Leukemia (2021) 35:1745–1750 https://doi.org/10.1038/s41375-020-01022-2 ARTICLE Myelodysplastic syndrome Toxic iron species in lower-risk myelodysplastic syndrome patients: course of disease and effects on outcome Marlijn Hoeks 1,2,3 ● Tim Bagguley 4 ● Corine van Marrewijk 3 ● Alex Smith4 ● David Bowen5 ● Dominic Culligan6 ● Seye Kolade7 ● Argiris Symeonidis 8 ● Hege Garelius9 ● Michail Spanoudakis10,11 ● Saskia Langemeijer3 ● Rian Roelofs12 ● Erwin Wiegerinck12 ● Aurelia Tatic13 ● Sally Killick14 ● Panagiotis Panagiotidis15 ● Oana Stanca16 ● Eva Hellström-Lindberg17 ● Jaroslav Cermak18 ● Melanie van der Klauw19 ● Hanneke Wouters19 ● Marian van Kraaij3 ● Nicole Blijlevens3 ● Dorine W. Swinkels12 ● Theo de Witte20 ● on behalf of the EUMDS Registry Participants Received: 30 April 2020 / Revised: 3 August 2020 / Accepted: 6 August 2020 / Published online: 18 September 2020 © The Author(s) 2020. This article is published with open access Introduction Red blood cell transfusions (RBCT) remain the cornerstone of supportive care in lower-risk myelodysplastic syndrome (LRMDS) [1]. Transfusion dependency in LRMDS patients is associated with inferior outcomes, mainly attributed to severe bone marrow failure [2]. However, iron toxicity, due to frequent RBCT or ineffective erythropoiesis, may be an additional negative prognostic factor [3–6]. Recently, much progress has been made in unraveling the iron metabolism. The peptide hormone hepcidin is the key regulator by inhibiting iron uptake through degradation of ferroportin, a cellular iron exporter [7]. Erythroferrone and GDF15, pro- duced by erythroblasts, inhibit hepcidin production, which leads to increased uptake and cellular release of iron for the purpose of erythropoiesis [8]. Members of the EUMDS Registry Participants are listed below Acknowledgements. * Marlijn Hoeks marlijn.hoeks@radboudumc.nl 1 Centre for Clinical Transfusion Research, Sanquin Research, Leiden, The Netherlands 2 Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands 3 Department of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands 4 Epidemiology and Cancer Statistics Group, University of York, York, UK 5 St. James’s Institute of Oncology, Leeds Teaching Hospitals, Leeds, UK 6 Department of Hematology, Aberdeen Royal Infirmary, Aberdeen, UK 7 Department of Hematology, Blackpool Victoria Hospital, Blackpool, Lancashire, UK 8 Department of Medicine, Division of Hematology, University of Patras Medical School, Patras, Greece 9 Department of Medicine, Sect. of Hematology and Coagulation, Sahlgrenska University Hospital, Göteborg, Sweden 10 Department of Hematology, Airedale NHS Trust, Airdale, UK 11 Department of Haematology, Warrington and Halton Teaching Hospitals NHS foundation Trust, Cheshire, UK 12 Department of Laboratory Medicine, Hepcidinanalysis.com, and Radboudumc Expertise Center for Iron Disorders, Radboud University Medical Center, Nijmegen, The Netherlands 13 Center of Hematology and Bone Marrow Transplantation, Fundeni Clinical Institute, Bucharest, Romania 14 Department of Hematology, Royal Bournemouth Hospital, Bournemouth, UK 15 Department of Haematology, 1st Department of Propedeutic Internal Medicine, National and Kapodistrian University of Athens, Medical School, Laikon General Hospital, Athens, Greece 16 Department of Hematology, Coltea Clinical Hospital, Bucharest, Romania 17 Department of Medicine, Division of Hematology, Karolinska Institutet, Stockholm, Sweden 18 Department of Clinical Hematology, Institute of Hematology and Blood Transfusion, Praha, Czech Republic 19 Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands 20 Nijmegen Center for Molecular Life Sciences, Department of Tumor Immunology, Radboud University Medical Center, Nijmegen, The Netherlands Supplementary information The online version of this article (https:// doi.org/10.1038/s41375-020-01022-2) contains supplementary material, which is available to authorized users. 