PONE-D-21-16062

Cardiovascular Disease (CVD) risk in liver transplant recipients for HCV, HBV± HDV-associated liver disease

PLOS ONE

Dear Dr. Maggi,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

The Editor reviewed the manuscript. This work requires more relevant information to make suggested conclusions.

The Editor's comments:

The title needs to be modified. What is “HCV, HBV+/- HDV-associated liver disease”? This is not obvious or even clear for a professional and especially for a lay reader. The title needs to be better expressing the entire idea. 

In the Abstract, the authors use multiple abbreviations (ASCVD, IMT, CVD) without an explanation; all abbreviations need to be spelled out when used the first time. 

The conclusion sentences in the Abstract need to be re-written as “Liver transplant recipients for HCV, HBV±HDV-associated liver disease are at high risk of CVD. Comparing the high percentage of subclinical carotid lesions with data of the risk charts, the latter seem to underestimate the real extent of the endothelial damage. A chronic inflammatory status could play a key role. It’s important to raise the awareness of cardiovascular risk in liver transplant patients to prevent cardiovascular diseases and improve the timing of early diagnosis of premature vascular lesions” is not clear. The first sentence does not clearly state the main findings. The second sentence also needs to be better expressed. 

It is confusing the use of CV as cumulative cardiovascular risk as well as CVD as clinical cardiovascular disease. What is the difference? It is not convincing why the authors use these two similar terms. Please explain better each term or use one universal term. The risk of “a 10-year CVD risk 2.5-3.5% higher in HCV-infected subjects compared to the HCV-negative population” is not very impressive. If the risk is for example 20% and an increase is to 22.5% such increase may be biologically not significant. The argument is not convincing. Please explain better this argument. 

The last paragraph in the Introduction section needs to be re-written. For example it should be: “The objective of this study was to evaluate the risk of cardiovascular disease or at least subclinical vascular damage among liver transplant recipients infected with HCV and/or HBV.” 

The authors fail to explain the principal idea for their work. After reading the Abstract and the Introduction, the reader still does not understand what is “HBV ± HDV-associated liver disease”. The abbreviations need to be explained and the combination of HBV +/- HDV should be clearly spelled out and explained.   

The best description of this study would be: “This an observational study of patients with orthotopic liver transplants (OLT) admitted for a routine follow-up between June 2019 and September 2020 at the Infectious Disease outpatient clinic of the University of Campania Luigi Vanvitelli, Naples, Italy. All adult (age ≥ 18 years) patients with liver transplants due to viral hepatitis who signed informative consent were included.” Some form of this description should be in the Abstract.

The authors need to provide the list of all abbreviations with spell out text. 

All abbreviations used in the Results section needs to be explained “were transplanted for HCV, 27 (18.4%) for HBV, 46 (31.5%) for dual infection HBV-HDV, 10 (6.8%) for dual infection HBV-HCV and 4 (2.7%) for triple infection HBV-HDV-HCV. For 87 patients (59.5%)”.

The Introduction section must explain very clearly about different types of hepatitis. There is no any information about what is hepatitis. Only after looking at a website, one can learn “Hepatitis is most commonly caused by the viruses hepatitis A, B, C, D and E. The authors need to write a section with an explanation about hepatitis with explained abbreviations. What are the differences among patients with hepatitis B, C and D versus combination of two different types?

The title of this study is about cardiovascular disease risk in liver recipients with hepatitis. There is no convincing argument that these patients are indeed at higher risk than any other group of patients. Please provide more data and the comparison with non-infected patients for their risk for cardiovascular diseases. The statement at the end of the Discussion section is not satisfactory “Possible limits of our study are the number of enrolled subjects, and the absence of a control group.” In addition, the authors state “However, this is the first study among long term liver transplant recipients for viral hepatitis, revealing an unexpectedly high presence of patients at high CVD risk, and an even higher number of patients with subclinical epiaortic vessel lesions.” The argument needs to be supported by the comparison with other groups of patients. 

