Prognostic Impact of Iron Overload During Follow-up After Allogeneic Stem Cell Transplantation

Abstract Abstract 347 Introduction: Iron overload is frequent in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) due to multiple red blood cell transfusions in the pre- and post-transplant period. Serum ferritin is a routine marker for iron overload. Along with transferrin saturation and soluble transferrin receptor, it was recently shown to strongly impact on survival after HSCT. Reduction of iron overload – e.g. by chelation - might improve the outcome after allogeneic transplantation. To analyze whether patients might benefit from post-transplant interventions aimed at reducing iron overload, we evaluated the impact of iron parameters on survival in a cohort of patients in which complete iron parameters were assessed before and at multiple time-points after transplantation. Methods: We studied 153 consecutive patients undergoing unmanipulated T-cell replete allogeneic transplantation at our center between 2005 and 2009. Among 90 males and 63 females with a median age of 46.5 years (range 18 – 70 years), underlying diseases were AML/MDS (n=87), ALL (n=25), lymphoma/myeloma (n=25), CML/MPN (n=12) and non-malignant (n=4). Donors were HLA-identical (n=78) or one-antigen mismatched (n=2) siblings, or unrelated volunteer donors (n=73). Patients with lymphoma received conditioning with BEAM, fludarabine and single dose total body irradiation (TBI). All other patients were treated with cyclophosphamide and busulfan, or cyclophosphamide and TBI +/− etoposide. Graft-vs-host disease prophylaxis was with Cylosporin A plus either methotrexate or mycophenolate. Serum iron parameters including ferritin, transferrin saturation, transferrin, iron and soluble transferrin receptor (sTfR) were determined before HSCT as well as 3, 6, 12, 24, 36 and 60 months post-transplant. Patients were categorized into groups with high or low iron parameters according to values above or below median at each time-point. Predictors of transplant outcome were further evaluated in multivariable Cox models using disease and stage as covariates. Results: Of the 153 patients, 83 were alive at last contact with a median follow-up of 3.4 years. Ferritin was strongly elevated before HSCT (median 1344 ng/ml, range 16–6507 ng/ml), peaked 3 months post-transplant (median 2508 ng/ml, range 71–9756 ng/ml) and continuously decreased to reach values within the normal range at 5 years (median 242.5 ng/ml, range 28–984ng/ml). Transferrin saturation and iron analogously peaked in the early post-transplant period and subsequently lowered, while transferrin and sTfR increased after an early post-transplant nadir up to 5 years. The post-transplant course of all iron parameters is shown in Fig 1. As demonstrated previously, survival analysis showed a poor survival of patients with a pre-transplant ferritin value above the median (hazard ratio 2.4, p=0.001). Time-stratified landmark survival analysis showed that iron overload (as assessed by ferritin levels above the median at the respective time-point) had a detrimental effect on survival in all periods analyzed (0–6 months p=0.01; 6–12 months p<0.001; 1–2 years p=0.07; and 2–5 years p=0.02. Figure 2). Interestingly, no patient with a ferritin level below the median died more than six months post-transplant. Excess mortality in patients with high ferritin was due to increased transplant related mortality. After adjustment for disease and stage, elevated ferritin values retained their prognostic significance. Analysis of the other iron parameters showed similar trends, but their prognostic value was lower than that of ferritin. Conclusions: Iron overload before HSCT as well as during the post-transplant follow-up confers an increased risk of death. Iron parameters significantly impact on survival during all post-transplant intervals analyzed. Thus, our data suggest that patients may benefit from interventions to reduce iron overload after HSCT. Disclosures: No relevant conflicts of interest to declare.

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Prognostic Impact of Different Iron Parameters In Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Blood ◽

10.1182/blood.v116.21.168.168 ◽

2010 ◽

Vol 116 (21) ◽

pp. 168-168

Author(s):

Godwin Nosakhare Bazuave ◽

Andreas S. Buser ◽

Sabine Gerull ◽

André Tichelli ◽

Martin Stern

Keyword(s):

Stem Cell ◽

Stem Cell Transplantation ◽

Iron Overload ◽

Cell Transplantation ◽

Transferrin Receptor ◽

Transferrin Saturation ◽

Soluble Transferrin Receptor ◽

Reactive Protein ◽

Kaplan Meier ◽

Iron Parameters

Abstract Abstract 168 Pre-transplant iron overload contributes to increased transplant related mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Serum ferritin is a useful marker to detect iron overload, and is strongly associated with survival rates after allogeneic HSCT. Ferritin is also elevated in patients with inflammatory conditions and may therefore lack specificity as a marker of iron overload. Other iron parameters such as the soluble transferrin receptor (which is not elevated during acute phase reactions), or transferrin saturation (which strongly correlates with non-transferrin bound iron causing tissue damage) might be superior as prognostic parameters. We retrospectively studied pre-transplant serum iron parameters (ferritin, transferrin, transferrin saturation, iron, soluble transferrin receptor [sTfR]) in 230 consecutive patients undergoing myeloablative allogeneic stem cell transplantation at our centre between 2002 and 2009. C-reactive protein (CRP) was measured as a marker for inflammatory diseases. Median age at transplant was 45 (range 17–70), 132 patients were male, 98 female. Diagnoses were ALL (n=43), AML (n=123), lymphoma (2=37), MPN (n=20), and non-malignant disorders (n=7). Conditioning was with Cy/TBI +/− VP 16 (n=109), BEAM/Fludarabine/TBI (n=29), BuCy (n=88), or other (n=4). All patients received pharmacological GvHD prophylaxis with CSA/MTX (n=201) or CSA/MMF (n=29). Median values of iron parameters were: ferritin 1342 ng/ml (range 7-7'260); transferrin 1.9 g/l (range 0.8–3.5); transferrin saturation 36% (range 4–106%); iron 18 μ mol/l (range 3–52); sTfR 3.2 mg/l (range 0.3–73). Interestingly, no significant correlation was found between ferritin and CRP (r=0.09, p=0.16). All iron parameters predicted survival, when patients were categorized into those with levels below or above the median. In Kaplan-Meier analysis, transferrin saturation showed the highest predictive power (5 year survival if below median 64±5%; if above median 32±5%; likelihood ratio [LR] 23.2, p<10e5, Figure 1). Ferritin, in comparison, had lower prognostic significance (survival 61±5% versus 39±5%, LR13.1, p=0.0003). The predictive power of sTfR was between that of ferritin and transferrin saturation (34±5% versus 65±5%, LR 20.2, p<10e5), whereas transferrin and iron fared markedly worse and were not further analyzed. In multivariate Cox models adjusted for diagnosis, disease stage, CRP, stem cell source, donor type, and year of transplant, hazard ratios with borderline significance were found for ferritin (HR 1.51, 95% CI 0.98–2.33, p=0.06) and sTfR (HR 1.50, 95% CI 0.96–2.34, p=0.07). In contrast, transferrin saturation retained clear prognostic significance (HR 1.90, 95% CI 1.23–2.94, p=0.004). Receiver operating characteristic curve analysis confirmed the superiority of transferrin saturation as a predictor of transplant outcome over a wide range of cutoff values (area under the curve for transferrin saturation 0.715, for ferritin 0.657, Figure 2). Iron overload strongly influences outcome of allogeneic stem cell transplantation. In this population of patients with a history of repeated red blood cell transfusions, serum ferritin levels were not significantly influenced by inflammatory states, as assessed by the lack of association with elevated CRP levels. Of the iron parameters studied, serum transferrin saturation had the highest predictive power in both univariate and multivariate models. Figure 1. Kaplan-Meier estimates of survival after allogeneic HSCT in patients stratified according to below- or above-median pre-transplant iron parameters and C-reactive protein Figure 1. Kaplan-Meier estimates of survival after allogeneic HSCT in patients stratified according to below- or above-median pre-transplant iron parameters and C-reactive protein Figure 2. Receiver operating characteristics (ROC) curve for pretransplant ferritin, soluble transferrin receptor, and transferrin saturation levels as predictors for 5-year overall survival Figure 2. Receiver operating characteristics (ROC) curve for pretransplant ferritin, soluble transferrin receptor, and transferrin saturation levels as predictors for 5-year overall survival Disclosures: No relevant conflicts of interest to declare.

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Comparative Evaluation of the Reticulocyte Hemoglobin Content Assay When Screening for Iron Deficiency in Elderly Anemic Patients

Anemia ◽

10.1155/2011/925907 ◽

2011 ◽

Vol 2011 ◽

pp. 1-3 ◽

Cited By ~ 17

Author(s):

Torbjörn Karlsson

Keyword(s):

Iron Deficiency ◽

Sensitivity And Specificity ◽

Transferrin Receptor ◽

Transferrin Saturation ◽

Deficiency Anemia ◽

Mean Corpuscular Hemoglobin ◽

Soluble Transferrin Receptor ◽

Hemoglobin Content ◽

Iron Parameters ◽

Reticulocyte Hemoglobin Content

The aim of this study was to evaluate sensitivity and specificity for reticulocyte hemoglobin content (CHr) compared to other hematimetric and biochemical iron parameters, in particular, mean corpuscular hemoglobin (MCH), when screening for iron deficiency in elderly anemic patients. Bone marrow staining negative for iron was used as the gold standard criterion for iron deficiency anemia (IDA). Sensitivity and specificity for CHr, soluble transferrin receptor (sTfR), soluble transferrin receptor/log ferritin (TfR-F index), ferritin, MCH, and transferrin saturation were determined. The best cut-off point for CHr was 30.5 pg corresponding to a sensitivity and specificity of 93% and 69% for IDA, respectively. For MCH, a sensitivity of 93% and a specificity of 86%, respectively, correspond to an optimal cut-off of 28.5 pg. Analysis of CHr was not superior to MCH with respect to sensitivity and specificity when screening for IDA in elderly anemic patients.

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The role of soluble transferrin receptor in iron overload in children with chronic hemolytic anemia

Menoufia Medical Journal ◽

10.4103/1110-2098.126144 ◽

2013 ◽

Vol 26 (2) ◽

pp. 132

Author(s):

RedaI Rakha ◽

SamarM.K. El-Din Fathallah ◽

FathiaM El-Nemr ◽

FaridaH El-Rashidi ◽

SehamM Ragab

Keyword(s):

Iron Overload ◽

Hemolytic Anemia ◽

Transferrin Receptor ◽

Soluble Transferrin Receptor ◽

Chronic Hemolytic Anemia

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Increased Serum Transferrin Saturation Is Associated with Lower Serum Transferrin Receptor Concentration

Clinical Chemistry ◽

10.1093/clinchem/45.12.2191 ◽

1999 ◽

Vol 45 (12) ◽

pp. 2191-2199 ◽

Cited By ~ 16

Author(s):

Anne C Looker ◽

Mark Loyevsky ◽

Victor R Gordeuk

Keyword(s):

Iron Deficiency ◽

Iron Overload ◽

Transferrin Receptor ◽

Iron Status ◽

Transferrin Saturation ◽

Reference Interval ◽

Serum Transferrin ◽

Reactive Protein ◽

Serum Transferrin Receptor ◽

Health And Nutrition

Abstract Background: Serum transferrin receptor (sTfR) concentrations are increased in iron deficiency. We wished to examine whether they are decreased in the presence of potential iron-loading conditions, as reflected by increased transferrin saturation (TS) on a single occasion. Methods: We compared sTfR concentrations between 570 controls with normal iron status and 189 cases with increased serum TS on a single occasion; these latter individuals may be potential cases of iron overload. Cases and controls were selected from adults who had been examined in the third National Health and Nutrition Examination Survey (1988–1994) and for whom excess sera were available to perform sTfR measurements after the survey’s completion. Increased TS was defined as >60% for men and >55% for women; normal iron status was defined as having no evidence of iron deficiency, iron overload, or inflammation indicated by serum ferritin, TS, erythrocyte protoporphyrin, and C-reactive protein. Results: Mean sTfR and mean log sTfR:ferritin were ∼10% and 24% lower, respectively, in cases than in controls (P <0.002). Cases were significantly more likely to have an sTfR value <2.9 mg/L, the lower limit of the reference interval, than were controls (odds ratio = 1.8; 95% confidence interval, 1.04–2.37). Conclusion: Our results support previous studies that suggested that sTfR may be useful for assessing high iron status in populations.

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Serum Soluble Transferrin Receptor in Heterozygous β-Thalassaemia: Application in the Diagnosis of Iron Deficiency and as Hematologic Marker of Erythroid Activity According to Thalassaemic Genotypes (β0 vs β+).

Blood ◽

10.1182/blood.v108.11.3828.3828 ◽

2006 ◽

Vol 108 (11) ◽

pp. 3828-3828

Author(s):

Jose Manuel Calvo-Villas ◽

María Francisca Zapata ◽

Ivan Alvarez ◽

Silvia de la Iglesia ◽

Jorge Cuesta ◽

...

Keyword(s):

Iron Deficiency ◽

Transferrin Receptor ◽

Biochemical Parameters ◽

Iron Status ◽

Direct Sequencing ◽

Saturation Index ◽

Transferrin Saturation ◽

Soluble Transferrin Receptor ◽

Iron Deficient ◽

Significant Difference

Abstract Although an increased level of serum soluble transferrin receptor (sTfR) have been found in both heterozygous β-thalassaemia patients with iron deficiency and in those with more severe genotype (β0), it is not a useful marker of iron deficiency status associated to β-thalassaemia. The aim of this study was to analyse the use of two biochemical parameters (sTfR and sTfR/log of ferritin ratio) to determine the iron status and to evaluate the degree of erythropoietic activity in a group of 221 β-thalassaemic heterozigotes patients (155 β0 and 66 β+). Serum ferritin and transferrin saturation index were measured in order to establish the iron status. Of the whole group, 51 patients were iron defficient (βthal-ID) while the remaining 170 were iron sufficient (βthal-IS). Based on the combination of β-thalassaemia genotype and iron status, patients were classified into four subgroups: β0thalassaemia and iron-sufficient (β0thal-IS) (n=124); β0thalassaemia and iron-deficient (β0thal-ID) (n=31); β+thalassaemia and iron-sufficient (β+thal-IS) (n=46); β+thalassaemia and iron-deficient (β+thal-ID) (n=20). 258 healthy and 56 iron-deficient individuals were used as controls. All the haematological parameters were measured by using analyzer Coulter® GEN-S™. Haemoglobins A2 (Hb A2) and F (HbF) were analysed by high performance liquid chromatography and molecular analysis was performed by real-time PCR and direct sequencing techniques. Chemical, inmunoturbidimetrical and nephelometric methods were used to measure iron status as well as sTfR. Comparison of haemalogical and biochemical parameters between subgroups was performed by using the t-student test and correlation analysis was calculated by using least-squares regression model. Mean sTfR level obtained was 2.63 ± 0.8 mg/dL and 2.57 ± 1.1 mg/dL in βthal-ID and βthal-IS patients respectively (p=0.783). Soluble transferrin receptor showed a positive correlation with HbA2, HbF and reticulocyte count values in βthal-IS patients (r=0.208 [p<0.05], r=0.440 [p<0.0001] and r=0.393 [p<0.00001] respectively) while it did not reach a significant correlation in βthal-ID patients. Mean sTfR/log sFt ratio was 2.75 ± 1.6 and 1.34 ± 0.5 in βthal-ID and βthal-IS patients (p<0.001). Interestingly, sTfR level was significantly higher in β0thal-IS patients when compared with β+thal-IS patients (2.76 ± 0.9 vs 1.42 ± 0.4) (p<0.001) as a result of an increased globin chains imbalance related to the β0 genotype. In the other hand, in the comparison between β0thal-ID and β+thal-ID subgroups neither sTfr level (2.71 ± 0.7 vs 2.40 ± 1.1) (p=0.417) nor sTfR/log sFt ratio (2.93 ± 1.7 vs 2.24 ± 1.3) (p=0.371) showed significant difference. In summary, sTfR/log sFt ratio is a valid parameter for diagnosis of iron deficiency associated to heterozygous β-thalassaemia. Unlike the findings observed in β-thalassaemic heterozigotes with normal iron status, sTfR level is not useful to evaluate the genotype severity in those with iron deficiency. Consequently, iron status should be determined before using sTfR as a parameter to provide a reliable estimation of the ineffective erythropoiesis related to the severity of β-thalassaemia genotypes.

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Iron Overload in C282Y Heterozygotes: Identification of New Rare HFE Gene Mutants and a Step Strategy for Diagnosis.

Blood ◽

10.1182/blood.v112.11.1859.1859 ◽

2008 ◽

Vol 112 (11) ◽

pp. 1859-1859

Author(s):

Patricia Aguilar-Martinez ◽

Severine Cunat ◽

Fabienne Becker ◽

Francois Blanc ◽

Marlene Nourrit ◽

...