12 34 56 78 90 () ;,: 12 34 56 78 90 (); ,: http://crossmark.crossref.org/dialog/?doi=10.1038/s41375-020-01022-2&domain=pdf http://crossmark.crossref.org/dialog/?doi=10.1038/s41375-020-01022-2&domain=pdf http://crossmark.crossref.org/dialog/?doi=10.1038/s41375-020-01022-2&domain=pdf http://orcid.org/0000-0003-3136-3739 http://orcid.org/0000-0003-3136-3739 http://orcid.org/0000-0003-3136-3739 http://orcid.org/0000-0003-3136-3739 http://orcid.org/0000-0003-3136-3739 http://orcid.org/0000-0002-6150-3467 http://orcid.org/0000-0002-6150-3467 http://orcid.org/0000-0002-6150-3467 http://orcid.org/0000-0002-6150-3467 http://orcid.org/0000-0002-6150-3467 http://orcid.org/0000-0002-9547-908X http://orcid.org/0000-0002-9547-908X http://orcid.org/0000-0002-9547-908X http://orcid.org/0000-0002-9547-908X http://orcid.org/0000-0002-9547-908X http://orcid.org/0000-0002-3685-3473 http://orcid.org/0000-0002-3685-3473 http://orcid.org/0000-0002-3685-3473 http://orcid.org/0000-0002-3685-3473 http://orcid.org/0000-0002-3685-3473 mailto:marlijn.hoeks@radboudumc.nl https://doi.org/10.1038/s41375-020-01022-2 https://doi.org/10.1038/s41375-020-01022-2 The pathophysiology of iron metabolism in MDS is still not completely understood. Exceedingly high reactive oxygen species (ROS) levels are associated with iron toxi- city, disease development, and progression in MDS patients [9–12]. Malondialdehyde (MDA), resulting from lipid per- oxidation of polyunsaturated fatty acids, is a biomarker of oxidative stress [10, 12]. Currently, little is known about the prognostic impact of ROS in MDS patients. The aim of this study is twofold: (1) describe iron and oxidative stress parameters over time in LRMDS patients and (2) to assess their effect on overall and progression-free survival. Materials and methods The EUMDS registry prospectively collects observational data on newly diagnosed LRMDS patients from 148 centers in 16 countries in Europe and Israel as of January 2008. All patients provided informed consent. Clinical data were col- lected at baseline and at each six-monthly follow-up visit. Serum samples were collected prospectively at each visit from 256 patients included in six participating countries. Conven- tional iron parameters were measured with routine assays. We additionally analyzed hepcidin, growth differentiation factor 15 (GDF15), soluble transferrin receptor (sTfR), non- transferrin bound iron (NTBI), labile plasma iron (LPI), and MDA. Subjects were prospectively followed until death, loss to follow-up, or withdrawal of consent. All iron parameters were measured centrally at the department of Laboratory Medicine of the Radboudumc, Nijmegen, The Netherlands. Serum samples were collected just prior to transfusion in transfusion-dependent patients and stored at −80 °C. Details on the assays and reference ranges of hepcidin, GDF15, sTfR, NTBI, LPI, and MDA are provided in the supplement. The Spearman rank test was used to evaluate correlations between iron parameters. We stratified the results by transfu- sion dependency per visit and the presence of ring side- roblasts. When evaluating temporal changes in iron parameters, with linear quantile mixed models, we excluded patients from the timepoint they received iron chelation ther- apy. Overall survival (OS) was defined as the time from MDS diagnosis to death or, in case of progression-free survival, to date of progression or death; patients still alive at the end of follow-up were censored. Time-dependent Kaplan–Meier curves and cox proportional hazards models were used. Results In total, 256 consecutive patients, were included in this study. Over five six-monthly visits, 1040 samples were Table 1 Baseline