Review for 10.1186/s12876-017-0613-x (2017)

Reviewer ’s report  
 
Title: Vitamin D -related gene polymorphism predict treatment response to pegylated interferon -
based therapy in Thai chronic hepatitis C patients  
 
Version: 0 Date: 23 Feb 2017  
 
Reviewer: Hyun Woong Lee  
 
Reviewer's report:  
 
Dear Authors  
 
"Vitamin D -related gene polymorphism predict treatment response to pegylated interferon -based 
therapy in Thai chronic hepatitis C patients" This is a study to determine whether genetic 
polymorphisms of genes in the vitamin D pathway are associated with treatment responses to 
pegylated interferon (PEG -IFN) -based therapy in patients with chronic H CV infection  
This is a well written paper that tries to evaluate whether genetic polymorphisms of genes in the 
vitamin D pathway are associated with treatment responses to pegylated interferon (PEG -IFN) -
based therapy in CHC patients  
However, there are mino r problems that should be address.  
1. After development of direct antiviral agent (DAA), SVR rate with DAA is more than 90% in 
chronic hepatitis C patients. It would be clinically less important to find the predictive 
factors for SVR in treatment of interf eron with ribavirin, especially for compensated liver 
disease in the era of DAA.   
 
2. We find the data on Vitamin D -related gene polymorphism in genotype 1 as a predictor of 
SVR to be very interesting. However, it is wonder why Vitamin D -related gene 
polym orphism is only a predictor of SVR in genotype 1.  
 
3. I wonder whether Vitamin D -related gene polymorphism is associated with the level of 
serum 25(OH) D level or not.  
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the auth ors. 
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would you recommend an  
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further  
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscr ipt: 
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an  
organisation that may  in any way gain or lose financially from the publication of this  
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose  
financially from the publication of this manuscript, either n ow or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds  or has applied for patents relating t o the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have no competing int erests' 
below.  If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests.  
 
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