首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Iron-chelating therapy with deferoxamine in patients with thalassemia major has dramatically altered the prognosis of this previously fatal disease. The successes achieved with deferoxamine, as well as the limitations of this treatment, have stimulated the design of alternative strategies of iron-chelating therapy, including orally active iron chelators. The development of the most promising of these, deferiprone, has progressed rapidly over the last 5 years; data from several trials have provided direct and supportive evidence for its short-term efficacy. At the same time, the toxicity of this agent mandates a careful evaluation of the balance between risk and benefit of deferiprone in patients with thalassemia, in most of whom long-term deferoxamine is safe and efficacious therapy.  相似文献   

2.
Serum ferritin levels, hepatic histology and iron concentration were studied in a 'veteran' group of seven Swiss beta-thalassaemic patients after 93-99 months of treatment with the oral iron chelator deferiprone (L1), and another four patients who had received 54-82 months of L1 therapy. Despite continuous compliance, unexplained resurgence of serum ferritin levels occurred in 4/7 patients of the 'veteran' group after 4-5 years on L1. In three of these a concomitant increase of liver iron was also observed. Hepatic histology revealed significantly higher degrees of fibrosis in 6/11 hepatitis C (HC)-positive patients (fibrosis scores 1-5, mean 3.0) than in the HC-negative group (fibrosis score 0-2, mean 0.8). Two HC-negative patients had no detectable fibrosis after 98 and 93 months on deferiprone. Therefore the hepatic pathology in these patients cannot definitely be attributed as a side-effect of deferiprone. Chronic active hepatitis C and the accumulation of iron are the major causative factors to be considered.  相似文献   

3.
Over 15 years, 14 patients with yersiniosis in two North American comprehensive thalassemia clinics (0.6 cases per 100 patient-years) presented with fever (100%), diarrhea (86%), right-lower-quadrant abdominal pain (71%), bacteremia (57%), a palpable abdominal mass (36%), and pharyngitis (28%). Clinically apparent infection occurred within 10 days of blood transfusion in 57% of patients. Nine patients (64%) had only a modest elevation in serum level of ferritin (< 2,000 micrograms/L). Patients with focal abdominal findings had a higher body iron burden, as estimated by the serum ferritin level, and significant intraabdominal suppurative complications. Two patients were not receiving iron-chelating therapy with deferoxamine; one patient was receiving the experimental chelator deferiprone (L1). Iron-loaded patients with beta-thalassemia are at greatly increased risk for severe yersiniosis, even when their body iron burden (as indicated by the serum ferritin level) is only moderately elevated and they are not receiving iron-chelating therapy with deferoxamine.  相似文献   

4.
OBJECTIVES: To assess efficacy and safety of oral iron chelating agent deferiprone (DFP) in patients with beta thalassemia and hemoglobin E-beta thalassemia. DESIGN: Non-randomized study. SETTING: Hematology Out-Patient Department. SUBJECTS: Forty-one patients of beta thalassemia and hemoglobin E-beta thalassemia. INTERVENTIONS: DFP was given to 20 patients, 10 patients of beta thalassemia and 10 with hemoglobin E-beta thalassemia; the rest were taken as controls. RESULTS: A significant fall in serum ferritin was observed in the study group along with rise in urinary iron excretion (p < 0.05). Adverse effects of DFP were nausea and vomiting (30%), significant arthropathy requiring stopping of the drug (30%), and reversible neutropenia in one patient. All these complications could be managed easily with medical supervision and no death or permanent disability was seen. CONCLUSIONS: DFP is an effective and fairly well tolerated oral iron chelating agent. The side effects that occur can be tackled easily if monitored properly.  相似文献   