Keyword(s):

Iron Overload ◽

Iron Status ◽

Hereditary Hemochromatosis ◽

Genetic Defect ◽

Transferrin Saturation ◽

Hfe Gene ◽

Compound Heterozygous ◽

Exon 2 ◽

High Iron ◽

Iron Parameters

Abstract Introduction: Homozygozity for the p.Cys282Tyr (C282Y) mutation of the HFE gene is the main genotype associated with the common form of adult hereditary hemochromatosis. C282Y carriers do not usually develop iron overload, unless they have additional risk factors such as liver diseases, a dysmetabolic syndrome or an associated genetic defect. The commonest is the compound heterozygous state for C282Y and the widespread p.His63Asp (H63D) variant allele. However, a few rare HFE mutations can be found on the 6th chromosome in trans, some of which are of clinical interest to fully understand the disorder. Patients and Methods: We recently investigated four C282Y carrier patients with unusually high iron parameters, including increased levels of serum ferritin (SF), high transferrin saturation (TS) and high iron liver content measured by MRI. They were males, aged 37, 40, 42, 47 at diagnosis. Two brothers (aged 40 and 42) were referred separately. The HFE genotype, including the determination of the C282Y, H63D and S65C mutations was performed using PCR-RFLP. HFE sequencing was undertaken using the previously described SCA method (1). Sequencing of other genes (namely, HAMP, HJV/HFE2, SLC40A1, TFR2) was possibly performed in a last step using the same method. Results: We identified three rare HFE mutant alleles, two of which are undescribed, in the four studied patients. One patient bore a 13 nucleotide-deletion in exon 6 (c.[1022_1034del13], p.His341_Ala345>LeufsX119), which is predicted to lead to an abnormal, elongated protein. The two brothers had a substitution of the last nucleotide of exon 2 (c.[340G>A], p.Glu114Lys) that may modify the splicing of the 2d intron. The third patient, who bore an insertion of a A in exon 4 (c.[794dupA],p.[trp267LeufsX80]), has already been reported (1). Discussion: A vast majority of C282Y carriers will not develop iron overload and can be reassured. However, a careful step by step strategy at the clinical and genetic levels may allow to correctly identify those patients deserving further investigation. First, clinical examination and the assessment of iron parameters (SF and TS) allow identifying C282Y heterozygotes with an abnormal iron status. Once extrinsic factors such as heavy alcohol intake, virus or a dysmetabolic syndrome have been excluded, MRI is very useful to authenticate a high liver iron content. Second, HFE genotype must first exclude the presence of the H63D mutation. Compound heterozygozity for C282Y and H63D, a very widespread condition in our area, is usually associated with mild iron overload. Third, HFE sequencing can be undertaken and may identify new HFE variants as described here. The two novel mutations, a frameshift modifying the composition and the length of the C terminal end of the HFE protein and a substitution located at the last base of an exon, are likely to lead to an impaired function of HFE in association with the C282Y mutant. However, it is noteworthy that three of the four patients were diagnosed relatively late, after the 4th decade, as it is the case for C282Y homozygotes. Three further unrelated patients are currently under investigation in our laboratory for a similar clinical presentation. Finally, it can be noted that in those patients who will not have a HFE gene mutant identified, analysis of other genes implicated in iron overload must be performed to search for digenism or multigenism. None of our investigated patients had an additional gene abnormality.

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One-Year Post-Transplant Serum Ferritin Level Is a Predictor of Long-Term Survival Following Allogeneic Transplantation.

Blood ◽

10.1182/blood.v116.21.3453.3453 ◽

2010 ◽

Vol 116 (21) ◽

pp. 3453-3453 ◽

Cited By ~ 1

Author(s):

Stuart L Goldberg ◽

Marc Elmann ◽

Mark Kaminetzky ◽

Eriene-Heidi Sidhom ◽

Anthony R Mato ◽

...

Keyword(s):

