scholarly journals Iron overload in transfusion-dependent patients

Hematology ◽  
2019 ◽  
Vol 2019 (1) ◽  
pp. 337-344 ◽  
Author(s):  
Thomas D. Coates
Keyword(s):  
Iron Overload ◽  
Iron Homeostasis ◽  
Prolonged Exposure ◽  
Iron Chelation ◽  
Close Relation ◽  
Therapeutic Strategies ◽  
Clinical Approach ◽  
Iron Loading ◽  
Marrow Activity

Abstract Before the advent of effective iron chelation, death from iron-induced cardiomyopathy occurred in the second decade in patients with transfusion-dependent chronic anemias. The advances in our understanding of iron metabolism; the ability to monitor iron loading in the liver, heart, pancreas and pituitary; and the availability of several effective iron chelators have dramatically improved survival and reduced morbidity from transfusion-related iron overload. Nevertheless, significantly increased survival brings about new complications such as malignant transformation resulting from prolonged exposure to iron, which need to be considered when developing long-term therapeutic strategies. This review discusses the current biology of iron homeostasis and its close relation to marrow activity in patients with transfusion-dependent anemias, and how biology informs clinical approach to treatment.

scholarly journals Pharmacological and clinical evaluation of deferasirox formulations for treatment tailoring

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrea Piolatto ◽  
Paola Berchialla ◽  
Sarah Allegra ◽  
Silvia De Francia ◽  
Giovanni Battista Ferrero ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Renal Impairment ◽  
Observational Study ◽  
Iron Overload ◽  
Iron Loading ◽  
Comprehensive Comparison ◽  
Dispersible Tablets ◽  
One Year ◽  
Safety Features

AbstractDeferasirox (DFX) is the newest among three different chelators available to treat iron overload in iron-loading anaemias, firstly released as Dispersible Tablets (DT) and more recently replaced by Film-Coated Tablets (FCT). In this retrospective observational study, pharmacokinetics, pharmacodynamics, and safety features of DFX treatment were analyzed in 74 patients that took both formulations subsequently under clinical practice conditions. Bioavailability of DFX FCT compared to DT resulted higher than expected [Cmax: 99.5 (FCT) and 69.7 (DT) μMol/L; AUC: 1278 (FCT) and 846 (DT), P < 0.0001]. DFX FCT was also superior in scalability among doses. After one year of treatment for each formulation, no differences were observed between the treatments in the overall iron overload levels; however, DFX FCT but not DT showed a significant dose–response correlation [Spearman r (dose-serum ferritin variation): − 0.54, P < 0.0001]. Despite being administered at different dosages, the long-term safety profile was not different between formulations: a significant increase in renal impairment risk was observed for both treatments and it was reversible under strict monitoring (P < 0.002). Altogether, these data constitute a comprehensive comparison of DFX formulations in thalassaemia and other iron-loading anaemias, confirming the effectiveness and safety characteristics of DFX and its applicability for treatment tailoring.

Family Perceptions of Barriers and Facilitators of Treatment Protocols for Secondary Stroke Prevention in Children with Sickle Cell Disease

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4805-4805
Author(s):  
Eve S Puffer ◽  
Melanie J Bonner ◽  
Courtney D Thornburg
Keyword(s):  
Iron Overload ◽  
Sickle Cell ◽  
Stroke Prevention ◽  
Recurrent Stroke ◽  
Iron Chelation ◽  
Secondary Stroke Prevention ◽  
Treatment Protocols ◽  
History Of ◽  
Family Perceptions

