Review for 10.1186/1471-230X-8-34 (2008)

Reviewer's report
Title:Five mucosal transcripts of interest in ulcerative colitis identified by
quantitative real-time PCR: a prospective study
Version: 1Date:10 September 2007
Reviewer: alexandra zahn
Reviewer's report:
General
Eriksson et al. studied the expression levels of five mucosal transcripts in
ulcerative colitis by quantitative real-time PCR.
These transcripts of interest were identified in a former study by using
whole-genome microarray technique. The microarray results and the
immunohistologic examination of one of them, namely elafin are already
published (Flach CF, et al. InflammBowelDis. 2006 Sep;12(9):837-42).
In the present study Eriksson et al. could show an interesting expression pattern
of aldolase B, elafin, MST-1, simNIPhom and SLC6A14 in the rectal mucosa in
ulcerative colitis patients compared to controls. The interpretation of these results
is plausible but speculative. Unfortunately, in caecal biopsies the above
mentioned expression pattern was not reproducible. As only elafin and
simNIPhom were significantly regulated.
The authors assume that the different transcript levels in rectal and caecal
mucosa may reflect distinct inflammatory involvement.
Furthermore, the authors describe a relation between the expression levels of the
five genes and the clinical severity of ulcerative colitis.
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Major Compulsory Revisions (that the author must respond to before a decision
on publication can be reached)
1. The main problem of this study is that the authors only examined mRNA levels
of different genes. To be able to assume the validity and the relevance of these
findings the results should be confirmed on protein level e. g. by Western Blot
before publication.
2. In the initial publication only four genes of interest were mentioned. The
authors should explain why MST-1 is additionally examined in this study.
3. The information whether the biopsies were taken from inflamed or from
non-inflamed areas is essential. Only the analysis of non-inflamed mucosa may
allow to identify subclinical defects or at least permit a greater emphasis on
epithelial cell gene expression, unaffected by marked influx of inflammatory cell
populations. Otherwise, like the authors already mentioned it in the discussion, it
is likely that they only detected secondary phenomenons in long lasting
ulcerative colitis.
4. It would be interesting to examine if patients medication influences the
transcript levels of the different genes. The authors should perform a subgroup
analysis especially concerning the transcript levels of SLC6A14 and MST-1 in the
corticosteroid, the aminosalicylate and the immunosuppressant group.
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Minor Essential Revisions (such as missing labels on figures, or the wrong use of
a term, which the author can be trusted to correct)
The authors should give a short statement concerning the possible role of
simNIPhom.
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Discretionary Revisions (which the author can choose to ignore)
What next?: Unable to decide on acceptance or rejection until the authors have
responded to the major compulsory revisions
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
'I declare that I have no competing interests'