera from 10 dust mite allergic patients containing Der p7 specific IgE antibody were used to compare IgE specific binding. SDS-PAGE analyses, probing immunoblots with Cry1F monoclonal antibodies and dust mite allergic patient sera were conducted. Normal human serum was used as a negative control for immunoblots for Der p7-specific monoclonal antibody and immunoblots for detection of IgE binding to the the separated maize protein.
Implied with measurements.
Cross-reactivity with Der p7 and Cry1F in dust mite-allergic patients.
Timing of Measurements
- Immunoblotting done with Der p7 specific monoclonal antibody and dust mite allergic patient sera completed once during screening process
- Completed at one point during investigation:
- SDS analyses
- Probing immunoblots with Cry1F monoclonal antibodies
- Probing immunoblots with dust mite allergic patient sera.
Dependent VariablesIgE binding study results regarding reactivity of Cry1F and Der p7 proteins.
Presence of dust mite allergy.
- Initial N: Sera of 20 subjects screened; sera of 10 subjects entered into study
- Attrition (final N): N=10 subjects (gender not described)
- Ethnicity: Not described; sera samples were obtained from Taiwan and United States
- Location: Sera samples from Taiwan and United States.
- No evidence of cross-reactivity was observed between Cry1F and Der p7
- Amino acid sequence comparisons:
- No significant similarity as defined by the PAO/WHO was demonstrated with any of the allergens contained in the Pioneer Allergen Database
- No contiguous identical eight amino acid matches were observed between Cry1F protein and known allergens
- One single amino acid match was identified between the Cry1F protein and Der p7 protein of the dust mite.
- IgE binding study with Cry1F containing maize grain and sera from dust mite-allergic patients containing IgE to the Der p7 protein:
- Sera from 10 dust mite allergic subjects had IgE antibodies that bound to Der p7, protein band in lane three
- None of these subjects had IgE antibodies recognizing Cry1F, a 61kDa protein expressed in maize
- Sufficient Cry1F protein in the maize extract to be readily identified by Cry1f-specific antibody and sufficient Der p7-specific IgE antibody in the human sera to cause an identifiable reaction with the Der p7 protein
- No evidence that dust mite-allergic individuals possess cross-reactive IgE antibodies to corn transfected with the Cry1F protein.
|Other:||Funding source not described|
|In-Kind support reported by Industry:||Yes|
Quality Criteria Checklist: Primary Research
|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)||Yes|
|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)||Yes|
|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?||???|
|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?||Yes|
|2.2.||Were criteria applied equally to all study groups?||Yes|
|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?||N/A|
|3.1.||Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)||N/A|
|3.2.||Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?||N/A|
|3.3.||Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)||N/A|
|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?||Yes|
|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?||Yes|
|6.1.||In RCT or other intervention trial, were protocols described for all regimens studied?||Yes|
|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?||Yes|
|6.4.||Was the amount of exposure and, if relevant, subject/patient compliance measured?||Yes|
|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?||Yes|
|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?||No|
|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?||Yes|
|8.7.||If negative findings, was a power calculation reported to address type 2 error?||N/A|
|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?||???|
|10.1.||Were sources of funding and investigators' affiliations described?||No|
|10.2.||Was the study free from apparent conflict of interest?||Yes|