characteristics. N (%) Total 256 (100.0) Sex Males 169 (66.0) Females 87 (34.0) Age 35–44 2 (0.8) 45–54 7 (2.7) 55–64 51 (19.9) 65–74 78 (30.5) 75+ 118 (46.1) Mean (sd) 72.1 (9.5) Median (min–max) 74.0 (37.0–95.0) MDS diagnosis RCMD 114 (44.5) RARS 56 (21.9) RA 45 (17.6) RAEB-1 16 (6.3) RCMD-RS 10 (3.9) 5q-syndrome 10 (3.9) MDS-U 5 (2.0) Group NonRS-TI 143 (55.9) NonRS-TD 47 (18.4) RS-TI 48 (18.8) RS-TD 18 (7.0) IPSS-R category Very low/low 195 (76.2) Intermediate 23 (9.0) High/very high 4 (1.6) Not known 34 (13.3) IPSS category Low risk 144 (56.3) Intermed-1 75 (29.3) Intermed-2 1 (0.4) Not known 36 (14.1) Karnofsky performance status Able to work and normal activity 193 (75.4) Unable to work 48 (18.8) Unable to care for self 1 (0.4) Not known 14 (5.5) Comorbidity index Low risk 158 (61.7) Intermediate risk 79 (30.9) High risk 19 (7.4) EQ5D index score Mean (sd) 0.77 (0.24) Median (p10–p90) 0.80 (0.52–1.00) 1746 M. Hoeks et al. collected. Table 1 describes the patient characteristics. Most patients without ring sideroblasts were transfusion- independent at diagnosis (nonRS-TI; 55.9%), 18.8% with ring sideroblasts were transfusion-independent (RS-TI), 18.4% without ring sideroblasts were transfusion-dependent (nonRS-TD), and 7% with ring sideroblasts were transfusion-dependent patients (RS-TD). The median follow-up time was 6.6 years (95% CI 5.9–7.0). LPI was positively correlated with transferrin saturation (TSAT) (r= 0.15, p < 0.001, Fig. S1). LPI values increased exponentially at TSAT values above 80%. This effect was most pronounced in the transfusion-dependent groups, but also observed in the RS-TI group. MDA was weakly cor- related with NTBI (r= 0.09, p= 0.069) and negatively correlated with hemoglobin level (r=−0.1, p= 0.033). GDF15 and hepcidin were negatively correlated in the RS- TI and nonRS-TD group and significantly negatively cor- related in the RS-TD group (r=−0.34, p= 0.007, Fig. S2). Serum ferritin levels were elevated in all subgroups with a mean value of 858 µg/L at visit 5. The highest serum ferritin levels were observed in the RS-TD group (mean value at visit 5: 2092 µg/L, Table S1). Serum ferritin increased significantly per visit in the RS-TD group (beta 454.46 µg/L; 95% CI 334.65–574.27), but not in the other groups (Table S2). All subgroups, except for the nonRS-TI, had elevated TSAT levels. TSAT levels were most markedly increased in the RS-TD group with a mean TSAT of 88% at visit 5 (Table S1). In both transfusion-dependent groups the median increase per visit was significant (Table S2). LPI was elevated in the RS-TD group exclusively with a mean value of 0.59 µmol/L at visit 5 (Table S1). NTBI was elevated in all subgroups, with the highest values in the RS- TD group (Table S1). The increase in median NTBI level was significant in both transfusion-dependent groups (Table S2). Hepcidin levels were markedly elevated in the nonRS- TD group. Interestingly, hepcidin levels were lower in the RS-TD group, probably reflecting ineffective erythropoi- esis, likewise supported by lower hepcidin/ferritin ratios in RS groups (Table S1). Median hepcidin levels increased over time in the transfusion-dependent subgroups only (Table S2). GDF15 levels, analyzed in the light of its potential role in hepcidin suppression, were increased in all subgroups (Table S1). The RS subgroups had higher GDF15 levels compared to the nonRS groups, reflecting increased erythropoiesis. Mean sTfR levels were within the reference range in all subgroups except for the RS-TI group, which showed ele- vated levels, reflecting increased erythropoiesis (Table S1). MDA levels were within the reference range in the nonRS-TI group and above the upper limit of the reference range in all other subgroups with the highest levels in the RS-TD group (Table S1). MDA levels at diagnosis were