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:6 August 2007
Reviewer: Klaus Fellermann
Reviewer's report:
General
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Major Compulsory Revisions (that the author must respond to before a decision
on publication can be reached)
The submitted manuscript presents RT-PCR data of genes recently shown to be
upregulated in ulcerative colitis (UC) by cDNA microarray analysis. Four
identified genes were measured in cecal and rectal biopsy specimens from
controls and UC patients. In summary, they confirmed their previous findings in a
larger set of patients. Striking enough that these analyses have not accompanied
the former paper.
Major comments
Two groups of patients were investigated, controls and UC. It would be
interesting to see what happens in Crohn´s disease (CD) although the cDNA
microarray analysis was restricted to UC only. A full original paper regarding
RT-PCR only should adress this question.
The cohort of UC patients has been characterized according to the Montreal
classification. This in turn results in several subgroups limiting comparison.
However, one of the findings is that rectal biospies are more reliable than
specimen of cecal origin (matter of extent ?). Thus, the analysis has some
drawbacks. Helpful is the comparison of expression levels in normal individuals,
showing differences of expression levels with regard to location. Reasons given
are speculative in nature. Differences to UC are striking though all patients were
included in the analysis (Fig. 2 and 3). In my view it is reasonable to include
patients with active inflammation at the respective site, meaning all E S1-3 in
rectal biopsies, and E3 S1-3 in cecal specimen. Remission is no good comparitor
neither is E1and 2 in cecal specimens. The figures should be corrected as such.
May be, the authors are willing to state their findings regarding remission (S0) in
the text or adopt fig. 2 and 3 accordingly.
The information given in fig. 4 is that severity increases the differences between
controls and UC in rectal biopsies. It would be sufficient to state the observations
of fig. 4 in the text and combine S1-3 as there do not seem to be any differences
between them. Debateble is fig. 5 as well. Why should extent of disease have
any influence on rectal expression? The figure substantiates this view. Findings
should be described in the text as well. Fig. 6 is unnecessary when information of
remission is presented in fig. 2 and 3 or in the text.
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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)
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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: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing interests