Creation of an MRI phantom based on super-paramagnetic nanoparticles of iron oxide (SPIO) for standardization of the conversion of T2 * values in the concentration of iron in the liver

In this study the standardization method for T2* maps acquisition on various MR scanners (3T and 1.5T) is proposed. The reproducibility of the obtained T2* values is realized through the MR-compatible phantom containing paramagnetic complex iron oxide nanoparticles. The repeatability of measurements results has shown that the created phantom retains all the required characteristics (homogeneity, stability of concentrations and manifested paramagnetic properties) over a long period of time. The application of standardized T2* values allows to use previously received T2*, [ms] to iron concentrations in the dry substance of the liver (LIC), [mg/ml] conversion formulas for accurate, fast and non-invasive MRI diagnostics of liver iron overload.

Non-invasive measurement of liver iron concentration by magnetic resonance imaging and its clinical usefulness

Determination of liver iron concentration by magnetic resonance imaging (MRI) is becoming the new technique of choice for the diagnosis of iron overload in hereditary haemochromatosis and other liver iron surcharge diseases. Determination of hepatic iron concentration obtained by liver biopsy has been the gold standard for years. The development of MRI techniques, via signal intensity ratio methods or relaxometry, has provided a non-invasive and more accurate approach to the diagnosis of liver iron overload. This article reviews the available MRI methods for the determination of liver iron concentration and also evaluates the technique for the diagnosis and quantification of iron overload in different clinical practice scenarios.

Adherence to Iron Chelation Therapy and Its Determinants

Background: Thalassemia is a chronic disease requiring lifelong treatment. The adherence to regular iron chelation therapy is important to ensure complication-free survival and good quality of life. The study aim to assess the adherence to iron chelation therapy (ICT) in patients with transfusion-dependent thalassemia (TDT), evaluate various causes of non-adherence and study the impact of non-adherence on the prevalence of complications secondary to iron overload. Materials and Methods: Patients with TDT on ICT for > 6 months were enrolled in the study. Hospital records were reviewed for demographic details, iron overload status, treatment details, and the prevalence of complications. A study questionnaire was used to collect information on adherence to ICT, knowledge of patients, and the possible reasons for non-adherence. Results: A total of 215 patients with a mean age of 15.07+7.68 years and an M: F ratio of 2.2:1 were included in the study. Non-adherence to ICT was found in 10.7% of patients. Serum ferritin levels were significantly higher in the non-adherent group (3129.8+1573.2 µg/l) than the adherent population (2013.1+1277.1 µg/l). Cardiac as well as severe liver iron overload was higher in the non-adherent patients. No correlation was found between disease knowledge and adherence to ICT. Difficulties in drug administration and many medicines to be taken daily were statistically significant reasons for non-adherence. There was no difference in the co-morbidities arising due to the iron overload in the two groups. Conclusion: Nearly 11% of patients with TDT were non-adherent to ICT. Non-adherence results in higher iron overload.

Mobilization of Auto-Stem Cells in the Thalassemia Major and Relationship with Iron Overload

Objectives: The hematopoietic stem cells transplantation (HSCT) is the only curable treatment in current for thalassemia major (TM).The quantity of auto stem cell of TM patients are very important for rescue the patients in case of failure of HSCT, and auto stem cells of TM will be used as target cells for gene therapy (GT) in the near future. Iron overload (IOL) can damage the hematopoiesis of TM. How to collect the auto stem cells in TM patients? How about the affects of iron overload in the mobilization and collection of auto stem cell? The aim of this study was to analyze quantity of auto stem cells in the TM and the affects of iron overload (IOL). Methods: We retrospectively analyzed a total of 134 patients and 25 normal donors undergoing PBSCs collection between January 2012 and December 2019. Patients with serum ferritin levels over 1,000 ng/mL and with a history of red blood cell transfusions prior to stem cell collection were defined as a group having transfusion-associated iron overload (IOL). In total one hundred and thirty-four patients and twenty-five donors were subcutaneous administrated G-CSF (Granulocyte Colony Stimulating Factor) 10 mg/kg/d Injection for 5 days, PBSCs was collected using a large volume leukapheresis (LVL) procedure. The data of WBC, MNC and CD34+ in product were analyzed by SPSS 20 software. Results: In 134 patients, median age is 8.60 range: (1-17),and 25 Normal donors, median age is 7.5 range: (1-18). The results demonstrated that cells either in patients with thalassemia or normal donors were effectively mobilized by G-CSF (10 mg / kg/d),as these children showed a marked increase in white blood cells and MNC cells in peripheral blood, reaching a peak in 4 to 5 days after the injection of G- CSF alone. Comparison of the MNC [(6.7±3.5) ×10⁸/kg vs (7.2±4.77) ×10⁸/kg] and CD34+cells [(10.29±4.5)×10⁶/kg vs (10.9±6.8)×10⁶/kg] in collected product in TM patients and normal donors groups revealed no significant difference. There was no significant difference between different Ferritin level (Mild, Intermediate and Severe) on WBC, MNC, and CD34+ in each group at the time point studied. But there was significant difference on MNC number (Normal liver iron (7.73±2.69)×10⁸/kg, Mild liver iron overload (7.66±4.64)×10⁸/kg, Intermediate (6.18± 2.84) ×10⁸/kg compared to Severe liver iron (4.45±3.34)×10⁸/kg, P=0.039. Significant difference was also can be seen in number of MNC of product in patients with intermediate cardiac iron overload compared to normal cardiac iron overload and mild cardiac iron overload (2.76±0.97) ×10⁶/kg vs(6.86±3.39) ×10⁶/kg and (6.88±3.72)×10⁶/kg, P=0.030. There was a statistically significant difference positive correlation between median age (P=0.011) and MNC/Kg (P=0.030). Conclusion:The quantity of mobilization of PBSC in TM patients had no significant difference compare to normal donor. The MNC in product was statistically decreased in intermediate cardiac iron overload and severe liver iron overload (IOL) subgroup. It indicated that iron overload (IOL) in organs may negatively relate to proliferation and mobilization of stem cells in TM. Further quality study of PBSC such as stem cell culture and ability of proliferation should be more evaluated. The sufficient quantity and high quality auto stem cell from TM patient can be more used in the future. Disclosures No relevant conflicts of interest to declare.