markedly higher in the RCMD-RS group compared to other subtypes (Table S3.1). As expected, in the group with ele- vated MDA levels, the transfusion density was markedly higher as compared with patients with low MDA levels (Table S3.2). Overall MDA levels increased over time (p < 0.0001). The steepest increase was observed in transfusion- dependent patients, with the highest median levels over time in the RS-TD group (Table S3.3). Overall survival (OS) Figure 1 shows a Kaplan–Meier curve for OS, stratified by LPI above or below the lower limit of detection (LLOD) and transfusion status as time-varying variables. Transfusion-dependent patients with elevated LPI levels have inferior OS compared to other subgroups. The Cox model shows an adjusted hazard ratio (HR) for OS, cor- rected for age at diagnosis and IPSS-R, of 2.7 (95% CI 1.5–5.0, p= 0.001) for LPI > LLOD. With the transfusion- Table 1 (continued) N (%) ESA No 159 (62.1) Yes 97 (37.9) Iron chelation No 241 (94.1) Yes 15 (5.9) Desferoxamine 5 (2.0) Deferiprone/deferasirox 11 (4.3) Hypomethylating agents No 245 (95.7) Yes 11 (4.3) Overall survival Median (95% CI) 4.8 (3.9—not reached) Cause of death MDS unrelated 15 (34.1) MDS related 24 (54.5) Unknown 5 (11.4) Follow-up time (censored last EUMDS visit) Median (95% CI) 6.6 (5.9–7.0) sd standard deviation, MDS myelodysplastic syndrome, RCMD refractory cytopenia with multilineage dysplasia, RARS refractory anemia with ring sideroblasts, RA refractory anemia, RAEB refractory anemia with excess blasts, RCMD-RS refractory cytopenia with multilineage dysplasia with ring sideroblasts, MDS-U myelodysplastic syndrome unspecified, RS ring sideroblasts, TI transfusion-indepen- dent, TD transfusion-dependent, IPSS(-R) (revised) international prognostic scoring system, EQ5D EuroQoL five dimension scale, ESA erythroid stimulating agents. Toxic iron species in lower-risk myelodysplastic syndrome patients: course of disease and effects on. . . 1747 independent group with LPI values LLOD was 4.5 (95% CI 1.4–13.9, p= 0.01), for the transfusion-dependent group with LPI < LLOD: 3.9 (95% CI 1.5–10.4, p= 0.006), and for the transfusion-dependent group with LPI > LLOD: 6.7 (95% CI 2.5–17.6, p < 0.001, Table S4). The adjusted HR for OS for elevated NTBI was 1.6 (95% CI 0.8–3.1, p= 0.17). Transfusion-independent patients with normal NTBI levels have superior OS when compared with the other subgroups, who have significantly increased HRs for OS (Table S5). Elevated TSAT (>80%) alone did not influence OS. However, when we repeated the analysis in the whole EUMDS registry as a dichotomous and continuous variable (n= 1076, 2853 visits), elevated TSAT did influence OS with an adjusted HR of 2.1 (95% CI 1.6–2.7, p < 0.001) and 1.009 (95% CI 1.004–1.014, p < 0.001), respectively. Transfusion-dependent patients with a TSAT ≥ 80% had the worst OS with an adjusted HR of 4.2 (95% CI 2.9–5.9, p < 0.001). Progression-free survival In line with the effect of LPI on OS progression-free sur- vival is significantly inferior in transfusion-dependent patients with LPI levels >LLOD (HR 9.2, 95% CI 3.8–22.5, p < 0.001). Discussion The results of this study suggest that LRMDS patients who are transfusion-dependent and have a MDS subtype with ring sideroblasts have the highest levels for markers that reflect iron toxicity. Likewise, the highest hepcidin levels were observed in the transfusion-dependent nonRS group, but importantly, hepcidin levels and hepcidin/ferritin ratios were markedly lower in the transfusion-dependent patients with ring sideroblasts. Despite the excess of iron due to RBCT, hepcidin levels were lower than expected, thereby increasing the iron uptake from the gut and release of iron from the reticulo-endothelial system. Transfusion depen- dency is a known risk factor for iron