MicroRNAs—A Promising Tool for Asthma Diagnosis and Severity Assessment: A Systematic Review
, Elena Vladimirovna Vorobeva 1, Dilini M. Kothalawala 4,5, Wei Chern Gavin Fong 1,2,4, Peijun He 6, Collin L. Sones 6, Mohammad Al-Zahrani 1,7, Tilman Sanchez-Elsner 1,2, Syed Hasan Arshad 1,2,4 and Ramesh J. Kurukulaaratchy 1,2,4,*
Round 1
Reviewer 1 Report
In their systematic review “MicroRNAs: a promising tool for asthma diagnosis and severity assessment. A systematic review”, Kyyaly et al. performed a comprehensive literature search in three databases aiming to find suitable miRNAs panels that can be applied as biomarkers for diagnosis of asthma and severity risk assessment of the disease. The authors described in details their strategy and inclusion criteria used for the literature analysis. As a result, they suggest two panels of miRNAs that can be used for development of efficient non-invasive methods for asthma diagnosis and evaluation of the severity risk.
I have some remarks that need to be taken into account before publishing.
- As the review is too descriptive, I think it will be more useful for readers and clinicians if the authors discuss the proposed panels of miRNAs and express their opinion in terms of their specificity and reliability for diagnosis and severity risk assessment. It is even desirable that the proposed panels contain a smaller number miRNAs (now they are 10 and 6), but with high specificity and reliability, which will allow easier validation in the clinical practice. The current discussion is focused on the functionality of miRNAs according to the authors of the analyzed publications.
- It is good in the Introduction to give more information about the patients with asthma worldwide, not only for UK. If the study is local than the authors have to analyze the literature related only to UK patients.
- Some technical notes:
- Within the text is clear that one of the database is SCOPUS, but in the abstract is written Web od Science Core Collection;
- Line 138 is written “…1415 duplicate articles…”, which is different from that given in Figure 1.
- Delete lines 228-241.
- Figure 2A is not necessary and it is not readable. You can keep only Figure 2B as Figure 2.
- It would be good if the arrangement of the cited tissues in the text and in the legend of Figure 3 to be the same.
- Line 265 in Discussion – it is written “…a novel qualitative systematic review…”. What is the novelty?
Author Response
Thank you very much for taking time to review our paper. We really appreciate your comments which improved our paper. We tried to address all comments below:
- Comment: As the review is too descriptive, I think it will be more useful for readers and clinicians if the authors discuss the proposed panels of miRNAs and express their opinion in terms of their specificity and reliability for diagnosis and severity risk assessment. It is even desirable that the proposed panels contain a smaller number miRNAs (now they are 10 and 6), but with high specificity and reliability, which will allow easier validation in the clinical practice. The current discussion is focused on the functionality of miRNAs according to the authors of the analyzed publications.
Response: Thank you very much for this insightful suggestion. For specificity, most of the studies included in this review haven’t studied the specificity for the identified miRNAs separately. Therefore, the detailed source data to do as suggested is lacking. However, it would be great if we could study the specificity for the miRNAs concluded in this review (as a panel) which will add great value to these panels but unfortunately this will require pooling all samples for different miRNAs from each panel and performing meta-analysis which we will consider as a future further project to assess whether that improves the quality of our panels. The number of miRNAs in each panel was obtained after following specific criteria described L190-195 for diagnostic panel and L220-233 for the severity assessment panel.
- Comment: It is good in the Introduction to give more information about the patients with asthma worldwide, not only for UK. If the study is local than the authors have to analyze the literature related only to UK patients.
Response: We thank the reviewer for highlighting this point and have amended the Introduction to reflect that this is not a local study
- Comment: Some technical notes:
- Within the text is clear that one of the database is SCOPUS, but in the abstract is written Web od Science Core Collection;
- Line 138 is written “…1415 duplicate articles…”, which is different from that given in Figure 1.
- Delete lines 228-241.
- Figure 2A is not necessary and it is not readable. You can keep only Figure 2B as Figure 2.
