首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Seventeen non-transfusion-dependent Chinese haemoglobin H (Hb H) disease patients (age 29-76 years) with serum ferritin >900 microg/l were treated with deferiprone for up to 18 months. One patient withdrew and data from 16 patients were analysed. Sixteen other Hb H patients with ferritin <900 microg/l, matched for age and genotype, acted as controls. Treatment was well tolerated except for mild arthralgia. Serum ferritin fell with treatment, reaching significance at 6 and 18 months (from 1492.3 +/- 901.4 to 519.4 +/- 405.4 microg/l at 18 months, P = 0.0008). Nine of 16 patients had levels below 397 microg/l before 18 months. Serum ferritin remained stable 6 months after stopping treatment. In contrast, there was no change in ferritin levels in the control group. Magnetic resonance imaging was used for measurement of liver iron content. Spin echo T(1)-signal intensity ratio (T(1)-SIR) and gradient echo T(2)-signal intensity ratio (T(2)-SIR) increased with treatment. T(2)-SIR rose from 0.17 +/- 0.08 pretreatment to 0.58 +/- 0.50 at 2 years (P = 0.0055). Improvement occurred in 12 of 16 patients, reaching normal in three patients. Using echocardiography, peak early diastolic : late diastolic blood flow (E/A) remained unchanged with treatment, but isovolumic relaxation time (IVRT) was prolonged at 2 years indicating mild impairment of diastolic function. All systolic function parameters were normal. A longer treatment period is desirable to demonstrate improvement in cardiac function.  相似文献   

2.
β‐thalassemias result from diminished β‐globin synthesis and are associated with ineffective erythropoiesis and secondary iron overload caused by inappropriately low levels of the iron regulatory hormone hepcidin. The serine protease TMPRSS6 attenuates hepcidin production in response to iron stores. Hepcidin induction reduces iron overload and mitigates anemia in murine models of β‐thalassemia intermedia. To further interrogate the efficacy of an RNAi‐therapeutic downregulating Tmprss6, β‐thalassemic Hbbth3/+ animals on an iron replete, an iron deficient, or an iron replete diet also containing the iron chelator deferiprone were treated with Tmprss6 siRNA. We demonstrate that the total body iron burden is markedly improved in Hbbth3/+ animals treated with siRNA and chelated with oral deferiprone, representing a significant improvement compared to either compound alone. These data indicate that siRNA suppression of Tmprss6, in conjunction with oral iron chelation therapy, may prove superior for treatment of anemia and secondary iron loading seen in β‐thalassemia intermedia. Am. J. Hematol. 90:310–313, 2015. © 2015 The Authors. American Journal of Hematology Published by Wiley Periodicals, Inc.  相似文献   

3.
The definition ‘iron loading anaemias’ encompasses a group of inherited and acquired anaemias characterized by ineffective erythropoiesis, low hepcidin levels, excessive iron absorption and secondary iron overload. Non‐transfusion‐dependent β‐thalassaemia is the paradigmatic example of these conditions that include dyserythropoietic and sideroblastic anaemias and some forms of myelodysplasia. Interrupting the vicious cycle between ineffective erythropoiesis and iron overload may be of therapeutic benefit in all these diseases. Induction of iron restriction by means of transferrin infusions, minihepcidins or manipulation of the hepcidin pathway prevents iron overload, redistributes iron from parenchymal cells to macrophage stores and partially controls anaemia in β‐thalassaemic mice. Inhibition of ineffective erythropoiesis by activin ligand traps improves anaemia and iron overload in the same models. Targeting iron loading or ineffective erythropoiesis shows promise in preclinical studies; activin ligand traps are in clinical trials with promising results and may be useful in patients with ineffective erythropoiesis.  相似文献   

