Liver iron concentrations and urinary hepcidin in beta-thalassemia

Tocilizumab, a Humanized Anti-interleukin-6 Receptor Antibody, Induces Hepatic Iron Overload in a Susceptible Patient

A 75-year-old woman visited to our hospital with liver dysfunction. The patient's liver function was normal. She had been treated with tocilizumab for rheumatoid arthritis for two years. One year after initiation of tocilizumab treatment, liver dysfunction was observed. Serum ceruloplasmin concentration was low. We diagnosed hepatic iron overload because of a high ferritin concentration and a liver biopsy. The cessation of tocilizumab and phlebotomy improved the liver function. We believe that tocilizumab induced iron accumulation. We should be aware of the possibility that tocilizumab induces iron overload in susceptible patients and monitor iron status in patients treated with tocilizumab.

Effects of Dietary Ferric EDTA Levels on Vegetables and Mirror Carp (Cyprinus carpio var. specularis) in Aquaponics System

This study investigated the effects of dietary iron supplementation on water quality, plant growth, and fish health in an aquaponic system over 90 days. Iron supplementation significantly improved plant growth, with increased plant height, stem diameter, leaf count, and fruit yield in tomatoes (Solanum lycopersicum) and pak choi (Brassica rapa subsp. Chinensis) (p < 0.05). The water pH fluctuated with varying iron content, and higher iron levels promoted better plant growth by improving iron availability (p < 0.05). During the first 60 days, all red blood cell counts and hemoglobin levels increased, but the growth and nutritional composition of mirror carp (Cyprinus carpio var. specularis) showed no significant differences. By day 90, fish in the T3 group (800 mg/kg iron) exhibited significantly reduced growth and feed conversion rates (p < 0.05). Histological analysis of liver tissue indicated iron-induced liver damage; additionally, excessive iron intake suppressed erythropoiesis, leading to lower red blood cell counts and hemoglobin levels (p < 0.05). The results indicate that moderate iron supplementation improves plant growth, but excessive iron can negatively impact fish health, particularly liver function and blood formation. These findings provide valuable insights for optimizing iron levels in aquaponic systems.

In vivo silencing of intestinal DMT1 mitigates iron loading in β-thalassemia intermedia (Hbbth3/+) mice

ABSTRACT

β-thalassemia is an iron-loading anemia caused by homozygous mutation of the hemoglobin subunit β (HBB) gene. In β-thalassemia intermedia (βTI), a non-transfusion-dependent form of the disease, iron overload is caused by excessive absorption of dietary iron due to inappropriately low production of the iron-regulatory hormone hepcidin. Low hepcidin stabilizes the iron exporter ferroportin (FPN) on the basolateral membrane of enterocytes. High FPN activity may deplete intracellular iron and enhance expression of the predominant iron importer divalent metal-ion transporter 1 (DMT1). In mice, DMT1 mediates normal iron absorption under physiological conditions and excessive iron absorption in pathological iron overload (eg, hereditary hemochromatosis). Here, we hypothesized that DMT1 drives elevated iron absorption in βTI. Accordingly, we crossed Hbbth3/+ mice, a preclinical model of βTI, with intestine-specific DMT1-knockout mice. Ablation of intestinal DMT1 in Hbbth3/+ mice caused a pathophysiological shift from iron overload to an iron-deficiency phenotype with exacerbated anemia. DMT1 is thus required for iron absorption and iron loading in Hbbth3/+ mice. Based upon these outcomes, we further logically postulated that in vivo knockdown of intestinal DMT1 would mitigate iron loading in Hbbth3/+ mice. Ginger-derived, lipid nanoparticles carrying DMT1-specific (or control) small interfering RNAs (siRNAs) were administered by oral, intragastric gavage to 4-week-old Hbbth3/+ mice daily for 16 days. siRNA treatment reduced DMT1 expression by >80% and blunted iron loading, as indicated by significant reductions in liver iron and serum ferritin (which reflect body iron stores). These notable experimental outcomes establish intestinal DMT1 as a plausible therapeutic target to mitigate iron overload in βTI.

Gene Therapy: A Revolutionary Step in Treating Thalassemia

Beta thalassemia is an inherited blood disorder that results in inefficient erythropoiesis due to genetic mutation that leads to the reduction or absence of the hemoglobin beta-globulin protein. Approximately 8.5% of UAE residents suffer from β-thalassemia, a significant health and financial problem. The treatment options available for β-Thalassemia major are limited and associated with a wide range of complications. β-thalassemia gene therapy is emerging as a potential novel treatment option that eliminates the complications caused by the current long-term treatment modalities and the associated economic burden. This paper reviews the scientific literature related to emerging gene therapy for β-Thalassemia by analyzing all the articles published from January 2010 to December 2023 in the English language on Databases like PubMed, Scopus, ProQuest, and CINAHL. The use of gene therapy has demonstrated promising outcomes for a permanent cure of β-Thalassemia. To conclude, gene therapy is an innovative solution. It demonstrates a promising future, but does come with its own setbacks and is something that must be tackled in order to revolutionize it in the medical world. FDA-approved ZYNTEGLO is a potentially one-time curative treatment for β-Thalassemia. Although cutting-edge, its use is limited because of the high cost-a price of USD 2.8 million per patient.

Acute and Chronic Effects of Interval Aerobic Exercise on Hepcidin, Ferritin, and Liver Enzymes in Adolescents With Beta-Thalassemia Major

PURPOSE

This study aimed to determine the acute and chronic effects of interval aerobic exercise on hepcidin, ferritin, and liver enzymes in adolescents with beta-thalassemia major.

METHODS

Twenty-six beta-thalassemia major adolescents referred to the Thalassemia Clinic and Research Center were selected as study participants and randomly divided into control (n = 13) and training (n = 13) groups. Participants performed 3 sessions per week for 45 minutes in each session for 8 weeks of aerobic interval exercise with an intensity of 50% to 65% of the heart rate reserve. Blood samples were taken before, immediately after the exercise session, and 48 hours after the last training session, and liver enzymes aspartate aminotransferase, alanine aminotransferase (ALT), alkaline phosphatase (ALP), ferritin, and hepcidin were evaluated.

RESULTS

The results showed a decrease in aspartate aminotransferase, ALT, ALP, ferritin, and hepcidin levels due to 8 weeks of aerobic interval training (P = .14, P = .97, P = .03, P < .001, P < .001; respectively). Intergroup changes in all variables except ALT and hepcidin were significant (P < .05). Besides, acute aerobic exercise increased levels of aspartate aminotransferase, ALT, ferritin, and hepcidin (P = .04, P = .52, P < .001, P < .001; respectively), whereas ALP levels decreased (P < .001). In addition, changes in ALP and hepcidin levels were significant between the 2 groups (P = .05, P < .001; respectively).

CONCLUSION

Based on the study's results, it can be concluded that 8 weeks of aerobic interval training can decrease ferritin and hepcidin levels, but acute aerobic exercise increases them.

Anemia and iron overload as prognostic markers of outcomes in β-thalassemia

INTRODUCTION

Ineffective erythropoiesis and subsequent anemia as well as primary and secondary (transfusional) iron overload are key drivers for morbidity and mortality outcomes in patients with β-thalassemia.

AREAS COVERED

In this review, we highlight evidence from observational studies evaluating the association between measures of anemia and iron overload versus outcomes in both non-transfusion-dependent and transfusion-dependent forms of β-thalassemia.

EXPERT OPINION

Several prognostic thresholds have been identified with implications for patient management. These have also formed the basis for the design of novel therapy clinical trials by informing eligibility and target endpoints. Still, several data gaps persist in view of the challenge of assessing prospective long-term outcomes in a chronic disease. Pooling insights on the prognostic value of different measures of disease mechanism will be key to design future scoring systems that can help optimize patient management.

Magnetic Resonance Evaluation of Tissue Iron Deposition and Cardiac Function in Adult Regularly Transfused Thalassemia Intermedia Compared with Thalassemia Major Patients

Objectives: This multicenter, retrospective, population-based, matched-cohort study compared clinical characteristics and magnetic resonance imaging (MRI) findings, including hepatic, pancreatic, and cardiac iron levels and cardiac function, between 135 adult regularly transfused thalassemia intermedia (TI) patients (44.73 ± 12.16 years, 77 females) and 135 age- and sex-matched thalassemia major (TM) patients (43.35 ± 9.83 years, 77 females), enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network. Methods: The MRI protocol included the quantification of hepatic, pancreatic, and cardiac iron levels (R2* technique), the assessment of biventricular function parameters (cine images), and the detection of replacement myocardial fibrosis (late gadolinium enhancement technique). Results: Age, sex, frequency of splenectomy and chelation, and serum ferritin levels were not significantly different (p > 0.05) between the two groups, but TI patients started regular transfusions significantly later (p < 0.0001) and showed significantly lower pre-transfusion hemoglobin levels (p = 0.005). No difference was found in hepatic iron levels (p = 0.853). TI patients exhibited significantly lower pancreatic R2* values (p < 0.0001), also correcting for the duration of regular transfusions, and significantly lower cardiac R2* values (p < 0.0001). In the receiver operating characteristic analysis, pancreatic iron was the strongest discriminator between the two diseases. Left and right ventricular end-diastolic volume indexes were significantly higher in TI than in TM patients (p = 0.003 and p = 0.046, respectively), but the correction for the duration of regular transfusions removed the disease-specific differences (p > 0.05). Left ventricular (LV) mass index was significantly higher in TI (p = 0.049), while no difference (p > 0.05) was found in biventricular ejection fractions and replacement myocardial fibrosis. Conclusions: TI patients showed lower pancreatic and cardiac iron burden and more pronounced LV hypertrophy. These differences could not be explained by the different duration of the transfusional regimen.

