Higher Hepcidin Concentrations Research Articles

Hepcidin as a Diagnostic Biomarker in Anaemic Lung Cancer Patients.

We aim to describe the characteristics of hepcidin, IL-6, and TNF-α levels in anaemia of lung cancer patients with operative tumour as well as to investigate the potential diagnostic capabilities of hepcidin in combination with IL-6, TNF-α, and acute phase proteins. We present a retrospective study of 112 lung cancer patients (41 women and 71 men) who were surgically treated at the Lower Silesian Centre for Lung Diseases in Wroclaw, Poland. Serum blood samples were collected from all these patients prior to any surgical treatment and used to determine hepcidin, IL-6, TNF-α, SAA1, and CRP concentrations. Patients were also examined with a complete blood count several times during their hospitalization. The female and male groups were divided based on the occurrence of anaemia during their hospitalization. Patients who developed anaemia post-operatively had significantly lower hepcidin concentrations than non-anaemic patients (p = 0.000694 in females with ≥3 complete blood count examinations and p = 0.007905 in males with 2 complete blood count examinations), whereas patients with anaemia since hospital admission had higher hepcidin concentrations. We observed two hepcidin roles related to two cancer anaemia pathogeneses: (1) higher hepcidin concentrations in patients with anaemia since hospital admission (anaemia of inflammation) and (2) lower hepcidin concentrations in patients who developed anaemia after surgery (anaemia of iron deficiency). Our data support the role of hepcidin, IL-6, and TNF-α in cancer-related anaemia and provide diagnostic values for predicting post-operative anaemia in lung cancer patients.

Greater blood volume and Hb mass in obese women quantified by the carbon monoxide-rebreathing method affects interpretation of iron biomarkers and iron requirements

Background/objectiveIron deficiency (ID) is common in overweight and obese individuals (OW/OB) but the mechanism is uncertain. Greater blood volume (BV) in OW/OB may increase hemoglobin (Hb) mass and iron requirements, and confound iron biomarkers by hemodilution. Quantification of BV/PV changes in OW/OB is challenging and a formula to estimate BV/PV based on anthropometric indices would be valuable. In normal weight (NW) and OW/OB women, we aimed at: (1) measure BV and assess whether differences in BV affect concentrations and total circulating mass of Hb and iron biomarkers; (2) develop an algorithm describing BV in OW/OB.Subjects/methodsIn a cross-sectional study, we measured BV in NW, OW, and OB non-anemic women (n = 62) by using the carbon monoxide-rebreathing method, body composition by dual energy X-ray absorptiometry, and iron and inflammatory status.ResultsOW and OB women had 11 and 16% higher mean BV and PV compared to NW (P < 0.05), respectively. In OW/OB compared to NW, total circulating masses of IL-6, hepcidin, Hb, and sTfR were higher, while total mass of serum iron was lower (for all, P < 0.05). An equation including height, body mass and lean mass to estimate BV in all BMI groups (R2 = 0.76).ConclusionAn equation based on anthropometric indices provides a good estimate of increased BV in OW/OB women. In OW/OB women, there is an increase in Hb mass that likely increases iron requirements for erythropoiesis and circulating TfR mass. At the same time, higher hepcidin concentrations may lower serum iron mass. Both these mechanisms may increase risk for ID in OW/OB women.

Serum Hepcidin Concentration in Individuals with Sickle Cell Anemia: Basis for the Dietary Recommendation of Iron

Dietary iron requirements in patients with sickle cell disease (SCD) remain unclear. SCD is a neglected hemoglobinopathy characterized by intense erythropoietic activity and anemia. Hepcidin is the hormone mainly responsible for iron homeostasis and intestinal absorption. Intense erythropoietic activity and anemia may reduce hepcidin transcription. By contrast, iron overload and inflammation may induce it. Studies on SCD have not evaluated the role of hepcidin in the presence and absence of iron overload. We aimed to compare serum hepcidin concentrations among individuals with sickle cell anemia, with or without iron overload, and those without the disease. Markers of iron metabolism and erythropoietic activity such as hepcidin, ferritin, and growth differentiation factor 15 were evaluated. Three groups participated in the study: the control group, comprised of individuals without SCD (C); those with the disease but without iron overload (SCDw); and those with the disease and iron overload (SCDio). Results showed that hepcidin concentration was higher in the SCDio > C > SCDw group. These data suggest that the dietary iron intake of the SCDio group should not be reduced as higher hepcidin concentrations may reduce the intestinal absorption of iron.

