Letter to the Editor

To the Editor,

We thank the authors for their interest and comments on our manuscript entitled “The concentration of interleukin-33 in heart failure with reduced ejection fraction” (1).

There was no significant difference between blood sample and storage time in each group. Both patients and healthy volunteers were included in the study. Storage time did not exceed a month. Interquartile ranges in all groups were presented in the tables; however, the Reviewers advised us to exclude them. Therefore, our tables were changed as suggested by the reviewers. It is obvious that statistical methods have their limitations. Some patients had IL-33 concentration below the limit of detection; therefore, the averaged levels of this cytokine in patients with higher levels and undetectable concentrations were near the limit of detection.