toxicity. However, ineffective erythropoiesis in RS subgroups evidently leads to additional iron toxicity and potentially to increased morbidity and mortality [13–15]. Therefore, transfusion- dependent LRMDS patients with ring sideroblasts should be closely monitored for signs of iron toxicity and treated accordingly. Our data suggest that LPI levels above the LLOD are associated with inferior overall and progression-free survi- val, irrespective of transfusion status. This highlights the importance of rational RBCT strategies in LRMDS patients. Novel hepcidin regulators as erythroferrone, hepcidin ago- nists, and early start of iron chelation are subjects for future research. Overall MDA levels, as a marker of oxidative stress, increased significantly over time in our patient group. Oxidative stress due to iron toxicity could lead to organ damage as well as mutagenesis and clonal instability con- tributing to a higher progression risk [9–12]. Nevertheless, MDA is not an exclusive marker for oxidative stress, future research should focus on both oxidant and antioxidant factors thereby unraveling the exact relation between iron toxicity and oxidative stress. In conclusion, iron toxicity is associated with inferior survival in LRMDS patients. More restrictive RBCT stra- tegies and pre-emptive iron reducing interventions may prevent or reverse these unwanted effects. Acknowledgements The authors would like to thank the other EUMDS Steering Committee members, local investigators and their teams (Table S4), and patients for their contribution to the EUMDS Registry; Jan Verhagen for his contribution in the measurement of the iron parameters; Margot Rekers, Karin van der Linden, and Siem Klaver for sample handling; Elise van Pinxten-van Orsouw and Linda van der Landen for data entry of all iron parameters; and Louise de Swart for her contribution to the analyses on the iron parameters. EUMDS Registry Participants R. Stauder21, A. Walder22, M. Pfeil- stöcker23, A. Schoenmetzler-Makrai23, S. Burgstaller24, J. Thaler24, I. Mandac Rogulj25, M. Krejci26, J. Voglova27, P. Rohon28, A. Jona- sova29, J. Cermak30, D. Mikulenkova30, I. Hochova31, P. D. Jensen32, M. S. Holm33, L. Kjeldsen34, I. H. Dufva35, H. Vestergaard36, D. Re37, B. Slama38, P. Fenaux39, B. Choufi40, S. Cheze41, D. Klepping42, B. Salles42, B. de Renzis43, L. Willems44, D. De Prost45, J. Gutnecht46, S. Courby47, V. Siguret48, G. Tertian49, L. Pascal50, M. Chaury51, E. Wattel52, A. Guerci53, L. Legros54, P. Fenaux55, R. Itzykson55, L. Ades55, F. Isnard56, L. Sanhes57, R. Benramdane58, A. Stamatoullas59, 0.00 0.25 0.50 0.75 1.00 su rv iv al 8 31 32 11 2 0lpi>=llod,TD 55 62 43 8 2 0lpi=llod,TI 170 128 73 29 1 0lpi=llod,TI lpi=llod,TD Fig. 1 Kaplan–Meier curve overall survival stratified by labile plasma iron above or below the lower limit of detection and transfusion status as time-dependent variables. LPI labile plasma iron, LLOD lower limit of detection, TI transfusion-independent, TD transfusion-dependent. 1748 M. Hoeks et al. S. Amé60, O. Beyne-Rauzy61, E. Gyan62, U. Platzbecker63, C. Badra- kan64, U. Germing65, M. Lübbert66, R. Schlenk67, I. Kotsianidis68, C. Tsatalas68, V. Pappa69, A. Galanopoulos70, E. Michali70, P. Panagio- tidis71, N. Viniou71, A. Katsigiannis72, P. Roussou72, E. Terpos73, A. Kostourou74, Z. Kartasis75, A. Pouli76, K. Palla77, V. Briasoulis78, E. Hatzimichael78, G. Vassilopoulos79, A. Symeonidis80, A. Kourakli80, P. Zikos81, A. Anagnostopoulos82, M. Kotsopoulou83, K. Mega- lakaki83, M. Protopapa84, E. Vlachaki85, P. Konstantinidou86, G. Stemer87, A. Nemetz88, U. Gotwin89, O. Cohen89, M. Koren89, E. Levy90, U. Greenbaum90, S. Gino-Moor91, M. Price92, Y. Ofran93, A. Winder94, N. Goldshmidt95, S. Elias, R. Sabag95, I. Hellman96, M. Ellis96, A. Braester97, H. Rosenbaum98, S. Berdichevsky99, G. Itz- haki100, O. Wolaj100, S. Yeganeh101, O. Katz101, K. Filanovsky102, N. Dali103, M. Mittelman104, L. Malcovati105, L. Fianchi106, A. vd