Iron is an essential element in our daily diet. Most iron is required for the de novo synthesis of red blood cells, where it plays a critical role in oxygen binding to hemoglobin. Thus, iron deficiency causes anemia, a major public health burden worldwide. On the other extreme, iron accumulation in critical organs such as liver, heart, and pancreas causes organ dysfunction due to the generation of oxidative stress. Therefore, systemic iron levels must be tightly balanced. Here we focus on the regulatory role of the hepcidin/ferroportin circuitry as the major regulator of systemic iron homeostasis. We discuss how regulatory cues (e.g., iron, inflammation, or hypoxia) affect the hepcidin response and how impairment of the hepcidin/ferroportin regulatory system causes disorders of iron metabolism.

Bone morphogenetic protein (BMP) signaling induces hepatic expression of the peptide hormone hepcidin. Hepcidin reduces serum iron levels by promoting degradation of the iron exporter ferroportin. A relative deficiency of hepcidin underlies the pathophysiology of many of the genetically distinct iron overload disorders, collectively termed hereditary hemochromatosis. Conversely, chronic inflammatory conditions and neoplastic diseases can induce high hepcidin levels, leading to impaired mobilization of iron stores and the anemia of chronic disease. Two BMP type I receptors, Alk2 (Acvr1) and Alk3 (Bmpr1a), are expressed in murine hepatocytes. We report that liver-specific deletion of either Alk2 or Alk3 causes iron overload in mice. The iron overload phenotype was more marked in Alk3- than in Alk2-deficient mice, and Alk3 deficiency was associated with a nearly complete ablation of basal BMP signaling and hepcidin expression. Both Alk2 and Alk3 were required for induction of hepcidin gene expression by BMP2 in cultured hepatocytes or by iron challenge in vivo. These observations demonstrate that one type I BMP receptor, Alk3, is critically responsible for basal hepcidin expression, whereas 2 type I BMP receptors, Alk2 and Alk3, are required for regulation of hepcidin gene expression in response to iron and BMP signaling.

The authors dissect the transcriptional regulatory pathway by which the iron regulatory hormone hepcidin is suppressed by erythroferrone in response to erythropoietin.

BACKGROUND: Perioperative anemia is challenging during hospital stay because anemia and red blood cell (RBC) transfusions are associated with an increased morbidity and mortality. With the implementation of patient blood management (PBM), a preanesthesia assessment clinic to screen and treat anemia before elective surgery was institutionalized at Muenster University Hospital, Germany. The main objective of this study was to evaluate the association between treating preoperative anemic patients with intravenous iron (IVI) and (primarily) presurgical hemoglobin levels and (secondarily) use of RBCs and mortality. METHODS: Between April 1, 2014, and July 4, 2016, patients scheduled for elective surgery with a risk for RBC transfusions >10% in 2013 were screened for preoperative anemia and, if indicated, treated with IVI. Patients’ data, time span between visit in the anesthesia/PBM clinic and surgery, demographic data, type of surgery, the difference of hemoglobin levels between visit and surgery, RBC transfusion, infectious-related International Classification of Disease codes during hospital stay, and 1-year survival were determined retrospectively by screening electronic data files. In addition, patients were interviewed about adverse events, health-related events, and infections via telephone 30, 90, and 365 days after visiting the anesthesia/PBM clinic. RESULTS: A total of 1101 patients were seen in the anesthesia/PBM clinic between days −28 and −1 (median [Q1–Q3], −3 days [−1, −9 days]) before elective surgery. Approximately 29% of patients presented with anemia, 46.8% of these anemic patients were treated with ferric carboxymaltose (500–1000 mg). In the primary analysis, hemoglobin levels at median were associated with a reduction between the visit in the anesthesia/PBM clinic and the surgery in all nonanemic patients on beginning of medical treatment (nonanemic patients at median −2.8 g/dL [−4, −0.9 g/dL], while anemic patients without IVI presented with median differences of −0.8 g/dL [−2, 0 g/dL] and anemic patients with IVI of 0 g/dL [−1.0, 0.5 g/dL]). Hemoglobin levels raised best at substitution 22–28 days before surgery (0.95 g/dL [−0.35, 1.18 g/dL]). Due to the selection criteria, transfusion rates were high in the cohort. Overall, there was no association between IVI treatment and the use of RBC transfusions (odds ratio for use of RBCs in anemic patients, no IVI versus IVI: 1.14; 95% confidence interval, 0.72–1.82). Patients treated with or without IVI presented a comparable range of International Classification of Disease codes related to infections. Telephone interviews indicated similar adverse events, health-related events, and infections. Cox regression analysis showed an association between anemia and reduced survival, regardless of IVI. CONCLUSIONS: An anemia clinic within the preanesthesia assessment clinic is a feasible and effective approach to treat preoperative anemia. The IVI supplementation was safe but was associated with decreased RBC transfusions in gynecology/obstetric patients only. The conclusions from this retrospective analysis have to be tested in prospective, controlled trials.