Abstract Abstract 4805 Children with sickle cell anemia (SCA) and a primary overt stroke are at high risk of recurrent (secondary) stroke. Chronic blood transfusion (CBT) dramatically reduces but does not eliminate this high risk, and results in transfusion-related hemosiderosis. We previously reported the use of hydroxyurea/phlebotomy as an alternative to CBT to reduce the risk of secondary stroke and improve management of iron overload (Ware et al. J Pediatr 2004). This study examines the caregiver and child experience with secondary stroke prevention. Individual semi-structured interviews were conducted with primary caregivers and children/adolescents (age > 5 years) recruited from the Duke Pediatric Sickle Cell Program. The interviewer (E.P.) asked about perceptions of risk of recurrent stroke and iron overload with and without therapy and facilitators and barriers of therapy. Interviews were coded and analyzed independently by two investigators (E.P and C.T.). The sample included 14 youth (10 males) with a median age of 12.5 years (range 3–17). All primary caregivers were female. Twelve children had a history of overt stroke and 2 had a history of silent stroke. All children had experience with CBT and 9 were receiving CBT at the time of the interview. Eleven children had experience taking hydroxyurea and 5 were taking hydroxyurea at the time of the interview. All caregivers agreed that their child was at risk of recurrent stroke, identified benefit of current treatment and reported high motivation to adhere to treatment protocols. They noted significant impact that stroke had on school functioning, attention, personality, participation in sports and overall quality of life. Caregiver-reported barriers to CBT and hydroxyurea fell into three main categories: (1) missed work and school and related consequences; (2) unexpected resource-related challenges; and (3) inconvenience of clinic appointments, all of which contributed to burden on the family and sometimes missed clinic appointments and treatments. There were higher levels of concern expressed by caregivers of children on CBT related to the higher frequency and longer length of medical appointments compared with those taking hydroxyurea. The primary child-reported barrier was dislike of needles or shots (although this decreased with age as expected); those taking hydroxyurea also noted that they sometimes forgot to take the medication if they were busy with other activities or fell asleep. Caregiver-reported facilitators of CBT and hydroxyurea included: (1) understanding importance of stroke prevention and connection to consistent treatment; (2) ancillary benefits of treatments in addition to stroke prevention; (3) link between treatment and long-term benefits. Caregivers were able to overcome treatment barriers via the following: (1) logistical supports including appointment and medication reminders; (2) shared responsibility with other family members including the child; (3) trust in medical staff; and (4) faith. Although children disliked needles and shots, many enjoyed the clinic visits due to fun activities in the clinic setting and rewards. In addition, iron overload was a significant concern for caregivers. For those with children on CBT, knowledge of the risks of iron overload motivated adherence with oral iron chelation. Automatic refills facilitated adherence with chelation therapy, but the taste of the medication was a major barrier to adequate iron chelation. Caregivers of children taking hydroxyurea noted the benefit of avoiding iron overload. Of those who had undergone phlebotomy, in-home phlebotomy was noted as a facilitator, though requirement for IV contributed to negative perception. In summary, as clinicians review options for secondary stroke prevention with families, they should discuss family perceptions and individual barriers and facilitators which may impact adherence with therapy and long-term outcome. Future research should also investigate whether these family perceptions predict actual adherence to protocols and treatment outcomes. Disclosures: Off Label Use: Hydroxyurea for secondary stroke prevention in sickle cell disease.

Occurrence of Neoplastic Diseases in a Large Cohort of Thalassemic Patients in Greece

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3264-3264
Author(s):  
Alexandra Kouraklis ◽  
Antonia Chatziliami ◽  
Antonis Kattamis ◽  
Efthimia Vlachaki ◽  
Evangelos Briasoulis ◽  
...  
Keyword(s):  
Iron Overload ◽  
Serum Ferritin ◽  
Cell Lymphoma ◽  
Iron Chelation ◽  
Beta Thalassemia ◽  
Thalassemia Intermedia ◽  
Neoplastic Diseases ◽  
Median Serum ◽  
Neoplastic Disorders