Loos- drecht107, V. Matthijssen108, A. Herbers109, H. Pruijt109, N. Aboosy110, F. de Vries110, G. Velders111, E. Jacobs112, S. Langemeijer113, M. MacKenzie113, C. Lensen114, P. Kuijper115, K. Madry116, M. Camara117, A. Almeida117, G. Vulkan118, O. Stanca Ciocan119, A. Tatic120, A. Savic121, C. Pedro122, B. Xicoy123, P. Leiva124, J. Munoz125, V. Betés126, C. Benavente127, M. Lozano128, M. Marti- nez128, P. Iniesta129, T. Bernal130, M. Diez Campelo131, D. Tormo132, R. Andreu Lapiedra133, G. Sanz134, E. Hesse Sundin135, H. Garelius136, C. Karlsson137, P. Antunovic138, A. Jönsson138, L. Brandefors139, L. Nilsson140, P. Kozlowski141, E. Hellstrom-Lindberg142, M. Grövdal143, K. Larsson144, J. Wallvik144, F. Lorenz145, E. Ejerblad146, D. Culli- gan147, C. Craddock148, S. Kolade149, P. Cahalin149, S. Killick150, S. Ackroyd151, C. Wong152, A. Warren152, M. Drummond153, C. Hall154, K. Rothwell155, S. Green156, S. Ali156, D. Bowen157, M. Karakantza157, M. Dennis158, G. Jones159, J. Parker160, A. Bowen160, R. Radia161, E. Das-Gupta161, P. Vyas162, E. Nga163, D. Creagh164, J. Ashcroft165, J. Mills166, L. Bond167 21Medical University of Innsbruck, Innsbruck, Austria; 22Bezirk- skrankenhaus, Lienz, Austria; 23Hanusch Krankenhaus, Vienna, Austria; 24Klinikum Kreuzschwestern, Wels, Austria; 25Clinical Hospital Merkur, Zagreb, Croatia; 26The University Hospital Brno, Brno, Czech Republic; 27Charles University Faculty of Medicine, Hradec Kralove, Czech Republic; 28University Hospital, Olomouc, Czech Republic; 29General University Hospital, 1st Clinic of Internal Medicine, Prague, Czech Republic; 30General University Hospital, Institute of Hematology and Blood Transfusion, Prague, Czech Republic; 31University Hospital Motol, Prague, Czech Republic; 32University Hospital, Aalborg, Denmark; 33University Hospital, Aarhus, Denmark; 34University Hospital: Rig- shospitalet, Copenhagen, Denmark; 35Herlev Hospital, Herlev Ringvej, Herlev, Denmark; 36Odense University Hospital, Odense, Denmark; 37Hospital Center D’antibes Juan-Les-Pins, Antibes, France; 38Centre Hospital, Avignon, France; 39Hospital Avicenne, Bobigny, France; 40Centre Hospital Boulogne-sur-Mer, Boulogne-sur-Mer, France; 41Cen- tre Hospital Universitaire Clemenceau, Caen, France; 42Centre Hospital William Morey, Chalon-sur-Saone, France; 43Centre Hospital Uni- versitaire, Clermont-Ferrand, France; 44Hospital Hotel Dieu, Cochin, France; 45Louis-Mourier Hospital, Colombes, France; 46CHI Frejus Saint Raphael, Frejus, France; 47CHU Albert Michallon, Grenoble, France; 48Hopital Charles-Foix Ap-Hp, Ivry-sur-Seine, France; 49Hospital Bicetre, Le Kremlin-Bicetre, France; 50Hospital St Vincent de Paul, Lille, France; 51CHU Limoges Hospital Dupuytren, Limoges, France; 52Hospital Edouard Herriot, Lyon, France; 53CHU Nancy: Hospital Brabois (Vandoeuvre Les Nancy), Nancy, France; 54CHU de Nice: Hospital l’Archet, Nice, France; 55Hopital St Louis, Paris, France; 56Hospital Saint-Antoine, Paris, France; 57Centre Hospital Marechal Joffre, Perpignan, France; 58Centre Hospital de Pon- toise, Pontoise, France; 59CHU de Rouen: Hospital Charles-Nicolle, Rouen, France; 60CHU Hospital Hautepierre de Strasbourg, Strasbourg, France; 61CHU Toulouse: Hospital Purpan, Toulouse, Toulouse, France; 62CHRU de Tours, Tours, France; 63University Hospital Carl Gustav Carus, Dresden, Germany; 64HELIOS: St. Johannes Hospital in Hamborn, Duisburg, Germany; 65Heinrich-Heine University Hospital, Dusseldorf, Germany; 66University Hospital Freiburg, Freiburg, Germany; 67University Hospital Ulm, Ulm, Germany; 68Democritus University of Thrace, Alexandroupolis, Greece; 69General Hospital Attikon, University of Athens Medical School, Athens, Greece; 