Dear Editor,
I read with great interest the study by Hulkoti and colleagues reporting that a high concentration of serum ferritin was a prognostic marker in severe coronavirus disease (COVID-19).[1] As they stated,[1] ferritin has tended to be a forgotten marker among markers relevant to clinical decision-making concerning COVID-19; therefore, their finding of ferritin is unique. As measuring ferritin is readily performed and relatively inexpensive, their idea of including ferritin in clinical practice for COVID-19 cases[1] also appears quite useful. Further studies should be conducted to determine the correlation of ferritin levels with the severity and cut-off levels of ferritin for identifying the likelihood of critical outcomes in patients with COVID-19.
However, we should take care to conduct such studies using the threshold serum ferritin concentration. Ferritin data can differ even among assay systems that are commonly used, despite efforts at inter-assay harmonization of ferritin measurements.[2] These variations of data may markedly affect clinical judgement, especially in cases of high ferritin concentrations.[2] In future studies based on serum ferritin concentrations, clinicians should make plans while considering the assay systems used for serum ferritin measurements. Further progress in the harmonization of ferritin measurements is required among laboratory professionals. We await further advances in research using ferritin to improve clinical practice for COVID-19 following the Hulkoti study.[1]
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Conflicts of interest
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References
- 1.Hulkoti VS, Acharya S, Kumar S, Talwar D, Khanna S, Annadatha A, et al. Association of serum ferritin with COVID-19 in a cross-sectional study of 200 intensive care unit patients in a rural hospital:Is ferritin the forgotten biomarker of mortality in severe COVID-19? J Family Med Prim Care. 2022;11:2045–50. doi: 10.4103/jfmpc.jfmpc_1921_21. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Braga F, Pasqualetti S, Frusciante E, Borrillo F, Chibireva M, Panteghini M. Harmonization status of serum ferritin measurements and implications for use as marker of iron-related disorders. Clin Chem. 2022;68:1202–10. doi: 10.1093/clinchem/hvac099. [DOI] [PubMed] [Google Scholar]