4.
In previous trials, the orally active iron chelator deferiprone (L1) has been associated with sporadic agranulocytosis, milder forms of neutropenia and other side-effects. To determine the incidence of these events, we performed a multicentre prospective study of the chelator. Blood counts were performed weekly, and confirmed neutropenia mandated discontinuation of therapy. Among 187 patients with thalassaemia major, the incidence of agranulocytosis (neutrophils < 0.5 x 109/l) was 0.6/100 patient-years, and the incidence of milder forms of neutropenia (neutrophils 0.5-1.5 x 109/l) was 5.4/100 patient-years. All cases of neutropenia resolved after interruption of therapy. Neutropenia occurred predominantly in non-splenectomized patients. Nausea and/or vomiting occurred early in therapy, was usually transient and caused discontinuation of deferiprone in three patients. Mild to moderate joint pain and/or swelling did not require permanent cessation of deferiprone and occurred more commonly in patients with higher ferritin levels. Mean alanine transaminase (ALT) levels rose during therapy. Increased ALT levels were generally transient and occurred more commonly in patients with hepatitis C. Persistent changes in immunological studies were infrequent, although sporadic abnormalities occurred commonly. Mean zinc levels decreased during therapy. Ferritin levels did not change in the overall group but decreased in those patients with baseline levels > 2500 microgram/l. This study characterized the safety profile of deferiprone, and, under the specific conditions of monitoring, demonstrated that agranulocytosis is less common than previously predicted.  相似文献   

5.
 We performed an open, nonrandomized, multicenter phase-II trial to evaluate the efficacy and toxicity of 1 year of treatment with the oral iron chelator deferiprone in 38 mainly nonthalassemic patients with transfusional iron overload. Initial serum ferritin varied between 996 and 11.644 μg/l. Patients were treated with 3–6 g of deferiprone daily. Mean urinary iron excretion (UIE) in 36 evaluable patients was 21.0 mg/24 h and was significantly higher in the patients with thalassemia than in those with myelodysplasia. Negative iron balance was achieved in 20 patients (56%). The median duration of treatment was 10 months; due to side effects and other causes only 20 patients completed 1 year of treatment. Mean serum ferritin levels decreased from 3563 μg/l at the start of the trial to 2767 μg/l at 6 months (26 patients, p<0.004) and to 2186 μg/l at 12 months (20 patients, p<0.005). Serum ferritin levels normalized in two patients who were no longer transfusion dependent. Deferiprone was clearly not effective in three patients (two with myelofibrosis, one with myelodysplasia). One patient with myelodysplasia developed agranulocytosis after 12 months of treatment; this was rapidly reversible after stopping deferiprone. Three patients had a mild and transient decrease in white blood cell count. Other side effects leading to withdrawal from the trial consisted mainly of nausea (3 patients), arthralgia (2), and skin rash (1). No clinical signs of zinc deficiency were seen, although zinc excretion was increased in three patients. No changes were seen in liver enzymes, creatinine, antinuclear factor, T-cell subsets, cardiac function, visual acuity, and audiogram. Although our results confirm deferiprone as an effective iron chelator in patients with thalassemia and in some patients with other forms of iron overload, there is still some concern about the safety of this drug, which therefore, at this time, should be used exclusively in well-controlled clinical trials. Received: 13 August 1996 / Accepted: 20 August 1996  相似文献   

6.
Mild hepatic iron overload has been demonstrated by magnetic susceptibility measurements in a 22-year-old man with hereditary sideroblastic erythropoiesis despite hemoglobin levels in the normal range and a normal erythropoietin level. His grandfather's sideroblastic anemia has been found to be responsive to pyridoxine; his mother's hemoglobin has persisted in the normal range but red cell volume distribution analysis demonstrated two subpopulations; 30% with estimated geometric mean of 68 fl and 70% an estimated mean of 93 fl. Red cell distribution analysis of the grandson demonstrated two microcytic subpopulations; 46% with an estimated geometric mean of 45 fl and 54% an estimated mean of 70 fl. A therapeutic regimen is outlined to reduce to normal his iron stores and to prevent the future development of excessive iron overload. © 1993 Wiley-Liss, Inc.  相似文献   