Abstract Abstract 3264 Life expectancy of thalassemic patients, appropriately transfused and adequately iron-chelated, has been substantially extended the last decades. However, these patients are subjected to particular risks which might favor the development of neoplasia, such as transfusional iron overload, high prevalence of viral diseases, particularly HCV infection, and transfusion-associated alteration of their immune status. The occurrence of neoplastic diseases has not been extensively investigated in this patient population. We sought to investigate the occurrence of neoplastic diseases during a 16.5 year-period, in a large cohort of 1972 thalassemic patients (homozygous beta-thalassemia N=1448, thalassemia intermedia N=352 and sickle-cell/beta thalassemia N=172), followed-up in 6 large Greek Thalassemic Units. All documented cases of neoplastic diseases, diagnosed during the period between 1.1.1996 and 30.6.2012 were collected and analyzed. The frequency of each type of neoplasia was then correlated with specific factors, potentially influencing the occurrence of these disorders, and particularly age at first transfusion, frequency of transfusions, previous splenectomy, smoking, use of hydroxyurea, previous autoimmune disorders, presence of HBV, HCV and HIV infection, adequacy of iron chelation and the degree of hepatic siderosis. Totally 38 cases of neoplastic disorders were documented among the 1972 patients. These were Hepatocellular carcinoma (10 cases), non-Hodgkin's Lymphoma (6 cases in total: Marginal-zone lymphoma N=2, Mantle-cell lymphoma N=1, Diffuse large B-cell lymphoma N=1, Burkitt's lymphoma N=1, T-cell lymphoblastic lymphoma N=1), Thyroid carcinoma (3 cases in total: papillary N=2, follicular N=1), Hodgkin's lymphoma (3 cases in total, classical N=2, LPHD N=1), Renal cell cancer (N=3), Colon cancer (N=3), Breast cancer (N=2), Cholangiocarcinoma (N=2), Pre-B Acute Lymphoblastic Leukemia (N=2), Testicular cancer (2 cases in total, seminoma N=1, teratoma N=1), melanoma (N=1), and Renal oncocytoma (N=1). Twenty-eight cases were diagnosed among patients with homozygous beta-thalassemia, 6 among patients with thalassemia intermedia and 4 among patients with sickle-cell/beta thalassemia. Median age at diagnosis of the neoplastic disease was 39 years (age range 21 to 63 years). Twenty-nine cases (76.3%) were diagnosed among previously splenectomized patients, although splenectomy had been performed in 41% of the total cohort of patients. All patients were HIV-negative, 3/31 (9.7%) were HBsAg-positive, whereas 22/37 (59.5%) had HCV infection. Patients were then classified according to the level of liver siderosis and the effectiveness of their iron chelation treatment, estimated by their annual median serum ferritin levels. Eleven patients were found to be adequately chelated (median serum ferritin 310 ng/ml), 16 were moderately-effectively chelated (median serum ferritin 1240 ng/ml) and 11 were inadequately chelated (median serum ferritin 2552 ng/ml). There was no difference in patient's age or in the type of neoplastic disorders occurred in each of the 3 categories, however 3/11 poorly chelated patients were long term survivors, versus 8/16 moderately chelated and 9/11 adequately chelated patients. In conclusion, the prolongation of overall survival of thalassemic patients results in increasing occurrence of neoplastic diseases among this patient population. Splenectomized and HCV-infected patients appear to represent higher-risk groups, whereas the role of iron overload appears not to influence the occurrence of neoplastic diseases but may have an impact on the long-term outcome and clearly deserves further investigation. Disclosures: No relevant conflicts of interest to declare.

Long Term Efficacy, Safety and Tolerability (>24 Months) of Twice Daily Dosing of Deferasirox in Transfusion Dependent Thalassemias Who Were Unresponsive to Standard Once Daily Dose

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 958-958
Author(s):  
Bunchoo Pongtanakul ◽  
Vip Viprakasit
Keyword(s):  
Iron Overload ◽  
Iron Concentration ◽  
Iron Chelation ◽  
Once Daily ◽  
Term Efficacy ◽  
Before And After ◽  
Baseline Levels ◽  
Median Change