70General Hospital G. Gennimatas, Athens, Greece; 71General Hospital Laikon, University of Athens Medi- cal School, Athens, Greece; 72General Hospital Sotiria, University of Athens Medical School, Athens, Greece; 73Hellenic 251 Air Force Gen- eral Hospital, Athens, Greece; 74Pammakaristos Hospital, Athens, Greece; 75Patission Prefectural General Hospital: Halkida, Athens, Greece; 76St. Savvas Oncology Hospital of Athens, Athens, Greece; 77General Hospital of Chania, Chania, Greece; 78Uni- versity Hospital of Ioannina, Ioannina, Greece; 79University Hospital of Larissa, Larissa, Greece; 80General University Hospital of Patras, Patras, Greece; 81St. Andreas General Hospital, Patras, Greece; 82General Hospital of Thessaloniki George Papanikolaou, Pilea Chortiatis, Greece; 83Metaxa Hospital, Piraeus, Greece; 84General Hospital of Serres, Serres, Greece; 85Hippokration—General Hospital of Thessaloniki, Thessaloniki, Greece; 86Theageneio General Hospital, Thessaloniki, Greece; 87HaEmek Medical Center, Afula, Israel; 88Barzilai Medical Center, Ashkelon, Israel; 89Asaf-Harofe Medical Center, Be’er Ya’akov, Israel; 90Soroka Medical Center, Beersheba, Israel; 91Bnai Zion Medical Center, Haifa, Israel; 92Carmel Medical Center, Haifa, Israel; 93Rambam Medical Centre, Haifa, Israel; 94Wolfson Med- ical Center, Holon, Israel; 95Hadassah Medical Center, Jerusalem, Israel; 96Meir Medical Center, Kfar Saba, Israel; 97The Western Galilee Hospital, Nahariya, Israel; 98Nazareth Towers Medical Center, Nazareth, Israel; 99Laniado Hospital, Netanya, Israel; 100Rabin Medical Center, Petah Tikva, Israel; 101Baruch Padeh Medical Center Poriya, Tiberias, Israel; 102Kaplan Medical Center, Rehovot, Israel; 103Ziv Med- ical Center, Safed, Israel; 104Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel; 105IRCCS San Matteo Hospital Foundation, Pavia, Italy; 106University Cattolica del Sacro Cuore, Policlinico Gemelli, Rome, Italy; 107VU University Medical Center, Amsterdam, The Neth- erlands; 108Rijnstate Hospital, Arnhem, The Netherlands; 109Jeroen Bosch Hospital, Den Bosch, The Netherlands; 110Slingeland Hospital, Doetinchem, The Netherlands; 111Gelderse Vallei Hospital, Ede, The Netherlands; 112Elkerliek Hospital, Helmond, The Netherlands; 113Rad- boudumc, Nijmegen, The Netherlands; 114Bernhoven Hospital, Uden, The Netherlands; 115Maxima Medical Center, Veldhoven, The Netherlands; 116Warszawski Uniwersytet Medyczny, Warsaw, Poland; 117Centro Hospitalar de Lisboa, Lisbon, Portugal; 118Districtual Hospital, Brasov, Romania; 119Coltea Clinical Hospital, Bucharest, Romania; 120Fundeni Clinical Institute, Bucharest, Romania; 121Clinical Center of Vojvodina, Novi Sad, Serbia; 122Hospital del Mar, Barcelona, Spain; 123Hospital Universitari Germans Trias i Pujol, Barcelona, Spain; 124Hospital Del Sas, Jerez De La Frontera, Cadiz, Spain; 125Hospital Universitario Puerta del Mar, Cadiz, Spain; 126Institute de Investigacion Biomedica, Lleida, Spain; 127Hospital Clinico Universitario San Carlos, Madrid, Spain; 128Hospital Uni- versitario Meseguer, Murcia, Spain; 129Hospital Universitario Virgen de la Arrixaca, Murcia, Spain; 130Hospital Universitario Central de Asturias, Oviedo, Spain; 131Hospital Universitario de Salamanca, Salamaca, Spain; 132Hospital Clinico Universitario de Valencia, Valencia, Spain; 133Hospital Dr. Peset, Valencia, Spain; 134Hospital Universitario La Fe, Valencia, Spain; 135Malarsjukhuset, Eskilstuna, Sweden; 136Sahl- grenska University Hospital, Göteborg, Sweden; 137Teaching Hospital of Halmstad, Halmstad, Sweden; 138University Hospital Linköping, Linköping, Sweden; 139Sunderby Hospital, Lulea, Sweden; 140Lund University Hospital, Lund, Sweden; 141Orebro University Hospital, Orebro, Sweden; 142Karolinska University Hospital, Stockholm, Sweden; 143Södersjukhuset, Stockholm, Sweden; 144Sundsvalls sjukhus, Sundsvall, Sweden; 145Umea Regional Hospital, Umea, Sweden; 146Uppsala University, Uppsala, Sweden; 147Aberdeen Royal Toxic iron species in lower-risk myelodysplastic syndrome patients: course of disease and effects on. . . 