7.
BACKGROUND AND OBJECTIVES: From 1954 to 1987, flour in Denmark was fortified with 30 mg carbonyl iron per kg. This mandatory fortification was abolished in 1987. The aim of this study was to compare iron status in Danish men before and after abolition of iron fortification. METHODS: Iron status (serum ferritin, haemoglobin), was assessed in population surveys in Copenhagen County during 1983-84 comprising 1324 Caucasian men (1024 non-blood-donors, 300 blood donors) and in 1993-94 comprising 1288 Caucasian men (1103 non-blood-donors, 185 donors), equally distributed in age cohorts of 40, 50, 60 and 70 yr. RESULTS: In the 1984 survey median serum ferritin values in the four age cohorts in non-blood-donors were 136, 141, 133 and 111 microg/L, and in the 1994 survey 177, 173, 186 and 148 microg L(-1), respectively. The difference was significant in all age groups (P<0.001). There was no significant difference between the two surveys concerning the prevalence of small iron stores (ferritin 16-32 micro g L(-1)), depleted iron stores (ferritin <16 microg L(-1)) or iron-deficiency anaemia (ferritin <13 microg L(-1) and Hb <5th percentile for iron-replete men). However, from 1984 to 1994, the prevalence of iron overload (ferritin >300 microg L(-1)) increased from 11.3% to 18.9% (P<0.0001). During the study period there was an increase in body mass index (P<0.0001), alcohol consumption (P<0.03) and use of non-steroid anti-inflammatory drugs (NSAID) (P<0.0001), and a decrease in the use of vitamin-mineral supplements (P<0.04) and in the prevalence of tobacco smoking (P<0.0001). In contrast, median ferritin in blood donors showed a significant fall from 1984 to 1994 (103 vs. 74 micro g L(-1), P<0.02). CONCLUSION: Abolition of iron fortification reduced the iron content of the Danish diet by an average of 0.24 mg MJ(-1), and the median dietary iron intake in men from 17 to 12 mg d(-1). From 1984 to 1994, body iron stores and the prevalence of iron overload in Danish men increased significantly, despite the abolition of food iron fortification. The reason appears to be changes in dietary habits, with a lower consumption of dairy products and eggs, which inhibit iron absorption, and a higher consumption of alcohol, meat, and poultry, containing haem iron and enhancing iron absorption. The high prevalence of iron overload in men may constitute a health risk.  相似文献   

8.
9.
BACKGROUND AND OBJECTIVES: From 1954 to 1986, flour in Denmark was fortified with 30 mg carbonyl iron per kilogram. This mandatory enrichment of cereal products was abolished in 1987. The aim was to evaluate iron status in the Danish female population before and after abolishment of iron fortification. METHODS: Iron status, serum ferritin and haemoglobin, was assessed in population surveys in 1983-1984 comprising 1221 Caucasian women (1089 non-blood-donors, 130 donors) and in 1993-1994 comprising 1261 women (1155 non-blood-donors, 104 donors) equally distributed in age cohorts of 40, 50, 60 and 70 yr. RESULTS: In the 1984 survey, median ferritin values in the four age cohorts in non-blood-donors were 44, 57, 84 and 80 microg/L, and in the 1994 survey 40, 67, 97 and 95 microg/L, respectively. In 1984, premenopausal women had median ferritin of 43 microg/L and in 1994 of 39 microg/L (NS). In 1984, postmenopausal women had median ferritin of 75 microg/L and in 1994 of 93 microg/L (P < 0.0001). The prevalence of depleted iron stores (ferritin < 16 microg/L) was not significantly different in 1984 and 1994 either in premenopausal or in postmenopausal women. The prevalence of small + depleted iron stores (ferritin 300 microg/L) was unchanged in premenopausal women and had increased from 2.4% to 5.5% in postmenopausal women (P = 0.003). During the study period there was an increase in body mass index both in premenopausal and postmenopausal women (P = 0.06 and P = 0.008). Postmenopausal women displayed an increase in alcohol consumption (P < 0.0001) and a decrease in tobacco smoking (P < 0.001). In premenopausal women, there was a marked increase in the use of non-steroid anti-inflammatory drugs (P < 0.0001) in the study period, while this was unchanged in postmenopausal women. In premenopausal blood donors, median ferritin decreased from 1984 to 1994 (36 microg/L vs. 24 microg/L, P < 0.06). In postmenopausal blood donors, ferritin was not significantly different from 1984 to 1994 (50 microg/L vs. 41 microg/L, P = 0.15). CONCLUSION: Abolition of iron fortification reduced the median dietary iron intake in Danish women from 12 to 9 mg/d. Despite the absence of food iron fortification, from 1984 to 1994, body iron stores were unchanged in premenopausal women, whereas iron stores and the prevalence of iron overload in postmenopausal women had increased significantly. The reason appears to be the changes in dietary habits with a lower consumption of dairy products and eggs, which inhibit iron absorption, and a higher consumption of alcohol, meat and poultry, containing heme iron and enhancing iron absorption.  相似文献   

