Genetic and Non-Genetic Contributions to Eosinophilic Granulomatosis with Polyangiitis: Current Knowledge and Future Perspectives

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 

The genetic complexity of ANCA-associated vasculitis: current knowledge and future perspectives on Eosinophilic granulomatosis with polyangiitis

This manuscript covers an interesting topic. However, some points need to be addressed.

Page	Line	Manuscript	Comments
1	19	Abstract	It will be better if the abstract started with a brief background about the topic.
1		we present Then, we describe  Finally, we discuss	The authors did not follow the rules of scientific writing. It is not preferred to use the word “we” in multiple times like that.
1	38	EGPA prevalence ranges between 2.0 and 22.3 cases per million 38 people and equally affects both males	The authors should follow the rules for citing references .Here is a sentence without its reference ,which is not appropriate .
2	Figure 1	Graphical 50 overview of the risk 51 factors and organ	The title of the figure is usually written below the figure. If the figure was taken from another paper, its reference should be cited with permission from the authors. If the figure was prepared by the authors, so, it should be more clear as the text is to some extent hazy .
2	64	As per their 64 name, AAVs are	Although the manuscript is specifically about EGPA, the authors wrote multiple sentences and paragraphs about AAV which made the introduction redundant and not attractive to the authors .
2	89-79		Again, citing references is not appropriate.
3	99	Currently, the determinants of EGPA are unknown: a growing number of studie	English editing and grammar revision are mandatory in the whole manuscript.
3	99	Currently, the determinants of EGPA are unknown: a growing number of studies	This sentence is followed by reference 11, dating from 2012 ,which is not appropriate after the word “currently “.
3		Introduction	The research gap is not clear .
3	103	In this review, we describe the known risk factors for EGPA, with a special emphasis 103 on its genetic aspects. Starting with a general	The aim of the study should be concise and clear. Here, the authors used multiple sentences with the same meaning which made the aim of the study to some extent redundant.
4	161	Initially, candidate-gene studies were employed to dissect the genetic components of 161 AAVs. Several genes were indiv	The references again ...

 

 

Comments on the Quality of English Language

Moderate

Author Response

Comment 1: Page 1. Line 19.: It will be better if the abstract started with a brief background about the topic.

Response 1: Following the reviewer’s suggestion, we edited the abstract, adding a brief background regarding EGPA, as follows: “In this work, we present a comprehensive overview of the genetic and non-genetic complexity of eosinophilic granulomatosis with polyangiitis (EGPA). EGPA is a rare complex systemic disease that occurs in people presenting with severe asthma and high eosinophilia. After briefly introducing EGPA and its relation with the anti-neutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis (AAVs), we delve into the complexity of this disease.”

 

Comment 2: Page 1: The authors did not follow the rules of scientific writing. It is not preferred to use the word “we” in multiple times like that.

Response 2: Following the reviewer’s suggestion and the rules of scientific writing, we edited the abstract, accordingly.

 

Comment 3: Page 1. Line 38: The authors should follow the rules for citing references. Here is a sentence without its reference, which is not appropriate.

Response 3: We thank the reviewer for precisely pointing out this issue. The sentence has been corrected following the appropriate citing rules.

 

Comment 4: Page 2. Figure 1: The title of the figure is usually written below the figure. If the figure was taken from another paper, its reference should be cited with permission from the authors. If the figure was prepared by the authors, so, it should be more clear as the text is to some extent hazy.

Response 4: The title “Eosinophilic Granulomatosis with Polyangiitis (EGPA)” was removed from the figure. Since the figure is an original image, we edited the caption accordingly, as suggested by the reviewer, as reported in the following sentences: “Graphical overview of the risk factors and organ involvement in eosinophilic granulomatosis with polyangiitis (EGPA). The figure illustrates the complex nature of EGPA, highlighting the most important biological factors, genetic and environmental influences, and the various affected organs described in this review.”

 

Comment 5: Page 2. Line 64: Although the manuscript is specifically about EGPA, the authors wrote multiple sentences and paragraphs about AAV which made the introduction redundant and not attractive to the authors.

Response 5: Following the reviewer suggestion, we synthesized and reduced the information regarding AAV, thus focusing more on EGPA.

 

Comment 6: Page 2. Line 89-79: Again, citing references is not appropriate

Response 6: We corrected the manuscript according to the reviewer comment, as for the following sentences: “Recent studies have suggested the existence of two different eosinophil-related facet of EGPA, named systemic and respiratory-limited phenotypes [16,17]. As reported by Matucci and colleagues, these two phenotypes have been identified using the blood eosinophil count as a disease biomarker, displaying commonalities and differences.”

 

 

Comment 7: Page 3. Line 99: English editing and grammar revision are mandatory in the whole manuscript.

