Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
Clin Transplant. 2022 Jul;36(7):e14695. doi: 10.1111/ctr.14695. Epub 2022 Jun 1.
The randomized IronIC trial evaluated the effect of intravenous ferric derisomaltose on physical capacity in iron-deficient, maintenance heart transplant (HTx) recipients. Iron deficiency was defined as in heart failure with high cut-points for ferritin to compensate for inflammation. However, intravenous iron did not improve physical capacity except in patients with ferritin <30 μg/L. We aimed to explore determinants of iron status in the 102 IronIC participants to better define iron deficiency in the HTx population.
We assessed key governors of iron homeostasis, such as hepcidin, soluble transferrin receptor (sTfR), and interleukin-6 (IL-6). We also measured growth factors and inflammatory markers with relevance for iron metabolism. The results were compared to those of 21 healthy controls.
Hepcidin did not differ between HTx recipients and controls, even though markers of inflammation were modestly elevated. However, HTx recipients with ferritin <30 μg/L or sTfR above the reference range had significantly reduced hepcidin levels suggestive of true iron deficiency. In these patients, intravenous iron improved peak oxygen uptake. Hepcidin correlated positively with ferritin and negatively with sTfR.
HTx recipients with iron deficiency as defined in heart failure do not have elevated hepcidin levels, although inflammatory markers are modestly increased. The high ferritin cut-offs used in heart failure may not be suitable to define iron deficiency in the HTx population. We suggest that hepcidin and sTfR should be measured to identify patients with true iron deficiency, who might benefit from treatment with intravenous iron.
随机对照的 IronIC 试验评估了静脉铁右旋糖酐铁对缺铁性维持性心脏移植（HTx）受者体力的影响。铁缺乏的定义为心力衰竭时，使用较高的铁蛋白切点来补偿炎症。然而，静脉铁除了在铁蛋白<30μg/L 的患者中外，并没有改善体力。我们旨在探索 102 名 IronIC 参与者的铁状态决定因素，以便更好地定义 HTx 人群中的铁缺乏。
我们评估了铁稳态的关键调节因子，如铁调素、可溶性转铁蛋白受体（sTfR）和白细胞介素-6（IL-6）。我们还测量了与铁代谢相关的生长因子和炎症标志物。将结果与 21 名健康对照者进行比较。
尽管炎症标志物略有升高，但 HTx 受者与对照组之间的铁调素并无差异。然而，铁蛋白<30μg/L 或 sTfR 高于参考范围的 HTx 受者的铁调素水平显著降低，提示存在真正的铁缺乏。在这些患者中，静脉铁可改善峰值摄氧量。铁调素与铁蛋白呈正相关，与 sTfR 呈负相关。
根据心力衰竭的定义，铁缺乏的 HTx 受者的铁调素水平并没有升高，尽管炎症标志物略有升高。在心力衰竭中使用的高铁蛋白切点可能不适合定义 HTx 人群中的铁缺乏。我们建议测量铁调素和 sTfR 以识别真正的铁缺乏患者，这些患者可能受益于静脉铁治疗。