Reviewer # 1:

The manuscript presents the results of a observational study which assessed cardiovascular risk in long-term liver transplant recipients (most >5 years) transplanted for viral hepatitis using different risk charts and subclinical intima-media damage via carotid ultrasound. Many recipients had high CV risk and the majority had either IMT or a carotid plaque on CD carotid ultrasound.

The study lacks control groups as was observed in the discussion, however the authors did not draw any exaggerated conclusions Only proportions were reported, with no formal statistical testing, which is in line with the study design.

Table 1 stated that 39,7% of patients had previous cardiovascular disease, how was it defined?

As the present cross-sectional study was not designed to record adverse events at all, carotid ultrasound was used as surrogate. Even though it was previously established that IMT correlates with major adverse cardiovascular events, the risk scores were not originally designed to asses endothelial damage. The risk scores used in the study also differ in outcomes; Heart Score only evaluates the risk of fatal major adverse cardiovascular events, while ASCVD and the Framingham risk score include non-fatal events. Limitations regarding differences in outcomes should be noted in the discussion.

Another observation is that the authors stated in their discussion that patients on tacrolimus monotherapy seemed more prone to developing vessel lesions although the proportions reported were similar to those of the total study population (around 31%).

Reviwer # 2:

The paper by Dr. Magii et al. is a description of a brief observational study of a group of liver transplant recipients whose initial liver failure was due to viral etiology. Some questions should be addressed before publication.

1.     What was the medical history of patients before liver transplantation? Please make sure to include summarized and statistically analyzed information on parameters relevant to CVD risk, such as CVD diagnosis, BMI, diet and lifestyle, lipid profiles etc. Please comment on the change in the CVD risk factors before and after transplantation. This is one way to address the lack of a healthy control group in the study.

2.     The statement about correlation between echo-Doppler features and immunosuppression regimen has to be accompanied with statistical confirmation (probably Chi-squared test).

3.     Please make sure percentages in Table 3 add up to 100 (may require checking rounding).

4.     The manuscript will benefit from proofreading to fix language errors.

==============================

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Kind regards,

Stanislaw Stepkowski

Academic Editor

PLOS ONE

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Additional Editor Comments:

The Editor reviewed the manuscript. This work requires more relevant information to make suggested conclusions.

The Editors comments:

The title needs to be modified. What is “VCV, HBV+/- HDV-associated liver disease”? This is not obvious or even clear for a professional and especially for a lay reader. The title needs to be better expressing the entire idea.

In the Abstract, the authors use multiple abbreviations (ASCVD, IMT, CVD) without an explanation; all abbreviations need to be spelled out when used the first time.

The conclusion sentences in the Abstract need to be re-written as “Liver transplant recipients for HCV, HBV±HDV-associated liver disease are at high risk of CVD. Comparing the high percentage of subclinical carotid lesions with data of the risk charts, the latter seem to underestimate the real extent of the endothelial damage. A chronic inflammatory status could play a key role. It’s important to raise the awareness of cardiovascular risk in liver transplant patients to prevent cardiovascular diseases and improve the timing of early diagnosis of premature vascular lesions” is not clear. The first sentence does not clearly state the main findings. The second sentence also needs to be better expressed.

It is confusing the use of CV as cumulative cardiovascular risk as well as CVD as clinical cardiovascular disease. What is the difference? It is not convincing why the authors use these two similar terms. Please explain better each term or use one universal term. The risk of “a 10-year CVD risk 2.5-3.5% higher in HCV-infected subjects compared to the HCV-negative population” is not very impressive. If the risk is for example 20% and an increase is to 22.5% such increase may be biologically not significant. The argument is not convincing. Please explain better this argument.

The last paragraph in the Introduction section needs to be re-written. For example it should be: “The objective of this study was to evaluate the risk of cardiovascular disease or at least subclinical vascular damage among liver transplant recipients infected with HCV and/or HBV.”

The authors fail to explain the principal idea for their work. After reading the Abstract and the Introduction, the reader still does not understand what is “HBV ± HDV-associated liver disease”. The abbreviations need to be explained and the combination of HBV +/- HDV should be clearly spelled out and explained.

