EAL

CD: Oats and Gluten Intolerance (2005)

Citation:

Picarelli A, Di Tola M, Sabbatella L, Gabrielli F, Di Cello T, Anania MC, Mastracchio A, Silano M, De Vincenzi M. Immunologic evidence of no harmful effect of oats in celiac disease. Am J Clin Nutr 2001; 74: 137-140.

PubMed ID: 11451729

Study Design:

Non-Randomized Controlled Trial

Class:

C - Click here for explanation of classification scheme.

Quality Rating:

NEUTRAL: See Quality Criteria Checklist below.

Research Purpose:

To better define the controversial role of oats in CD to determine whether oats can be safely included in a GFD.

Inclusion Criteria:

Duodenal villous atrophy and positive for serum EMAs on gluten-containing diet. After one year consumption of well-controlled GFD, no clinical symptoms of CD and negative testing for serum EMAs. No histologic signs of mucosal atrophy and no EMAs in undiluted supernatant fluid from biopsy specimens cultured with medium alone.

Exclusion Criteria:

None defined.

Description of Study Protocol:

Recruitment

20 adult CD patients enrolled in study. 30 patients with other GI diseases enrolled as controls.

Design

Nonrandomized controlled trial using in vitro model.

Blinding used (if applicable)

No blinding used.

Intervention (if applicable)

Duodenal biopsy specimens from adult CD patients cultured with and without peptic-tryptic digest (PT) of gliadin and avenin (from oats) and in medium alone.

Statistical Analysis

Data was descriptive in nature and not statistically analyzed.

Data Collection Summary:

Timing of Measurements

Biopsy specimens taken from adult patients and cultured with and without PT-gliadin or PT-avenin.

Dependent Variables

EMAs detected through indirect immunofluorescence
Duodenal biopsy specimens obtained by esophagogastroduodenoscopy per patient and submitted to histologic morphometric analysis to measure villous height:crypt depth ratio and to assess presence of inflammatory cells infiltrating the lamina propria of the duodenal mucosa, as well as the cultures.

Independent Variables

Peptic-tryptic digest of gliadin and avenin obtained by enzymatic sequential digestion of prolamine fractions extracted from pure varieties of wheat bread and oats. The C fraction of avenin was prepared using affinity chromatography.

Description of Actual Data Sample:

Initial N: 20 adult CD patients (nine men, 11 women) and 30 controls (15 men and 15 women) with other disease
Attrition (final N): 13 adult CD patients and 30 controls
Age: CD patients 27.5 years (18-59 years); controls 31.7 years (21-60 years)
Ethnicity: Not mentioned
Location: Rome, Italy.

Summary of Results:

Number of patients in whom EMAs were produced in supernatant fluid

	Treated CD Patients (n=13)	Control Patients (n=30)
Medium Alone	0	0
Medium + PT-gliadin	13	0
Medium + PT-avenin	0	0

Other Findings

EMAs were detected in specimens from all 13 patients after the challenge with gliadin but not after culture in medium alone. By contrast, no EMAs were detected in any of the specimens cultured with PT-avenin and its C fraction.

Author Conclusion:

In agreement with the findings of other studies, we conclude that oats can be safely included in the GFD of CD patients. In addition, the organ culture system is suitable for testing the toxicity of different cereals in CD patients.

Funding Source:

Reviewer Comments:

Small sample size. Only 13 out of 20 met criteria for inclusion in study.

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)	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

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?		???
	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?	???
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
3.	Were study groups comparable?		Yes
	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?	Yes
	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?		No
	4.1.	Were follow-up methods described and the same for all groups?	No
	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%.)	No
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	No
	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?		N/A
	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.)	N/A
	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?	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?		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?	No
	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)?	???
	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?	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?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes