INTRODUCTION: Major clinically relevant inflammatory events such as septic shock and severe COVID-19 trigger dynamic changes in the host immune system, presenting promising candidates for new biomarkers to improve precision diagnostics and patient stratification. Hepcidin, a master regulator of iron metabolism, has been intensively studied in many pathologies associated with immune system activation, however these data have never been compared to other clinical settings. Thus, we aimed to reveal the dynamics of iron regulation in various clinical settings and to determine the suitability of hepcidin and/or ferritin levels as biomarkers of inflammatory disease severity. COHORTS: To investigate the overall predictive ability of hepcidin and ferritin, we enrolled the patients suffering with three different diagnoses - in detail 40 patients with COVID-19, 29 patients in septic shock and eight orthopedic patients who were compared to nine healthy donors and all cohorts to each other. RESULTS: We showed that increased hepcidin levels reflect overall immune cell activation driven by intrinsic stimuli, without requiring direct involvement of infection vectors. Contrary to hepcidin, ferritin levels were more strongly boosted by pathogen-induced inflammation - in septic shock more than four-fold and in COVID-19 six-fold in comparison to sterile inflammation. We also defined the predictive capacity of hepcidin-to-ferritin ratio with AUC=0.79 and P = 0.03. DISCUSSION: Our findings confirm that hepcidin is a potent marker of septic shock and other acute inflammation-associated pathologies and demonstrate the utility of the hepcidin-to-ferritin ratio as a predictor of mortality in septic shock, but not in COVID-19.

1st Department of Internal Medicine Cardioangiology Faculty of Medicine Masaryk University Brno Czechia

Celica BIOMEDICAL Ljubljana Slovenia

Department of Anesthesiology and Intensive Care Faculty of Medicine Masaryk University Brno Czechia

Department of Biology Faculty of Medicine Masaryk University Brno Czechia

Department of Modern Immunotherapy Institute of Hematology and Blood Transfusion Prague Czechia

Division of Neurology University Medical Centre Ljubljana Slovenia

Institute of Clinical Immunology and Allergology Faculty of Medicine Masaryk University Brno Czechia

International Clinical Research Center St Anne's University Hospital Brno Czechia

Intrinsic Lifesciences La Jolla CA United States

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Nairz M, Weiss G. Iron in infection and immunity. Mol Aspects Med (2020) 75:1–18. doi: 10.1016/j.mam.2020.100864 PubMed DOI

Drakesmith H, Prentice AM. Hepcidin and the iron-infection axis. Science (2012) 338(6108):768–72. doi: 10.1126/science.1224577 PubMed DOI

Girelli D, Marchi G, Busti F, Vianello A. Iron metabolism in infections: Focus on COVID-19. Semin Hematol (2021) 58(3):182–7. doi: 10.1053/j.seminhematol.2021.07.001 PubMed DOI PMC

Leon-Sicairos N, Reyes-Cortes R, Guadrón-Llanos AM, Madueña-Molina J, Leon-Sicairos C, Canizalez-Román A. Strategies of intracellular pathogens for obtaining iron from the environment. BioMed Res Int (2015) 1–17. doi: 10.1155/2015/476534 PubMed DOI PMC

Yan Q, Zhang W, Lin M, Teymournejad O, Budachetri K, Lakritz J, et al. . Iron robbery by intracellular pathogen via bacterial effector-induced ferritinophagy. Proc Natl Acad Sci U.S.A. (2021) 118(23):e2026598118. doi: 10.1073/pnas.2026598118 PubMed DOI PMC

Melnick L A, Sheng MC. Ironing out ferroportin. Physiol Behav (2016) 176(1):100–6. doi: 10.1016/j.cmet.2015.09.006 DOI

Ganz T. Systemic iron homeostasis. Physiol Rev (2013) 93(4):1721–41. doi: 10.1152/physrev.00008.2013 PubMed DOI

Tan TCH, Crawford DHG, Franklin ME, Jaskowski LA, Macdonald GA, Jonsson JR, et al. . The serum hepcidin:ferritin ratio is a potential biomarker for cirrhosis. Liver Int (2012) 32(9):1391–9. doi: 10.1111/j.1478-3231.2012.02828.x PubMed DOI

Seyoum Y, Baye K, Humblot C. Iron homeostasis in host and gut bacteria - a complex interrelationship. Gut Microbes (2021) 13(1):1–19. doi: 10.1080/19490976.2021.1874855 PubMed DOI PMC

Nicolas G, Chauvet C, Viatte L, Danan JL, Bigard X, Devaux I, et al. . The gene encoding the iron regulatory peptide hepcidin is regulated by anemia, hypoxia, and inflammation. J Clin Invest. (2002) 110(7):1037–44. doi: 10.1172/JCI0215686 PubMed DOI PMC

Pigeon C, Ilyin G, Courselaud B, Leroyer P, Turlin B, Brissot P, et al. . A new mouse liver-specific gene, encoding a protein homologous to human antimicrobial peptide hepcidin, is overexpressed during iron overload. J Biol Chem (2001) 276(11):7811–9. doi: 10.1074/jbc.M008923200 PubMed DOI

Nemeth E, Tuttle MS, Powelson J, Vaughn MD, Donovan A, Ward DMV, et al. . Hepcidin regulates cellular iron efflux by binding to ferroportin and inducing its internalization. Science (2004) 306(5704):2090–3. doi: 10.1126/science.1104742 PubMed DOI

Wessling-Resnick M. Iron homeostasis and the inflammatory response. Annu Rev Nutr (2010) 30:105–22. doi: 10.1146/annurev.nutr.012809.104804 PubMed DOI PMC

Camaschella C, Nai A, Silvestri L. Iron metabolism and iron disorders revisited in the hepcidin era. Haematologica (2020) 105(2):260–72. doi: 10.3324/haematol.2019.232124 PubMed DOI PMC

Hortová-Kohoutková M, Lázničková P, Bendíčková K, De Zuani M, Andrejčinová I, Tomášková V, et al. . Differences in monocyte subsets are associated with short-term survival in patients with septic shock. J Cell Mol Med (2020) 24(21):12504–12. doi: 10.1111/jcmm.15791 PubMed DOI PMC

Wang CY, Babitt JL. Hepcidin regulation in the anemia of inflammation. Curr Opin Hematol (2016) 23(3):189–97. doi: 10.1097/MOH.0000000000000236 PubMed DOI PMC

Kernan KF, Carcillo JA. Hyperferritinemia and inflammation. Int Immunol (2017) 29(9):401–9. doi: 10.1093/intimm/dxx031 PubMed DOI PMC

Kell DB, Pretorius E. Serum ferritin is an important inflammatory disease marker, as it is mainly a leakage product from damaged cells. Metallomics. (2014) 6(4):748–73. doi: 10.1039/C3MT00347G PubMed DOI

Thachil J. The beneficial effect of acute phase increase in serum ferritin. Eur J Intern Med (2016) 35:e16–7. doi: 10.1016/j.ejim.2016.07.020 PubMed DOI

Liu Q, Davidoff O, Niss K, Haase VH. Hypoxia-inducible factor regulates hepcidin via erythropoietin-induced erythropoiesis. J Clin Invest. (2012) 122(12):4635–44. doi: 10.1172/JCI63924 PubMed DOI PMC

Weiss G, Ganz T, Goodnough LT. Anemia of inflammation. Blood. (2019) 133(1):40–50. doi: 10.1182/blood-2018-06-856500 PubMed DOI PMC

Jiang Y, Jiang FQ, Kong F, An MM, Jin BB, Cao D, et al. . Inflammatory anemia-associated parameters are related to 28-day mortality in patients with sepsis admitted to the ICU: a preliminary observational study. Ann Intensive Care (2019) 9(1):1–11. doi: 10.1186/s13613-019-0542-7 PubMed DOI PMC