The best description of this study would be: “This an observational study of patients with orthotopic liver transplants (OLT) admitted for a routine follow-up between June 2019 and September 2020 at the Infectious Disease outpatient clinic of the University of Campania Luigi Vanvitelli, Naples, Italy. All adult (age ≥ 18 years) patients with liver transplants due to viral hepatitis who signed informative consent were included.” Some form of this description should be in the Abstract.

The authors need to provide the list of all abbreviations with spell out text.

All abbreviations used in the Results section needs to be explained “were transplanted for HCV, 27 (18.4%) for HBV, 46 (31.5%) for dual infection HBV-HDV, 10 (6.8%) for dual infection HBV-HCV and 4 (2.7%) for triple infection HBV-HDV-HCV. For 87 patients (59.5%)”.

The Introduction section must explain very clearly about different types of hepatitis. There is no any information about what is hepatitis. Only after looking at a website, one can learn “Hepatitis is most commonly caused by the viruses hepatitis A, B, C, D and E. The authors need to write a section with an explanation about hepatitis with explained abbreviations. What are the differences among patients with hepatitis B, C and D versus combination of two different types?

The title of this study is about cardiovascular disease risk in liver recipients with hepatitis. There is no convincing argument that these patients are indeed at higher risk than any other group of patients. Please provide more data and the comparison with non-infected patients for their risk for cardiovascular diseases. The statement at the end of the Discussion section is not satisfactory “Possible limits of our study are the number of enrolled subjects, and the absence of a control group.” In addition, the authors state “However, this is the first study among long term liver transplant recipients for viral hepatitis, revealing an unexpectedly high presence of patients at high CVD risk, and an even higher number of patients with subclinical epiaortic vessel lesions.” The argument needs to be supported by the comparison with other groups of patients.

Reviewer # 1:

The manuscript presents the results of a observational study which assessed cardiovascular risk in long-term liver transplant recipients (most >5 years) transplanted for viral hepatitis using different risk charts and subclinical intima-media damage via carotid ultrasound. Many recipients had high CV risk and the majority had either IMT or a carotid plaque on CD carotid ultrasound.

The study lacks control groups as was observed in the discussion, however the authors did not draw any exaggerated conclusions Only proportions were reported, with no formal statistical testing, which is in line with the study design.

Table 1 stated that 39,7% of patients had previous cardiovascular disease, how was it defined?

As the present cross-sectional study was not designed to record adverse events at all, carotid ultrasound was used as surrogate. Even though it was previously established that IMT correlates with major adverse cardiovascular events, the risk scores were not originally designed to asses endothelial damage. The risk scores used in the study also differ in outcomes; Heart Score only evaluates the risk of fatal major adverse cardiovascular events, while ASCVD and the Framingham risk score include non-fatal events. Limitations regarding differences in outcomes should be noted in the discussion.

Another observation is that the authors stated in their discussion that patients on tacrolimus monotherapy seemed more prone to developing vessel lesions although the proportions reported were similar to those of the total study population (around 31%).

Reviwer # 2:

The paper by Dr. Magii et al. is a description of a brief observational study of a group of liver transplant recipients whose initial liver failure was due to viral etiology. Some questions should be addressed before publication.

1. What was the medical history of patients before liver transplantation? Please make sure to include summarized and statistically analyzed information on parameters relevant to CVD risk, such as CVD diagnosis, BMI, diet and lifestyle, lipid profiles etc. Please comment on the change in the CVD risk factors before and after transplantation. This is one way to address the lack of a healthy control group in the study.

2. The statement about correlation between echo-Doppler features and immunosuppression regimen has to be accompanied with statistical confirmation (probably Chi-squared test).

3. Please make sure percentages in Table 3 add up to 100 (may require checking rounding).

4. The manuscript will benefit from proofreading to fix language errors.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: No

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: No

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: No

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The manuscript presents the results of a observational study which assessed cardiovascular risk in long-term liver transplant recipients (most >5 years) transplanted for viral hepatitis using different risk charts and subclinical intima-media damage via carotid ultrasound. Many recipients had high CV risk and the majority had either IMT or a carotid plaque on CD carotid ultrasound.