10.
Congenital anaemias due to ineffective erythropoiesis may be associated with excessive iron absorption and progressive iron loading. We investigated whether the soluble transferrin receptor (TfR) level was related to the degree of iron overload in 20 patients with thalassaemia intermedia, six patients with congenital dyserythropoietic anaemia type II (CDA II) and four patients with X-linked congenital sideroblastic anaemia (XLSA). All but two patients had increased serum ferritin levels (median 601 microgram/l, range 105-2855 microgram/l). Multiple regression analysis showed that 62% (P < 0.0001) of the variation in serum ferritin was explained by age and by changes in soluble TfR.  相似文献   

11.
Abnormal iron regulation in patients with thalassaemia intermedia may lead to iron overload even in the absence of transfusions. There are limited data on iron chelator use in patients with thalassaemia intermedia and no guidelines exist for the management of iron overload. We present data from 11 patients with thalassaemia intermedia treated with deferasirox (Exjade®, 10–20 mg/kg/d) for 24 months. Liver iron concentration and serum ferritin levels significantly decreased over the first 12 months (P = 0·005) and continued to decrease over the remainder of the study (P = 0·005). This small‐scale study indicated that deferasirox may be suitable for controlling iron levels in patients with thalassaemia intermedia.  相似文献   

12.
beta-Thalassemia is an inherited anemia in which synthesis of the hemoglobin beta-chain is decreased. The excess unmatched alpha-globin chains accumulate in the growing erythroid precursors, causing their premature death (ineffective erythropoiesis). Clinical features of beta-thalassemia include variably severe anemia and iron accumulation due to increased intestinal iron absorption. The most anemic patients require regular blood transfusions, which exacerbate their iron overload and result in damage to vital organs. The hepatic peptide hepcidin, a key regulator of iron metabolism in mammals, was recently found to be low in the urine of beta-thalassemia patients, compared with healthy controls, despite their iron overload. In our work, we measured by RQ-PCR the liver mRNA expression of hepcidin and other iron regulatory genes in beta-thalassemia major mouse model (C57Bl/6 Hbb(th3/th3)), and compared it with beta-thalassemia intermedia mouse model (C57Bl/6 Hbb(th3/+)) and control mice. We found decreased expression of hepcidin and TfR2 and increased expression of TfR1 and NGAL in the beta-thalassemia mouse models, compared with the control mice. Significant down-regulation of hepcidin expression in beta-thalassemia major, despite iron overload, might explain the increased iron absorption typically observed in thalassemia.  相似文献   