- It would be good if the arrangement of the cited tissues in the text and in the legend of Figure 3 to be the same.
Response: Thank you for identifying these points which have all been addressed in the accompanying revision.
- Comment - Line 265 in Discussion – it is written “…a novel qualitative systematic review…”. What is the novelty?
Response: We thank the reviewer for highlighting this point. We have amended the text to highlight that the novelty lies in the use of this systematic review to define miRNA panels with potential clinical utility in asthma.
Reviewer 2 Report
1) Interesting the way in which the study is conducted. One major flaw is that authors have failed to mention the clinical and therapeutic state of the patients or studygroup that are included in this investigation. For example, the existing exclusion and inclusion criterias are solid. However, there is no information on if and whether these patients were on any form of therapeutic intervention, and the time point post diagnosis.
2) Of all the robustly altered microRNAs that the authors propose as potential non-invasive biomarkers, it will be nice to present a relative expression profile of the top 5 miRNAs in blood and lung tissue(given the primary site of disease). moreover, it is also known that small RNAs such as miRNAs get exported from tissue microenvironment via exosomes in the bloodstream. Conducting such analysis between blood and lung tissue in healthy datasets may provide more clarity with regards to if these miRNAs found in blood post disease are naturally expressed or could have been exported via exosomal pathways from lung tissue.
3) In relation to query # 2 above, authors should clarify that miRNAs have a certain half-life. Could alteration in any of of these miRNAs in circulation have side-effects, such as these miRs could target respective messenger RNAs and suppress their maturation/translation?
4) Please detail the figure legends, statistical methods and improve the quality of figures/fonts, legibility.
5) some additional studies to consider: https://www.sciencedirect.com/science/article/pii/S0091674919322766?via%3Dihub
https://www.jacionline.org/article/S0091-6749(20)30121-4/fulltext
https://respiratory-research.biomedcentral.com/articles/10.1186/s12931-018-0828-6
https://respiratory-research.biomedcentral.com/articles/10.1186/s12931-020-01351-x
https://www.frontiersin.org/articles/10.3389/fmolb.2021.703307/full
Author Response
Thank you very much for taking the time to review our paper. We really appreciate your comments which improved our paper. We tried to address all comments below:
1) Interesting the way in which the study is conducted. One major flaw is that authors have failed to mention the clinical and therapeutic state of the patients or studygroup that are included in this investigation. For example, the existing exclusion and inclusion criterias are solid. However, there is no information on if and whether these patients were on any form of therapeutic intervention, and the time point post diagnosis.
Response: Thank you very much for highlighting this point. The therapeutic statues and time points are massively varied among the different studies and not even mentioned in many of them. This is why we couldn't use these elements in our criteria. However, taking into consideration the small number of studies looking at miRNAs in asthma currently, we think that it is worth looking at these elements in future studies where more research is done about using miRNAs for asthma diagnosis. We have added reference to this limitation of our data and the need to focus more on it in future research in the Discussion.
2) Of all the robustly altered microRNAs that the authors propose as potential non-invasive biomarkers, it will be nice to present a relative expression profile of the top 5 miRNAs in blood and lung tissue(given the primary site of disease). moreover, it is also known that small RNAs such as miRNAs get exported from tissue microenvironment via exosomes in the bloodstream. Conducting such analysis between blood and lung tissue in healthy datasets may provide more clarity with regards to if these miRNAs found in blood post disease are naturally expressed or could have been exported via exosomal pathways from lung tissue.
Response: Thank you for this insightful suggestion. We agree that this comparison of relative expression for the top 5 miRNAs in both lung and blood would be great and will enrich our review, but the fact that it is a very small number of studies that discussed the alteration in miRNAs expression in the lung will make this comparison is very difficult at the moment because of the lack of information. However, this suggestion will be considered in our future work. We have alluded to that future research need in the Discussion.
3) In relation to query # 2 above, authors should clarify that miRNAs have a certain half-life. Could alteration in any of of these miRNAs in circulation have side-effects, such as these miRs could target respective messenger RNAs and suppress their maturation/translation?