Zhao K, Huang J, Dai D, Feng Y, Liu L, Nie S. Serum iron level as a potential predictor of coronavirus disease 2019 severity and mortality: A retrospective study. Open Forum Infect Dis (2020) 7(7):1–8. doi: 10.1093/ofid/ofaa250 PubMed DOI PMC

Hippchen T, Altamura S, Muckenthaler MU, Merle U. Hypoferremia is associated with increased hospitalization and oxygen demand in COVID-19 patients. HemaSphere. (2020) 4(6):1–9. doi: 10.1097/HS9.0000000000000492 PubMed DOI PMC

Ehsani S. COVID-19 and iron dysregulation: distant sequence similarity between hepcidin and the novel coronavirus spike glycoprotein. Biol Direct. (2020) 15(1):1–13. doi: 10.1186/s13062-020-00275-2 PubMed DOI PMC

Garrick MD, Ghio AJ. Iron chelation may harm patients with COVID-19. Eur J Clin Pharmacol (2021) 77(2):265–6. doi: 10.1007/s00228-020-02987-w PubMed DOI PMC

Abobaker A. Reply: Iron chelation may harm patients with COVID-19. Eur J Clin Pharmacol (2021) 77(2):267. doi: 10.1007/s00228-020-02988-9 PubMed DOI PMC

Tacke F, Nuraldeen R, Koch A, Strathmann K, Hutschenreuter G, Trautwein C, et al. . Iron parameters determine the prognosis of critically ill patients. Crit Care Med (2016) 44(6):1049–58. doi: 10.1097/CCM.0000000000001607 PubMed DOI

Giamarellos-Bourboulis EJ, Netea MG, Rovina N, Akinosoglou K, Antoniadou A, Antonakos N, et al. . Complex immune dysregulation in COVID-19 patients with severe respiratory failure. Cell Host Microbe (2020) 27(6):992–1000.e3. doi: 10.1016/j.chom.2020.04.009 PubMed DOI PMC

Schultze JL, Aschenbrenner AC. COVID-19 and the human innate immune system. Cell (2021) 184(7):1671–92. doi: 10.1016/j.cell.2021.02.029 PubMed DOI PMC

De Zuani M, Lazničková P, Tomašková V, Dvončová M, Forte G, Stokin GB, et al. . High CD4-to-CD8 ratio identifies an at-risk population susceptible to lethal COVID-19. Scand J Immunol (2022) 95(3):1–11. doi: 10.1111/sji.13125 PubMed DOI PMC

Frost JN, Hamilton F, Arnold D, Elvers KT, Shah A, Armitage AE, et al. . Evaluation of perturbed iron-homeostasis in a prospective cohort of patients with COVID-19. Wellcome Open Res (2022) 7:173. doi: 10.12688/wellcomeopenres.17904.1 PubMed DOI PMC

Singer M, Deutschman CS, Seymour CW, Shankar-Hari M, Annane D, Bauer M, et al. . The third international consensus definitions for sepsis and septic shock (Sepsis-3). Am Med Assoc (2016), 315(8):801–10. doi: 10.1001/jama.2016.0287 PubMed DOI PMC

Rhodes A, Evans LE, Alhazzani W, Levy MM, Antonelli M, Ferrer R, et al. . Surviving sepsis campaign: International guidelines for management of sepsis and septic shock: 2016. Crit Care Med (2017) 45:486–552. doi: 10.1097/CCM.0000000000002255 PubMed DOI

Hortová-Kohoutková M, De Zuani M, Lázničková P, Bendíčková K, Mrkva O, Andrejčinová I, et al. . Polymorphonuclear cells show features of dysfunctional activation during fatal sepsis. Front Immunol (2021) 12. doi: 10.3389/fimmu.2021.741484 PubMed DOI PMC

Vymazal O, Bendíčková K, De Zuani M, Vlková M, Hortová-Kohoutková M, Frič J. Immunosuppression affects neutrophil functions: Does calcineurin-NFAT signaling matter? Front Immunol (2021) 12:4629. doi: 10.3389/fimmu.2021.770515 PubMed DOI PMC