Cancer is a life-threatening disease that causes every fourth death. It is often hard to determine the time point of progression. Therefore, biomarkers for cancer entities that indicate disease progression or aggressiveness and thereby guide therapeutic decisions are required. Unfortunately, reliable biomarkers are rare. In this study, the potential of serum hepcidin and serum GDF-15 as biomarkers that correlate with patient’s survival in the two entities upper urinary tract urothelial carcinomas (UUTUC) and renal cell carcinoma (RCC) were analyzed. In this retrospective study n = 38 patients suffering from UUTUC, n = 94 patients suffering from RCC and n = 21 patients without infections or cancer, all hospitalized at the University Hospital Muenster, were included. Serum samples of patients were retrospectively analyzed. Serum hepcidin and GDF-15 levels were measured and correlated to aggressiveness and progression of the disease as well as patient’s outcome. For both entities, UUTUC and RCC, serum hepcidin levels as well as serum GDF-15 levels were increased compared to sera of controls. High serum hepcidin and GDF-15 levels were associated with metastases and cancer relapse. Also, in both entities, the overall survival was decreased in patients with increased serum hepcidin and GDF-15 levels. Hence, high serum hepcidin and GDF-15 levels correlated with patient’s outcome. To conclude, the data of this study show a correlation of high serum hepcidin and GDF-15 levels with aggressiveness and progression of the disease and demonstrate potential prognostic properties of serum hepcidin and GDF-15 levels. The data support the further assessment of serum hepcidin and GDF-15 as prognostic markers in RCC and UUTUC.

Background: Iron deficiency (ID) is one of the most common nutritional deficiencies in children worldwide and may result in iron deficiency anemia (IDA). The reticulocyte hemoglobin equivalent (Ret-He) provides information about the current availability of iron in erythropoiesis. This study aims to examine the validation of Ret-He as a screening marker for ID and IDA in children. Methods: Blood samples were retrospectively obtained from medical records. Anemia was defined according to the definition provided by the World Health Organization (WHO) for children. ID was defined by transferrin saturation (TSAT) < 20% and ferritin < 100 ng/mL. Children were classified into four groups: IDA, non-anemia iron deficiency (NAID), control and others. Results: Out of 970 children, 332 (34.2%) had NAID and 278 (28.7%) presented with IDA. Analysis revealed that Ret-He significantly correlates with ferritin (rho = 0.41; p < 0.001), TSAT (rho = 0.66; p < 0.001) and soluble transferrin receptor (sTfR) (rho = −0.72; p < 0.001). For ROC analysis, the area under the curve (AUC) was 0.771 for Ret-He detecting ID and 0.845 for detecting IDA. The cut-off value for Ret-He to diagnose ID was 33.5 pg (sensitivity 90.7%; specificity 35.8%) and 31.6 pg (sensitivity 90.6%; specificity 50.4%) to diagnose IDA. Conclusions: The present study demonstrates Ret-He to be a screening marker for ID and IDA in children. Furthermore, Ret-He can be used as a single screening parameter for ID and IDA in children without considering other iron parameters. Economically, the use of Ret-He is highly relevant, as it can save one blood tube per patient and additional costs.