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PubMed2006

Hepatic iron overload associated with a decreased serum ceruloplasmin level in a novel clinical type of aceruloplasminemia.

BACKGROUND & AIMS: Aceruloplasminemia is a novel hereditary iron overload disease caused by a mutation in the ceruloplasmin gene and characterized by a complete deficiency of serum ceruloplasmin and iron accumulation in the liver and brain. METHODS: We herein studied a novel clinical type of aceruloplasminemia in which a low amount of ceruloplasmin was detected in the serum of a patient. The patient presented with an asymptomatic hepatic iron overload, retinal degeneration, and diabetes mellitus. Magnetic resonance imaging of the liver and basal ganglia showed T2-hypointensity signals associated with parenchymal iron accumulation because of an absence of the ferroxidase activity in ceruloplasmin. RESULTS: A gene analysis showed a novel G969S mutation in the ceruloplasmin gene. A biochemical analysis of the patients' serum and a biogenesis study of G969S mutant ceruloplasmin using mammalian cell culture system resulted in the synthesis and secretion of only apoceruloplasmin without any ferroxidase activity. CONCLUSIONS: This novel clinical type of aceruloplasminemia should therefore be considered in the differential diagnosis of unexplained hemochromatosis, which is associated with a decrease in the serum ceruloplasmin level.

Aged↗
PubMed2004

Prevention of secondary stroke and resolution of transfusional iron overload in children with sickle cell anemia using hydroxyurea and phlebotomy.

OBJECTIVE: Transfusions prevent secondary stroke in children with sickle cell anemia (SCA) but also cause iron overload. Alternatives for stroke prophylaxis with effective therapy to reduce iron burden are needed. STUDY DESIGN: For 35 children with SCA and stroke, transfusions were prospectively discontinued. Hydroxyurea was prescribed for stroke prophylaxis, and phlebotomy removed excess iron. Initial patients discontinued transfusions before hydroxyurea therapy, but later patients overlapped transfusions with hydroxyurea until tolerating full-dose therapy. RESULTS: Children received hydroxyurea for 42 +/- 30 months (range, 3-104 months). Hydroxyurea (26.7 +/- 4.8 mg/kg per day) led to mild neutropenia (3.9 +/- 2.3 x 10(9)/L) with significant increases in hemoglobin concentration, mean corpuscular volume, and fetal hemoglobin. Stroke recurrence rate was 5.7 events per 100 patient-years, but children receiving overlapping hydroxyurea therapy had only 3.6 events per 100 patient-years. For 26 children with >6 months of phlebotomy, 14,311 +/- 12,459 mL blood (315 +/- 214 mL/kg) was removed, with serum ferritin decreasing from a median of 2722 to 298 ng/mL. Among patients completing phlebotomy, liver biopsy documented normal histology and no excess iron deposition. CONCLUSIONS: For children with SCA and stroke, hydroxyurea effectively prevents secondary stroke and serial phlebotomy leads to complete resolution of transfusional iron overload.

Adolescent↗
PubMed1976

Subcutaneous infusion and intramuscular injection of desferrioxamine in patients with transfusional iron overload.

The effects of intramuscular injection and subcutaneous infusion of desferrioxamine (D.F.) on urinary iron excretion were compared in eleven patients with thalassaemia major and one with congenital sideroblastic anaemia who were being maintained on regular blood-transfusions. Total (48-hour) urinary iron excretion ranged from 3-3 to 40-3 mg (mean 16-3 mg) in nine patients who received 750 mg D.F. intramuscularly before transfusion and from 3-9 to 32-3 mg (mean 11-9 mg) in ten patients who received D.F. by the same route after transfusion. In all 9 patients studied before transfusion, continuous subcutaneous infusion of 750 mg D.F. over 24 hours increased iron excretion by 61-5 to 135-8% (mean 101+/-25-4 S.D.%) compared with intramuscular injection of a similar dose. In the 10 patients studied after transfusion, the iron excretion produced by continuous subcutaneous infusion was from 18-9 to 213% (mean 128+/-74-3%) more than that produced by a single intramuscular injection of D.F. When the subcutaneous dose over 24 hours was increased to 1500 mg in six patients, 48-hour iron excretion ranged from 29-2 to 81-2 mg (mean 52-4 mg) and was increased by 80-2--794% (mean 429%) compared with the excretion when 750 mg was given by intramuscular injection. It is concluded that continuous subcutaneous infusion of D.F. produces more iron excretion in patients with iron overload than intramuscular injection. Providing a suitable portable pump can be carried by the patients, continuous subcutaneous infusion of desferrioxamine may prove a valuable means of preventing or treating iron overload in anaemic patients maintained on regular transfusions.

Adolescent↗
PubMed2000

Transfusional iron overload and chelation therapy with deferoxamine and deferiprone (L1).

