Impact of SARS-CoV-2 Infection on the Course of Inflammatory Bowel Disease in Patients Treated with Biological Therapeutic Agents: A Case-Control Study

Round 1

Reviewer 1 Report

This is an important study that aims to evaluate the effect of SARS-CoV-2 infection to IBD relapse. There are several studies that implicate a connection among Covid-19 and IBD relapse. However this study presents with scientific soundness different findings. Therefore, I believe that is should be published. Discussion is very interesting  and confirms that further studies should be conducted on the matter. 

 

I find this paper important as it addresses to the question whether or not IBD flair ups are associated with the SARS-Cov-2 infection. It is relevant to the filed. Although there are other similar studies through the countries, it is original for the Italy case and it is important as there are several controversies on the matter. Several other published material that seek to investigate the SARS-Cov-2 infection effects on Crohn disease and ulcerative colitis present different results. Thus, it is important to investigate further as the specific findings implicate no association at all.

Methodology is fine. The statistical analysis is the appropriate for the case. The authors could mention in details the possible missing data of their study due to the retrospective nature of it. The conclusions are consistent with the main question. The references are appropriate and recent.   All tables are necessary to be presented and well designed. The figure 1 is not important but it depicts locations graphically, which is nice for readers.

 

Author Response

Point 1. The authors could mention in detail the possible missing data of their study due to its retrospective nature.

Response 1. We thank the Reviewer for his comment. We added in the discussion the details of the missing data due to the study's retrospective nature.

Reviewer 2 Report

The author investigates the prevalence of COVID-19 amongst IBD patients. The results are nicely presented, which makes it easy to understand the data. Overall the paper is of great interest to those, who might think that biological treatment might increase the severity of COVID-19 infection. 

 

The author studies the effect of COVID 19 infection in IBD patients and if the patients infected with COVID 19 will have disease relapses. IBD patients were compared with healthy controls. The study results show no differences between IBD and non-IBD patients.

I think the topic is original and relevant in the field and I see no gap in the field.

The author refers to references from Canada where their results show that infection with COVID 19 causes disease relapses and a Danish study shows short-term disease relapses after infection with COVID 19. However, not the same medication/ biological therapy was used in all these studies, which might have a huge impact on the course of the infection with COVID 19, since biological medication and steroids affect the adaptive immunity which is also active when infected with the virus.

I do not think it is needed other controls than IBD and non-IBD patients.

The conclusions are consistent with the evidence and arguments
presented and they address the main question posed.

The references appropriate.

The studies done so far might be different, since the treatment given to IBD patients is also different. It is recommended to separate IBD patients into groups, depending on what medication they receive, analyze the results for each group and compare them with each other to see if there are differences between groups. 

 

Author Response

Point 1. It is recommended to separate IBD patients into groups, depending on what medication they receive, analyze the results for each group and compare them with each other to see if there are differences between groups. 

Response 1. We thank the Reviewer for his comments. In the Results paragraph, we added data regarding the different rates of disease flare-up according to the various biological agents and COVID-19 status.