Background: Clinical efficacy, safety and tolerability of deferasirox (DFX); a once daily oral iron chelator in transfusion dependent thalassemias (TDT) with iron overload can be achieved by appropriate dosage adjustment based on iron burden and ongoing transfusion iron overload. However, even with recommended DFX dosage, at least 40% of our Thai TDT patients did not appropriately respond to DFX. Patients with unresponsiveness to DFX (UR) was defined as (1) having a rising serum ferritin (SF) trend or (2) having a reduction of SF < 30% of baseline levels (BL) at least 3 consecutive mths, with more than two SF measurements >1500 ng/mL; and (3) receiving once daily DFX at an average dosage > 30 mg/kg/day for at least 6 mths. Previously, twice daily dosing (TWD) of DFX was shown to be effective in patients with UR (Pongtanakul B, et al. Blood Cells Mol Dis. 2013) but long term efficacy, safety and tolerability of TWD of DFX is still lacking. Methods: Patients with UR who received TWD of DFX with the same total dose per day > 24 mths were included. CBC, renal function, urine analysis were performed every 3 wks to monitor possible side effect. SF and liver function test were checked every 6 wks. Tolerability and compliance to DFX were evaluated by direct history taking and drug account prescribed. Responsiveness to TWD of DFX (RP) was defined as the patients who showed a decrease of SF or reduction of liver iron concentration (LIC) by MRI > 30% of the BL at 6 or 12 mths. Results: Twenty four TDT patients received TWD of DFX; 4 patients were excluded due to poor compliance and a short follow up period and 4 patients did not meet RP criteria. Sixteen patients were enrolled; 9 male (56%) with a mean (± SD) age of 9.08 ± 3.84 yrs (range 2.1-24.2 yrs). Clinical diagnoses include; Hb E/β thalassemia. (n=12), β thalassemia major (n=3) and Hb Barts hydrops (n=1). Mean follow up time before switching dose were 17.3 ± 7.3 mths. Average SF at BL before DFX and before TWD were 3,039 ± 1,713.7.02 and 3,500 ± 1,403.2 ng/mL, with median % change of SF was +27.58 % (range; -13.4 to +104%). Mean actual DFX dose during 6 mths before switching was 36.3 ± 2.2 mg/kg/day. None had symptoms of gastrointestinal irritation. After TWD, 13 (81.25%) and 16 patients (100%) showed a significant decrease of SF (> 30% of the baseline levels) at 6 and 12 months. Mean SF and median % change of SF at 6 and 12 months after switching were 2,527.56 ± 1,191.80 ng/mL; -29.24 % and 1,695.83 ± 859.16 ng/mL; -53.14%, with statistical significance compared to BL and before switching (p <0.05). Mean transfusion iron load before and after switching were not different (range 0.2-0.4 mg/kg/day). One patient had a SF reduction < 30%, but LIC was significant reduction at 12 months. Nine out of 16 patients were evaluated for LIC; average LIC at BL and at the end of study were reduced from 6.7 to 3.2 mg/g dry wt. None had cardiac T2* < 20 msec. All patients except one tolerated well with DFX at before and after switching (>24 months) with minor adverse events. One patient had severe transaminitis (ALT > 3 times of ULN) but after investigation, this was thought to be result from acute viral hepatitis. This patient could be successfully restarted DFX at the same TWD. Five patients could decrease DFX dosage to < 20 mg/kg/day and switched back to daily dosing (mean dosage was 17.04 mg/kg/day). However, 4 patients, after decreased DFX dosage and switched back to daily dosing; their SF increased and required to increase DFX dosage with TWD to maintain SF. Seven patients continued to receive TWD of DFX with mean dosage was 36.4 mg/kg/day. Mean follow up time after TWD of DFX was 44.1 + 9.8 mths (range 24 - 72 mths). Conclusion: Herein, we show that TWD of DFX effectively reduced iron burden in TDT with iron overload. Safety and tolerability of this dosing are not different from once daily dosing. Most patients could decrease DFX dosage and switched back to once daily dosing when iron burden decreased. However, 25% (4/16) of these patients still required twice daily dosing with higher dosage to maintain optimal body iron levels. Interestingly, 16% (4/24) of our patients who received TWD could not achieve effective iron chelation. This group of patients may represent those who have different pharmacogenetic background that affect directly to efficacy of DFX causing a resistant to iron chelation therapy. This population confirms for improving iron chelation measures by means of a newer iron chelation agent or a combination of DFX with other iron chelation. Disclosures Off Label Use: Twice daily dosing instead of standard daily dosing.

Clinical conundrum: managing iron overload after renal transplantation

2021 ◽  
Vol 14 (2) ◽  
pp. e239568
Author(s):  
Binayak Upadhyay ◽  
Steven D Green ◽  
Nabin Khanal ◽  
Aśok C Antony
Keyword(s):  
Iron Overload ◽  
Haemoglobin Concentration ◽  
Iron Chelation ◽  
Immunosuppressive Drug ◽  
Drug Induced ◽  
Hepatic Iron Overload ◽  
Combined Use ◽  
Mild Anaemia ◽  
Parenteral Iron

Iatrogenic iron overload, which is not uncommon in patients undergoing long-term haemodialysis, arises from a combination of multiple red cell transfusions and parenteral iron infusions that are administered to maintain a haemoglobin concentration of approximately 10 g/dL. Although iron overload due to genetic haemochromatosis is conventionally managed by phlebotomy, patients with haemoglobinopathies and chronic transfusion-induced iron overload are treated with iron-chelation therapy. However, the management of iron overload in our patient who presented with hepatic dysfunction and immunosuppressive drug-induced mild anaemia in the post-renal transplant setting posed unique challenges. We report on the decision-making process used in such a case that led to a successful clinical resolution of hepatic iron overload through the combined use of phlebotomy and erythropoiesis stimulating agents, while avoiding use of iron-chelating agents that could potentially compromise both hepatic and renal function.