Response 7: The manuscript underwent grammar and syntax revision and English editing.

 

Comment 8: Page 3. Line 99: This sentence is followed by reference 11, dating from 2012, which is not appropriate after the word “currently”.

Response 8: We thank the reviewer for pointing out these discordant terms. We edited the manuscript, proposing the following sentences: “Currently, the determinants of EGPA are unknown. In the last decade, a growing number of studies started identifying multiple genetic and environmental factors that may contribute to an increased risk of development of this disease, either in terms of genetic and environmental predispositions or as a trigger of immune dysregulation [11,18,19].”

 

Comment 9: Page 3. Introduction: The research gap is not clear.

Response 9: We thank the reviewer for pointing out this issue. Giving the aim of this review, we did not report any research gap in the “Introduction”, which aims at presenting EGPA. However, we provide research gaps and future perspectives in chapters 4 (“Latest research on EGPA”) and 5 (“Conclusion and future perspectives”), where we showed the current research efforts to address the unknown aspects of EGPA.

 

Comment 10: Page 3. Line 103: The aim of the study should be concise and clear. Here, the authors used multiple sentences with the same meaning which made the aim of the study to some extent redundant.

Response 10: We rephrased the paragraph, making clear the aim of this review. The manuscript text was edited accordingly, as follows: “In this review, we delve into the genetics of EGPA. Starting from a general overview, we provide a comprehensive description of the research efforts, spanning from candidate gene studies to genome-wide association studies (GWAS), including familial cases. Additionally, we briefly discuss the environmental triggers of EGPA, giving glimpses on the non-genetic components of this disease. Finally, we summarize the latest omic findings, offering new insights and perspectives on future approaches to understand the genetic causes of EGPA.”

 

Comment 11: Page 4. Line 161: The references again…

Response 11: We thank the reviewer for pointing out this issue. We adjusted the text accordingly: “Heckmann and colleagues [36] identified variants in HLA-DPB1 gene and in the ring finger protein 1 (RING1), a gene in close proximity to the HLA class II region, to be associated with GPA.”. Moreover, references were corrected in the whole manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

The evaluated article tries to discuss the known data, as well as future perspectives related to the genetics of one of the three ANCA-positive vasculitis, namely, EGPA. The idea is laudable and potentially interesting.

Some comments and suggestions

- the abstract is much too short and totally irrelevant compared to the text, it sounds more like the agenda of an oral presentation. Also, please pay attention to the way phrases are formulated “overview of genetic complexity……focus on it’s genetics”

- row 30 better to mention “formerly” known as Churg-Strauss syndrome

- rows 36-38 please use just one prevalence data, is somehow unclear

- rows 71-75 please provide references

- rows 95-98 I think one table just comparing the two suggested subtypes would add some clarity and easiness to read to the text – also providing reference for each finding. taking into account the discussion that follows in the article and the topic of study, is there any identified genetic particularity for the individuals belonging to each entity?

-rows 103-110 are somehow unnecessary

- row 119 please provide GWAS explanation

How did you select your studies for review? The authors list keywords used in the review but dot not provide a list databases, number of papers reviewed, and other criteria for inclusion. – Methodology!!!!!

Since the authors also discuss about other aspects besides genetics (environmental determinants) title should be updated and not referring only to genetics. Also it should be checked if some link could be find between genetics and environmental determinants.

Finally, please try to make the article easier to follow, now it is quite difficult to read it!

 

Author Response

Comment 1: The abstract is much too short and totally irrelevant compared to the text, it sounds like the agenda of an oral presentation. Also, please pay attention to the way phrases are formulated “overview of genetic complexity…...focus on it’s genetics”

Response 1: Following the reviewer’s suggestions, we expanded the abstract and rephrased misleading sentences, as follows: “In this work, we present a comprehensive overview of the genetic and non-genetic complexity of eosinophilic granulomatosis with polyangiitis (EGPA). EGPA is a rare complex systemic disease that occurs in people presenting with severe asthma and high eosinophilia. After briefly introducing EGPA and its relation with the anti-neutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis (AAVs), we delve into the complexity of this disease. At first, the two main biological actors, ANCA and eosinophils, are presented. Biological and clinical phenotypes related to ANCA positivity or negativity are explained as well as the role of eosinophils and their pathological subtypes, pointing out their intricate relations with EGPA. Then, the genetics of EGPA is described, providing an overview of the research effort to unravel it. Candidate gene studies have investigated biologically relevant candidate genes; the more recent genome-wide association studies and meta-analyses, able to analyze the whole genome, have confirmed previous associations and discovered novel risk loci; in the end, family-based studies have dissected the contribution of rare variants and the heritability of EGPA. Then, we briefly present the environmental contribution to EGPA, reporting seasonal events and pollutants as triggering factors. In the end, the latest omic research has been discussed; the most recent epigenomic, transcriptomic and microbiome studies were presented, highlighting the current challenges, open questions and suggesting approaches to unravel this complex disease.”