1749 Infirmary, Aberdeen, UK; 148Queen Elizabeth Hospital, Birmingham, UK; 149Blackpool Victoria Hospital, Blackpool, UK; 150Royal Bournemouth Hospital, Bournemouth, UK; 151Bradford Royal Infirmary, Bradford, UK; 152Addenbrooke’s Hospital, Cambridge, UK; 153Western Infirmary, Glasgow, UK; 154Harrogate Dis- trict Hospital, Harrogate, UK; 155Huddersfield Royal Infirmary, Huddersfield, UK; 156Hull and East Yorkshire Hospitals NHS Trust, Hull, UK; 157Leeds Teaching Hospitals, Leeds, UK; 158Christie Hospital, Manchester, UK; 159Royal Victoria Infirmary, Newcastle upon Tyne, UK; 160Northampton General Hospital, Northampton, UK; 161City Hos- pital, Nottingham, UK; 162John Radcliffe Hospitals NHS Trust, Oxford, UK; 163Airedale NHS Trust, Steeton, UK; 164Royal Cornwall Hospital, Truro, UK; 165Mid Yorkshire Hospitals, Wakefield, UK; 166Worcestershire Acute Hospitals NHS Trust, Worcester, UK; 167York Hospital, York, UK Funding The EUMDS Registry is supported by an educational grant from Novartis Pharmacy B.V. Oncology Europe, and Amgen Limited. This work is part of the MDS-RIGHT activities, which has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 634789 MDS- RIGHT—“Providing the right care to the right patient with Myelo- Dysplastic Syndrome at the right time.” The Lifelines Biobank initiative has been made possible by subsidy from the Dutch Ministry of Health, Welfare and Sport, the Dutch Ministry of Economic Affairs, the University Medical Center Groningen (UMCG the Netherlands), University Groningen, and the Northern Provinces of the Netherlands. The authors wish to acknowledge the services of the Lifelines Cohort Study, the contributing research centers delivering data to Lifelines, and all the study participants. Author contributions Design: MH, TB, CvM, ASm, SL, TdW; pro- vision of patients, assembly of data: DB, DC, SK, ASy, HG, MS, SL, AT, SK, PP, OS, EH-L, JC, MvK, HW, RR, EW, DWS; statistical analysis and interpretation: MH, TB, CvM, ASm, TdW; manuscript writing: all authors; final approval: all authors. Compliance with ethical standards Conflict of interest CvM: project manager of the EUMDS Registry, is funded by the EUMDS and MDS-RIGHT project budget; ASm: research funding from Novartis, Cilag-Janssen, and Boehringer Ingelheim; ASy: honoraria and consulting fees from Amgen, Celgene/ GenesisPharma, Genzyme/Sanofi, Gilead, Janssen-Cilag, Pfizer, MSD, and Novartis; HG: honoraria from Celgene, Novartis, and Alexion; SK: honoraria from Novartis, Jazz, and Celgene; EH-L: research funding from Celgene; NB: research funding from Novartis, Bristol Meyer Squibb, Pfizer, Ariad, MSD, Astellas, Xenikos, and Celgene, educational grant from Novartis, Celgene, and Janssen-Cilag; DWS: paid employee of RadboudUMC, which offers hepcidin measurements via Hepcidinanalysis.com at a fee for service basis; TdW: research funding from Amgen, Celgene, and Novartis, as project coordinator EUMDS. The other authors declare that they have no conflict of interest. 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Serum hepcidin measured with an improved ELISA correlates with parameters of iron metabolism in patients with myelodys- plastic syndrome. Ann Hematol. 2013;92:1617–23. 1750 M. Hoeks et al. http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/ Toxic iron species in lower-risk myelodysplastic syndrome patients: course of disease and effects on outcome Introduction Materials and methods Results Overall survival (OS) Progression-free survival Discussion ACKNOWLEDGMENTS Compliance with ethical standards ACKNOWLEDGMENTS References