Acute Leukemia ◽

Iron Overload ◽

Serum Ferritin ◽

Cox Regression ◽

Allogeneic Transplantation ◽

Term Survival ◽

Post Transplant ◽

Kaplan Meier ◽

One Year

Abstract Abstract 3453 Individuals undergoing allogeneic transplantation receive multiple red blood cell transfusions both as part of the transplant procedure and as part of the pre-transplant care of the underlying disease. Therefore these patients may be at risk for complications of transfusional iron overload. Several studies have noted that individuals entering the transplant with baseline elevated serum ferritin values have decreased overall survival and higher rates of disease relapse. Whether the iron is a direct contributor to inferior outcomes or is a marker of more advanced disease (thereby requiring greater transfusions) is unclear. Little is known about the incidence and consequences of iron overload among long-term survivors of allogeneic transplantation. Methods: Using Kaplan-Meier and Cox regression analyses, we performed a single center, retrospective cohort study of consecutive allogeneic transplants performed at Hackensack University Medical Center from January 2002 through June 30, 2009 to determine the association between serum ferritin (measured approximately 1 yr post allogeneic transplant) and overall survival. Results: During the study time frame, 637 allogeneic transplants (Donor Lymphocyte Infusion procedures excluded) were performed at our center and 342 (54%) survived ≥ one year. Among 1-year survivors 240 (70%) had post-transplant serum ferritin values available for review, including 132 (55%) allogeneic sibling, 68 (28%) matched unrelated, and 40 (17%) mismatched unrelated donor transplants. The median post-transplant ferritin value among 1-year survivors of allogeneic transplant was 628 ng/ml (95% CI 17, 5010), with 93 (39%) above 1000 ng/ml and 40 (17%) above 2500 ng/ml. The median post-transplant ferritin levels varied by underlying hematologic disease (aplastic anemia = 1147, acute leukemia = 1067, MDS = 944, CLL = 297, CML = 219, lymphoma = 123, multiple myeloma = 90). The Kaplan-Meier projected 5-year survival rate was 76% for the cohort that had survived one year and had available ferritin values. Fifty late deaths have occurred; causes of late death were disease relapse (n=37, 74%), GVHD (n=7, 14%), infection (n=4, 8%), cardiac (n=1, 2%) and second malignancy (n=1, 2%). The 1-year post-transplant serum ferritin value was a significant predictor of long term survival. Using a cut-off ferritin value of 1000 ng/ml, the 5-year projected survivals were 85% (95 CI 75%-91%) and 64% (95% CI 52–73%) for the low and high ferritin cohorts respectively (Figure, log-rank p<0.001), with a hazard ratio of 3.5 (95% CI 2–6.4, p<0.001). Similarly a serum ferritin value >2500 ng/ml was associated with inferior survival (HR 2.97, p<0.001). Underlying hematologic disease also correlated with 5-year projected survival including 70%, 83%, and 89% for acute leukemia/MDS, lymphoma/myeloma/CLL, and aplastic anemia/CML groupings, respectively (log-rank p<0.01 for leukemia/MDS vs other groupings). Patients receiving bone marrow grafts did better than those receiving peripheral blood stem cells (HR = 2.2; p = 0.03). Age, gender, donor type (sibling, matched unrelated, mismatch unrelated) and intensity of regimen (ablative vs. non-myeloablative) were not predictive of inferior survival in univariate analysis. In the multivariate Cox-regression analysis, elevated post-transplant ferritin >1000 ng/ml (HR 3.3, 95%CI 1.6–6.1; p<0.001) and diagnosis of acute leukemia/MDS (HR 4.5, 95%CI 1.1–18.7; p=0.04) remained independent predictors of inferior survival, even when adjusted for age, gender, type of graft, donor type, and intensity of conditioning regimen. Relapse deaths (25% vs. 9%; p<0.001) and GVHD deaths (6% vs 0.6%; p=0.03) were more common in the high ferritin cohort. Conclusions: Among patients who have survived one-year following allogeneic transplantation, a post-transplant serum ferritin value greater than 1000 ng/ml is a predictor of inferior long-term outcomes. To our knowledge this is the first report on the importance of late monitoring of serum ferritin, but it is in agreement with prior studies suggesting a pre-transplant ferritin value is a predictor of outcomes. Prospective studies attempting to modify outcomes by reducing post-transplant iron overload states are needed. Disclosures: No relevant conflicts of interest to declare.

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Implications of Low Zinc and Copper Levels As Well As Altered Iron Trafficking Proteins on Oxidant Stress in Patients with Transfusion Dependant Thalassemia

Blood ◽

10.1182/blood.v128.22.1289.1289 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1289-1289

Author(s):

Patrick B Walter ◽

Michael Minkley ◽

Caitlin Curtis ◽

Hodge Maeve ◽

Razavi Morty ◽

...