 

Comment 2: Row 30: better to mention “formerly” known as Churg-Strauss syndromes

Response 2: We added the suggestion in the manuscript, as reported in the following sentence: “Eosinophilic granulomatosis with polyangiitis (EGPA), firstly described by Churg and Strauss and formerly known as Churg-Strauss syndrome, is a rare complex systemic disease [1,2].”

 

Comment 3: Row 36-38: please use just one prevalence data, is somehow unclear

Response 3: Following the suggestion, we edited the following sentence: “EGPA fulfills the definition of rare disease (fewer than 1 in 2000 individuals in any WHO regions), equally affecting both males and females with a median age of onset of about 55 years old and with an estimated prevalence ranging between 2.0 and 22.3 cases per million people [4,5].”

 

Comment 4: Row 71-75: please provide references

Response 4: We corrected the manuscript according to the reviewer comment, as for the following sentences: “Recent studies have suggested the existence of two different eosinophil-related facet of EGPA, named systemic and respiratory-limited phenotypes [16,17]. As reported by Matucci and colleagues, these two phenotypes have been identified using the blood eosinophil count as a disease biomarker, displaying commonalities and differences.”

 

 

Comment 5: Row 95-98: I think one table just comparing the two suggested subtypes would add some clarity and easiness to read to the text – also providing reference for each finding. Taking into account the discussion that follows in the article and the topic of study, is there any identified genetic particularity for the individuals belonging to each entity?

Response 5: We thank the reviewer for this meaningful suggestion. We added a table (Table 1) to our manuscript, reported at the end of the “Introduction”. Moreover, we referred to the before mentioned table with the following sentences: “An overview of the EGPA subsets is reported in Table 1.”

 

Comment 6: Rows 103-110: are somehow unnecessary

Response 6: We thank the reviewer for pointing out this issue. To keep an introduction for chapter 2, we reduced the mentioned lines and we thus propose the following adjustments: “To date, two main genomic approaches have been used to investigate the genetic factors underlying EGPA and AAVs. At first, candidate-gene association studies were applied to investigate loci that were likely to be associated with these diseases, according to knowledge-based hypotheses. Then, with the advent of next generation sequencing technologies, GWAS took over, allowing to scan the entire genome to identify associated signals [20–22].”

 

Comment 7: Row 119: please provide GWAS explanation

Response 7: Following the reviewer’s suggestion, we edited the caption of the specified lines, making more clear the contents related to GWAS, as follows: “Figure 2. Network of the genes associated with AAVs. The figure shows a STRING [23] network representing the connection between the reported susceptibility genes. The displayed genes were reported at either suggestive (p < 5 x 10-5) or genome-wide (p < 5 x 10-8) significance in at least one genetic study. The majority of the genes belongs to a common network whereas four genes (DSP, ARHGAP18, GPA33, LPP) do not show any connection. The different subsets of ANCA-associated vasculitis are encoded as follows: GPA = granulomatosis with polyangiitis (red); MPA = microscopic polyangiitis (blue); EGPA = eosinophilic granulomatosis with polyangiitis (green); PR3+ = PR3-ANCA-positive (yellow); MPO+ = MPO-ANCA-positive (magenta); ANCA- = ANCA-negative (gray).”

 

Comment 8: How did you select your studies for review? The authors list keywords used in the review but do not provide a list databases, number of papers reviewed, and other criteria for inclusion. - Methodology!!!!!

Response 8: The manuscript does not represent a systematic review, but aims at reporting a summary of the genetic knowledge regarding EGPA. Hence, as commonly done for this kind of review, we did not provide any keyword, database, number and other inclusion criteria to the manuscript. However, we referenced and acknowledged all the reported material according to MDPI’s instructions.

 

Comment 9: Since the authors also discuss about other aspects besides genetics (environmental determinants) title should be updated and not referring only to genetics. Also it should be checked if some link could be find between genetics and environmental determinants.

Response 9: We thank the reviewer for this comment. We propose this new title for our manuscript: “Genetic and non-genetic contributions to eosinophilic granulomatosis with polyangiitis: current knowledge and future perspectives”. Moreover, we added some considerations regarding the interaction between genetics and environmental determinants.

Comment 10: Finally, please try to make the article easier to follow, not it is quite difficult to read it!

Response 10: The manuscript underwent syntax revision and English editing, to make it easier to be read.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript has been improved 

Comments on the Quality of English Language

minor

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for updating the article, it is now much more relevant.