Serum Ferritin Predicts Liver but Not Cardiac Iron Burden by Noninvasive MRI in Sickle Cell Disease (SCD.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1421-1421 ◽  
Author(s):  
Robert I. Liem ◽  
Cynthia Rigsby ◽  
Richard J. Labotka ◽  
Andrew DeFreitas ◽  
Alexis A. Thompson
Keyword(s):  
Iron Overload ◽  
Serum Ferritin ◽  
Iron Content ◽  
Iron Loading ◽  
Cell Disease ◽  
Liver Iron ◽  
Cardiac Iron ◽  
Liver Iron Content ◽  
The Mean

Abstract BACKGROUND: Assumptions about iron loading as well as the utility of ferritin to predict transfusional iron overload among individuals with sickle cell disease (SCD) are largely based on extrapolation from data generated in patients with thalassemia major (TM). Yet recent studies suggest the natural history of iron overload in patients with SCD differs significantly from chronically transfused patients with TM. We sought to evaluate the extent of myocardial and hepatic siderosis using noninvasive imaging in chronically transfused patients with SCD and examine its clinical associations, including relationship to long-term trends in serum ferritin, transfusion history, chelation status and markers of hemolysis and inflammation. METHODS: We evaluated 17 subjects (mean age 15±3.6 yrs, range 9 to 20). The mean transfusion duration was 7.3±3.6 yrs (range 2 to 15). Thirteen (76%) patients were on chelation with deferasirox at the time of screening; 4 were not on chelation Rx. MRI T2*/R2* of the heart and liver using a multiple gradient echo sequence was performed on a single 1.5T GE scanner. Hepatic iron concentration (HIC) values were predicted from liver R2* values. RESULTS: Mean HIC in subjects was 9.9±6.7 mg/gm liver dry weight (range 2.5 to 20.8) and was ≥15 mg/gm in 6/17 (35%) subjects. The mean long-term serum ferritin (past 5 yrs, or duration of transfusion if &lt; 5yrs) was 2318±1122 ng/mL (range 541 to 4225). Using Pearson’s correlation coefficient, we observed a significant relationship between HIC and ferritin (r=0.765, p=&lt;0.001). We generated a receiver operator characteristic (ROC) curve to assess the utility of ferritin as a predictor of elevated HIC, using a threshold HIC thought to predict serious iron-related complications. A ferritin cut-off value ≥2164 ng/mL correctly identified 80% of cases of HIC ≥15 mg/gm (AUC 0.96, p=0.003) in our subjects with 83% sensitivity and 73% specificity. Despite markedly elevated HIC and ferritin values in some subjects, none had myocardial siderosis. All 17 subjects had cardiac MRI T2* values in the normal range &gt; 25 ms. Cardiac iron load measured by T2* did not correlate with HIC or serum ferritin. We examined C-reactive protein (CRP) and B-type natriuretic peptide (BNP) as markers for inflammation and myocardial strain, respectively, in our subjects but neither demonstrated a significant relationship to ferritin or MRI findings. BNP, however, did correlate modestly with both age (r=−0.574, p=0.013) and left ventricular ejection fraction on cardiac MRI (r=0.510, p=0.036). A subset of subjects (n=8) had histologic iron measurements by percutaneous liver biopsy (LBx) within 6 months of MRI. While liver iron content by LBx correlated significantly with HIC by MRI (r=0.759, p=0.03), liver iron content by LBx did not correlate with ferritin (r=0.312, p=0.452). CONCLUSION: We found that serum ferritin is a good predictor of liver iron by MRI R2*, and that long term ferritin values ≥2164 ng/mL predict significant hepatic iron overload as assessed by this noninvasive method. We did not observe appreciable cardiac iron loading in our subjects with SCD, which otherwise might have been predicted by elevated HIC alone, as in individuals with TM. These data suggest that reliable, long term surveillance of transfusion-induced iron overload in SCD may be achieved using serum ferritin and HIC by MRI R2* as surrogate markers of hepatic siderosis rather than relying on liver iron content measured invasively by LBx. Also, previously determined thresholds for significant cardiac iron loading in TM, based on degree of hepatic siderosis, may not be applicable in SCD. Further investigation into alternative mechanisms of iron loading or distribution in these related but distinct disorders is warranted.