The study lacks control groups as was observed in the discussion, however the authors did not draw any exaggerated conclusions Only proportions were reported, with no formal statistical testing, which is in line with the study design.

Table 1 stated that 39,7% of patients had previous cardiovascular disease, how was it defined?

As the present cross-sectional study was not designed to record adverse events at all, carotid ultrasound was used as surrogate. Even though it was previously established that IMT correlates with major adverse cardiovascular events, the risk scores were not originally designed to asses endothelial damage. The risk scores used in the study also differ in outcomes; Heart Score only evaluates the risk of fatal major adverse cardiovascular events, while ASCVD and the Framingham risk score include non-fatal events. Limitations regarding differences in outcomes should be noted in the discussion.

Another observation is that the authors stated in their discussion that patients on tacrolimus monotherapy seemed more prone to developing vessel lesions although the proportions reported were similar to those of the total study population (around 31%).

Reviewer #2: The paper by Dr. Magii et al. is a description of a brief observational study of a group of liver transplant recipients whose initial liver failure was due to viral etiology. Some questions should be addressed before publication.

1. What was the medical history of patients before liver transplantation? Please make sure to include summarized and statistically analyzed information on parameters relevant to CVD risk, such as CVD diagnosis, BMI, diet and lifestyle, lipid profiles etc. Please comment on the change in the CVD risk factors before and after transplantation. This is one way to address the lack of a healthy control group in the study.

2. The statement about correlation between echo-Doppler features and immunosuppression regimen has to be accompanied with statistical confirmation (probably Chi-squared test).

3. Please make sure percentages in Table 3 add up to 100 (may require checking rounding).

4. The manuscript will benefit from proofreading to fix language errors.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: Yes: Dulat Bekbolsynov

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Cardiovascular Disease risk in liver transplant recipients for chronic viral hepatitis

PONE-D-21-16062R1

Dear Dr. Maggi,

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.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

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Kind regards,

Vanessa Carels

Staff Editor

PLOS ONE

Additional Editor Comments (optional):

Please modify the title to ensure that it is meeting PLOS’ guidelines (https://journals.plos.org/plosone/s/submission-guidelines#loc-title). In particular, the title should be "specific, descriptive, concise, and comprehensible to readers outside the field" and in this case we recommend the reviewer's suggestion "Cardiovascular Disease risk in liver transplant recipients transplanted due to chronic viral hepatitis"

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

Reviewer #2: This is an important study that provides new results about cardiovascular disease risk in patients with liver transplants who had different types of liver infections. I do not have new comments to add on this manuscript, as it appears solid and important to me, and resort to providing my opinion about how the comments by previous reviewers were addressed.

For points addressing the title of the manuscript, I feel like its updated version is still imperfect in terms of grammar. I would recommend changing the title to something like "Cardiovascular Disease risk in liver transplant recipients transplanted due to chronic viral hepatitis".

Regarding point 11 from the Editor, I agree with the authors that measuring cardiovascular disease risk in non-infected patients was beyond the scope of this manuscript. Going back and revising the study to include comparison to non-infected patients would equate to rejecting the manuscript that otherwise has a valid and important message to deliver. Expanding this study to statistically measure the relative risk of cardiovascular complications in infected and non-infected liver transplant patients can be viewed as a follow-up project to this study.

Reviewer 1 - I feel like their comment about the difference between cardiovascular and Framingham and ASCVD risk scores could be addressed better. The Discussion section does contain a few sentences on this matter (rows 231-234), so it can be argued that the manuscript does not need further revision due to this comment.

Reviewer 2 - while the point 1 about previous medical history is valid, I feel like information provided in Table 1 in the context of the authors' note about long follow-up in most of patients is a satisfactory response.

Overall, I believe this manuscript is in the form suitable for publication.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: Yes: Dulat Bekbolsynov