Review for 10.1186/s12876-021-01707-7 (2021)

Reviewer’s report
Title: 
Gene Expression Profiling of Inflammatory Cytokines in Esophageal
Biopsies of Different Phenotypes of Gastroesophageal Reflux Disease: a cross-
sectional study
Version: 
0 
Date: 
23 May 2020
Reviewer's report:
The authors studied the expression of proinflammatory cytokines using
esophageal biopsies taken from patients with reflux symptoms. They compared
those expression levels among control, erosive esophagitis, Barrett's esophagus
and NERD with accurate phenotyping and consequently they found some
differences in proinflammatory cytokines. 
Even though the study is mostly descriptive, it assesses a fairly large number of
samples and provides a comprehensive profile of cytokines in each reflux
phenotype. Nevertheless, an inadequate explanation of their results makes the
manuscript hard to interpret.
Major comments:
1. They described biopsies were taken from both Barrett's mucosa or esophageal
erosion and their adjacent macroscopically normal esophageal mucosa in BE and
RE (line 132-136). However, the results (Fig 1 and 2) did not explain which
biopsies they evaluated.
2. In terms of patients with NERD, they stated that ph-metry classified them into
normal and pathological acid exposure. However, it is impossible to know
NERD in the results indicates which phenotype. The comparison among control,
NERD abnormal or NERD normal acid exposure would be the most novel thing
of this study. Strictly speaking, NERD should have abnormal acid exposure,
whereas normal endoscopy with normal acid exposure should be reflux
hypersensitivity or functional heartburn according to Rome criteria.
3. Please show all the comparison of cytokines, as per your methods, among
control, NERD with pathological or normal acid exposure, BE (>3cm or < 3cm)
and RE with their adjacent macroscopically normal mucosa.
4. Please clarify if pH-monitoring were performed on-PPI or Off-PPI.
Minor comment:
1. Please clarify a breakdown of erosive esophagitis according to the Los
Angeles classification.
2. "Classification of Angeles" should be "Los Angeles classification".
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
No
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the
authors.
Yes
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
No
Are you able to assess any statistics in the manuscript or would you
recommend an additional statistical review?
If an additional statistical review is recommended, please specify what aspects
require further assessment in your comments to the editors.
I am able to assess the statistics
Quality of written English
Please indicate the quality of language in the manuscript:
Needs some language corrections before being published
Declaration of competing interests
Please complete a declaration of competing interests, considering the following
questions:
1
. 
Have you in the past five years received reimbursements, fees, funding, or
salary from an organisation that may in any way gain or lose financially
from the publication of this manuscript, either now or in the future?
2
. 
Do you hold any stocks or shares in an organisation that may in any way
gain or lose financially from the publication of this manuscript, either now
or in the future?
3
. 
Do you hold or are you currently applying for any patents relating to the
content of the manuscript?
4
. 
Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
the manuscript?
5
. 
Do you have any other financial competing interests?
6
. 
Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
I declare that I have no competing interests
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