Pre‐operative anaemia, intra‐operative hepcidin concentration and acute kidney injury after cardiac surgery: a retrospective observational study

Acute kidney after cardiac surgery is more common in anaemic patients, whereas haemolysis during cardiopulmonary bypass may lead to iron-induced renal injury. Hepcidin promotes iron sequestration by macrophages: hepcidin concentration is reduced by anaemia and increased by inflammation. We analysed the associations in 525 patients between pre-operative anaemia (haemoglobin < 130 g.l-1 in men and < 120 g.l-1 in women), intra-operative hepcidin concentration and acute kidney injury (dialysis or > 26.4 μmol.l-1 or > 50% creatinine increase during the first two days after cardiac surgery. Rates of pre-operative anaemia and postoperative kidney injury were 109/525 (21%) and 36/525 (7%), respectively. The median (IQR [range]) intra-operative hepcidin concentration was 20 (10-33 [0-125]) μg.l-1 and was lower in anaemic patients than those who were not: 15 (4-28 [0-125]) μg.l-1 vs. 21 (12-33 [0-125]) μg.l-1 , respectively, p = 0.002. Four variables were independently associated with postoperative kidney injury, for which the beta-coefficients (SE) were: minutes on cardiopulmonary bypass, 0.016 (0.004), p < 0.001; intra-operative hepcidin concentration, 0.032 (0.008), p < 0.001; pre-operative anaemia, 1.97 (0.56), p < 0.001; and Cleveland clinic risk score, 0.88 (0.35), p = 0.005. Contrary to generally increased rates of kidney injury in patients with higher hepcidin concentrations, rates of kidney injury in anaemic patients were lower in patients with higher hepcidin concentrations, beta-coefficient (SE) -0.037 (0.01), p = 0.007. In cardiac surgical patients the rate of postoperative acute kidney injury predicted by the Cleveland risk score might be adjusted for pre-operative anaemia and intra-operative cardiopulmonary bypass time and hepcidin concentration. Pre-operative correction of anaemia, reduction in intra-operative bypass time and modification of iron homeostasis and hepcidin concentration might reduce acute kidney injury.

Changes in Hepcidin and Hemoglobin After Anti-TNF-alpha Therapy in Children and Adolescents With Crohn Disease.

Anemia is the most common systemic complication of inflammatory bowel disease, is more common in affected children than in adults, and is mediated in large part by chronic inflammation. Inflammation increases levels of the iron-regulatory protein hepcidin, which have been elevated in adults with Crohn disease. We measured serum hepcidin-25 and hemoglobin (Hgb) in 40 children and adolescents with Crohn disease at baseline and 10 weeks after initiation of anti-tumor necrosis factor (TNF)-α therapy. Measures of disease activity, inflammatory markers, and cytokines were obtained in all subjects. Anemia was defined by World Health Organization criteria. At baseline hepcidin and C-reactive protein levels were correlated, and 95% of subjects were anemic. After anti-TNF-α therapy, median (interquartile range) hepcidin concentrations decreased significantly and the distribution narrowed (27.9 [16.2, 52.9] vs 23.2 [11.1, 37.7] ng/mL, P = 0.01). Mean (standard deviation) Hgb also increased significantly (10.6 ± 1.2 to 10.9 ± 1.1 g/dL, P = 0.02), and the increase was sustained at 12 months, although 90% of participants continued to meet anemia criteria at 10 weeks. Disease activity and markers of inflammation also decreased and albumin levels increased. In generalized estimating equation analyses, higher TNF-α, interleukin 6, erythrocyte sedimentation rate, and C-reactive protein were associated with higher hepcidin concentrations (P = 0.04, P = 0.03, P = 0.003, and P < 0.001, respectively), and increased levels of disease activity were associated with higher hepcidin. In children with Crohn disease, anti-TNF-α therapy is associated with decreased levels of hepcidin and increased Hgb 10 weeks after induction. Improvement in anemia may be a secondary benefit for children who receive this therapy.

Low Serum Retinol Concentration Explain Higher Hepcidin Levels In Mexican Older Adults