Iron Chelation with Deferasirox (Exjade®) Improves Iron Burden in Patients with Myelodysplastic Syndromes (MDS)

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 634-634 ◽  
Author(s):  
Alan F List ◽  
Maria R Baer ◽  
David Steensma ◽  
Azra Raza ◽  
Jason Esposito ◽  
...  
Keyword(s):  
Iron Overload ◽  
Iron Status ◽  
Iron Chelation ◽  
Underlying Disease ◽  
Endocrine Function ◽  
Transfusion Rate ◽  
Open Label ◽  
The Mean ◽  
New Onset

Abstract INTRODUCTION: The majority of patients (pts) with MDS require red blood cell transfusions, which can result in iron overload and its clinical sequelae. The US03 trial is designed to evaluate the long-term efficacy and safety of the once-daily, oral iron chelator, deferasirox (DFX), in pts with lower-risk MDS. In this ongoing study 93/176 pts have now completed 12 months of treatment. METHODS: US03 is a Phase II, open-label, 3-year trial in pts with Low- or Int-1 IPSS-risk MDS and transfusional iron overload (serum ferritin [SF] 1000 μg/L and &gt;20 units RBC transfusions), with serum creatinine (SCr) 2-fold the upper limit of normal (ULN). Initial DFX dose was 20 mg/kg/day and could be increased to 40 mg/kg/day based on tolerability and response. SF was monitored monthly; labile plasma iron (LPI), the reactive species of non-transferrin-bound iron, was assessed quarterly. BASELINE FEATURES: 176 pts were enrolled at 45 centers. Mean age: 70 years (range 21–90); 105 men and 71 women; IPSS Low risk (n=47; 27%); Int-1 (n=126; 72%); other (n=3; 2%). Mean baseline iron status was: SF, 3397 μg/L (863–36,280); LPI, 0.4 μmol/L (0.0–3.6). Forty-one percent of pts had elevated LPI at baseline (≥0.5 μmol/L). Mean number of lifetime prior transfusions: 63; mean duration of transfusions: 3.5 years (0–34). MDS therapy at study entry included azacitidine, hydroxyurea, lenalidomide, thalidomide or decitabine in 25 pts, and growth factors in 48 pts. Calculated creatinine clearance was normal (&gt;80 mL/min) in 77 pts and abnormal (abn) in 99: mildly abn (51– 80 mL/min) in 71; moderately abn (30–50 mL/min) in 25; severely abn (&lt;30 mL/min) in 3. RESULTS: Over 12 months, the mean dose of DFX was 21 mg/kg/day, and the mean transfusion rate was 3.4 units/month. Mean SF±SEM (μg/L) values at baseline, 3, 6, 9 and 12 months were 3397±233 (n=176), 3057±144 (n=143), 2802±128 (n=126), 2635±148 (n=109) and 2501±139 (n=93), respectively. In pts with elevated baseline LPI, sustained suppression of mean LPI to the normal range was achieved after 3 months of treatment. The figures show reductions (±SEM) in SF, and in LPI in pts with baseline LPI ≥0.5 μmol/L. Hematological improvement by IWG 2000 criteria was achieved in 8 pts (5%): erythroid response in 5 (major 3; minor 2); platelet in 1 (major); neutrophil in 1 (major); and combined platelet and neutrophil in 1. SAFETY: Of 173 pts, 18 (10%) discontinued DFX because of suspected adverse events (AEs), and an additional 5 (3%) because of serious AEs (SAEs). The most common AEs were diarrhea (n=9), rash (n=3) and nausea (n=2), while the most common SAEs were rash (n=2) and diarrhea (n=1). Of 147 pts with normal baseline SCr, 26 (18%) increased &gt;ULN on at least two occasions (3.0 mg/dL max SCr). There were 9/172 (5%) and 22/168 (13%) new onset cases of grade 3–4 thrombocytopenia and neutropenia, respectively, none suspected to be related to DFX; 7 and 11 of these pts, respectively, were receiving other MDS treatment therapies, including lenalidomide, decitabine, hydroxyurea and azacitidine. There were 17 deaths (10%), due to sepsis/infection (n=8), disease progression (n=4), intracranial bleed (n=2), cardio-respiratory arrest (n=2) and renal failure (n=1), all thought to be unrelated to DFX. CONCLUSIONS: In these heavily iron-overloaded pts, DFX was generally well tolerated. New onset cytopenias were consistent with the underlying disease. A 2-year extension phase of this study will assess the long-term safety and efficacy of DFX as well as the clinical impact on cardiac, hepatic and endocrine function. Figure Figure