Revisiting iron overload status and change thresholds as predictors of mortality in transfusion-dependent β-thalassemia: a 10-year cohort study

Data on iron overload status and change thresholds that can predict mortality in patients with transfusion-dependent β-thalassemia (TDT) are limited. This was a retrospective cohort study of 912 TDT patients followed for up to 10 years at treatment centers in Italy (median age 32 years, 51.6% female). The crude mortality rate was 2.9%. Following best-predictive threshold identification through receiver operating characteristic curve analyses, data from multivariate Cox-regression models showed that patients with Period Average Serum Ferritin (SF) > 2145 vs ≤ 2145 ng/mL were 7.1-fold (P < 0.001) or with Absolute Change SF > 1330 vs ≤ 1330 ng/mL increase were 21.5-fold (P < 0.001) more likely to die from any cause. Patients with Period Average Liver Iron Concentration (LIC) > 8 vs ≤ 8 mg/g were 20.2-fold (P < 0.001) or with Absolute Change LIC > 1.4 vs ≤ 1.4 mg/g increase were 27.6-fold (P < 0.001) more likely to die from any cause. Patients with Index (first) cardiac T2* (cT2*) < 27 vs ≥ 27 ms were 8.6-fold (P < 0.001) more likely to die from any cause. Similarly, results at varying thresholds were identified for death from cardiovascular disease. These findings should support decisions on iron chelation therapy by establishing treatment targets, including safe iron levels and clinically meaningful changes over time.

Association of serum ferritin trends with liver enzyme patterns in β-thalassemia major: A longitudinal correlational study

Background

β-Thalassemia major patients require lifelong blood transfusions, leading to iron overload and liver injury. This study examines the longitudinal association between serum ferritin and liver function over 5 years in pediatric patients.

Methods

This retrospective study included 582 transfusion-dependent thalassemia patients aged 1-18 years. Serum ferritin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and albumin were measured annually. Correlation and linear regression analyses assessed associations between ferritin trajectories and liver enzymes.

Results

Mean ferritin rose from 1820 ± 960 ng/mL at baseline to 4500 ± 1900 ng/mL at year 5, indicating worsening iron overload. AST and ALT levels also steadily climbed over follow-up, whereas albumin declined slightly. Ferritin correlated positively with AST (r = 0.675, P < 0.01) and ALT (r = 0.607, P < 0.01), but not with albumin (r = -0.143, P = 0.153) annually. The regression interaction term showed within-patient ferritin increases over time were independently associated with escalating AST and ALT (P < 0.05), after adjusting for confounders.

Conclusion

Rising ferritin levels predict progressive liver injury in regularly transfused pediatric thalassemia patients. Tighter control of iron overload may help preserve hepatic function.

Multiparametric cardiac magnetic resonance in patients with thalassemia intermedia: new insights from the E-MIOT network

PURPOSE

In a relatively large cohort of thalassemia intermedia (TI) patients, we systematically investigated myocardial iron overload (MIO), function, and replacement fibrosis using cardiac magnetic resonance (CMR), we assessed the clinical determinants of global heart T2* values, and we explored the association between multiparametric CMR findings and cardiac complications.

MATERIALS AND METHODS

We considered 254 beta-TI patients (43.14 ± 13.69 years, 138 females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia project. MIO was quantified by T2* technique and biventricular function and atrial areas by cine images. Macroscopic myocardial fibrosis was detected by late gadolinium enhancement technique.

RESULTS

Compared to never/sporadically transfused patients, regularly transfused (RT)-TI patients exhibited significantly lower global heart T2* values, biventricular end-diastolic volume indexes, left ventricular mass index, and cardiac index. In RT-TI patients, age and serum ferritin levels were the strongest predictors of global heart T2* values. Independently from the transfusional state, cardiac T2* values were not associated with biventricular function. Of the 103 (40.6%) patients in whom the contrast medium was administrated, 27 (26.2%) had replacement myocardial fibrosis. Age, sex distribution, cardiac iron, and biventricular function parameters were comparable between patients without and without replacement myocardial fibrosis. Twenty-five (9.8%) patients had a history of cardiac complications (heart failure and arrhythmias). Increased age and replacement myocardial fibrosis emerged as significant risk markers for cardiac complications.

CONCLUSIONS

In TI, regular transfusions are associated with less pronounced cardiac remodeling but increase the risk of MIO. Replacement myocardial fibrosis is a frequent finding associated with cardiac complications.

Impact of genotype on multi-organ iron and complications in patients with non-transfusion-dependent β-thalassemia intermedia

We evaluated the impact of the genotype on clinical and hematochemical features, hepatic and cardiac iron levels, and endocrine, hepatic, and cardiovascular complications in non-transfusion-dependent (NTD) β-thalassemia intermedia (TI) patients. Sixty patients (39.09 ± 11.11 years, 29 females) consecutively enrolled in the Myocardial Iron Overload in Thalassemia project underwent Magnetic Resonance Imaging to quantify iron overload, biventricular function parameters, and atrial areas and to detect replacement myocardial fibrosis. Three groups of patients were identified: homozygous β+ (N = 18), heterozygous β0β+ (N = 22), and homozygous β0 (N = 20). The groups were homogeneous for sex, age, splenectomy, hematochemical parameters, chelation therapy, and iron levels. The homozygous β° genotype was associated with significantly higher biventricular end-diastolic and end-systolic volume indexes and bi-atrial area indexes. No difference was detected in biventricular ejection fractions or myocardial fibrosis. Extramedullary hematopoiesis and leg ulcers were significantly more frequent in the homozygous β° group compared to the homozygous β+ group. No association was detected between genotype and liver cirrhosis, hypogonadism, hypothyroidism, osteoporosis, heart failure, arrhythmias, and pulmonary hypertension. Heart remodelling related to a high cardiac output state cardiomyopathy, extramedullary hematopoiesis, and leg ulcers were more pronounced in patients with the homozygous β° genotype compared to the other genotypes analyzed. The knowledge of the genotype can assist in the clinical management of NTD β-TI patients.

Mitapivat improves ineffective erythropoiesis and iron overload in adult patients with pyruvate kinase deficiency

ABSTRACT

Pyruvate kinase (PK) deficiency is a rare, hereditary disease characterized by chronic hemolytic anemia. Iron overload is a common complication regardless of age, genotype, or transfusion history. Mitapivat, an oral, allosteric PK activator, improves anemia and hemolysis in adult patients with PK deficiency. Mitapivat's impact on iron overload and ineffective erythropoiesis was evaluated in adults with PK deficiency who were not regularly transfused in the phase 3 ACTIVATE trial and long-term extension (LTE) (#NCT03548220/#NCT03853798). Patients in the LTE received mitapivat throughout ACTIVATE/LTE (baseline to week 96; mitapivat-to-mitapivat [M/M] arm) or switched from placebo (baseline to week 24) to mitapivat (week 24 to week 96; placebo-to-mitapivat [P/M] arm). Changes from baseline in markers of iron overload and erythropoiesis were assessed to week 96. Improvements in hepcidin (mean, 4770.0 ng/L; 95% confidence interval [CI], -1532.3 to 11 072.3), erythroferrone (mean, -9834.9 ng/L; 95% CI, -14 328.4 to -5341.3), soluble transferrin receptor (mean, -56.0 nmol/L; 95% CI, -84.8 to -27.2), and erythropoietin (mean, -32.85 IU/L; 95% CI, -54.65 to -11.06) were observed in the M/M arm (n = 40) from baseline to week 24, sustained to week 96. No improvements were observed in the P/M arm (n = 40) to week 24; however, upon transitioning to mitapivat, improvements similar to those observed in the M/M arm were seen. Mean changes from baseline in liver iron concentration by magnetic resonance imaging at week 96 in the M/M arm and the P/M arm were -2.0 mg Fe/g dry weight (dw; 95% CI, -4.8 to -0.8) and -1.8 mg Fe/g dw (95% CI, -4.4 to 0.80), respectively. Mitapivat is the first disease-modifying pharmacotherapy shown to have beneficial effects on iron overload and ineffective erythropoiesis in patients with PK deficiency. This trial was registered at www.ClinicalTrials.gov as #NCT03548220 (ACTIVATE) and #NCT03853798 (LTE).

Serum hepcidin levels in chronic liver disease: a systematic review and meta-analysis

OBJECTIVES

Dysregulation of hepcidin-iron axis is presumed to account for abnormal iron status in patients with chronic liver disease (CLD). Our aim is to determine the effect of specific etiologies of CLD and of cirrhosis on serum hepcidin levels.

METHODS

PubMed, Embase, Web of Science were searched for studies comparing serum hepcidin levels in patients with CLD to that in controls using enzyme-linked immunosorbent assay. The study was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Guidelines. Statistical analysis was carried out with STATA using random effects model to calculate the mean difference (MD) between two groups.