Keyword(s):

Oxidative Stress ◽

Iron Overload ◽

Transferrin Receptor ◽

Oxidative Stress Markers ◽

Soluble Transferrin Receptor ◽

Secondary Complications ◽

Plasma Iron ◽

Stress Markers ◽

Iron Trafficking ◽

Redox Active

Abstract Introduction:Patients with transfusion dependent thalassemia (TDT) have a genetic anemia that causes incomplete erythropoiesis and iron overload. Plasma zinc deficiency is also seen in roughly 25% of patients with TDT. Iron overload is thought to be related to a number of secondary complications in TDT including cardiomyopathy and diabetes. However, in TDT the effects of altered Zn status are not as well characterized and the effects of low copper (Cu) are even less well known. One possible cause of these complications is oxidative damage to tissues. This oxidative stress can be caused by labile plasma iron (LPI), a component of the non-transferrin bound iron pool, which is often seen in individuals suffering from iron overload. LPI is both redox-active and chelatable and is the likely culprit distributing iron to extra-hepatic tissues. Through reactive Fenton chemistry, LPI, can also cause lipid peroxidation releasing malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), which are damage-associated molecular patterns and markers of oxidative tissue damage that activate the immune system to induce inflammation. Incomplete erythropoiesis as well as transfusional iron overload are responsible for an increase in the amount of poorly handled, redox active LPI in TDT. Thus, we hypothesized that changes in the levels of key iron trafficking proteins (such as soluble transferrin receptor (sTfR) or hemopexin) would affect oxidative stress levels in TDT. We also hypothesized that metal dyshomeostasis, such as a functional Zn or Cu deficiency would affect oxidative stress. Aims: The purpose of this pilot project is to 1) Determine the state of circulating levels of oxidative stress markers and iron trafficking proteins in TDT patients and 2) Explore the relationship between the markers and proteins measured in (1)and the Zn and Cu status of TDT patients. Methods:39 subjects with informed consent were enrolled (29 patients with TDT and 10 controls). Liver iron concentration (LIC) was measured by a superconducting quantum interference device (SQUID™). LPI was measured using dihydrorhodamine 123. Both MDA and MDA + 4-HNE were measured using N-methyl-2-phenylindole. The iron trafficking proteins sTfR, transferrin, haptoglobin and hemopexin were measured by immunoassay isolation followed by multiplex multiple reaction monitoring mass spectrometry. Zn and Cu were assessed by inductively coupled plasma atomic emission spectroscopy. Fructosamine was measured by quantitative spectrophotometry. Results: Patients with TDT had elevated LIC levels of 2681 ± 2424 ug iron/g wet weight. Plasma levels of the iron trafficking proteins, transferrin, hemopexin and haptoglobin were all decreased in TDT patients (P<0.001) with a corresponding increase in soluble transferrin receptor (StfR) and the LPI (P<0.001). Serum Zn was significantly reduced in TDT patients (p = 0.028) and urinary Zn was significantly elevated (p =0.024). Serum Cu was also significantly reduced in TDT patients (p =0.026). Reduced Zn levels in TDT patients correlated with elevated MDA levels (p = 0.0195, R = -0.382) as were serum Cu levels (p = 0.0158, R = -0.394). Reduced levels of plasma iron trafficking proteins (haptoglobin, hemopexin, and transferrin) were correlated with elevated levels of MDA and LPI (all p-values < 0.05). Plasma MDA was also correlated with fructosamine levels (p < 0.001, R= 0.57). Conclusion: Metal dyshomeostasis involving Zn and Cu may be important contributors to oxidative stress and iron injury in TDT. We confirm previous findings in TDT of elevated levels of LPI as well as the oxidative stress markers MDA and 4-HNE. We expand previous findings of reduced transferrin levels in TDT to show a similar reduction in both haptoglobin and hemopexin. StfR levels were elevated in TDT patients, possibly due to a strong erythropoietic drive. Both reduced haptoglobin and hemopexin as well as decreased Zn and Cu levels and increased Zn excretion appear to be present in TDT. These preliminary findings suggest that low levels of Zn, Cu, haptoglobin and hemopexin may be related to increased oxidative stress and LPI in TDT, which could be important contributors to secondary complications of TDT. Disclosures Walter: Apopharma: Research Funding.

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Markers of Iron Overload Are Poor Prognostic Factors in Stem Cell Transplantation.

Blood ◽

10.1182/blood.v106.11.5228.5228 ◽

2005 ◽

Vol 106 (11) ◽

pp. 5228-5228

Author(s):

Rebecca Connor ◽

Istvan Molnar ◽

James Lovato ◽

Manisha Grover ◽

David Hurd ◽

...