The renal hepcidin/ferroportin axis controls iron reabsorption and determines renal and hepatic susceptibility to iron overload

ABSTRACTThe hepcidin/ferroportin axis controls systemic iron homeostasis by regulating iron acquisition from the duodenum and the reticuloendothelial system, respective sites of iron absorption and recycling. Ferroportin is also abundant in the kidney, where it has been implicated in iron reabsorption. However, it remains unknown whether hepcidin regulates ferroportin-mediated iron reabsorption and whether such regulation is important for systemic iron homeostasis. To address these questions, we generated a novel mouse model with an inducible renal-tubule specific knock-in of fpnC326Y, which encodes a hepcidin-resistant FPNC326Y. Under iron-replete conditions, female mice harbouring this allele had lower renal iron content and higher serum and liver iron levels than controls. Under conditions of excess iron availability, male and female mice harbouring this allele had greater liver iron overload, but lower renal iron overload relative to controls. In addition, hemochromatosis mice harbouring a ubiquitous knock-in of fpnC326Y did not develop renal iron overload otherwise seen in the setting of excess iron availability. These findings are the first formal demonstration that hepcidin regulates ferroportin-mediated iron reabsorption. They also show that loss of this regulation contributes to liver iron overload while protecting the kidney in the setting of hemochromatosis. Our findings have important implications. First, they indicate that targeting the hepcidin/ferroportin axis for treating iron overload disorders will inhibit iron reabsorption and increase renal iron content. Second, they suggest that inhibition of iron reabsorption by raised hepcidin in chronic inflammatory conditions contributes to iron deficiency and that parenteral iron supplementation in this setting may cause renal iron overload.

Association of vitamin D deficiency and bone mass with liver and heart iron overload in transfusion dependent thalassemia

Background: Transfusion dependent thalassemia patients are reported to have Vitamin D insufficiency/deficiency in many countries. Vitamin D hydroxylation occurs in the liver; whether liver iron overload interferes with this step has not been addressed till date. This study helps to establish an association between liver iron concentration (LIC) and heart iron concentration (MIC) with vitamin D levels and Bone Mass Density in these patients.Methods: A cross sectional study was done by including transfusion dependent Thalassemia patients (TM) if they had an assessment of Liver and cardiac iron done by T2*MRI and bone mineral density by DEXA. Clinical data regarding age, gender, type of iron chelation therapy and laboratory data of S. ferritin and Vitamin D was collected. Data was assessed using appropriate statistical methods.Results: Among 40 TM patients were taken and mean age was 17.6 years. Vitamin D deficiency was identified in 26(65%). 20 out of them had an LIC>7mg/g DW and 6 had MIC>1.65mg/g DW. There was a significant association between LIC>7mg/g and vitamin D level<20 ng/ml and a significant inverse correlation between LIC and vitamin D, suggesting that liver iron overload may indeed affect vitamin D metabolism. Osteopenia was present in 32.5% and osteoporosis was present in 27.5 % of all TM patients. Reduced Bone Mass Density was also found to be linked with iron over load.Conclusions: Regular monitoring of vitamin D levels and supplementation is required in patients with severe liver and heart iron load. More studies are needed to confirm these results.