RESULTS

Hepcidin levels were significantly lower in subjects with hepatitis C virus (16 studies) [MD -1.6 (95 % CI: -2.66 to -0.54), p<0.01] and alcoholic liver disease (3 studies) [MD -0.84 (95 % CI: -1.6 to -0.07), p=0.03] than controls. Serum hepcidin was significantly higher in subjects with non-alcoholic fatty liver disease (12 studies) [MD 0.62 (95 % CI: 0.21 to 1.03), p<0.01], but did not differ in subjects with hepatitis B and controls (eight studies) [MD -0.65 (95 % CI: -1.47 to 0.16), p=0.12]. Hepcidin levels were significantly lower in patients with cirrhosis of any etiology (four studies) [MD -1.02 (CI: -1.59 to -0.45), p<0.01] vs. controls (CI: confidence interval).

CONCLUSIONS

Serum hepcidin levels are altered in common forms of CLD albeit not in a consistent direction. Additional study is needed to determine how changes in hepcidin levels are related to dysregulation of iron metabolism in CLD.

Comparison of oral iron chelators in the management of transfusion-dependent β-thalassemia major based on serum ferritin and liver enzymes

Background

Excess iron deriving from a chronic transfusion and dietary intake increases the risk for cardiac complications in β-thalassemia major patients. Deferiprone and deferasirox are commonly prescribed to thalassemic patients who are at risk of iron overload. This study aimed to compare the performance and toxicity of deferiprone and deferasirox in β-thalassemia major patients.

Methods

A cross-sectional observation was performed on 102 patients with β-thalassemia major. Serum ferritin along with total, indirect, and direct bilirubin levels were measured. Levels of liver enzymes, transaminase (ALT), and aspartate transaminase (AST), were also determined. Ferritin correlations with serum ALT, AST, and total bilirubin were constructed based on Spearman's rank correlation. Statistical differences based on the serum parameters were analyzed between deferiprone and deferasirox groups. The differences of iron chelators' effects between those receiving short-term (≤7 years) and long-term (>7 years) blood transfusion were also analyzed.

Results

The averaged levels of bilirubin, ALT, AST, and ferritin were found to be high. Ferritin was positively correlated with ALT (r=0.508 and p<0.001) and AST ((r=0.569; p<0.001). There was no statistical difference in ferritin levels between the deferiprone and deferasirox groups ( p=0.776). However, higher total bilirubin and ALT were observed in the deferasirox group than in the deferiprone group ( p=0.001 and 0.022, respectively). Total ( p<0.001), indirect ( p<0.001), and direct bilirubin levels ( p=0.015) were significantly higher in patients with long-term transfusions than those receiving short-term transfusions. Higher ferritin was found with a statistical significance of p=0.008 in the long-term transfusions group.

Conclusions

Ferritin is high in people with transfusion-dependent β-thalassemia major and positively correlated with ALT and AST. Deferasirox might pose a higher risk of developing hepatic injury as compared with deferiprone. Yet, no significant change of deferasirox efficacy (based on ferritin level) was found between those receiving short-term and long-term transfusions.

Circulating microRNAs and hepcidin as predictors of iron homeostasis and anemia among school children: a biochemical and cross-sectional survey analysis

BACKGROUND

MicroRNAs (miRNAs) can control several biological processes. Thus, the existence of these molecules plays a significant role in regulating human iron metabolism or homeostasis.

PURPOSE

The study aimed to determine the role of circulating microRNAs and hepcidin in controlling iron homeostasis and evaluating possible anemia among school children.

METHODS

The study was based on a biochemical and cross-sectional survey study that included three hundred fifty school children aged 12-18 years old. RT-PCR and immunoassay analysis were accomplished to estimate iron concentration, Hgb, serum ferritin (SF), soluble transferrin receptor (sTfR), total body iron stores (TIBs), total oxidative stress (TOS), total antioxidant capacity (TAC), α-1-acid glycoprotein (AGP), high sensitive C-reactive protein (hs-CRP), and miRNAs; miR-146a, miR-129b, and miR-122 in 350 school adolescents.

RESULTS

Iron disorders were cross-sectionally predicted in 28.54% of the study population; they were classified into 14.26% with ID, 5.7% with IDA, and 8.6% with iron overload. The overall proportion of iron depletion was significantly higher in girls (20.0%) than in boys (8.6%). MicroRNAs; miR-146a, miR-125b, and miR-122 were significantly upregulated with lower hepcidin expression in adolescence with ID and IDA compared to iron-overloaded subjects, whereas downregulation of these miRNAs was linked with higher hepcidin. Also, a significant correlation was recorded between miRNAs, hepcidin levels, AGP, hs-CRP, TAC, and other iron-related indicators.

CONCLUSION

Molecular microRNAs such as miR-146a, miR-125b, and miR-122 were shown to provide an additional means of controlling or regulating cellular iron uptake or metabolism either via the oxidative stress pathway or regulation of hepcidin expression via activating genes encoding Hfe and Hjv activators, which promote iron regulation. Thus, circulating miRNAs as molecular markers and serum hepcidin could provide an additional means of controlling or regulating cellular iron and be associated as valuable markers in diagnosing and treating cases with different iron deficiencies.

Novel potential therapeutics to modify iron metabolism and red cell synthesis in diseases associated with defective erythropoiesis

Under normal conditions, iron metabolism is carefully regulated to sustain normal cellular functions and the production of hemoglobin in erythroid cells. Perturbation to the erythropoiesis-iron metabolism axis can result in iron imbalances and cause anemia or organ toxicity. Various congenital and acquired diseases associated with abnormal red cell production are characterized by aberrant iron absorption. Several recent studies have shown that improvements in red blood cell production also ameliorate iron metabolism and vice versa. Many therapeutics are now under development with the potential to improve a variety of hematologic diseases, from β-thalassemia and iron-refractory iron deficiency anemia to anemia of inflammation and polycythemia vera. This review summarizes selected mechanisms related to red cell production and iron metabolism and describes potential therapeutics and their current uses. We also consider the potential application of the discussed therapeutics on various diseases, alone or in combination. The vast repertoire of drugs under development offers new opportunities to improve the clinical care of patients suffering from congenital or acquired red blood cell disorders with limited or no treatment options.

How I treat non-transfusion-dependent β-thalassemia

The intricate interplay of anemia and iron overload under the pathophysiological umbrella of ineffective erythropoiesis in non-transfusion-dependent β-thalassemia (NTDT) results in a complex variety of clinical phenotypes that are challenging to diagnose and manage. In this article, we use a clinical framework rooted in pathophysiology to present 4 common scenarios of patients with NTDT. Starting from practical considerations in the diagnosis of NTDT, we delineate our strategy for the longitudinal care of patients who exhibit different constellations of symptoms and complications. We highlight the use of transfusion therapy and novel agents, such as luspatercept, in the patient with anemia-related complications. We also describe our approach to chelation therapy in the patient with iron overload. Although tackling every specific complication of NTDT is beyond the scope of this article, we touch on the management of the various morbidities and multisystem manifestations of the disease.

Erythroferrone exacerbates iron overload and ineffective extramedullary erythropoiesis in a mouse model of β-thalassemia

β-thalassemia is characterized by chronic hepcidin suppression and iron overload, even in patients who have not undergone transfusion. The HbbTh3/+ (Th3/+) mouse model of nontransfusion-dependent β-thalassemia (NTDBT) partially recapitulates the human phenotype but lacks chronic hepcidin suppression, progressive iron accumulation into adulthood, or the interindividual variation of the rate of iron loading observed in patients. Erythroferrone (ERFE) is an erythroid regulator that suppresses hepcidin during increased erythropoiesis. ERFE concentrations in the sera of patients with NTDBT correlate negatively with hepcidin levels but vary over a broad range, possibly explaining the variability of iron overload in patients. To analyze the effect of high ERFE concentrations on hepcidin and iron overload in NTDBT, we crossed Th3/+ mice with erythroid ERFE-overexpressing transgenic mice. Th3/ERFE-transgenic mice suffered high perinatal mortality, but embryos at E18.5 showed similar viability, appearance, and anemia effects as Th3/+ mice. Compared with Th3/+ littermates, adult Th3/ERFE mice had similarly severe anemia but manifested greater suppression of serum hepcidin and increased iron accumulation in the liver, kidney, and spleen. The Th3/ERFE mice had much higher concentrations of serum ERFE than either parental strain, a finding attributable to both a higher number of erythroblasts and higher production of ERFE by each erythroblast.Th3/+ and Th3/ERFE mice had similar red blood cell count and shortened erythrocyte lifespan, but Th3/ERFE mice had an increased number of erythroid precursors in their larger spleens, indicative of aggravated ineffective extramedullary erythropoiesis. Thus, high ERFE concentrations increase the severity of nontransfusional iron overload and ineffective erythropoiesis in thalassemic mice but do not substantially affect anemia or hemolysis.

Pathogenic Mechanisms in Thalassemia II: Iron Overload

Iron overload remains a lethal complication of β-thalassemia and other anemias caused by ineffective erythropoiesis. This review discusses the pathogenetic mechanisms of iron overload in thalassemia, at organismal, cellular, and molecular levels.

Hereditary Hyperferritinemia

Ferritin is a ubiquitous protein that is present in most tissues as a cytosolic protein. The major and common role of ferritin is to bind Fe²⁺, oxidize it and sequester it in a safe form in the cell, and to release iron according to cellular needs. Ferritin is also present at a considerably low proportion in normal mammalian sera and is relatively iron poor compared to tissues. Serum ferritin might provide a useful and convenient method of assessing the status of iron storage, and its measurement has become a routine laboratory test. However, many additional factors, including inflammation, infection, metabolic abnormalities, and malignancy-all of which may elevate serum ferritin-complicate interpretation of this value. Despite this long history of clinical use, fundamental aspects of the biology of serum ferritin are still unclear. According to the high number of factors involved in regulation of ferritin synthesis, secretion, and uptake, and in its central role in iron metabolism, hyperferritinemia is a relatively common finding in clinical practice and is found in a large spectrum of conditions, both genetic and acquired, associated or not with iron overload. The diagnostic strategy to reveal the cause of hyperferritinemia includes family and personal medical history, biochemical and genetic tests, and evaluation of liver iron by direct or indirect methods. This review is focused on the forms of inherited hyperferritinemia with or without iron overload presenting with normal transferrin saturation, as well as a step-by-step approach to distinguish these forms to the acquired forms, common and rare, of isolated hyperferritinemia.

Hepcidin and Iron in Health and Disease

Hepcidin, the iron-regulatory hormone, determines plasma iron concentrations and total body iron content. Hepcidin, secreted by hepatocytes, functions by controlling the activity of the cellular iron exporter ferroportin, which delivers iron to plasma from intestinal iron absorption and from iron stores. Hepcidin concentration in plasma is increased by iron loading and inflammation and is suppressed by erythropoietic stimulation and during pregnancy. Hepcidin deficiency causes iron overload in hemochromatosis and anemias with ineffective erythropoiesis. Hepcidin excess causes iron-restrictive anemias including anemia of inflammation. The development of hepcidin diagnostics and therapeutic agonists and antagonists should improve the treatment of iron disorders.

Foetal haemoglobin inducers for reducing blood transfusion in non-transfusion-dependent beta-thalassaemias

BACKGROUND

Non-transfusion-dependent β-thalassaemia (NTDβT) is a subset of inherited haemoglobin disorders characterised by reduced production of the β-globin chain of haemoglobin leading to anaemia of varying severity. Although blood transfusion is not a necessity for survival, it may be required to prevent complications of chronic anaemia, such as impaired growth and hypercoagulability. People with NTDβT also experience iron overload due to increased iron absorption from food sources which becomes more pronounced in those requiring blood transfusion. People with a higher foetal haemoglobin (HbF) level have been found to require fewer blood transfusions, thus leading to the emergence of treatments that could increase its level. HbF inducers stimulate HbF production without altering any gene structures. Evidence for the possible benefits and harms of these inducers is important for making an informed decision on their use.

OBJECTIVES

To compare the effectiveness and safety of the following for reducing blood transfusion for people with NTDβT: 1. HbF inducers versus usual care or placebo; 2. single HbF inducer with another HbF inducer, and single dose with another dose; and 3. combination of HbF inducers versus usual care or placebo, or single HbF inducer.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 21 August 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs comparing single HbF inducer with placebo or usual care, with another single HbF inducer or with a combination of HbF inducers; or comparing different doses of the same HbF inducer.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were blood transfusion and haemoglobin levels. Our secondary outcomes were HbF levels, the long-term sequelae of NTDβT, quality of life and adverse events.

MAIN RESULTS

We included seven RCTs involving 291 people with NTDβT, aged two to 49 years, from five countries. We reported 10 comparisons using eight different HbF inducers (four pharmacological and four natural): three RCTs compared a single HbF inducer to placebo and seven to another HbF inducer. The duration of the intervention lasted from 56 days to six months. Most studies did not adequately report the randomisation procedures or whether and how blinding was achieved. HbF inducer against placebo or usual care Three HbF inducers, HQK-1001, Radix Astragali or a 3-in-1 combined natural preparation (CNP), were compared with a placebo. None of the comparisons reported the frequency of blood transfusion. We are uncertain whether Radix Astragali and CNP increase haemoglobin at three months (mean difference (MD) 1.33 g/dL, 95% confidence interval (CI) 0.54 to 2.11; 1 study, 2 interventions, 35 participants; very low-certainty evidence). We are uncertain whether Radix Astragali and CNP have any effect on HbF (MD 12%, 95% CI -0.74% to 24.75%; 1 study, 2 interventions, 35 participants; very low-certainty evidence). Only medians on haemoglobin and HbF levels were reported for HQK-1001. Adverse effects reported for HQK-1001 were nausea, vomiting, dizziness and suprapubic pain. There were no prespecified adverse effects for Radix Astragali and CNP. HbF inducer versus another HbF inducer Four studies compared a single inducer with another over three to six months. Comparisons included hydroxyurea versus resveratrol, hydroxyurea versus thalidomide, hydroxyurea versus decitabine and Radix Astragali versus CNP. No study reported our prespecified outcomes on blood transfusion. Haemoglobin and HbF were reported for the comparison Radix Astragali versus CNP, but we are uncertain whether there were any differences (1 study, 24 participants; low-certainty evidence). Different doses of the same HbF inducer Two studies compared two different types of HbF inducers at different doses over two to six months. Comparisons included hydroxyurea 20 mg/kg/day versus 10 mg/kg/day and HQK-1001 10 mg/kg/day, 20 mg/kg/day, 30 mg/kg/day and 40 mg/kg/day. Blood transfusion, as prespecified, was not reported. In one study (61 participants) we are uncertain whether the lower levels of both haemoglobin and HbF at 24 weeks were due to the higher dose of hydroxyurea (haemoglobin: MD -2.39 g/dL, 95% CI -2.80 to -1.98; very low-certainty evidence; HbF: MD -10.20%, 95% CI -16.28% to -4.12%; very low-certainty evidence). The study of the four different doses of HQK-1001 did not report results for either haemoglobin or HbF. We are not certain if major adverse effects may be more common with higher hydroxyurea doses (neutropenia: risk ratio (RR) 9.93, 95% CI 1.34 to 73.97; thrombocytopenia: RR 3.68, 95% CI 1.12 to 12.07; very low-certainty evidence). Taking HQK-1001 20 mg/kg/day may result in the fewest adverse effects. A combination of HbF inducers versus a single HbF inducer Two studies compared three combinations of two inducers with a single inducer over six months: hydroxyurea plus resveratrol versus resveratrol or hydroxyurea alone, and hydroxyurea plus l-carnitine versus hydroxyurea alone. Blood transfusion was not reported. Hydroxyurea plus resveratrol may reduce haemoglobin compared with either resveratrol or hydroxyurea alone (MD -0.74 g/dL, 95% CI -1.45 to -0.03; 1 study, 54 participants; low-certainty evidence). We are not certain whether the gastrointestinal disturbances, headache and malaise more commonly reported with hydroxyurea plus resveratrol than resveratrol alone were due to the interventions. We are uncertain whether hydroxyurea plus l-carnitine compared with hydroxyurea alone may increase mean haemoglobin, and reduce pulmonary hypertension (1 study, 60 participants; very low-certainty evidence). Adverse events were reported but not in the intervention group. None of the comparisons reported the outcome of HbF.

AUTHORS' CONCLUSIONS

We are uncertain whether any of the eight HbF inducers in this review have a beneficial effect on people with NTDβT. For each of these HbF inducers, we found only one or at the most two small studies. There is no information on whether any of these HbF inducers have an effect on our primary outcome, blood transfusion. For the second primary outcome, haemoglobin, there may be small differences between intervention groups, but these may not be clinically meaningful and are of low- to very low-certainty evidence. Data on adverse effects and optimal doses are limited. Five studies are awaiting classification, but none are ongoing.

SARS-CoV-2 Infection Dysregulates Host Iron (Fe)-Redox Homeostasis (Fe-R-H): Role of Fe-Redox Regulators, Ferroptosis Inhibitors, Anticoagulants, and Iron-Chelators in COVID-19 Control

Severe imbalance in iron metabolism among SARS-CoV-2 infected patients is prominent in every symptomatic (mild, moderate to severe) clinical phase of COVID-19. Phase-I - Hypoxia correlates with reduced O₂ transport by erythrocytes, overexpression of HIF-1α, altered mitochondrial bioenergetics with host metabolic reprogramming (HMR). Phase-II - Hyperferritinemia results from an increased iron overload, which triggers a fulminant proinflammatory response - the acute cytokine release syndrome (CRS). Elevated cytokine levels (i.e. IL6, TNFα and CRP) strongly correlates with altered ferritin/TF ratios in COVID-19 patients. Phase-III - Thromboembolism is consequential to erythrocyte dysfunction with heme release, increased prothrombin time and elevated D-dimers, cumulatively linked to severe coagulopathies with life-threatening outcomes such as ARDS, and multi-organ failure. Taken together, Fe-R-H dysregulation is implicated in every symptomatic phase of COVID-19. Fe-R-H regulators such as lactoferrin (LF), hemoxygenase-1 (HO-1), erythropoietin (EPO) and hepcidin modulators are innate bio-replenishments that sequester iron, neutralize iron-mediated free radicals, reduce oxidative stress, and improve host defense by optimizing iron metabolism. Due to its pivotal role in 'cytokine storm', ferroptosis is a potential intervention target. Ferroptosis inhibitors such as ferrostatin-1, liproxstatin-1, quercetin, and melatonin could prevent mitochondrial lipid peroxidation, up-regulate antioxidant/GSH levels and abrogate iron overload-induced apoptosis through activation of Nrf2 and HO-1 signaling pathways. Iron chelators such as heparin, deferoxamine, caffeic acid, curcumin, α-lipoic acid, and phytic acid could protect against ferroptosis and restore mitochondrial function, iron-redox potential, and rebalance Fe-R-H status. Therefore, Fe-R-H restoration is a host biomarker-driven potential combat strategy for an effective clinical and post-recovery management of COVID-19.

Transferrin receptor 2 (Tfr2) genetic deletion makes transfusion-independent a murine model of transfusion-dependent β-thalassemia

β-thalassemia is a genetic disorder caused by mutations in the β-globin gene, and characterized by anemia, ineffective erythropoiesis and iron overload. Patients affected by the most severe transfusion-dependent form of the disease (TDT) require lifelong blood transfusions and iron chelation therapy, a symptomatic treatment associated with several complications. Other therapeutic opportunities are available, but none is fully effective and/or applicable to all patients, calling for the identification of novel strategies. Transferrin receptor 2 (TFR2) balances red blood cells production according to iron availability, being an activator of the iron-regulatory hormone hepcidin in the liver and a modulator of erythropoietin signaling in erythroid cells. Selective Tfr2 deletion in the BM improves anemia and iron-overload in non-TDT mice, both as a monotherapy and, even more strikingly, in combination with iron-restricting approaches. However, whether Tfr2 targeting might represent a therapeutic option for TDT has never been investigated so far. Here, we prove that BM Tfr2 deletion improves anemia, erythrocytes morphology and ineffective erythropoiesis in the Hbb^th1/th2 murine model of TDT. This effect is associated with a decrease in the expression of α-globin, which partially corrects the unbalance with β-globin chains and limits the precipitation of misfolded hemoglobin, and with a decrease in the activation of unfolded protein response. Remarkably, BM Tfr2 deletion is also sufficient to avoid long-term blood transfusions required for survival of Hbb^th1/th2 animals, preventing mortality due to chronic anemia and reducing transfusion-associated complications, such as progressive iron-loading. Altogether, TFR2 targeting might represent a promising therapeutic option also for TDT.

Thalassemia Intermedia: Chelator or Not?

Thalassemia is the most common genetic disorder worldwide. Thalassemia intermedia (TI) is non-transfusion-dependent thalassemia (NTDT), which includes β-TI hemoglobin, E/β-thalassemia and hemoglobin H (HbH) disease. Due to the availability of iron chelation therapy, the life expectancy of thalassemia major (TM) patients is now close to that of TI patients. Iron overload is noted in TI due to the increasing iron absorption from the intestine. Questions are raised regarding the relationship between iron chelation therapy and decreased patient morbidity/mortality, as well as the starting threshold for chelation therapy. Searching all the available articles up to 12 August 2022, iron-chelation-related TI was reviewed. In addition to splenectomized patients, osteoporosis was the most common morbidity among TI cases. Most study designs related to ferritin level and morbidities were cross-sectional and most were from the same Italian study groups. Intervention studies of iron chelation therapy included a subgroup of TI that required regular transfusion. Liver iron concentration (LIC) ≥ 5 mg/g/dw measured by MRI and ferritin level > 300 ng/mL were suggested as indicators to start iron chelation therapy, and iron chelation therapy was suggested to be stopped at a ferritin level ≤ 300 ng/mL. No studies showed improved overall survival rates by iron chelation therapy. TI morbidities and mortalities cannot be explained by iron overload alone. Hypoxemia and hemolysis may play a role. Head-to-head studies comparing different treatment methods, including hydroxyurea, fetal hemoglobin-inducing agents, hypertransfusion as well as iron chelation therapy are needed for TI, hopefully separating β-TI and HbH disease. In addition, the target hemoglobin level should be determined for β-TI and HbH disease.

Does Hepcidin Tuning Have a Role among Emerging Treatments for Thalassemia?

The treatments available for thalassemia are rapidly evolving, with major advances made in gene therapy and the modulation of erythropoiesis. The latter includes the therapeutic potential of hepcidin tuning. In thalassemia, hepcidin is significantly depressed, and any rise in hepcidin function has a positive effect on both iron metabolism and erythropoiesis. Synthetic hepcidin and hepcidin mimetics have been developed to the stage of clinical trials. However, they have failed to produce an acceptable efficacy/safety profile. It seems difficult to avoid iron over-restricted erythropoiesis when directly using hepcidin as a drug. Indirect approaches, each one with their advantages and disadvantages, are many and in full development. The ideal approach is to target erythroferrone, the main inhibitor of hepcidin expression, the plasma concentrations of which are greatly increased in iron-loading anemias. Potential means of improving hepcidin function in thalassemia also include acting on TMPRSS6, TfR1, TfR2 or ferroportin, the target of hepcidin. Only having a better understanding of the crosslinks between iron metabolism and erythropoiesis will elucidate the best single option. In the meantime, many potential combinations are currently being explored in preclinical studies. Any long-term clinical study on this approach should include the wide monitoring of functions, as the effects of hepcidin and its modulators are not limited to iron metabolism and erythropoiesis. It is likely that some of the aspects of hepcidin tuning described briefly in this review will play a role in the future treatment of thalassemia.

Hepcidin-to-Ferritin Ratio as an Early Diagnostic Index of Iron Overload in β-Thalassemia Major Patients

Hepcidin (HEPC) hormone production is expected to be elevated in cases accompanying iron overload, but the opposite impact of ineffective erythropoiesis in β-thalassemia major (β-TM) patients overrides this effect. The role of the HEPC-to-ferritin (FER) ratio and its components in iron metabolism along with their diagnostic cutoff values, sensitivity, specificity, and accuracy in β-TM patients with iron overload, were examined in this study. This was a 1:1 case-control study with 120 participants, ages ranging from 2 to 30 years of both sexes, who were assigned into two groups: 60 β-TM patients with iron overload, and a control group, comprising 60 healthy individuals matched by gender and age. In the present study, we found slightly elevated serum HEPC concentration (21.9 ng/mL) compared to the controls (9.9 ng/mL), which was not statistically significant (p =0.1), and the median HEPC-to-FER ratio of the cases was significantly lower than the controls, with the median case-control difference of (-0.366; p < 0.001). Our results revealed a statistically significant impact (p < 0.001) of mean age on the serum HEPC level with the inverse linear correlation of (-0.487, p < 0.001). The area under the curve of the HEPC-to-FER ratio was 0.999 and the optimum cutoff value was 0.046 ng/mL (p < 0.001) with 100.0% sensitivity and 98.3% specificity. In conclusion, we found that serum HEPC-to-FER ratio, with an accuracy of 99.2%, may serve as an excellent index for the diagnosis of iron overload in β-TM patients differentiating them from nonthalassemic controls.

Hemochromatosis classification: update and recommendations by the BIOIRON Society

Hemochromatosis (HC) is a genetically heterogeneous disorder in which uncontrolled intestinal iron absorption may lead to progressive iron overload (IO) responsible for disabling and life-threatening complications such as arthritis, diabetes, heart failure, hepatic cirrhosis, and hepatocellular carcinoma. The recent advances in the knowledge of pathophysiology and molecular basis of iron metabolism have highlighted that HC is caused by mutations in at least 5 genes, resulting in insufficient hepcidin production or, rarely, resistance to hepcidin action. This has led to an HC classification based on different molecular subtypes, mainly reflecting successive gene discovery. This scheme was difficult to adopt in clinical practice and therefore needs revision. Here we present recommendations for unambiguous HC classification developed by a working group of the International Society for the Study of Iron in Biology and Medicine (BIOIRON Society), including both clinicians and basic scientists during a meeting in Heidelberg, Germany. We propose to deemphasize the use of the molecular subtype criteria in favor of a classification addressing both clinical issues and molecular complexity. Ferroportin disease (former type 4a) has been excluded because of its distinct phenotype. The novel classification aims to be of practical help whenever a detailed molecular characterization of HC is not readily available.

Iron Mining for Erythropoiesis

Iron is necessary for essential processes in every cell of the body, but the erythropoietic compartment is a privileged iron consumer. In fact, as a necessary component of hemoglobin and myoglobin, iron assures oxygen distribution; therefore, a considerable amount of iron is required daily for hemoglobin synthesis and erythroid cell proliferation. Therefore, a tight link exists between iron metabolism and erythropoiesis. The liver-derived hormone hepcidin, which controls iron homeostasis via its interaction with the iron exporter ferroportin, coordinates erythropoietic activity and iron homeostasis. When erythropoiesis is enhanced, iron availability to the erythron is mainly ensured by inhibiting hepcidin expression, thereby increasing ferroportin-mediated iron export from both duodenal absorptive cells and reticuloendothelial cells that process old and/or damaged red blood cells. Erythroferrone, a factor produced and secreted by erythroid precursors in response to erythropoietin, has been identified and characterized as a suppressor of hepcidin synthesis to allow iron mobilization and facilitate erythropoiesis.

Iron overload in alcoholic liver disease: underlying mechanisms, detrimental effects, and potential therapeutic targets

Alcoholic liver disease (ALD) is a global public health challenge due to the high incidence and lack of effective therapeutics. Evidence from animal studies and ALD patients has demonstrated that iron overload is a hallmark of ALD. Ethanol exposure can promote iron absorption by downregulating the hepcidin expression, which is probably mediated by inducing oxidative stress and promoting erythropoietin (EPO) production. In addition, ethanol may enhance iron uptake in hepatocytes by upregulating the expression of transferrin receptor (TfR). Iron overload in the liver can aggravate ethanol-elicited liver damage by potentiating oxidative stress via Fenton reaction, promoting activation of Kupffer cells (KCs) and hepatic stellate cells (HSCs), and inducing a recently discovered programmed iron-dependent cell death, ferroptosis. This article reviews the current knowledge of iron metabolism, regulators of iron homeostasis, the mechanism of ethanol-induced iron overload, detrimental effects of iron overload in the liver, and potential therapeutic targets.

Association between left ventricular strain and cardiac iron load in beta-thalassaemia major: a cardiac magnetic resonance study

OBJECTIVE

To evaluate the utility of cardiac magnetic resonance feature tracking-derived left ventricular strain in assessing cardiac dysfunction and investigate the correlation between left ventricular strain and myocardial T2* in patients with beta-thalassaemia major.

METHODS

Forty-two patients with beta-thalassaemia major, having a mean age of 22.49 ± 8.48 years, and age-matched healthy controls were enrolled in the study. The observer drew regions of interest on the interventricular septum, and T2* decay curves were calculated accordingly. The short-axis cine images were used to derive left ventricular circumferential and radial strains, and the long-axis four-chamber and two-chamber images were used to assess left ventricular longitudinal strain.

RESULTS

The mean global left ventricular strains were lower in beta-thalassaemia major patients than the controls (p < 0.05). Left ventricular strains of beta-thalassaemia major patients with cardiac T2* values of > 20 ms were also significantly reduced compared with the controls (p < 0.05); there was no difference between the mean left ventricular ejection fractions of the two groups (p = 0.84). Cardiac T2* showed a weak correlation with left ventricular ejection fraction (r = 0.33, p = 0.03), while the left ventricular circumferential strain showed a good positive correlation with cardiac T2* (r = 0.6, p < 0.0001).

CONCLUSION

Compared with healthy controls, patients with beta-thalassaemia major, including those with myocardial T2* values of >20 ms, showed reduced global left ventricular strains. Left ventricular circumferential strain was positively correlated with myocardial T2*. Left ventricular strain analysis using cardiac magnetic resonance feature tracking may have utility in beta-thalassaemia major assessment.Key FindingsPatients with beta-thalassaemia major, including those with myocardial T2* values of >20 ms, had reduced global left ventricular strains.Cardiac T2* showed a weak correlation with left ventricular ejection fraction, while the left ventricular circumferential strain showed a good positive correlation with cardiac T2*.ImportanceLeft ventricular strain using cardiac magnetic resonance feature tracking might be used as an adjunct in assessing cardiac functions in beta-thalassaemia major.

Coordination of iron homeostasis by bone morphogenetic proteins: Current understanding and unanswered questions

Iron homeostasis is tightly regulated to balance the iron requirement for erythropoiesis and other vital cellular functions, while preventing cellular injury from iron excess. The liver hormone hepcidin is the master regulator of systemic iron balance by controlling the degradation and function of the sole known mammalian iron exporter ferroportin. Liver hepcidin expression is coordinately regulated by several signals that indicate the need for more or less iron, including plasma and tissue iron levels, inflammation, and erythropoietic drive. Most of these signals regulate hepcidin expression by modulating the activity of the bone morphogenetic protein (BMP)-SMAD pathway, which controls hepcidin transcription. Genetic disorders of iron overload and iron deficiency have identified several hepatocyte membrane proteins that play a critical role in mediating the BMP-SMAD and hepcidin regulatory response to iron. However, the precise molecular mechanisms by which serum and tissue iron levels are sensed to regulate BMP ligand production and promote the physical and/or functional interaction of these proteins to modulate SMAD signaling and hepcidin expression remain uncertain. This critical commentary will focus on the current understanding and key unanswered questions regarding how the liver senses iron levels to regulate BMP-SMAD signaling and thereby hepcidin expression to control systemic iron homeostasis.

HeGRI: A Novel Index of Serum Hepcidin Suppression in Relation to the Degree of Renal Dysfunction among β-Thalassemia Major Patients

Background: The progressive renal function inadequacy results in altered hepcidin metabolism due to a shifting of its renal elimination, which consequently affects enteric iron absorption and iron stores’ availability. This study aimed to investigate and correlate renal function, iron status, and hepcidin in patients with β-thalassemia major through a novel index. Methods: In this 1:1 case–control study, serum hepcidin, serum ferritin, iron study, hematological and renal function parameters were compared between 60 β-thalassemia major patients with iron overload and 61 healthy individuals (2–30 years old). Results: The concentrations of serum hepcidin (21.898 vs. 9.941 ng/mL; p < 0.001) and eGFR (179.71 vs. 132.95; p < 0.001) were significantly higher in β-thalassemia major patients compared to the controls. The serum hepcidin levels decreased with increasing levels of total iron-binding capacity (TIBC; β = −0.442; p = 0.024), transferrin saturation (β = −0.343; p = 0.023), serum creatinine (β = −0.625; p = 0.0030), and eGFR (β = −0.496; p = 0.011). The mean hepcidin/ferritin ratio was significantly lower in the β-thalassemia major cases (0.0069 vs. 0.3970; p < 0.001). The novel hepcidin/eGFR ratio index (HeGRI) was significantly higher in the patient group compared to controls (0.12 vs. 0.09; p = 0.031), respectively. Conclusions: These results suggest that HeGRI could be a potential index of the appropriateness of serum hepcidin suppression associated with the degree of renal dysfunction among β-thalassemia major patients.

The Evaluation Of Iron Deficiency And Iron Overload

BACKGROUND

In the western world, 2-5% of women of child-bearing age suffer from irondeficiency anemia. Iron overload due to chronic treatment with blood transfusions or hereditary hemochromatosis is much rarer.

METHODS

This review is based on pertinent publications retrieved by a selective search on the pathophysiology, clinical features, and diagnostic evaluation of iron deficiency and iron overload.

RESULTS

The main causes of iron deficiency are malnutrition and blood loss. Its differential diagnosis includes iron-refractory iron deficiency anemia (IRIDA), a rare congenital disease in which the hepcidin level is pathologically elevated, as well as the more common anemia of chronic disease (anemia of chronic inflammation), in which increased amounts of hepcidin are formed under the influence of interleukin-6 and enteric iron uptake is blocked as a result. Iron overload comes about through long-term transfusion treatment or a congenital disturbance of iron metabolism (hemochromatosis). Its diagnostic evaluation is based on clinical and laboratory findings, imaging studies, and specific mutation analyses.

CONCLUSION

Our improving understanding of the molecular pathophysiology of iron metabolism aids in the evaluation of iron deficiency and iron overload and may in future enable treatment not just with iron supplementation or iron chelation, but also with targeted pharmacological modulation of the hepcidin regulatory system.

The Link of Pancreatic Iron with Glucose Metabolism and Cardiac Iron in Thalassemia Intermedia: A Large, Multicenter Observational Study

In thalassemia major, pancreatic iron was demonstrated as a powerful predictor not only for the alterations of glucose metabolism but also for cardiac iron, fibrosis, and complications, supporting a profound link between pancreatic iron and heart disease. We determined for the first time the prevalence of pancreatic iron overload (IO) in thalassemia intermedia (TI) and systematically explored the link between pancreas T2* values and glucose metabolism and cardiac outcomes. We considered 221 beta-TI patients (53.2% females, 42.95 ± 13.74 years) consecutively enrolled in the Extension–Myocardial Iron Overload in Thalassemia project. Magnetic Resonance Imaging was used to quantify IO (T2* technique) and biventricular function and to detect replacement myocardial fibrosis. The glucose metabolism was assessed by the oral glucose tolerance test (OGTT). Pancreatic IO was more frequent in regularly transfused (N = 145) than in nontransfused patients (67.6% vs. 31.6%; p < 0.0001). In the regular transfused group, splenectomy and hepatitis C virus infection were both associated with high pancreatic siderosis. Patients with normal glucose metabolism showed significantly higher global pancreas T2* values than patients with altered OGTT. A pancreas T2* < 17.9 ms predicted an abnormal OGTT. A normal pancreas T2* value showed a 100% negative predictive value for cardiac iron. Pancreas T2* values were not associated to biventricular function, replacement myocardial fibrosis, or cardiac complications. Our findings suggest that in the presence of pancreatic IO, it would be prudent to initiate or intensify iron chelation therapy to prospectively prevent both disturbances of glucose metabolism and cardiac iron accumulation.

Thalassemia and autoimmune diseases: Absence of evidence or evidence of absence?

The thalassemias are a group of inherited disorders of hemoglobin synthesis that continue to pause a global public health concern. The complex molecular and pathogenetic pathways involved in disease process lead to an array of comorbidities that require lifelong management. The disease and its treatment can also lead to alterations in immune function and a link to various autoimmune diseases has been frequently suggested. However, most data stem from single case reports and small studies that do not allow proper assessment of causal associations. Still, the high morbidity in thalassemia makes patients vulnerable to the added burden of coexisting autoimmune diseases, and special management considerations in this patient population are warranted. In this review, we explore insights and data from the literature on various autoimmune disease that have been observed in patients with thalassemia. The role of the thalassemia carrier state in modifying outcomes of patients with autoimmune diseases is also discussed.

Oral ferroportin inhibitor vamifeport for improving iron homeostasis and erythropoiesis in β-thalassemia: current evidence and future clinical development

INTRODUCTION

In β-thalassemia, imbalanced globin synthesis causes reduced red blood cell survival and ineffective erythropoiesis. Suppressed hepcidin levels increase ferroportin-mediated iron transport in enterocytes, causing increased iron absorption and potentially iron overload. Low hepcidin also stimulates ferroportin-mediated iron release from macrophages, increasing transferrin saturation (TSAT), potentially forming non-transferrin-bound iron, which can be toxic. Modulating the hepcidin-ferroportin axis is an attractive strategy to improve ineffective erythropoiesis and limit the potential tissue damage resulting from iron overload. There are no oral β-thalassemia treatments that consistently ameliorate anemia and prevent iron overload.

AREAS COVERED

The preclinical and clinical development of vamifeport (VIT-2763), a novel ferroportin inhibitor, was reviewed. PubMed, EMBASE and ClinicalTrials.gov were searched using the search term 'VIT-2763'.

EXPERT OPINION

Vamifeport is the first oral ferroportin inhibitor in clinical development. In healthy volunteers, vamifeport had comparable safety to placebo, was well tolerated and rapidly decreased iron levels and reduced TSAT, consistent with observations in preclinical models. Data from ongoing/planned Phase II studies are critical to define its potential in β-thalassemia and other conditions associated with iron overabsorption and/or ineffective erythropoiesis. If vamifeport potentially increases hemoglobin and reduces iron-related parameters, it could be a suitable treatment for non-transfusion-dependent and transfusion-dependent β-thalassemia.

Erythropoiesis and Iron Parameters in Transfusion-dependent and Nontransfusion-dependent Thalassemias

INTRODUCTION

To clarify mechanisms of ineffective erythropoiesis on iron metabolism, studies on erythroid factors that regulating hepcidin suppression have been carried out. The aim of the current study is to identify associations between erythropoiesis and iron homeostasis parameters in β-thalassemias.

MATERIALS AND METHODS

This study consisted of 83 subjects: 21 thalassemia major (TM), 20 thalassemia intermedia (TI), 20 thalassemia trait (TT), and 22 healthy subjects (HS). Erythroferrone (ERFE), hepcidin, growth differentiation factor-15 (GDF15), erythropoietin (EPO), and iron status parameters were measured.

RESULTS

Our results showed that TM and TI patients had higher hepcidin than the TT and control groups. The hepcidin/ferritin in TM patients was significantly lower than the other groups. GDF15 in TM and TI patients was significantly higher than in the TT and control groups. Also, TI group had significantly higher ERFE concentration and EPO activity when compared with the TM, TT, and HS groups. EPO activity showed positive correlation with ERFE and GDF15 concentrations. We could not find any correlation between ERFE and hepcidin concentrations.

CONCLUSIONS

ERFE may be one of the parameters used to demonstrate erythropoietic activity level in thalassemias. More detailed studies are needed to clarify the role of ERFE in iron metabolism in the patients with thalassemias.

Correlation Between Serum Ferritin and Viral Hepatitis in Thalassemia Patients

Serum ferritin is an acute phase protein; importantly, its level is noticeably increased in response to iron overload and systemic inflammation. The iron overload status in thalassemia patients has been recognized as a potential way to measure liver iron concentration (LIC) levels using magnetic resonance imaging (MRI). The aim of this study was to investigate the effect of chronic viral hepatitis on the level of serum ferritin in patients with thalassemia. A cross-sectional study was conducted involving chronic viral hepatitis infection. Mean serum ferritin and LIC levels were recorded. The LIC values were used to divide the patients into two groups; a higher LIC group (>5 mg Fe/g) and a lower LIC group (<5 mg Fe/g). Mean serum ferritin levels were then compared between the two LIC groups. We identified 32 thalassemia patients comprising of 13 chronic viral hepatitis patients, seven patients with hepatitis B virus (HBV), and six patients with hepatitis C virus (HCV). With regard to the group with higher LIC values, the mean serum ferritin levels in the hepatitis group were significantly higher than for those in the non hepatitis group (1776 ± 488 vs. 967 ± 860 ng/mL, p = 0.03). Furthermore, the linear correlation between the mean serum ferritin levels and the viral load in the non transfusion-dependent thalassemia (NTDT) group were found to be significantly correlated (r = 0.7, p = 0.04). Chronic viral hepatitis was determined to be a possible casualty of disproportionately high ferritin levels in the NTDT group.

Tackling the unknowns in understanding and management of hospital acquired anemia

Hospital acquired anemia (HAA) has been a recognized entity for nearly 50 years. Despite multiple hypotheses, a mechanistic understanding is lacking, and targeted interventions have not yet yielded significantly impactful results. Known risk factors include advanced age, multiple co-morbidities, low bone marrow reserve, admission to the intensive care unit, and frequent phlebotomy. However, confounding variables in many studies continues to complicate the identification of additional risk factors. Improved understanding of iron metabolism, erythropoiesis, and the erythroid iron restriction response in the last few decades, as well as the recent demonstration of poor outcomes correlating with increased transfusion have refocused attention on HAA. While retrospective database studies provide ample correlative data between 1) HAA and poor outcomes; 2) reduction of phlebotomy volume and decrease in transfusion requirement; and 3) over-transfusion and increased mortality, no causal link between reduced phlebotomy volume, decreased rates of HAA, and improved mortality or other relevant outcomes have been definitely established. Here, we review the current state of knowledge and provide a summary of potential directions to understand and mitigate HAA. There are at present no clear guidelines on whether and when to evaluate hospitalized patients for underlying causes of anemia. We thus provide a guide for clinicians in general practice toward identifying patients at the highest risk for HAA, decreasing blood loss through phlebotomy to the greatest degree feasible, and evaluating and treating reversible causes of anemia in a targeted population.

Relation of Serum Ferritin Level with Serum Hepcidin and Fucose Levels in Children with β-Thalassemia Major

The aim of this study was to assess serum ferritin, hepcidin, L-fucose, and protein binding fucose levels in β-thalassemia major (β-TM) patients and to correlate the serum ferritin level with hepcidin and fucose levels. A total 70 (26 males and 44 females) children with β-TM, ages ranging from 5 to 16 years (mean age 8.3 ± 2.7 years) and 50 (25 males and 25 females) apparently healthy subjects with matching age and sex were included as a control group. An especially designed questionnaire was used to collect age, gender, body mass index (BMI), hemoglobin (Hb), serum ferritin, hepcidin-25 peptide, α-L-fucose, and protein binding fucose (PBF) levels. β-Thalassemia major patients had significantly (p < 0.05) higher serum ferritin, fucose and PBF levels, but the serum hepcidin level was significantly (p < 0.05) lower when compared to the controls, and their levels were affected by the gender of the β-TM patients, as it was significantly (p < 0.05) higher in female in comparison to male patients. There was no significant (p > 0.05) correlation between serum ferritin with hepcidin and fucose levels as a marker of iron overload in β-TM. The regulation of hepcidin, and L-fucose levels in patients with β-TM is more affected by erythropoeitic activity than by iron overload, as there was no significant correlation between serum ferritin with hepcidin and fucose levels as a marker of iron overload in β-TM.

Relation of hepcidin gene expression in blood mononuclear cells with iron overload severity among β-thalassemia major patients

Iron overload is the main cause of morbidity and mortality in β-thalassemia major patients, and cardiac iron overload is the most common reason for death in these transfusion-dependent patients. Hepcidin, a liver-derived peptide hormone, plays a key role in plasma iron levels regulation by controlling two main stages, digestive iron absorption in enterocytes, and iron recycling in macrophages. Although hepcidin is mainly secreted from hepatocytes in the liver, it is also synthesized from mononuclear cells consisting of monocytes and lymphocytes. Binding of this molecule to ferroportin, a specific cellular exporter of iron, leads to degradation of the ligand-receptor complex, which reduces the iron overload by lowering the amounts of iron released into the plasma. Likewise, the same mechanism has been proved to be true for lymphocyte-drived hepcidin. The expression levels of hepcidin mRNA were evaluated using quantitative real time PCR (qRT-PCR) in 50 β-thalassemia major patients, as well as 25 healthy volunteers as the group of control. There was a significantly positive correlation between the cardiac iron concentration, showed by higher T2 values, and hepcidin levels in the patients (p = 0.028; r = 0.311). However, hepcidin expression levels did not significantly correlate with ferritin and liver iron concentrations. Hepcidin can act as a beneficial marker to determine iron overload degrees, particularly in the heart, in β-thalassemia major patients and be used as a logical therapeutic agent for treatment of β-thalassemia disorders.

Management of Iron Overload in Beta-Thalassemia Patients: Clinical Practice Update Based on Case Series

Thalassemia syndromes are characterized by the inability to produce normal hemoglobin. Ineffective erythropoiesis and red cell transfusions are sources of excess iron that the human organism is unable to remove. Iron that is not saturated by transferrin is a toxic agent that, in transfusion-dependent patients, leads to death from iron-induced cardiomyopathy in the second decade of life. The availability of effective iron chelators, advances in the understanding of the mechanism of iron toxicity and overloading, and the availability of noninvasive methods to monitor iron loading and unloading in the liver, heart, and pancreas have all significantly increased the survival of patients with thalassemia. Prolonged exposure to iron toxicity is involved in the development of endocrinopathy, osteoporosis, cirrhosis, renal failure, and malignant transformation. Now that survival has been dramatically improved, the challenge of iron chelation therapy is to prevent complications. The time has come to consider that the primary goal of chelation therapy is to avoid 24-h exposure to toxic iron and maintain body iron levels within the normal range, avoiding possible chelation-related damage. It is very important to minimize irreversible organ damage to prevent malignant transformation before complications set in and make patients ineligible for current and future curative therapies. In this clinical case-based review, we highlight particular aspects of the management of iron overload in patients with beta-thalassemia syndromes, focusing on our own experience in treating such patients. We review the pathophysiology of iron overload and the different ways to assess, quantify, and monitor it. We also discuss chelation strategies that can be used with currently available chelators, balancing the need to keep non-transferrin-bound iron levels to a minimum (zero) 24 h a day, 7 days a week and the risk of over-chelation.

Liver complications of haemoglobin H disease in adults

Haemoglobin H (HbH) disease is a type of non-transfusion-dependent thalassaemia. This cross-sectional study aimed at determining the prevalence and severity of liver iron overload and liver fibrosis in patients with HbH disease. Risk factors for advanced liver fibrosis were also identified. A total of 80 patients were evaluated [median (range) age 53 (24-79) years, male 34%, non-deletional HbH disease 24%]. Patients underwent 'observed' T2-weighted magnetic resonance imaging examination for liver iron concentration (LIC) quantification, and transient elastography for liver stiffness measurement (LSM) and fibrosis staging. In all, 25 patients (31%) had moderate-to-severe liver iron overload (LIC ≥7 mg/g dry weight). The median LIC was higher in non-deletional than in deletional HbH disease (7·8 vs. 2.9 mg/g dry weight, P = 0·002). In all, 16 patients (20%) had advanced liver fibrosis (LSM >7.9 kPa) and seven (9%) out of them had probable cirrhosis (LSM >11.9 kPa). LSM positively correlated with age (R = 0·24, P = 0·03), serum ferritin (R = 0·36, P = 0·001) and LIC (R = 0·28, P = 0·01). In multivariable regression, age ≥65 years [odds ratio (OR) 4·97, 95% confidence interval (CI) 1·52-17·50; P = 0·047] and moderate-to-severe liver iron overload (OR 3·47, 95% CI 1·01-12·14; P = 0·01) were independently associated with advanced liver fibrosis. The findings suggest that regular screening for liver complications should be considered in the management of HbH disease.

Assessment of ventricular dysfunction in Egyptian children with Beta-thalassemia major

OBJECTIVE/BACKGROUND

The purpose of this study was to evaluate serum cardiac troponin I and serum N-terminal (NT) pro-brain natriuretic peptide (pro-BNP) levels and the utility of tissue Doppler imaging in assessing cardiovascular changes following left ventricular (LV) dysfunction in children with beta-thalassemia major (β-TM). In children with β-TM who depend on regular blood transfusion, cardiac iron toxicity is a common serious complication. The most common cause of death among these patients is congestive heart failure.

METHODS

This is a cross-sectional study which included 50 patients with β-TM and 50 healthy controls. Tissue Doppler imaging was performed and levels of serum ferritin, cardiac troponin I, and NT pro-BNP were estimated for all included patients.

RESULTS

Serum NT pro-BNP and cardiac troponin (cTnI) showed a significant increase in patients with β-TM (p < .001). In patients with β-TM, LV dimensions (LV end systolic diameter) and (LV end diastolic diameter) were large (p < .01); LV mass (p < .01), E wave, and E/A ratio (p < .01) were high (p < .05); and deceleration time was short (p < .05). Besides, transmitral ratio (E/E_m) (p < .05) and tricuspid valve velocity were higher (p < .05), and early diastolic velocity (E_m) (p < .05) and systolic wave velocity (S_m) were lower in patients with β-TM (p < .05). A significant positive correlation was detected between the pro-BNP and E wave (r = 0.558, p < .001), E/A ratio (r = 0.403, p < .001), E/E_m ratio (r = 0.576, p < .001), and ferritin (r = 0.545, p < .001).

CONCLUSION

Pulsed wave tissue Doppler imaging and NT pro-BNP had a significant role in the estimation of ventricular dysfunction in children with β-TM.

Evaluation of endocrine complications in beta-thalassemia intermedia (β-TI): a cross-sectional multicenter study

BACKGROUND

Data on the prevalence and type of endocrine disorders in β-thalassemia intermedia (β-TI) patients are scarce. This multicenter study was designed to determine the prevalence of endocrine complications and the associated risk factors in a large group of β-TI patients.

METHODS

In this cross-sectional multicenter study, 726 β-TI patients, aged 2.5-80 years, registered at 12 thalassemic centers, from nine countries, were enrolled during 2017. In a subgroup of 522 patients (mean age 30.8 ± 12.1; range: 2.5-80 years) from Qatar, Iran, Oman, Cyprus, and Jordan detailed data were available.

RESULTS

Overall, the most prevalent complications were osteopenia/osteoporosis (22.3%), hypogonadism (10.1%), and primary hypothyroidism (5.3%). In the subgroup multivariate analysis, older age was a risk factor for osteoporosis (Odds ratio: 7.870, 95% CI: 4.729-13.099, P < 0.001), hypogonadism (Odds ratio: 6.310, 95% CI: 2.944-13.521, P < 0.001), and non-insulin-dependent diabetes mellitus (NIDDM; Odds ratio: 17.67, 95% CI: 2.217-140.968, P = 0.007). Splenectomy was a risk factor for osteoporosis (Odds ratio: 1.736, 95% CI: 1.012-2.977, P = 0.045). Hydroxyurea was identified as a "protective factor" for NIDDM (Odds ratio: 0.259, 95% CI: 0.074-0.902, P = 0.034).

CONCLUSIONS

To the best of our knowledge, this is the largest cohort of β-TI patients with endocrine disorders evaluated in extremely heterogenic thalassemic populations for age, clinical, hematological, and molecular composition. The study demonstrates that endocrine complications are less common in patients with β-TI compared with β-TM patients. However, regular monitoring with timely diagnosis and proper management is crucial to prevent endocrine complications in β-TI patients.

Consequences of parenteral iron-dextran loading investigated in minipigs. A new model of transfusional iron overload

Patients with blood transfusion-dependent anemias develop transfusional iron overload (TIO), which may cause cardiosiderosis. In patients with an ineffective erythropoiesis, such as thalassemia major, common transfusion regimes aim at suppression of erythropoiesis and of enteral iron loading. Recent data suggest that maintaining residual, ineffective erythropoiesis may protect from cardiosiderosis. We investigated the common consequences of TIO, including cardiosiderosis, in a minipig model of iron overload with normal erythropoiesis. TIO was mimicked by long-term, weekly iron-dextran injections. Iron-dextran loading for around one year induced very high liver iron concentrations, but extrahepatic iron loading, and iron-induced toxicities were mild and did not include fibrosis. Iron deposits were primarily in reticuloendothelial cells, and parenchymal cardiac iron loading was mild. Compared to non-thalassemic patients with TIO, comparable cardiosiderosis in minipigs required about 4-fold greater body iron loads. It is suggested that this resistance against extrahepatic iron loading and toxicity in minipigs may at least in part be explained by a protective effect of the normal erythropoiesis, and additionally by a larger total iron storage capacity of RES than in patients with TIO. Parenteral iron-dextran loading of minipigs is a promising and feasible large-animal model of iron overload, that may mimic TIO in non-thalassemic patients.

Antibodies against the erythroferrone N-terminal domain prevent hepcidin suppression and ameliorate murine thalassemia

Erythroferrone (ERFE) is produced by erythroblasts in response to erythropoietin (EPO) and acts in the liver to prevent hepcidin stimulation by BMP6. Hepcidin suppression allows for the mobilization of iron to the bone marrow for the production of red blood cells. Aberrantly high circulating ERFE in conditions of stress erythropoiesis, such as in patients with β-thalassemia, promotes the tissue iron accumulation that substantially contributes to morbidity in these patients. Here we developed antibodies against ERFE to prevent hepcidin suppression and to correct the iron loading phenotype in a mouse model of β-thalassemia [Hbb(th3/+) mice] and used these antibodies as tools to further characterize ERFE's mechanism of action. We show that ERFE binds to BMP6 with nanomolar affinity and binds BMP2 and BMP4 with somewhat weaker affinities. We found that BMP6 binds the N-terminal domain of ERFE, and a polypeptide derived from the N terminus of ERFE was sufficient to cause hepcidin suppression in Huh7 hepatoma cells and in wild-type mice. Anti-ERFE antibodies targeting the N-terminal domain prevented hepcidin suppression in ERFE-treated Huh7 cells and in EPO-treated mice. Finally, we observed a decrease in splenomegaly and serum and liver iron in anti-ERFE-treated Hbb(th3/+) mice, accompanied by an increase in red blood cells and hemoglobin and a decrease in reticulocyte counts. In summary, we show that ERFE binds BMP6 directly and with high affinity, and that antibodies targeting the N-terminal domain of ERFE that prevent ERFE-BMP6 interactions constitute a potential therapeutic tool for iron loading anemias.