The Effect of Supplemental Ascorbate on Defersirox Iron Chelation In the Iron-Loaded Gerbil

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2059-2059
Author(s):  
Maya Otto-Duessel ◽  
Casey Brewer ◽  
Aleya Hyderi ◽  
Jens Lykkesfeldt ◽  
Ignacio Gonzalez-Gomez ◽  
...  
Keyword(s):  
Iron Overload ◽  
Iron Content ◽  
Iron Concentration ◽  
Iron Chelation ◽  
Iron Dextran ◽  
Iron Loading ◽  
Liver Iron ◽  
Cardiac Iron ◽  
Liver Iron Content ◽  
Wet Weight

Abstract Abstract 2059 Introduction: Iron dextran injections are often used to induce iron overload in rodents, for the purposes of assessing iron chelation therapy. In gerbils, we have previously described that deferasirox therapy preferentially clears hepatocellular iron when compared with reticuloendothelial stores. Ascorbate deficiency, which is common in humans with iron overload, produces similar profound disparities between reticuloendothelial and parenchymal iron stores. We postulated that iron-induced ascorbate deficiency might be exaggerating reticuloendothelial iron retention in gerbils receiving deferasirox therapy. This study examined the effect of supplemental ascorbate on spontaneous iron loss and deferasirox chelation efficiency in the iron-dextran loaded gerbil. Methods: 48 female gerbils underwent iron dextran loading at 200 mg/kg/week for 10 weeks. Sixteen animals were sacrificed at 11 weeks to characterize iron loading; eight were on standard rodent chow and eight had chow supplemented with 2250 ppm of ascorbate. 32 additional animals that were not ascorbate supplemented during iron loading transitioned into the chelation phase. Half were subsequently placed on ascorbate supplemented chow and both groups were assigned to receive either deferasirox 100 mg/kg/day five days per week or sham chelation. Animals received iron chelation for twelve weeks. Liver histology was assessed using H & E and Prussian blue stains. Iron loading was ranked and graded on a five-point scale by an experienced pathologist screened to the treatment arm. Iron quantitation in liver and heart was performed by atomic absorption. Results: Table 1 one summarizes the findings. During iron dextran loading, ascorbate supplementation lowered wet weight liver iron concentration but not liver iron content suggesting primarily changes in tissue water content. Spontaneous iron losses were insignificant, regardless of ascorbate therapy. Deferasirox lowered liver iron content 56% (4.7% per week) in animals without ascorbate supplementation and 48.3% (4.0% per week) with ascorbate supplementation (p=NS). Cardiac iron loading, unloading and redistribution were completely unaffected by ascorbate supplementation. Spontaneous iron redistribution was large (1.9% – 2.3% per week). Deferasirox chelation did not lower cardiac iron to a greater degree than spontaneous cardiac iron redistribution. Histologic grading paralleled tissue wet weight iron concentrations. Ascorbate treatment lowered the rank and absolute iron score in liver during iron loading (p=0.003) and there was a trend toward lower iron scoring in sham treated animals (p=0.13). Ascorbate had no effect on histological score or relative compartment distributions of iron in deferasirox chelated animals (p=0.5). Ascorbate supplementation was sufficient to increase total plasma ascorbate levels from 25 ± 12.2 uM to 38.4 ± 11 uM at 10 weeks (p=0.03). In the liver, ascorbate increased from 1203 ± 212 nmol/g of tissue to 1515 ± 194 nmol/g of tissue (p=0.01) with supplementation. No significant change in total ascorbate was observed in the heart. Discussion: We hypothesized that ascorbate supplementation might improve reticuloendothelial iron accessibility to deferasirox by facilitating redox cycling. Although gerbils synthesize their own ascorbate, supplementation was able to raise both serum and hepatic total ascorbate levels. However, increasing ascorbate did not change either the amount or distribution of tissue iron in deferasirox-treated animals. Disclosures: Nick: Novartis: Employment. Wood:Novartis: Research Funding; Ferrokin Biosciences: Consultancy.

scholarly journals Iron Chelation Improves Erythropoiesis in a Mouse Model of Myelodysplastic Syndrome

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2335-2335
Author(s):  
Wenbin An ◽  
Maria Feola ◽  
Marc Ruiz Martinez ◽  
Amit Verma ◽  
Yelena Ginzburg
Keyword(s):  
Bone Marrow ◽  
Myelodysplastic Syndrome ◽  
Iron Overload ◽  
Iron Metabolism ◽  
Iron Chelation ◽  
Erythroid Differentiation ◽  
Mouse Bone Marrow ◽  
Iron Loading ◽  
Iron Restriction ◽  
Rbc Count