13.
Non‐transfusion‐dependent thalassaemias (NTDT ) encompass a spectrum of anaemias rarely requiring blood transfusions. Increased iron absorption, driven by hepcidin suppression secondary to erythron expansion, initially causes intrahepatic iron overload. We examined iron metabolism biomarkers in 166 NTDT patients with β thalassaemia intermedia (n  = 95), haemoglobin (Hb) E/β thalassaemia (n  = 49) and Hb H syndromes (n  = 22). Liver iron concentration (LIC ), serum ferritin (SF ), transferrin saturation (TfSat) and non‐transferrin‐bound iron (NTBI ) were elevated and correlated across diagnostic subgroups. NTBI correlated with soluble transferrin receptor (sTfR ), labile plasma iron (LPI ) and nucleated red blood cells (NRBC s), with elevations generally confined to previously transfused patients. Splenectomised patients had higher NTBI , TfSat, NRBC s and SF relative to LIC , than non‐splenectomised patients. LPI elevations were confined to patients with saturated transferrin. Erythron expansion biomarkers (sTfR , growth differentiation factor‐15, NRBC s) correlated with each other and with iron overload biomarkers, particularly in Hb H patients. Plasma hepcidin was similar across subgroups, increased with >20 prior transfusions, and correlated inversely with TfSat, NTBI , LPI and NRBC s. Hepcidin/SF ratios were low, consistent with hepcidin suppression relative to iron overload. Increased NTBI and, by implication, risk of extra‐hepatic iron distribution are more likely in previously transfused, splenectomised and iron‐overloaded NTDT patients with TfSat >70%.  相似文献   

14.

Background

There is still a clinical need for a well-tolerated and safe iron chelator for the treatment of transfusional iron overload. We describe the pharmacokinetic properties and safety data after 7 days of dosing of FBS0701, a novel oral, once-daily iron chelator.

Design and Methods

This phase 1b dose-escalation study to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of FBS0701, a novel oral iron chelator for the treatment of transfusional iron overload, was conducted in 16 adult patients with iron overloaded consequent to transfusions. FBS0701 was given daily for 7 days at doses up to 32 mg/kg and was well tolerated at all dose levels.

Results

Pharmacokinetics showed dose-proportionality. The maxium plasma concentration (Cmax) was reached within 60–90 minutes of dosing and the drug was rapidly distributed at the predicted therapeutic doses. The plasma elimination half-life (t1/2) was approximately 19 hours. There were no serious adverse events associated with the drug.

Conclusions

On the basis of these safety and pharmacokinetic data, FBS0701 warrants further clinical evaluation in patients with transfusional iron overload. (Clinicaltrials.gov identifier: NCT01186419)  相似文献   

15.
The thalassemia syndromes (α‐ and β‐thalassemia) are the most common and frequent disorders associated with ineffective erythropoiesis. Imbalance of α‐ or β‐globin chain production results in impaired red blood cell synthesis, anemia, and more erythroid progenitors in the blood stream. While patients affected by these disorders show definitive altered parameters related to erythropoiesis, the relationship between the degree of anemia, altered erythropoiesis, and dysfunctional iron metabolism has not been investigated in both α‐thalassemia carriers (ATC) and β‐thalassemia carriers (BTC). Here, we demonstrate that ATC have a significantly reduced hepcidin and increased soluble transferrin receptor levels but relatively normal hematological findings. In contrast, BTC have several hematological parameters significantly different from controls, including increased soluble transferrin receptor and erythropoietin levels. These changes in both groups suggest an altered balance between erythropoiesis and iron metabolism. The index sTfR/log ferritin and (hepcidin/ferritin)/sTfR are, respectively, increased and reduced relative to controls, proportional to the severity of each thalassemia group. In conclusion, we showed in this study, for the first time in the literature, that thalassemia carriers have altered iron metabolism and erythropoiesis.  相似文献   

16.
Diminished β‐globin synthesis in β‐thalassemia is associated with ineffective erythropoiesis, leading to secondary iron overload caused by inappropriately low levels of hepcidin and to splenomegaly in the symptomatic thalassemias. Splenectomy is often employed in patients with β‐thalassemia to reduce hemolysis. Expression of the iron regulatory peptide hormone hepcidin is repressed by the serine protease TMPRSS6. Hepcidin induction by RNAi‐mediated inhibition of TMPRSS6 expression reduces iron overload and mitigates anemia in murine models of β‐thalassemia intermedia. To interrogate the efficacy of RNAi‐mediated reduction of Tmprss6 in splenectomized β‐thalassemia, splenectomized β‐thalassemic Hbbth3/+ animals were treated with a GalNAc‐conjugated siRNA targeting Tmprss6 (GalNAc‐Tmprss6) and their hematological and iron parameters monitored. We demonstrate that treatment with GalNAc‐Tmprss6 significantly diminishes Tmprss6 expression and appropriately elevates hepcidin expression in splenectomized Hbbth3/+ animals. Similar to unsplenectomized animals, treated animals have markedly improved anemia due to diminished ineffective erythropoiesis and reduced iron loading in both serum and tissue. These results suggest that RNAi‐mediated reduction of Tmprss6 may have positive outcomes even in splenectomized β‐thalassemia patients.  相似文献   