5.
Recently, we demonstrated that administration of the orally active iron chelating agent deferiprone (1,2-dimethyl-3-hydroxypyrid-4-one (L1)) at 6-hour intervals results in significantly greater urinary iron excretion than that induced during administration of the drug at 12-hour intervals. That study was conducted in thalassemia patients, all of whom had received a packed red cell transfusion of 15 cc/kg. 72 hours prior to evaluation of urinary iron excretion, at a time when endogenous erythropoiesis would be expected to be at its lowest. In clinical practice however, thalassemia patients, suppression of endogenous erythropoiesis is not sustained between transfusions. We set out to determine the influence that administration of deferiprone has on urinary iron excretion at lower hemoglobin concentrations, immediately prior to transfusion. We hypothesized that hemoglobin levels will affect the ability of deferiprone to chelate iron. Ten regularly transfused patients with homozygous beta-thalassemia (HBT) aged mean +/- SD, 20.9 +/- 4.7, range 13 - 27 years, receiving long-term therapy with deferiprone, were treated with deferiprone 75 mg/kg/day, administered every 6 hours (or every 12 hours) for 72 hours immediately prior to a blood transfusion in the first month. One month later each patient received the other of the 2 dosing regimens for 72 hours immediately prior to transfusion. The deferiprone-induced 24-hour urinary iron excretion was similar during both dosing regimens; 0.56 +/- 0.45 mg/kg when L1 was given every 6 hours and 0.48 +/- 0.52 mg/kg when L1 was administered every 12 hours (p = 0.79). However, the calculated 24-hour area under the plasma concentration-time curve (AUC0-24) of deferiprone was significantly lower when deferiprone was administered at 6-hour intervals (6,762.8 +/- 1,601.6 mg*min/l), than that observed when deferiprone was administered every 12 hours (8,250.1 +/- 1,235.7 mg*min/l) (p = 0.04). The pharmacokinetics of deferiprone when administered immediately prior to transfusions are different from those following transfusions. More studies assessing total body iron excretion are needed to determine the contribution of the fecal route in iron excretion.  相似文献   

6.
BACKGROUND & AIMS: Impact of hepatitis C treatment has never taken into account the dynamics of fibrosis progression. This study assessed the impact of interferon on liver fibrosis progression in patients with chronic hepatitis C according to 3-month aminotransferase activity response. METHODS: We recruited 287 patients, 185 treated and 102 control, with paired biopsy specimens. Before follow-up, the fibrosis progression rate per year was estimated as the ratio between fibrosis stage in METAVIR units (1 U, 1 stage; 4 U, cirrhosis) and the duration of infection. During follow-up, fibrosis progression was assessed by the observed difference between stages divided by duration between biopsies. RESULTS: The median fibrosis progression rate in treated patients decreased compared with the rate before treatment from 0.103 F METAVIR U/yr (95% confidence interval [CI], 0.087-0.120) to 0.000 (95% CI, 0.000-0.000; P 相似文献   

7.
Bone changes in thalassemic patients receiving deferoxamine therapy for iron chelation include metaphyseal and growth plate irregularities. We present a case of an 8-year-old female with thalassemia major, who had magnetic resonance imaging after plain radiographs had shown metaphyseal changes in the distal femur. The signal characteristics of these abnormalities were consistent with hyaline cartilage; the surrounding marrow showed no evidence of iron overload.  相似文献   

8.
BACKGROUND/AIMS: The response to interferon therapy for chronic hepatitis is known to decrease with progression of the hepatic fibrosis. On the other hand, serum hyaluronate reflects hepatic sinusoidal capillarization or liver cirrhosis, and also serum type IV collagen, which is one of the main components of the basement membrane, rises with the progression of hepatic fibrosis. In this study, the relationship between the degree of hepatic fibrosis and the response to interferon-alpha was determined retrospectively in patients with chronic hepatitis C. In addition, whether the measurement of serum hyaluronate and type IV collagen before interferon-alpha therapy was useful for predicting the response to interferon-alpha therapy in chronic hepatitis C was determined. MATERIALS AND METHODS: Thirty-seven patients with elevated serum ALT levels for at least 6 months and histologically determined chronic hepatitis were studied. All patients were positive for anti-HCV and negative for hepatitis B surface antigen. Twenty-eight healthy adults with normal blood biochemical data, who were negative for hepatitis B antigen and HCV antibody tests, had limited alcohol intake were used as controls. The test group was given IFN-alpha by intramuscular injection for 14 days, and then were treated 3 times per week for 24 weeks. RESULTS: The extent of hepatic fibrosis, particularly, perisinusoidal fibrosis (P < 0.01) was significantly greater in nonresponders than in responders. The mean serum hyaluronate and type IV collagen levels were more elevated in nonresponders than in responders, especially, the serum hyaluronate level showed a significant difference (P < 0.01). Most of the patients having a serum hyaluronate level of more than 100 ng/ml were nonresponders who had chronic active hepatitis with bridging necrosis on liver biopsy. Serum hyaluronate and type IV collagen levels showed significant positive correlation with degree of the portal fibrosis (P < 0.01), perisinusoidal fibrosis (P < 0.001) and focal necrosis (P < 0.01) in histological findings of liver biopsy specimens. CONCLUSION: These results suggest that serum hyaluronate and type IV collagen levels reflect the extent of the hepatic fibrosis in chronic hepatitis C and also that serum hyaluronate level predicts the response to interferon-alpha therapy in patients with chronic hepatitis C.  相似文献   

