PONE-D-23-33615The impact of preservation solutions for static cold storage on kidney transplantation outcomes: results of a Brazilian nationwide multicenter studyPLOS ONE

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Additional Editor Comments:

the paper should include a comparison with data from the use of UW, outside of Brazil.

Euro-Collins is not the best solution for preservation and publishing just the results with Euro-Collins may send the wrong message.

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Reviewers' comments:

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Reviewer #1: Yes

Reviewer #2: Partly

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Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #1: Yes

Reviewer #2: No

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Reviewer #1: Thank you for the opportunity to review your manuscript. This is a very well-written document. The introduction, methods, results and discussion are all appropriate with excellent quality of the English language, tables and figures.

A few minor comments for the authors to consider:

1- it would be great to have a flow chart illustrating the entire process of selection and exclusion of the cohort

2- please correct your definition and use: pulsatile hypothermic perfusion pump when referring to the machine used to preserve the kidneys

3- i would invite the authors to create a histogram illustrating the incidence of DGF (%) for the different preservation groups

4- similarly, it would be great for the readers to see a histogram illustrating the incidence of prolonged DGF

Reviewer #2: Manuscript: PONE-D-23-33615

The work by Veras de Sandes-Freitas et al. titled ‘The impact of preservation solutions for static cold storage on kidney transplantation outcomes: results of a Brazilian nationwide multicenter study’ investigates the kidney procurement and preservation practices throughout Brazil and the impact on delayed graft function (DGF) and one year graft survival. Their primary finding is that the most commonly used preservation solution in Brazil, Euro-collins solution, is associated with higher rates of DGF and prolonged DGF, defined as requiring dialysis for more than 14 days. No difference is seen in 1 year graft survival. Their analysis includes a multivariate analysis to confirm that the choice of preservation solution is an independent predictor of DGF. The authors clearly demonstrate these differences with their focused analyses. These results could influence the practices within Brazil and significantly impact a large number of kidney transplant recipients in that country. Below are outlined comments/concerns regarding the manuscript in its current form.

Major points:

1) The scope of the work presented in this manuscript is limited to population level analyses of kidney preservation solution. It is likely better suited for a specialty journal that focuses on transplantation as opposed to a general scientific journal.

2) The overall applicability of the findings is limited due to the different practices using preservation solutions globally. As the article mentions, University of Wisconsin (UW) solution is very widely used and is the most commonly used preservation solution in the United States. Unfortunately, because of its limited use in Brazil, it is not included in this analysis. Thus, the overall results will have limited appeal outside of Brazil

3) The analysis is limited to a retrospective post hoc study that is not structured to provide any mechanistic insight into the reason why different preservation solutions impact graft health. An understanding of these mechanisms would deepen the impact of the manuscript and make it more broadly applicable.

Minor points:

1) As pointed out in the discussion, the original study has excluded primary non-function kidneys. This issue is potentially very important and should be discussed in more depth.

2) Table 1 provides an overview of the total cohort of patients in the study, but it does not provide a comparison between the preservation groups. While this information is available in a supplemental table, it may be better situated as Table 1 in the main text in order to provide context for the remaining analyses of the article.

3) The manuscript would generally benefit from work to improve the readability.

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Reviewer #1: Yes: Michele Molinari

Reviewer #2: No

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The impact of preservation solutions for static cold storage on kidney transplantation outcomes: results of a Brazilian nationwide multicenter study

PONE-D-23-33615R1

Dear Colleaque

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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Kind regards,

Boris Rubinsky, Ph.D.

Academic Editor

PLOS ONE

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