Abstract Myelodysplastic syndrome (MDS) is a heterogeneous group of bone marrow stem cell disorders characterized by ineffective hematopoiesis, cytopenias, and transformation to acute leukemia (AML). Low risk MDS patients exhibit a longer median survival, the lowest rate of progression to AML, and account for approximately two-thirds of all MDS patients, requiring recurrent RBC transfusions to alleviate symptomatic anemia. Transfusion-dependence results in iron overload which is associated with reduced overall survival. Methods to diagnose and treat (e.g. iron chelator deferiprone (DFP)) iron overload are available, but because retrospective studies to date only identify a correlative, not a causal, relationship between iron overload and reduced survival, there is little consensus on whether benefits of its diagnosis and treatment outweigh risks in this patient population. We aimed to evaluate and characterize the effect of iron loading and iron chelation on ineffective hematopoiesis in NUP98-HOXD13 transgenic (NHD13) mice, a highly penetrant model with peripheral blood cytopenias and ineffective hematopoiesis with dysplasia, consistent with MDS in humans [Lin Blood 2005]. We hypothesize that iron overload in MDS has deleterious biological effects on hematopoiesis with increased likelihood of worsening disease, reversible with iron chelation therapy. Our preliminary data demonstrates that 1) DFP enhances erythroid differentiation in CD34+ cells from MDS patients; and 2) exogenous iron suppresses erythropoiesis in wild type (WT) mice. The current experiments reveal the effect of exogenous iron and DFP in NHD13 mice. Age and gender matched 5 month old mice, 5-10 mice per group, were injected with 20mg iron dextran and/or treated with DFP (175 mg/mouse) in the drinking water over 4 weeks. Treated mice were analyzed and compared with PBS injected NHD13 mice and WT controls. Our experiments demonstrate that NHD13 mice exhibit anemia and leukopenia, increased serum erythropoietin (Epo) concentration, and higher MCV despite no difference in reticulocyte count relative to WT controls (Table I) and no splenomegaly (Fig 1a). In addition, erythroblast ROS concentration (Fig 1b) and iron load in the liver (Fig 1c) increase without differences in transferrin saturation or hepcidin expression in NHD13 relative to WT mice. These findings demonstrate characteristics consistent with human MDS patients. We then analyzed the effects of additional iron loading, iron chelation, or a combination of both on parameters of iron metabolism and erythropoiesis in NHD13 mice. Iron-treated NHD13 mice exhibit higher WBC count, RBC count, and hemoglobin, both DFP- and iron-treated NHD13 mice exhibit decreased serum Epo, and DFP+iron-treated NHD13 mice exhibit decreased serum Epo while increasing RBC count and hemoglobin (Table I). These findings suggest that exogenous iron increases Epo responsiveness and extramedullary erythroid mass in NHD13 mice in a manner similar to what we observed in iron-treated thalassemic mice [Ginzburg Exp Hem 2009]. Furthermore, spleen size increased (Fig 1a) and erythroblast ROS decreased (Fig 1b) only in iron-treated NHD13 mice. These findings suggest that erythroblast ROS is unrelated to excess iron in NHD13 mice. Liver iron increased in iron-treated and decreased in DFP-treated NHD13 mice (Fig 1c) as expected. In addition, CD71 (TfR1) surface expression on bone marrow erythroblasts is suppressed in all treated NHD13 mice but only significantly decreased in DFP-treated mice (Fig 1d), suggesting expected iron restriction. Lastly, DFP- and DFP+iron-treated (but not iron-treated) NHD13 mice decreased the proportion of bone marrow erythroblasts (Fig 1e) and increased erythroid differentiation in NHD13 mouse bone marrow (Fig 1f). Taken together, our findings demonstrate the robustness of NHD13 mice as a model of MDS to study erythropoiesis, the utility of iron injection in NHD13 mice to mimic robust iron overload in MDS, and the effectiveness of DFP in enhancing erythroid differentiation, reversal of erythroid expansion, and Epo responsiveness in NHD13 mice. Additional experiments (i.e. RBC survival, analysis of bone marrow signaling, erythroferrone expression, and parameters of the iron restriction response) to further explore the dysregulation of iron metabolism in NHD13 mice are ongoing. Disclosures No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document