9.
33 patients with chronic renal failure were divided into two groups. Group I consisted of 8 non-dialysed patients without any clinical or biochemical sign of liver disturbance nor any iron supplementation. Group II consisted of 25 maintenance hemodialysis (MHD) patients treated from 2 to 13 years. 19 subjects had chronic B hepatitis. Total exogenous iron load parenteral iron and/or blood transfusions) was calculated. Body iron overload (hemosiderosis) was assessed by liver iron concentration (LIC) in needle biopsy specimens according to Barry's method (less than 200 microgram/100 mg dry weight) and serum ferritin levels (less than 360 ng/ml). 4 patients whose serum ferritin was increased with or without hepatic fibrosis and with or without any organ dysfunction due to hemochromatosis received i.v. infusions of desferrioxamine in doses of 2 g at each dialysis. Serum ferritin levels were correlated with LIC (p less than 0.001) and iron load (p less than 0.001). Hemosiderosis was noted in 16 MHD patients (group II) and correlated with iron load. Hemochromatosis was noted in 4 patients (group II). 4 hemodialysed patients with iron overload were treated by desferrioxamine from 6 to 18 months. During this therapy, body iron stores fell and organ dysfunction (heart failure, hepatic cytolysis, anaemia, diabetes mellitus improved. Long-term chelation therapy by desferrioxamine was effective and the chelated iron was readily removed by dialysis. These data show the importance of precise evaluation of iron stores in MHD patients.  相似文献   

10.
BACKGROUND: We examined the relationships among vitronectin (VN), plasminogen activator inhibitor-1 (PAI-1), and transforming growth factor beta 1 (TGF-beta 1) in liver diseases to evaluate the presence of plasmin cascade in human hepatic fibrosis. METHODS: Blood and liver tissues were obtained from 57 patients with liver disease. Plasma VN, PAI-1 antigen, and PAI-1 activity levels were evaluated. Biopsied liver specimens were observed by light and electron microscopy after immunohistochemical staining. Morphometric analysis was performed on these specimens. RESULTS: Plasma VN and PAI-1 activity levels decreased significantly with the progression of hepatic fibrosis and were particularly marked in the liver cirrhosis group. Plasma PAI-1 antigen level increased significantly. The immunolocalization of the active form of TGF-beta became more intense with the progression of hepatic fibrosis, whereas that of the dual-stained positive areas of PAI-1 and VN (PAI-1.VN) decreased. There was a positive correlation between TGF-beta and PAI-1, whereas there was a negative correlation between TGF-beta and PAI-1.VN. Immunoelectron microscopy showed the localization of PAI-1-VN in the extracellular space around the sinusoidal cells or surface of aggregating platelets, TGF-beta mainly in Ito cells, and VN in hepatocytes near the focal necrotic area or fibrous septa. CONCLUSIONS: These findings suggest that VN and PAI-1 are related to the active form of TGF-beta and that it is possible that the plasmin cascade is present in the human liver.  相似文献   