BackgroundElevated hepcidin levels have been linked to anemia of inflammation (AI). Retinol deficiency has shown to modulate hepcidin expression in animals; however, no studies have explored low serum retinol (LSR) concentration in older adults (OA) and their possible association with hepcidin concentrations. Anemia affect 27% of Mexican OA and inflammation may play a role in the production of anemia in this population. Understanding the mechanisms that play a role in the control hepcidin secretion is an important goal in the prevention of AI.AimTo explore if low serum retinol is associated with higher serum hepcidin concentrations in Mexican older adults (≥60years).MethodsMexican OA were participants in a crossectional study to identify the main causes of anemia. They were recruited in August 2015. Fasting serum samples were collected in 535 OA. Serum retinol (SR) was measured by HPLC and LSR was defined if SR&lt;20μg/dL. Hepcidin (ng/mL) was measured using a commercial ELISA kit. Due to skewed distribution of hepcidin, a quantil regression model was used to associate the LSR and hepcidin, adjusting by sex, age, BMI, ferritin, transferrin receptor, vitamin B12 status, IL‐6, C reactive protein, Alpha‐1‐acid glycoprotein, diabetes, hypertension, tertil of socioeconomic status, sarcopenia and functional disability.ResultsMean age was 71.5y for male and 70.7y for female. LSR was present in 3.2% of OA. Mexican OA with low serum retinol had 12.2 ng/mL higher hepcidin levels than OA with normal serum retinol levels (p=0.03). Hepcidin adjusted median (by confounders) were (median±EE): 19.4± 1.0 ng/mL in OA with normal serum retinol and 31.9±5.7 ng/mL in OA with LSR. Sarcopenic OA had higher hepcidin levels (coef: 7.5 ng/mL, p=0.03) than OA non‐sarcopenic.ConclusionsLSR levels in OA explain their higher hepcidin concentrations. Retinol concentrations affects iron homeostasis but the mechanism is unclear. This data document for the first time that in humans, low serum retinol concentration is inversely associated with hepcidin concentrations. Further longitudinal studies are needed to understand the role of serum hepcidin and Retinol in the development of AI in OA.Support or Funding InformationCONACYT‐FONSEC SSA/IMSS/ISSSTE SALUD 2014‐1, S0008‐2014‐1‐000000000234157

Malaria and Age Variably but Critically Control Hepcidin Throughout Childhood in Kenya

Both iron deficiency (ID) and malaria are common among African children. Studies show that the iron-regulatory hormone hepcidin is induced by malaria, but few studies have investigated this relationship longitudinally. We measured hepcidin concentrations, markers of iron status, and antibodies to malaria antigens during two cross-sectional surveys within a cohort of 324 Kenyan children ≤8years old who were under intensive surveillance for malaria and other febrile illnesses. Hepcidin concentrations were the highest in the youngest, and female infants, declined rapidly in infancy and more gradually thereafter. Asymptomatic malaria and malaria antibody titres were positively associated with hepcidin concentrations. Recent episodes of febrile malaria were associated with high hepcidin concentrations that fell over time. Hepcidin concentrations were not associated with the subsequent risk of either malaria or other febrile illnesses. Given that iron absorption is impaired by hepcidin, our data suggest that asymptomatic and febrile malaria contribute to the high burden of ID seen in African children. Further, the effectiveness of iron supplementation may be sub-optimal in the presence of asymptomatic malaria. Thus, strategies to prevent and eliminate malaria may have the added benefit of addressing an important cause of ID for African children.

The role of hepcidin in the pathogenesis of anemia in Zimbabwean infants (1034.1)

Anemia is common in sub‐Saharan African infants, particularly in the context of HIV infection. Hepcidin is the major hormone regulating iron metabolism but its role in the pathogenesis of anemia during infancy is unclear. The aim of this study was to characterize hepcidin concentrations in anemic and non‐anemic infants and in HIV‐infected and HIV‐exposed uninfected (HEU) infants. Archived plasma samples from HIV‐unexposed (n=289), HIV‐exposed uninfected (HEU; n=354) and HIV‐infected (n=264) anemic and non‐anemic Zimbabwean infants at 3, 6 and 12mo of age were used to measure hepcidin, ferritin, transferrin receptor, AGP and CRP by ELISA. We undertook multivariate analysis of hepcidin, HIV and anemia status, adjusting for sex and age. Hepcidin concentrations were higher in HIV‐infected compared to HEU and HIV‐unexposed groups throughout infancy and higher in HEU compared to HIV‐unexposed infants. Hepcidin concentrations were correlated with levels of ferritin and CRP. Overall, anemia was not associated with hepcidin concentrations during infancy, except in HIV‐unexposed infants. Hepcidin declined with age in all groups; girls had higher hepcidin concentrations than boys. Plasma hepcidin concentrations are positively associated with inflammation in infants, as has been shown in adults. Future studies should explore whether elevated hepcidin contributes to the pathogenesis of HIV infection.Grant Funding Source: Supported by the Bill and Melinda Gates Foundation (OPP1021542); Department for International Develo