Keyword(s):

Overall Survival ◽

Stem Cell ◽

Stem Cell Transplantation ◽

Acute Leukemia ◽

Iron Overload ◽

Cell Transplantation ◽

Serum Ferritin ◽

Transferrin Receptor ◽

Serum Transferrin Receptor ◽

Iron Parameters

Abstract Transfusional iron overload is common in survivors of acute leukemia and hematopoietic stem cell transplantation and might cause long-term liver dysfunction. Routine evaluation for iron overload in such patients is recommended because excess iron can be readily removed from the body via phlebotomy or chelation. Iron overload might be associated with worse survival after stem cell transplantation in these diseases. We were interested in determining whether levels of the iron binding protein ferritin or the serum transferrin receptor (TfR) were predictive for survival. In a prospective study, we examined the correlation between iron parameters at the time of transplantation and overall survival. Serum ferritin, transferrin saturation, and TfR were measured before preparative regimen on patients who underwent hematopoietic stem cell transplantation between 1999 and 2004 for the diagnosis of aplastic anemia, MDS or acute leukemia (n=79). We used the number of transfusions before transplantation as a measure of iron load. Among these iron markers, serum ferritin correlated the most with the number of transfusions, regardless of remission status. High ferritin (>1,500 ng/ml), low TfR (≤4 μg/ml) and low TfR/log ferritin ratio (≤2) were associated with shorter survival (p=0.005, 0.04, and 0.001 respectively)(Figure 1). Among acute leukemia patients in remission, there was no difference in overall survival between patients with high or low iron markers. Markers of iron excess (serum ferritin >1,500 ng/ml, TfR/log ferritin ratio ≤2) at the time of stem cell transplantation is associated with shorter survival in MDS, aplastic anemia and acute leukemia with active disease. These results demonstrate that knowledge of patient ferritin and TfR levels can aid in risk stratification. The results also suggest that patients with high levels of ferritin may benefit from iron chelation before treatment. Figure 1: Overall Survival based on iron parameters (A) Serum Ferritin (B) Serum Transferrin Receptor (C) TfR (mcg/ml) divided by log ferritin (ng/ml) Figure 1:. Overall Survival based on iron parameters (A) Serum Ferritin (B) Serum Transferrin Receptor (C) TfR (mcg/ml) divided by log ferritin (ng/ml)

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The Effect of the Flavonol Rutin on Serum and Liver Iron Content in a Genetic Mouse Model of Iron Overload

Bioscience Reports ◽

10.1042/bsr20210720 ◽

2021 ◽

Author(s):

Zachary Hawula ◽

Eriza Secondes ◽

Daniel Wallace ◽

Gautam Rishi ◽

V. Nathan Subramaniam

Keyword(s):

Mouse Model ◽

Iron Overload ◽

Transferrin Receptor ◽

Iron Homeostasis ◽

Binding Capacity ◽

Hereditary Hemochromatosis ◽

Transferrin Saturation ◽

Iron Loading ◽

Genetic Mouse Model ◽

Transferrin Receptor 2

The flavonol rutin has been shown to possess antioxidant and iron chelating properties in vitro and in vivo. These dual properties are beneficial as therapeutic options to reduce iron accumulation and the generation of reactive oxygen species resultant from excess free iron. The effect of rutin on iron metabolism has been limited to studies performed in wild type mice either injected or fed high iron diets. The effect of rutin on iron overload caused by genetic dysregulation of iron homeostasis has not yet been investigated. In this study we examined the effect of rutin treatment on tissue iron loading in a genetic mouse model of iron overload, which mirrors the iron loading associated with Type 3 hereditary hemochromatosis patients who have a defect in Transferrin Receptor 2. Male Transferrin Receptor 2 knockout mice were administered rutin via oral gavage for 21 continuous days. Following treatment, iron levels in serum, liver, duodenum, and spleen were assessed. In addition, hepatic ferritin protein levels were determined by western blotting, and expression of iron homeostasis genes by quantitative real-time PCR. Rutin treatment resulted in a significant reduction in hepatic ferritin protein expression and serum transferrin saturation. In addition, trends towards decreased iron levels in the liver and serum, and increased serum unsaturated iron binding capacity were observed. This is the first study to explore the utility of rutin as a potential iron chelator and therapeutic in an animal model of genetic iron overload.

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