Evidence for the presence and diagnostic utility of SPM in human peripheral blood

Summary We thank O’Donnell et al, for their comments on our contribution and are grateful to be afforded this opportunity to formally respond to their critique24. We are surprised by the author’s assertion relating to the biological relevance of SPM because a simple literature search for related terms such as ‘resolvin’ in PubMed yields an abundance (>1,420 publications) of evidence supporting the potent biological activities and the diagnostic potential of some of these mediators. Several co-authors of the O’Donnell’s et al manuscript, have published on the resolvins and SPMs, including some publications within recent weeks. Importantly, O’Donnell et al, misreport as well as mis-apply criteria for peak identification reported in the Gomez et al, publication which lead to the flawed analysis they performed. In this response therefore, we provide a step-by-step clarification of the methodologies used in Gomez et al, and a side-by-side comparison of the underlying data to clarify any confusion. We also demonstrate that using the orthogonal criteria discussed by O’Donnell et al, we obtain essentially identical results thus providing additional validation of our techniques and support the conclusions.