Iron is essential for all living organisms. Under normal conditions there is no regulatory and rapid iron excretion in humans and body iron levels are mainly regulated from the absorption of iron from the gut. Regular blood transfusions in thalassaemia and other chronic refractory anaemias can result in excessive iron deposition in tissues and organs. This excess iron is toxic, resulting in tissue and organ damage and unless it is removed it can be fatal to those chronically transfused. Iron removal in transfusional iron overload is achieved using chelation therapy with the chelating drugs deferoxamine (DF) and deferiprone (L1). Effective chelation therapy in chronically transfused patients can only be achieved if iron chelators can remove sufficient amounts of iron, equivalent to those accumulated in the body from transfusions, maintaining body iron load at a non-toxic level. In order to maintain a negative iron balance, both chelating drugs have to be administered almost daily and at high doses. This form of administration also requires that a chelator has low toxicity, good compliance and low cost. DF has been a life-saving drug for thousands of patients in the last 40 years. It is mostly administered by subcutaneous infusion (40-60 mg/kg, 8-12 h, 5 days per week), is effective in iron removal and has low toxicity. However, less than 10% of the patients requiring iron chelation therapy worldwide are able to receive DF because of its high cost, low compliance and in some cases toxicity. In the last 10 years we have witnessed the emergence of oral chelation therapy, which could potentially change the prognosis of all transfusional iron-loaded patients. The only clinically available oral iron chelator is L1, which has so far been taken by over 6000 patients worldwide, in some cases daily for over 10 years, with very promising results. L1 was able to bring patients to a negative iron balance at doses of 50-120 mg/kg/day. It increases urinary iron excretion, decreases serum ferritin levels and reduces liver iron in the majority of chronically transfused iron-loaded patients. Despite earlier concerns of possible increased risk of toxicity, all the toxic side effects of L1 are currently considered reversible, controllable and manageable. These include agranulocytosis (0.6%), musculoskeletal and joint pains (15%), gastrointestinal complaints (6%) and zinc deficiency (1%). The incidence of these toxic side effects could in general be reduced by using lower doses of L1 or combination therapy with DF. Combination therapy could also benefit patients experiencing toxicity with DF and those not responding to either chelator alone. The overall efficacy and toxicity of L1 is comparable to that of DF in both animals and humans. Despite the steady progress in iron chelation therapy with DF and L1, further investigations are required for optimising their use in patients by selecting improved dose protocols, by minimising their toxicity and by identifying new applications in other diseases of iron imbalance.

Deferiprone↗
PubMed1997

Iron overload in patients with chronic viral hepatitis: how common is it?

OBJECTIVES: To establish the prevalence of increased hepatic iron content in patients with hepatitis C virus-related chronic hepatitis and to assess the accuracy of serum iron and ferritin in detecting tissue iron overload. METHODS: Serum iron, serum ferritin, and hepatic iron content were determined in 81 consecutive patients undergoing liver biopsy for chronic ALT elevation and hepatitis C virus infection. Moreover, in a subgroup of 28 patients, outcome of a 6-month course of interferon (IFN) treatment (6 million U of recombinant IFN, three times weekly) was determined after a mean follow-up of 24 +/- 6 months and the outcome was compared with the pretreatment values of hepatic iron content. RESULTS: Elevated serum iron or ferritin levels were detected in approximately 40% of patients, but elevated hepatic iron content was observed in only eight patients (10%). One of these patients had a hepatic iron index > 1.9, indicating hemochromatosis. Liver iron content and serum iron levels were not correlated. No differences in hepatic iron content were observed among patients with a sustained response to IFN (seven patients), short-term responders (seven patients), or nonresponders (14 patients). CONCLUSIONS: Ten percent of patients with chronic hepatitis C have elevated hepatic iron content. These patients cannot be identified using serum markers of iron status. The relationship between liver iron and response to IFN treatment requires further prospective investigations.

Adult↗
PubMed2000

Effect of transfusional iron overload on immune response.

Increased susceptibility to infectious disease is observed in persons with transfusion-dependent thalassemia and iron overload who experience increased exposure to pathogens and chronic immune stimulation. An abnormal low CD8(+) T (LT8) immune phenotype defines a subgroup of patients. The CD8(+) T cell immunophenotype is stable despite continued blood transfusion and is independent of age. CD8(+) T cells, but not CD4(+) T cells, were modulated during intravenous chelation with deferoxamine. Return to characteristic pretreatment levels of CD8 was observed in both the low and the normal groups, suggesting the possibility of a set point. Proliferative response to mitogens and antigens was increased by chelation. Because CD8(+) T cells are important in immune response to infectious disease, these studies suggest that intrinsic CD8(+) T cell subset differences may be a critical factor in determining susceptibility to infection independent of transfusional iron overload or alloantigen exposure.

Adolescent↗
PubMed1994

Hepatocellular adenoma in a beta-thalassemic woman having secondary iron overload.

An 18-year-old woman had a hepatocellular adenoma of 4 cm across in the right lobe of the liver which was severely hemosiderotic because of beta-thalassemia hemoglobin E disease with numerous blood transfusions. The lesion was an accidental postmortem finding. To our knowledge, this is the second example of liver-cell adenoma occurring in a patient with beta-thalassemia hemoglobin E disease with secondary iron overload. It is suggested that this is an association between hepatocellular adenoma and secondary iron overload of liver cells, a similar event to the relation observed in hepatocellular carcinoma and secondary iron overload of hepatocytes.

