IL-16 and BCA-1 Serum Levels Are Associated with Disease Severity of C. difficile Infection

Round 1

Reviewer 1 Report

Overall, this paper is informative and clearly written. The data collected are concisely and coherently presented. 

Introduction: What is the typical course of treatment in CDI? Does treatment differ between moderate CDI and severed CDI? How are people acquiring CDI in the community? What is the leading cause of CDI? 

Discussion: What do IL-21/IL-23 do? Why do the authors expect them to be elevated in severe CDI? Was there significant differences in any cytokine levels between male and female patients?

 

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

This article describes the association between serum cytokines (IL-16, BCA-1) levels and severity of Clostridioides difficile disease. The same cohort and study design in this study have been described previously (Zohar H et al., 2019, Microorganisms). The authors performed additional cytokine analysis (6 cytokines) in addition to that paper. I feel like the results of this article is not sufficient for an original research article but could be suitable as a Short Communications with additional analysis and discussion with the following points and comments.

• Association with other inflammatory markers (i.e. C reactive proteins, white blood cells etc. reported in previous paper)
• Are there PBMC samples collected to perform any T cell analysis?
• Th1/Th2 cytokine ratios as an indication of T cells responses

 

Major comments:

• The disease severity was characterised differently from the original paper- can the authors comment on this discrepancy?
• was association between patient characteristics and cytokine levels performed?
• Figure 1 and Table 1 report the same data- suggest removing one.
• What is the hypothesised immunopathology for IL-16 and BCA-1
• What are the co-morbidities in the patients and how likely that contribute to the study findings?
• There are also other cytokines associated with disease severity (GM-CSF, IL-1b,, IL-8, IL-2). How does the authors envisioned the detection of IL-16 and BCA-1 along with the other cytokines be used to predict disease severity.
• The authors acknowledged that the timing of blood collection and CDI is a limitation of this study. It might still be helpful to know whether the timing of samples influence the cytokine levels

 Minor comments:

• Table 1: Disease severity should be mild-moderate and severe

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Thank you for the revisions. Please see comments below:

• Abstract
  • Suggest rewording IL-16 and BCA-1 along with other cytokines and chemokines may serve as…..
  • Remove hopefully will reduce patient’s mortality

 

• Introduction
  • Remove the paragraph on cytokine (line 58)- this is generic and not specific to CDI
  • The authors should briefly describe the previous study (Hamo et al., 2019) in the introduction, and mention the difference between this study and the previous one i.e. “We have described association of cytokine and severity of disease in a previous study (Hamo et al., 2019). Here we investigated…..”

 

• Please revise Disease severity in Table 1 from moderate to severe
• Are the 6 cytokines all inflammatory mediators? If not, suggest changing Table 2 and 3 descriptions to serum cytokine levels
• Please be consistent throughout the paper with cytokines or inflammatory markers or immunological markers
• Line 113- reword didn’t to did not
• Line 120- pearsons correlation analysis should be in methods under statistical analyses
• Line 126- typo indicating
• Line 136-138-unclear- suggest reword
• The hypothesis provided for IL-16 and BCA-1 is pure speculative and not supported by study findings (Line 144-145 and Line 160-162)
  • the discussion should be why/how IL-16 and BCA-1 contributes to CDI severity
  • If the authors measure difficile antibodies, it would good to show the results.
• Line 151- typo
• Line 165- italics Helicobacter pylori
• Line 179-limitations- what is more severe disease? Life-threatening? Suggest removing the third limitations-mortality rate was low
• Line 183- typo
• Line 184- suggest remove “..not caused by it”
• Line 250-252- No recruitment and activation of various immune cells were measured or shown. Positive correlation was shown for IL-16 and WBC, and BCA-1 and lymphocytes, but BCA-1 had negative correlation neutrophils. This conclusion is not appropriate.
• Line252- there was no mention about hypothesis earlier
• Line 257-260-not all hospitals have access to Luminex machine, and as mentioned earlier by the authors, these IL-16 and BCA-1 are involved in other bacterial diseases. How does that influence diagnosis? Also, routine blood examinations could also mean patients blood test for non-CDI? Suggest rewording or remove

Author Response

A file is attached

Author Response File: Author Response.docx