Review for 10.1186/s12876-022-02486-5 (2022)

Title: Procalcitonin in early allograft dysfunction after orthotopic liver transplantation: A
retrospective single centre study
Version: 1 Date: 21 Jul 2022
Reviewer:  Ibtesam A. Hilmi
Reviewer's report:
Procalcitonin in early allograft dysfunction after orthotopic liver transplantation: A retrospective
single centre study
In this study the investigators tried to find association between IRI, EAD and PCT, as well as
to answer the query if the PCT can predict patient and graft outcomes. It is retrospective data
analysis study with relatively small sample size which the authors did address that issue. Overall,
it is scientifically valid issue to be investigated and in spite of the limitations of the study and
paucity of the data, the authors did nice job in explaining and elaborating on the results of the
data analysis. I have few comments and questions that I hope the authors can address.
1- In the method section, you included patients >18 years of age, what is about the patients who
were 18 years old?
2- You used few terminology that are not very well-known, such as DBD (deceased brain dead
donor), it is usually referred as deceased donors, assuming that these are brain dead before organ
harvesting. There are other few terminology in the article that may require a professional editing.
3- What do you mean by classic cava-replacement technique, I believe you meant Piggy-back
technique, please elaborate.
4- In section PCT measurements: You mentioned that the PCT was measured predominantly
in the 1st 3 day PO days, why you used only 1&2 PO day’s values? Also, you mentioned that
PCT was measured predominantly in the complicated cases during the 2016, did you include
this year? Do not you think that will affect validity of the data, since you will use the PCT for
complicated cases and not for everyone?
5- In section, Baseline characteristics and in some of the tables, you included all transplant
patients (231), I am not sure what is the value of this inclusion since you did not use their data
and you had already excluded them from the analysis, can you explain?
6- In the results section (181), the MELD score for the EAD group was lower than in the non-
EAD group, can you explain or elaborate on this finding?
7- In line (183 through 185), you mentioned there is no significant difference in cold ischemia
time between EAD and non-EAD group, but in table 2, there is a significant difference with
P=0.012, can you explain, the discrepancy?
8- In results section line 223, you mentioned that the PCT values at 90 days were higher in IRI
graft survival group than in lower graft survival group, but no mentioning about the EAD and
non-EAD group as far as 90 days graft and patient survival.
9- I understand that you presumed that the IRI is the main or the only etiology for EAD, which
can be true during the 1st PO week, but in 90 days or 12 month period there will be many
determined factors that may lead to graft loss or dysfunction and impact the M&M than just
simple IRI, can you elaborate on this issue.
10- You describe the decline in the PCT values after the 2nd PO day, but to what value the
decline was? The problem is we neither have preoperative values nor we have a baseline values
to compare to. The other issues are, we do not know what the PCT values were after the 1st few
PO transplant in patients with persistent EAD or any other PO complications. Having only the
initial PCT readings will be hard to assume the connections between the PO M&M even if the
statistical analysis gave us significant P value. Can you elaborate?
11- You made good effort to connect the dots and put good scientific explanation for the PCT
results, I do believe you shade light on the role pf PCT in liver transplant recipients, but we still
have long way to go.