17.
目的 探讨铁过载对脐带血(UCB)来源的造血干祖细胞及造血支持细胞,尤其是间充质干细胞(MSCs)的损伤作用.方法 体外培养脐带血单个核细胞(UCB-MNCs)和脐带血间充质干细胞(UCB-MSCs),向培养液中添加200 μmol/L的枸橼酸铁胺(FAC) 24 h建立铁过载模型.分为MNCs-CTL组、MNCs-FAC组、MSCs-CTL组、MSCs-FAC组,每组设3个复孔,实验重复3次.检测细胞内活性氧物质(ROS)水平变化、细胞增殖、分化、凋亡以及造血支持作用.结果 对UCB-MNCs进行铁过载,MNCs-FAC组造血集落形成单位(CFU-E、CFU-GM、BFU-E、CFU-mix)计数显著低于MNCs-CTL组(P<0.05),MNCs-FAC组造血干细胞(CD+34)、髓系造血细胞(CD+33)、红系造血细胞(GlyA+)比例及计数均显著低于MNCs-CTL组(P均<0.05);MNCs-FAC组的凋亡率高于MNCs-CTL组(P<0.05).MSCs-FAC组的群体倍增时间明显长于MSCs-CTL组,且其凋亡率亦高于MSCs-CTL组(P<0.05).结论 铁过载可抑制造血干祖细胞的增殖、分化,诱导其凋亡,也可抑制MSCs的增殖能力,诱导其凋亡,降低其造血支持能力,且此过程中ROS升高.  相似文献   

18.
19.
Over 80% of Caucasian patients with hereditary haemochromatosis are homozygotes for a C282Y mutation in the HFE gene on chromosome 6. Recent evidence suggests that a genetic factor may also be involved in the pathogenesis of African iron overload, although the locus has not been described. PCR analysis of DNA from 25 southern Africans, identified by segregation analysis as having a high probability of carrying the putative African iron-loading gene, failed to identify any subjects with the C282Y mutation. The possible genetic defect in African iron overload appears to be different from that described in most cases of hereditary haemochromatosis in Caucasians.  相似文献   

20.
Objectives: Hepcidin is the key regulator of iron homeostasis. The aims of this study were to determine serum hepcidin concentrations and reference ranges in pregnant women and cord blood of newborns at term and to evaluate the associations between hepcidin concentrations and iron status parameters. Methods: A total of 191 pregnant women–newborn pairs were studied in Kuopio University Hospital, Finland. The measured parameters were serum hepcidin, ferritin, transferrin receptor, transferrin saturation, red cell indices, and erythropoietin. Results: The hepcidin concentration in pregnant women was significantly lower than in cord blood at term [geometric mean concentration (GMC) (95% confidence intervals) in pregnant women 10.7 ng/mL (8.5–13.4 ng/mL) vs. GMC of cord blood hepcidin 69.3 ng/mL (55.3–86.8 ng/mL), P < 0.001, adjusted analysis of variance]. Hepcidin was undetectable in 12% of mothers. Hepcidin concentration in pregnant women was the lowest in those who had the lowest iron status. However, maternal hepcidin concentration was not associated with cord blood hepcidin or iron status markers. Hepcidin concentration in cord blood was associated with cord blood iron status, but not with maternal iron status. Conclusions: At term pregnancy, hepcidin concentrations are very low, allowing maximal availability of iron for the fetus. Maternal and cord blood hepcidin levels were independently associated with either maternal or cord blood iron status.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号