11.
AIM: To evaluate the prevalence of iron overload in chronic hepatitis C and its relationship with liver histology. PATIENTS AND METHODS: Serum iron, unsaturated iron binding capacity and ferritin levels were determined in 204 consecutive anti-hepatitis C virus positive subjects, whereas hepatic iron concentration, hepatic histological grading and staging, hepatitis C virus genotypes were further assessed in a subgroup of 50 patients who underwent liver biopsy for chronic hepatitis. RESULTS: An increase in the serum markers of iron metabolism was more frequently found in subjects with aminotransferase activities above the normal range, whereas hepatic iron overload, established by direct hepatic iron determination, was found only in 9/50 (18%) patients with chronic hepatitis C. No serum iron marker could reliably predict hepatic iron stores. Patients with mild iron overload usually showed active hepatitis and fibrosis, whereas iron overload was not present in patients without fibrosis or with very mild fibrosis. Two out of nine patients with iron overload were shown to be beta thalassaemia heterozygous, and two were heterozygous carriers of a putative haemochromatosis gene mutation (His63Asp). CONCLUSIONS: Many anti-hepatitis C virus positive patients with elevated aminotransferase activities have serum ferritin levels above the normal range, but only a minority of patients with chronic hepatitis C have a mild iron overload. In chronic hepatitis C, a relationship does exist between hepatic iron content and liver fibrosis.  相似文献   

12.
The synthesis of a range of 3-hydroxy-4(1H)-pyridinones with potential for the chelation of iron(III) is described. The pKa values of respective ligands and the stability constants of their iron(III) complexes are presented. The distribution coefficient values of a range of 48 hydroxypyridinones and their corresponding iron(III) complexes between 1-octanol and MOPS buffer (pH 7.4) are reported. The range of log Dcomplex values covers 7 orders of magnitude. The results suggest the existence of a biphasic relationship between the distribution coefficient values of the chelator and the corresponding iron(III) complexes. For ligands with a log Dligand = -1, a linear relationship exists with a value of the slope 2.53, whereas with ligands with a log Dligand < -1, a linear relationship exists with a slope of 0.49. The reduced slope for the more hydrophilic molecules of the series offers some advantage for this type of hydroxypyridinone as the distribution coefficients for such complexes do not change so rapidly with increasing ligand hydrophilicity. The ability of selected 3-hydroxypyridinones to facilitate the excretion of iron in bile was investigated in non-iron-overloaded, bile duct-cannulated rats and in a [59Fe]ferritin-loaded rat model. Both systems compare the ability of chelators to remove iron from the liver, the prime target organ in thalassemia. The N-(hydroxyalkyl)-3-hydroxypyridin-4-ones are demonstrated to be orally active under the in vivo conditions adopted. Thus both 1-(hydroxyalkyl)- and 1-(carboxyalkyl)pyridinones are able to remove iron from the liver. Although 1-(carboxyalkyl)hydroxypyridinones are active, they do not demonstrate any clear advantage over Deferiprone (1,2-dimethyl-3-hydroxypyridin-4-one). Indeed 1-(hydroxyalkyl)hydroxypyridinones which are known to be rapidly converted to 1-(carboxyalkyl)hydroxypyridinones are also marginally superior to Deferiprone. In contrast, 2-ethyl-1-(2'-hydroxyethyl)-3-hydroxypyridin-4-one, which is not metabolized to the corresponding (carboxyalkyl)hydroxypyridinone, was found to be superior to Deferiprone and therefore deserves further consideration as an orally active iron chelator with potential for the treatment of iron overload associated with transfusion-dependent thalassemia.  相似文献   

13.
14.
BACKGROUND/AIM: Quantitative measurement of hepatic iron by biochemical analysis of liver biopsy samples is required to assess hepatic iron stores accurately. Cirrhotic livers, however, contain variable amounts of fibrous tissue and the distribution of iron within the hepatic parenchyma is not always uniform. The aim of this study was to assess the variability in hepatic iron concentration measurement from needle-biopsy specimens. METHODS: The livers from eight patients with cirrhosis selected because of elevated serum ferritin were obtained at the time of liver transplantation (n = 6) or at autopsy (n = 2). Multiple needle biopsies were done, and hepatic iron concentration was measured by atomic absorption spectroscopy. The hepatic iron index was calculated as iron concentration divided by age. RESULTS: Four cases had a mean hepatic iron index above 2.0, in the range of that reported in patients with homozygous genetic hemochromatosis, whereas the other four had an hepatic iron index of less than 2.0. The intra-individual coefficient of variation for hepatic iron concentration ranged from 11.3 to 43.7%, averaging 24.9%. The coefficient of variation was smaller in biopsy samples > 4 mg dry weight than in samples < 4 mg (19.8% vs 28.6%, p < 0.05). Histological examination of surgical biopsies from these livers showed large amounts of fibrous tissue, and inhomogeneous distribution or iron in the hepatic parenchyma. CONCLUSIONS: This study demonstrates an important variability in the measurement of hepatic iron content from needle biopsy specimens in patients with severe cirrhosis.  相似文献   