The Red Cell: How Erythropoiesis Modulates Hepcidin Expression

Abstract SCI-24Erythroid precursors in the bone marrow require transferrin-bound iron for hemoglobin synthesis. Therefore, it is not surprising that the regulation of erythropoiesis and iron metabolism is interlinked. Iron demand for erythropoiesis is communicated to the iron-regulatory machinery through incompletely understood mechanisms. At the core of systemic iron homeostasis is the peptide hormone hepcidin, restricting cellular iron export to plasma by inducing the endocytosis and proteolysis of ferroportin. Hepcidin, a liver-synthesized peptide hormone, is released in response to increased iron load, and there is early evidence that circulating hepcidin concentrations affect the distribution of iron between the macrophage storage compartment (favored by higher hepcidin concentrations) and parenchymal cells, including cardiac myocytes and hepatocytes (favored by low hepcidin). Furthermore, ferroportin has recently been identified on erythroid precursors. Its purpose in this cell type and its function in the interface between erythropoiesis and iron metabolism are unclear. Additionally, in response to bleeding or the administration of erythropoietin, expansion of erythroid precursors suppresses hepcidin, most likely through one or more mediators released by the bone marrow and acting on hepatocytes. Iron-loading anemias with ineffective erythropoiesis, in particular β-thalassemia, demonstrate the effects of pathological “erythroid regulators” of hepcidin. Although erythrocyte transfusions are the main cause of iron loading in patients who receive them (β-thalassemia major), lethal iron overload is seen also in patients who are rarely or never transfused (β-thalassemia intermedia). Here, iron hyperabsorption is the cause of iron overload and, as in hereditary hemochromatosis, is caused by low hepcidin. Decreased hepcidin expression in β-thalassemia, with concurrent ineffective erythropoiesis and iron overload, indicates that the “erythroid regulator” may play an even more substantial role in iron metabolism than the “stores regulator.” Two members of the bone morphogenetic protein (BMP) family, growth differentiation factor (GDF) 15 and Twisted Gastrulation (TWSG1), have been implicated as candidate bone marrow-derived hepcidin suppressors in β-thalassemia. Neither factor is responsible for the physiologic hepcidin suppression in response to hemorrhage-induced stress erythropoiesis, and the physiologic suppressor is not known. We focus here on the current state of knowledge regarding the regulation of iron metabolism and attempt to elucidate the interface between iron regulation and erythropoiesis using evidence in part derived from animal models of β-thalassemia. A more complete understanding of the coregulation of erythropoiesis and iron metabolism may lay the foundation for improving diagnosis, increasing treatment options, and ultimately impacting the well-being of patients afflicted with different anemias and/or iron overload related-disorders. Disclosures:No relevant conflicts of interest to declare.

Hepcidin concentrations and iron homeostasis in preeclampsia

Plasma iron is increased in preeclampsia (PE) when compared to healthy pregnant women. This is in contrast to inflammation characteristic for PE. The link between iron homeostasis and inflammation is hepcidin. Our goal was to describe hepcidin concentrations and its association with iron homeostasis in PE. We obtained peripheral blood samples from 30 preeclamptic [gestational age: 36.5 (24-40) weeks] and 37 healthy pregnant women [gestational age: 36 (28-39) weeks] to determine plasma hepcidin and interleukin-6 (IL-6) concentrations, complete blood cell counts and parameters of iron homeostasis [plasma iron, transferrin and ferritin levels and total iron binding capacity (TIBC)]. Hepcidin was measured using mass spectrophotometry. The Mann-Whitney test was used for statistical analysis. Plasma hepcidin, IL-6, iron and ferritin concentrations were increased (p<0.05 for all), whereas plasma transferrin, TIBC and mean corpuscular hemoglobin concentrations were lower (p<0.05 for all) in PE compared to healthy pregnant women. No differences were seen in the other parameters investigated. Plasma iron concentrations are increased despite high hepcidin concentrations in PE. This might indicate a resistance to the iron-decreasing action of hepcidin.

Diagnostic accuracy of serum hepcidin for iron deficiency in critically ill patients with anemia

Inflammation-induced anemia is frequent among critically ill patients and can be aggravated by true iron deficiency (ID) resulting from blood losses. The serum hepcidin level controls the availability of iron for erythropoiesis, and its determination offers new perspectives for the diagnosis of ID in the presence of inflammation. We conducted a prospective observational study to determine the cutoff value and diagnostic accuracy of hepcidin levels for detecting ID in critically ill anemic patients. Patients suffering from anemia (hemoglobin <100 g/l) and expected to stay for more than 7 days in intensive care had weekly determinations of hematological and iron parameters, including hepcidin levels (ELISA test). The iron status for each set of measures was determined by the consensus of three experts, blinded to hepcidin values. Of 51 patients (36 male/15 female), 5 had ID at inclusion, while 8 developed ID during their stay. A total of 128 iron profiles were analyzed. Median hepcidin levels were 80.5 (0.05-548.3) and 526.6 (246.7-891.4) microg/l for ID and non-ID profiles, respectively. The onset of ID during the ICU stay led to a progressive decline in hepcidin levels, whereas a persistent inflammatory profile remained associated with high hepcidin concentrations. The optimal threshold for serum hepcidin for ID diagnosis was assessed by building 100 ROC curves using a resampling method and found at 129.5 microg/l [95% CI = (115.5-143.4)]. Hepcidin levels may be suppressed by ID even in case of inflammation. Serum hepcidin of 129.5 microg/l was the most accurate threshold for ID diagnosis in critically ill patients with anemia.