Renassia C, Louis S, Cuvellier S, Boussetta N, Deschemin JC, Borderie D, et al. . Neutrophils from hereditary hemochromatosis patients are protected from iron excess and are primed. Blood Adv (2020) 4(16):3853–63. doi: 10.1182/bloodadvances.2020002198 PubMed DOI PMC

Zhou C, Chen Y, Ji Y, He X, Xue D. Increased serum levels of hepcidin and ferritin are associated with severity of COVID-19. Med Sci Monit (2020) 26:1–6. doi: 10.12659/MSM.926178 PubMed DOI PMC

Moreira AC, Teles MJ, Silva T, Bento CM, Alves IS, Pereira L, et al. . Iron related biomarkers predict disease severity in a cohort of Portuguese adult patients during COVID-19 acute infection. Viruses (2021) 13:2482. doi: 10.3390/v13122482 PubMed DOI PMC

Nai A, Lorè NI, Pagani A, De Lorenzo R, Di Modica S, Saliu F, et al. . Hepcidin levels predict covid-19 severity and mortality in a cohort of hospitalized Italian patients. Am J Hematol (2021) 96(1):E32–5. doi: 10.1002/ajh.26027 PubMed DOI

Chakurkar V, Rajapurkar M, Lele S, Mukhopadhyay B, Lobo V, Injarapu R, et al. . Increased serum catalytic iron may mediate tissue injury and death in patients with COVID-19. Sci Rep [Internet]. (2021) 11(1):1–8. doi: 10.1038/s41598-021-99142-x PubMed DOI PMC

Scindia Y, Wlazlo E, Leeds J, Loi V, Ledesma J, Cechova S, et al. . Protective role of hepcidin in polymicrobial sepsis and acute kidney injury. Front Pharmacol (2019) 615. doi: 10.3389/fphar.2019.00615 PubMed DOI PMC

Zeng C, Chen Q, Zhang K, Chen Q, Song S, Fang X. Hepatic hepcidin protects against polymicrobial sepsis in mice by regulating host iron status. Anesthesiology (2015) 122(2):374–86. doi: 10.1097/ALN.0000000000000466 PubMed DOI

Stefanova D, Raychev A, Deville J, Humphries R, Campeau S, Ruchala P, et al. . Hepcidin protects against lethal escherichia coli sepsis in mice inoculated with isolates from septic patients. Infect Immun (2018) 86(7):1–12. doi: 10.1128/IAI.00253-18 PubMed DOI PMC

Prentice S, Jallow AT, Sinjanka E, Jallow MW, Sise EA, Kessler NJ, et al. . Hepcidin mediates hypoferremia and reduces the growth potential of bacteria in the immediate post-natal period in human neonates. Sci Rep (2019) 9(1):1–7. doi: 10.1038/s41598-019-52908-w PubMed DOI PMC

Abuga KM, Muriuki JM, Uyoga SM, Mwai K, Makale J, Mogire RM, et al. . Hepcidin regulation in Kenyan children with severe malaria and non-typhoidal salmonella bacteremia. Haematologica (2021) 107(7). doi: 10.3324/haematol.2021.279316 PubMed DOI PMC

Nemeth E, Valore EV, Territo M, Schiller G, Lichtenstein A, Ganz T. Hepcidin, a putative mediator of anemia of inflammation, is a type II acute-phase protein. Blood. (2003) 101(7):2461–3. doi: 10.1182/blood-2002-10-3235 PubMed DOI

Elgendy FM, Khatab AA, Badr HS, Fatah G, Fishawy AM El. Evaluation of hepcidin as a biomarker for neonatal sepsis. Menoufia Med J (2018) 31(3):977. doi: 10.4103/mmj.mmj_32_17 DOI

Olinder J, Ehinger D, Liljenborg E, Herwald H, Rydén C. Plasma levels of hepcidin and reticulocyte haemoglobin during septic shock. J Innate Immun (2020) 12(6):448–60. doi: 10.1159/000508561 PubMed DOI PMC

