Review for 10.1186/s12876-023-02907-z (2023)

Title: Differences in clinical characteristics and liver injury between patients diagnosed with the
Omicron subvariant BA.5.2 and the prototype of SARS-CoV-2: A single center retrospective
study
Version: 1 Date: 20 Jun 2023
Reviewer:  An#l Uçan
Reviewer's report:
Dear Author,
Thank you for submitting your article " Differences in clinical characteristics and liver injury
between patients diagnosed with the Omicron subvariant BA.5.2 and the prototype of SARS-
CoV-2: A single center retrospective study" Overall, I found the study to be informative and
well-structured. However, I have a few suggestions for improvement:
Check for consistency and clarity of language: I noticed a few instances where the language used
was inconsistent or unclear. I recommend carefully reviewing the manuscript for consistency of
terminology and phrasing and ensuring that all text is written in clear and concise language.
The phrase 'Omicron subvariant BA.5.2.' used throughout the entire study makes it difficult
to read. A related abbreviation (e.g. OS) in the introduction would reduce the number of
unnecessary words.
Introduction:
1- Line 50: There is a reference citation that is not appropriate for the structure of the journal.
This needs to be corrected.
2- Line 75: Please start the word the with a lowercase letter
3- Line 77: Please write the two words separately
4- In the last sentence of the introduction, it is more appropriate to clearly state what you are
aiming for rather than a passive structure
Methods
1- Line 95: A sentence about how patients are diagnosed with COVID could be added.  For
example, Did you make the diagnosis by PCR alone or were the CT findings accompanying the
suspicious clinical presentation sufficient for you?
2- Line 100: Other articles published in the journal should be reviewed in format. It is sufficient
to include the section on ethics at the end, not here.
3- Line 122: The term liver damage in the study's results needs to be clarified. The methodology
should specify which values and how high they are considered to correspond to liver injury
Results:
All results that can be shown in the table, which are significant but not crucial for the study
design, should be removed by referencing the tables. I found the 'Results' section difficult to
read and not user-friendly. Please simplify this section and your results. Undoubtedly the most
important outcome of the study is the demonstration of liver damage. These key findings can be
detailed. Other results should be reviewed again in order of importance. This will also reshape
your discussion
1- Line 244-247: This sentence should be included in the 'Discussion' as it comments on the
results
Discussion
1- Line 272-275: I think it is unnecessary to rewrite this statement as it has an analog in the
method
2- Line 286: ‘The mortality rate of patients infected with the prototype reached 7%, whereas no
severe disease or death occurred in patients infected with the Omicron subvariant BA.5.2.’ This
statement can be followed by a reference to some studies showing a milder course of subvariant.
3- Line 319-322: ‘Currently, no specific medicine exists for the treatment of SARS-CoV-2. In the
early stages of the outbreak, hormones, antibiotics, arbidol, and Chinese patent medicine, among
others, were widely used, which may directly or indirectly cause drug-induced liver injury.’
This sentence could be followed by referencing a study on Favipiravir used early in the
pandemic.
Ucan, A., Cerci, P., Efe, S. et al. Benefits of treatment with favipiravir in hospitalized patients
for COVID-19: a retrospective observational case–control study. Virol J 18, 102 (2021). https://
doi.org/10.1186/s12985-021-01577-1
No liver injury secondary to Favipiravir was detected in the study.
'In our study, none of the patients had progressive deterioration in liver functions. Besides,
improvement in the liver function tests without dose adjustment made it difficult for us to
associate these disorders with FPV.'
In the final part of the discussion, the limitations of the retrospective study should be emphasized
more broadly, and finally, what the study could still achieve.
It will be appropriate to re-evaluate after the corrections have been made
Kind regards