15.
OBJECTIVE: To observe the changes of abdominal sonography and 2 biochemical indicators for hepatic fibrosis before and after treatment with praziquantel in schistosomiasis japonica patients. METHODS: Fifty-five persons infected with Schistosoma japonicum and treated with praziquantel were examined with ultrasonography and serum hyaluronic acid (HA) and type III procollagen (PC III) before and 1 year after treatment, and their data were compared with those in 55 normal controls. RESULTS: With comparison of the data before praziquantel treatment, the length of the left liver lobe and the spleen in 55 patients all decreased (P < 0.01) 1 year after treatment. No significant change was seen in interior diameter (d) of the portal vein, while a decrease in the ratio of the exterior diameter (D) and interior diameter of the second branch of the portal vein was very significant (P < 0.01). Compared with the data in normal control, significantly higher levels in the thickness of the left lobe, the maximum oblique diameter of the right lobe, the length of the spleen, spleen index, the interior diameter of the portal vein and D/d ratio were seen in the patients both before and after treatment. The abnormal rate of the 2 serum parameters for hepatic fibrosis decreased significantly after treatment. CONCLUSIONS: Parameters of hepatic fibrosis either by ultrasonography or by the 2 biochemical tests showed a significant improvement in 55 patients 1 year after treatment, although some of the indices did not yet return to normal levels.  相似文献   

16.
Seven patients with varying psychiatric disorders were found to have iron overload as manifested by abnormal serum ferritin, transferrin saturation index (TSI), or excessive urinary iron. All possible sources of secondary iron overload were ruled out. The patients were treated with the specific iron chelator, deferoxamine, given IM for seven to 22 weeks which resulted in significant clinical improvements. These cases indicate a need to be aware that disordered iron metabolism is a somatic cause of psychiatric illness and that there is clinical improvement upon lowering elevated iron levels in patients with iron overload.  相似文献   

17.
Pulmonary disease, including thromboembolic problems, accounts for a large portion of the morbidity of sickle cell disease. Chronic transfusion therapy is now a part of long-term treatment of sickle cell patients with stroke and chest syndrome. The resultant iron overload must be treated with chelation therapy using deferoxamine. Poor compliance with subcutaneous chelation therapy has necessitated intravenous deferoxamine treatment. We describe two patients with sickle cell disease on such a regimen, who became hypoxic as a result of pulmonary thromboembolism, secondary to venous thrombophlebitis. The thrombophlebitis and subsequent pulmonary embolism probably reflect the hypercoagulable state seen in sickle cell and are not due to the deferoxamine therapy.  相似文献   

18.
Iron is required for cell proliferation of all living species. Moreover, iron excess may be involved in the development of hepatocellular carcinoma. In this study we analyzed the effects of deferoxamine, an iron chelator, on normal porcine hepatocyte proliferation. We confirmed that hepatocytes isolated from young pigs proliferate in the presence of insulin and fetal calf serum as shown by [3H] methyl-thymidine incorporation, presence of mitotic figures and increase in cell number. This was paralleled by nuclear expression of p34cdc2 and its associated histone H1 kinase activity. In the presence of deferoxamine, [3H] methyl-thymidine incorporation, expression of nuclear proteins (p34cdc2 and PCNA) and H1 kinase activity were drastically reduced. In addition, in contrast with control cultures, cells in S-phase were not detected by flow cytometry. These data suggest that iron chelation by deferoxamine can arrest the progression of porcine hepatocytes in the G1 phase of the cell cycle.  相似文献   