Response: Thank you very much for this comment. This is correct, during miRNAs biogenesis, the half-life of the most abundant miR strands is 11.4 hours but technically in the case of disease (asthma in our case) miRNAs will be up/down regulated consistently so the half-life time shouldn't affect the presence of specific miRNA. We are here trying to demonstrate the diagnostic value of the presence of specific miRNAs which make them a valuable biomarker for asthma diagnosis and severity assessment without discussing the biogenesis of miRNAs. We have clarified this point in the Discussion (under limitations and strengths).
4) Please detail the figure legends, statistical methods and improve the quality of figures/fonts, legibility.
Response: We changed figure 2 and made it only one figure to improve quality and changed the legend accordingly. The fonts are journal specific so we can't change them.
5) some additional studies to consider: https://www.sciencedirect.com/science/article/pii/S0091674919322766?via%3Dihub
https://www.jacionline.org/article/S0091-6749(20)30121-4/fulltext
https://respiratory-research.biomedcentral.com/articles/10.1186/s12931-018-0828-6
https://respiratory-research.biomedcentral.com/articles/10.1186/s12931-020-01351-x
https://www.frontiersin.org/articles/10.3389/fmolb.2021.703307/full
response: Thank you for providing these additional studies. We have added one of these references to our review (highlighted)
Reviewer 3 Report
Authors submitted qualitative systematic review to evaluate the diagnostic and severity-risk assessment value of miRNAs in asthma. They searched for articles in three databases and finally identified 75 studies that met certain search criteria. It has been found that 200 mRNAs were differently expressed in paetimst with asthma. Authors concluded that asthma severity panel and asthma diagnostic panel are based on different signatyre of the mRNAs and that new studies require to thoroughly investigate the role of these panals in asthma prediction. These results appear to be intriguing, but I have several issues to discuss.
- Lines 229-241 contain backgroud information for the article preparation and seem to be deleted.
- Please, provide heterogenisity index (<25%, 25%-50%, 50%-75%, >75%) for the enrolled articles' group
- Authors should report whether all studies enrolled in the systematic review were prospective, how many of them were retrospective. In addition, authors should provide separate evaluation of the prospective studies and discuss the results.
- Conclusion part sounds as section discussion, so that I propose to re-write this section to give more conclusive recommandation.
Author Response
Thank you very much for taking time to review our paper. We really appreciate your comments which improved our paper. We tried to address most of your comments and explain why we cannot do one of them below.
- Comment: Lines 229-241 contain backgroud information for the article preparation and seem to be deleted.
Response: We thank the reviewer for picking up on this and have deleted it as requested.
- Comment: Please, provide heterogenisity index (<25%, 25%-50%, 50%-75%, >75%) for the enrolled articles' group
Response: We thank the reviewer for raising this suggestion. We recognise that the heterogeneity index is important for a meta-analysis. However, we believe it is not appropriate for our work which is a qualitative/descriptive systematic review rather than a meta-analysis. Furthermore, it will also not be practical in this study to provide that heterogeneity index as the detailed source data to do so is lacking.
- Comment: Authors should report whether all studies enrolled in the systematic review were prospective, how many of them were retrospective. In addition, authors should provide separate evaluation of the prospective studies and discuss the results.
Response: We thank the reviewer for raising this point which we have addressed – see addition to L153 for confirmation that all studies were prospective. Therefore separate evaluation and discussion of results was not indicated.
- Comment: Conclusion part sounds as section discussion, so that I propose to re-write this section to give more conclusive recommandation.
Response: We thank the reviewer for making this very helpful recommendation which we have hopefully addressed in the revised Conclusion. Please see L396-405
Round 2
Reviewer 2 Report
Thank you for revising the manuscript to improve its quality and significance. All changes are accepted.
Reviewer 3 Report
Authors submitted a revised version of the article which is seemed to be sufficiently improved. I have no serious flaws to the article in its revised version