Carubbi F, Salvati L, Alunno A, Maggi F, Borghi E, Mariani R, et al. . Ferritin is associated with the severity of lung involvement but not with worse prognosis in patients with COVID-19: data from two Italian COVID-19 units. Sci Rep (2021) 11(1):1–11. doi: 10.1038/s41598-021-83831-8 PubMed DOI PMC

Ten Kate J, Drenth JPH, Kahn MF, Van Deursen C. Iron saturation of serum ferritin in patients with adult onset still’s disease. J Rheumatol (2001) 28(10):2213–5. doi: 10.1002/art.21164 PubMed DOI

Herbert V, Jayatilleke E, Shaw S, Rosman AS, Giardina P, Grady RW, et al. . Serum ferritin iron, a new test, measures human body iron stores unconfounded by inflammation. Stem Cells (1997) 15(4):291–6. doi: 10.1002/stem.150291 PubMed DOI

Cavezzi A, Troiani E, Corrao S. COVID-19: Hemoglobin, iron, and hypoxia beyond inflammation. A Narrative Review. Clin Pract (2020) 10(2):24–30. doi: 10.4081/cp.2020.1271 PubMed DOI PMC

Perricone C, Bartoloni E, Bursi R, Cafaro G, Guidelli GM, Shoenfeld Y, et al. . COVID-19 as part of the hyperferritinemic syndromes: the role of iron depletion therapy. Immunol Res (2020) 68(4):213–24. doi: 10.1007/s12026-020-09145-5 PubMed DOI PMC

Claise C, Saleh J, Rezek M, Vaulont S, Peyssonnaux C, Edeas M. Low transferrin levels predict heightened inflammation in patients with COVID-19: New insights. Int J Infect Dis (2022) 116:74–9. doi: 10.1016/j.ijid.2021.12.340 PubMed DOI PMC

Han MS, White A, Perry RJ, Camporez JP, Hidalgo J, Shulman GI, et al. . Regulation of adipose tissue inflammation by interleukin 6. Proc Natl Acad Sci U.S.A. (2020) 117(6):2751–60. doi: 10.1073/pnas.1920004117 PubMed DOI PMC

Sindhu S, Thomas R, Shihab P, Sriraman D, Behbehani K, Ahmad R. Obesity is a positive modulator of IL-6R and IL-6 expression in the subcutaneous adipose tissue: Significance for metabolic inflammation. PloS One (2015) 10(7):e0133494. doi: 10.1371/journal.pone.0133494 PubMed DOI PMC

Zeng MY, Inohara N, Nuñez G. Mechanisms of inflammation-driven bacterial dysbiosis in the gut. Mucosal Immunol (2017) 10(1):18–26. doi: 10.1038/mi.2016.75 PubMed DOI PMC

van den Munckhof ICL, Kurilshikov A, ter Horst R, Riksen NP, Joosten LAB, Zhernakova A, et al. . Role of gut microbiota in chronic low-grade inflammation as potential driver for atherosclerotic cardiovascular disease: a systematic review of human studies. Obes Rev (2018) 19(12):1719–34. doi: 10.1111/obr.12750 PubMed DOI

Xu YS, Liu XJ, Liu XX, Chen D, Wang MM, Jiang X, et al. . The roles of the gut microbiota and chronic low-grade inflammation in older adults with frailty. Front Cell Infect Microbiol (2021) 11:586. doi: 10.3389/fcimb.2021.675414 PubMed DOI PMC

Das NK, Schwartz AJ, Barthel G, Inohara N, Liu Q, Sankar A, et al. . Microbial metabolite signaling is required for systemic iron homeostasis. Cell Metab (2020) 31(1):115–130.e6. doi: 10.1016/j.cmet.2019.10.005 PubMed DOI PMC

Bessman NJ, Mathieu JRR, Renassia C, Zhou L, Fung TC, Fernandez KC, et al. . Dendritic cell-derived hepcidin sequesters iron from the microbiota to promote mucosal healing. Science (2020) 368(6487):186–9. doi: 10.1126/science.aau6481 PubMed DOI PMC