19.
Several life-threatening complications of the common disorder sickle cell disease require management with red blood cell transfusions and, hence, long-term iron-chelating therapy. The efficacy of the oral iron chelator 1,2-dimethyl-3-hydroxypyrid-4-one (L1) has not previously been determined in patients with sickle cell disease. We compared the efficacy of L1 to that of standard-dose subcutaneous deferoxamine in four regularly transfused patients with homozygous sickle cell disease, who had evidence of severe iron overload and a history of poor compliance with deferoxamine. Determination of 24-hour urinary iron excretion conducted over 5 days immediately after transfusion showed that the mean daily urinary iron excretion induced by L1 at 75 mg/kg/d (0.48 +/- 0.23 mg/kg) was equivalent to that induced by deferoxamine at 50 mg/kg/d (0.39 +/- 0.06 mg/kg). In two of three patients studied, a significant (P < .025) increase in mean daily urinary iron excretion was achieved when the dose of L1 was increased to 100 mg/kg/d. Total iron balance studies, which quantitated both urinary and stool iron excretion on L1 and deferoxamine, determined that mean total daily iron excretion induced by deferoxamine (0.88 +/- 0.05 mg/kg) was significantly greater (P < .05) than that induced by L1 (0.53 +/- 0.17 mg/kg), attributable to the significantly greater stool iron excretion during deferoxamine treatment (0.50 +/- 0.16 mg/kg/d) compared with that measured during L1 treatment (0.12 +/- 0.08 mg/kg/d, P < .01). Stool iron excretion accounted for a significantly greater percentage of total iron excretion during deferoxamine treatment (59% +/- 20%) than during L1 treatment (23% +/- 14%, P < .01). These iron balance studies are the first to compare total iron excretion induced by L1 with that achieved by deferoxamine. They demonstrate that the mean total daily iron excretion during L1 treatment (0.53 +/- 0.17 mg/kg) is sufficient to maintain net negative iron balance in most regularly transfused patients with sickle cell disease. Because long-term compliance with L1 has been shown previously to be superior to that with deferoxamine in patients with homozygous beta-thalassemia, the use of L1 should increase the long-term effectiveness of iron chelation in patients with sickle cell disease.  相似文献   

20.
The survival probability is 79% for patients with neuroblastoma stage 4S treated according to the German Society for Pediatric Oncology and Hematology (GPOH) treatment studies. Most of these patients (80%) have liver metastases. Patients are grouped according to their condition at diagnosis and tumour resectability to different risk groups (A, B, C). Chemotherapy is provided for patients who are initially diagnosed as critically ill, caused for example by excessive hepatomegaly due to liver metastases. The aim of this study is to clarify whether liver infiltration is associated with liver dysfunction and whether chemotherapy plays a role in this process. Hepatopathy was diagnosed when clinical signs were present and/or liver function tests revealed pathologic results. The charts of 48 patients (22 boys, 26 girls) diagnosed between 1990 and 1994 from the ongoing NB-90 treatment study were evaluated retrospectively. Median age at diagnosis was 52 days (range: 1-328). 41 patients (85%) had liver infiltration, 26 patients (54%) had bone marrow involvement and in nine patients (19%) skin metastases were found. 12 patients were in poor general condition at diagnosis (risk group C). 36 of 48 patients (75%) received chemotherapy, three children were treated with radiotherapy additionally, due to massive liver enlargement. 15 patients (31%) had signs of hepatic dysfunction at diagnosis or during their illness, 14 of these had liver metastases. All these 15 patients were treated with chemotherapy. 12 of 15 patients with hepatopathy were younger than two months at diagnosis. Five patients with liver dysfunction were not critically ill at diagnosis. Hepatomegaly > or = 6 cm was present in 10 of 15 patients with liver dysfunction. Hepatopathy was transient in eight patients, four patients died soon of multiorgan failure during progression of disease. Three children developed liver fibrosis with conversion to cirrhosis. Hepatopathy was correlated with distribution to risk groups (A and B (5/36) vs. C (10/12), p < 0.001). The appearance of hepatic dysfunction in patients with neuroblastoma stage 4S remains a serious problem especially for young children with excessive hepatic infiltration. Liver dysfunction was of short duration and reversible in most patients, however, even with age-adapted dosages of chemotherapy long-standing cases of hepatopathy were observed. A general recommendation for treatment strategy in this heterogeneous patient group is difficult. Attention should be given to for this complication.  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