Review for 10.1186/1471-230X-9-33 (2009)

Reviewer's report
Title:Food allergy alters jejunal circular muscle contractility and induces local
inflammatory cytokine expression in a mouse model
Version: 1Date:3 February 2009
Reviewer: Eva Untersmayr
Reviewer's report:
Review of manuscript entitled “Food allergy alters jejunal circular muscle
contractility and induces local inflammatory cytokine expression in a mouse
model” by Valeur J et al.
In this study the authors investigate the influence of OVA allergy on jejunal
motility in a murine model. After oral challenges of epicutaneously sensitized
animals the allergic phenotype was assessed by ELISA measurements of
specific antibodies, serum levels of mMCP1 and evaluation of fecal samples.
Additionally, jejunal sections were obtained and assessed for carbachol induced
contractility, which was found to be reduced in allergic mice. Real-time PCR
experiments revealed increased expression of IL-4 und IL-6 mRNA in the
jejunum of allergic animals.
The manuscript is providing insight in the influence of allergy towards orally
ingested proteins on the intestine. This is of interest as the relationship between
allergy and gastrointestinal motility has been discussed controversionally in
scientific literature.
However, several questions arise upon review of the manuscript:
Major Compulsory Revisions
1. Please provide detailed information how animals were evaluated for diarrhea.
Was the analysis performed by a blinded coworker? Moreover, on page 10 the
authors disclose that 5 out of 8 mice had diarrhea. At which time point of the
immunization regimen (as 10 intragastric challenges were performed)?
2. Table 1: It would be favorable to perform a quantification of allergen specific
antibody levels rather than providing plain optical density values.
3. Statistics: Please always provide mean ± standard deviation instead of mean ±
standard error of the mean.
4. Only regarding cytokine data the authors have compared jejunal and ileal
expression levels. However, it would be of major interest to compare data from
other intestinal areas to verify if carbachol induced contractility was found to be
reduced also in ileal or even colon sections.
5. Recently, two interesting research papers have been published investigating
the pathophysiological influence of food allergy on the intestinal tract in murine
models: Schouten B et al. (Int Arch Allergy Immunol 2008;147) reported a
reduced number of mMCP1+ cells in colon sections in whey- and
casein-sensitized mice whereas decreased isometric contractions were found
only in the colon of casein-sensitized mice. Additionally, Pali-Schöll and
colleagues (Exp Toxicol Pathol 2008;60) found the colon smooth muscle cell
layer to be thinned in allergic mice. The authors might consider comparing their
findings with these data and including the references in their manuscript.
6. The authors should be careful with general conclusions on small intestinal
dysmotility and diarrhea induced by food allergy, as only one part of the small
intestine was investigated.
Discretionary Revisions
1. In scientific literature dysmotility syndromes along the gastrointestinal tract
have been described to be associated with eosinophil infiltration. Did the authors
analyze their murine samples for eosinophilic markers?
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests