New Mutations in HFE2 and TFR2 Genes Causing Non HFE-Related Hereditary Hemochromatosis

Hereditary hemochromatosis (HH) is an iron metabolism disease clinically characterized by excessive iron deposition in parenchymal organs such as liver, heart, pancreas, and joints. It is caused by mutations in at least five different genes. HFE hemochromatosis is the most common type of hemochromatosis, while non-HFE related hemochromatosis are rare cases. Here, we describe six new patients of non-HFE related HH from five different families. Two families (Family 1 and 2) have novel nonsense mutations in the HFE2 gene have novel nonsense mutations (p.Arg63Ter and Asp36ThrfsTer96). Three families have mutations in the TFR2 gene, one case has one previously unreported mutation (Family A—p.Asp680Tyr) and two cases have known pathogenic mutations (Family B and D—p.Trp781Ter and p.Gln672Ter respectively). Clinical, biochemical, and genetic data are discussed in all these cases. These rare cases of non-HFE related hereditary hemochromatosis highlight the importance of an earlier molecular diagnosis in a specialized center to prevent serious clinical complications.

Mesenchymal Stem Cells Alleviate Post-resuscitation Cardiac and Cerebral Injuries by Inhibiting Cell Pyroptosis and Ferroptosis in a Swine Model of Cardiac Arrest

Following cardiopulmonary resuscitation (CPR), the ensuing cardiac and cerebral injuries contribute to the poor outcome of cardiac arrest (CA) victims, in which the pathogenetic process is possibly driven by cell pyroptosis and ferroptosis. Mesenchymal stem cells (MSCs) have been shown to be a promising strategy for post-resuscitation cardiac and cerebral protection in rat, but its effectiveness in the clinically relevant swine model and the potential protective mechanism remain unknown. The present study was designed to investigate whether MSCs administration could alleviate post-resuscitation cardiac and cerebral injuries through the inhibition of cell pyroptosis and ferroptosis in swine. Twenty-four male domestic swine were randomly divided into three groups: sham, CPR, and MSC. A dose of 2.5×106/kg of MSCs derived from human embryonic stem cells was intravenously infused at 1.5, and 3 days prior to CA. The animal model was established by 8 min of CA and then 8 min of CPR. After resuscitation, cardiac, cerebral function and injury biomarkers were regularly evaluated for a total of 24 h. At 24 h post-resuscitation, pyroptosis-related proteins (NLRP3, ASC, cleaved caspase-1, GSDMD), proinflammatory cytokines (IL-1β, IL-18), ferroptosis-related proteins (ACSL4, GPX4) and iron deposition in the heart, cortex and hippocampus were measured. Consequently, significantly greater cardiac, cerebral dysfunction and injuries after resuscitation were observed in the CPR and MSC groups compared with the sham group. However, the severity of cardiac and cerebral damage were significantly milder in the MSC group than in the CPR group. In addition, the expression levels of NLRP3, ASC, cleaved caspase-1, GSDMD and ACSL4, the contents of IL-1β and IL-18, and the level of iron deposition were significantly higher while the expression level of GPX4 was significantly lower in the heart, cortex and hippocampus in all resuscitated animals compared with the sham group. Nevertheless, MSCs administration significantly decreased post-resuscitation cardiac, cerebral pyroptosis and ferroptosis compared to the CPR group. Our results showed that the administration of MSCs significantly alleviated post-resuscitation cardiac and cerebral injuries in swine, in which the protective effects were related to the inhibition of cell pyroptosis and ferroptosis.

Analysis of deep grey nuclei susceptibility in early childhood: a quantitative susceptibility mapping and R2* study at 3 Tesla

Purpose Aging is the most significant determinant for brain iron accumulation in the deep grey matter. Data on brain iron evolution during brain maturation in early childhood are limited. The purpose of this study was to investigate age-related iron deposition in the deep grey matter in children using quantitative susceptibility (QSM) and R2* mapping. Methods We evaluated brain MRI scans of 74 children (age 6–154 months, mean 40 months). A multi-echo gradient-echo sequence obtained at 3 Tesla was used for the QSM and R2* calculation. Susceptibility of the pallidum, head of caudate nucleus, and putamen was correlated with age and compared between sexes. Results Susceptibility changes in all three nuclei correlated with age (correlation coefficients for QSM/R2*: globus pallidus 0.955/0.882, caudate nucleus 0.76/0.65, and putamen 0.643/0.611). During the first 2 years, the R2* values increased more rapidly than the QSM values, indicating a combined effect of iron deposition and myelination, followed by a likely dominating effect of iron deposition. There was no significant gender difference. Conclusion QSM and R2* can monitor myelin maturation processes and iron accumulation in the deep grey nuclei of the brain in early life and may be a promising tool for the detection of deviations of this normal process. Susceptibility in the deep nuclei is almost similar early after birth and increases more quickly in the pallidum. The combined use of QSM and R2* analysis is beneficial.

Iron Deposition and Ferroptosis in the Spleen in a Murine Model of Acute Radiation Syndrome

Total body radiation (TBI) can result in death associated with hematopoietic insufficiency. Although radiation causes apoptosis of white blood cells, red blood cells (RBC) undergo hemolysis due to hemoglobin denaturation. RBC lysis post-irradiation results in the release of iron into the plasma, producing a secondary toxic event. We investigated the impact of radiation-induced iron release on the spleen of mice following TBI and the effects of the radiation mitigator captopril. RBC and hematocrit were reduced ~7 days (nadir ~14 days) post-TBI. Prussian blue staining revealed ~20-60-fold increased Fe3+ in the spleen 7-14 days post-irradiation, also associated with altered expression of iron binding and transport proteins, determined by qPCR, western blotting, and immunohistochemistry. Captopril did not prevent iron deposition in the spleen, and did not significantly modulate most iron-binding proteins. Spleen volumes were markedly decreased 7-14 days, correlating with high Fe3+. At these time points, caspase-3 was activated and we identified four markers of ferroptosis, iron-dependent programmed cell death. Interestingly, p21/Waf1, a marker of accelerated senescence, was not upregulated in vivo. Macrophage inflammation is an important effect of TBI. We investigated the effects of radiation and Fe3+ on the cultured J774A.1 murine macrophage cell line. Radiation induced p21/Waf1 and ferritin, but not caspase-3, within 24 h. Radiation ± iron upregulated several markers of pro-inflammatory M1 polarization; radiation with iron also upregulated a marker of anti-inflammatory M2 polarization. Our data indicate that following TBI, iron accumulates in the spleen where it regulates iron binding proteins and triggers ferroptosis.

Frequency, Pattern, and Associations of Renal Iron Accumulation in Sickle Beta-Thalassemia

Background: Chronically transfused homozygous sickle cell disease (HbSS) patients were shown to have higher kidney iron deposition than thalassemia major patients, not associated to total body iron and mainly caused by chronic hemolysis. Kidney iron deposition has not been explored in sickle beta-thalassemia (Sβ-thal), resulting from the inheritance of both sickle cell and beta-thalssemia genes. Aim: This multi center study aimed to study frequency, pattern, and associations of renal iron accumulation in sickle beta-thalassemia. Methods: Thirty-three Sβ-thal patients (36.49±14.72 years; 13 females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia (E-MIOT) network were considered. Moreover, 20 healthy subjects, 14 HbSS patients and 71 thalassemia major (TM) patients were included as comparison groups. Hepatic, cardiac, pancreatic, and renal iron overload was quantified by the gradient-echo T2* technique. In each kidney T2* was measured in anterior, posterolateral, and posteromedial parenchymal regions and the global T2* value was calculated as the average of the two kidneys T2* values. Results. Global renal T2* were significantly higher in healthy subjects versus both Sβ-thal patients (49.68±10.09 ms vs 43.19±8.07 ms; P=0.013) and HbSS patients (49.68±10.09 ms vs 26.21±17.07 ms; P<0.0001). Sβ-thal patients showed comparable age, sex, frequency of regular transfusion, hematochemical parameters, and hepatic, cardiac and pancreatic iron load than HbSS patients, but they had a significant lower frequency of renal iron overload (global renal T2*<31 ms) (9.1% vs 57.1%; P=0.001). Regularly transfused patients (16 Sβ-thal and 10 HbSS) were compared with TM patients, homogeneous for age and sex, but TM started regular transfusions significantly earlier and they were more frequently chelated. No significant difference was detected in terms of hepatic and cardiac iron levels, but TM patients had significantly lower pancreas T2* values than both the other two groups and significantly higher global renal T2* values than HbSS patients (42.87±9.43 ms vs 24.39±15.74 ms; P=0.001). In Sβ-thal patients no significant difference was detected between T2* values in left and right kidneys, and global renal T2* values were not associated to age, gender, splenectomy, and they were comparable between regularly transfused and non transfused patients. No correlation was detected between renal T2* values and serum ferritin levels or iron load in the other organs. Global renal T2* values were not associated with serum creatinine levels but showed a significant inverse correlation with serum lactate dehydrogenase (Figure 1). Conclusion. Renal iron deposition is not common in Sβ-thal patients, with a prevalence significantly lower compared to that of HbSS patients, but with a similar underlying mechanism due to the chronic hemolysis. Figure 1 Figure 1. Disclosures Pepe: Bayer S.p.A.: Other: no profit support; Chiesi Farmaceutici S.p.A: Other: no profit support. Maggio: Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene Corp: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees.

The impact of magnetic resonance imaging in the assessment of iron overload in heart and liver in transfusion-dependent thalassemic children: Minia experience

Background Thalassemia is the most prevalent single-gene disorder. Myocardial and hepatic iron depositions lead to complications and eventually death. We aimed to assess the diagnostic efficacy of magnetic resonance imaging T2* (MRI T2*) in quantifying iron overload in liver and heart in transfusion-dependent B-thalassemia major (TDT) children. Methods Prospective clinical study was carried on sixty children diagnosed with TDT. All of them underwent laboratory investigations, including CBC, serum iron, and ferritin levels. MRI T2* of the heart and liver was carried out to measure the iron overload and estimate the left ventricular ejection fraction (LVEF). Results Thirty-eight males and 22 females with TDT with a mean age of 13.23 years were included. Twenty cases (33.3%) had severe liver iron overload, while 36 (60%) had normal cardiac iron. There was a moderate significant negative association between hepatic and cardiac iron deposition (P = 0.03). All cases with severe cardiac iron overload had impaired LVEF below 56%. A non-significant positive association was noticed between cardiac iron deposition and LVEF in T2* (P = 0.08). A moderate negative significant association was detected between hepatic iron deposition and serum ferritin, while a fair negative significant association was found between serum ferritin and cardiac iron deposition with P values of 0.04 and 0.02, respectively. Conclusion MRI T2* is the gold standard for monitoring and follow-up of iron overload in the heart and liver. It should be routinely performed in all TDT children as liver iron, and serum ferritin do not reflect cardiac iron overload.