Adenoma, Liver Cell↗
PubMed1982

Hepatic iron stores and markers of iron overload in alcoholics and patients with idiopathic hemochromatosis.

Liver iron concentrations were determined in 60 alcoholics with liver disease of varying severity, 15 patients with untreated idiopathic hemochromatosis, and 16 control subjects with biliary tract disease. Mean liver iron concentrations (microgram/100 mg dry weight) were significantly greater in the alcoholics (156.4 +/- 7.8 (SEM); P less than 0.05) and in patients with idiopathic hemochromatosis (2094.5 +/- 230.7; P less than 0.01) than in control subjects (53.0 +/- 7.0). Liver iron concentrations of greater than 140 micrograms/100 were found in 17 alcoholics (29%) and in all 15 patients with idiopathic hemochromatosis. Liver iron concentrations greater than 1000 micrograms/100 mg were found in all patients with idiopathic hemochromatosis but in none of the alcoholics. In the alcoholics no relationship existed between liver iron concentrations and the amount of alcohol consumed daily, the length of the drinking history, the amount of beverage iron consumed daily, or the severity of the liver disease. Serum ferritin concentrations reflected iron stores in patients with hemochromatosis and in alcoholics with minimal liver disease. However, in alcoholics with significant liver disease serum ferritin concentrations did not reflect iron stores accurately, although with normal values iron overload is unlikely. Serum iron concentration and percentage saturation of total iron-binding capacity were of little value in assessing iron status in either alcoholics or patients with hemochromatosis. Measurement of the liver iron concentration clearly differentiates between alcoholics with significant siderosis and patients with idiopathic hemochromatosis.

Alcoholism↗
PubMed2004

A model for acute iron overload in sea bass (Dicentrarchus labrax L.).

Evaluation of several parameters involved in iron metabolism was carried out after intraperitoneal (i.p.) injection with iron dextran (IDx) in sea bass (Dicentrarchus labrax L.). After treatment, a rapid mobilization of IDx from the peritoneal cavity to other organs was observed. This was followed by a modification of normal peripheral blood iron parameters. Total iron (TI) and transferrin saturation (TS) rose rapidly, to 4.14 microg/ml and 83.7%, respectively, on day 3. In contrast, unsaturated iron binding capacity (UIBC) dropped from 3.19 microg/ml (at day 0) to 0.90 microg/ml on day 3. Tissue iron content was determined by atomic absorption spectometry (AAS). Three days post-IDx injection, values of iron concentration in liver, spleen and head kidney were significantly higher than control values (15, 6 and 9-fold increase, respectively). Samples of liver, spleen and head kidney were processed for routine histology, and the Perl's method was used for iron staining. Histological sections of the IDx-treated animals showed iron deposition in all tissues studied. In the liver, the iron was evenly distributed over the whole organ, being present in the hepatocytes. In the head kidney and spleen, the iron deposition was mainly observed in the melanomacrophage centres (MMCs). The present study characterizes several parameters involved in iron metabolism, and develops a fish model, of iron overload, which can be used in further studies of iron toxicity and iron-induced susceptibility to bacterial infections.

Animals↗
PubMed1992

Iron overload in sub-Saharan Africa involves a genetic component.

A new study suggests that the iron overload observed in sub-Saharan Africans may be due to more than elevated iron intake. Genetic analysis indicates that a heritable, but unidentified, trait may account for a substantial portion of the variability in transferrin saturation seen in persons with iron overload. This defect may occur in over 30% of the population and appears to be distinct from the genetic factor controlling hemochromatosis in Caucasian populations.

Africa↗
PubMed2006

Improved R2* measurements in myocardial iron overload.

PURPOSE: To optimize R2*(1/T2*) measurements for cardiac iron detection in sickle cell and thalassemia patients. MATERIALS AND METHODS: We studied 31 patients with transfusion-dependent sickle cell disease and 48 patients with thalassemia major; myocardial R2* was assessed in a single midpapillary slice using a gated gradient-echo pulse sequence. Pixel-wise maps were coregistered among the patients to determine systematic spatial fluctuations in R2*. The contributions of minimum TE, echo spacing, signal-decay model, and region-of-interest (ROI) choice were compared in synthetic and acquired images. RESULTS: Cardiac relaxivity demonstrated characteristic circumferential variations regardless of the degree of iron overload. Within the interventricular septum, a gradient in R2* from right to left ventricle was noted at high values. Pixel-wise and ROI techniques yielded nearly identical values. Signal decay was exponential but a constant offset or second exponential term was necessary to avoid underestimation at high iron concentration. Systematic underestimation of R2* was observed for higher minimum TE, limiting the range of iron concentrations that can be profiled. Fat-water oscillations, although detectable, represented only 1% of the total signal. CONCLUSION: Clinical cardiac R2* measurements should be restricted to the interventricular septum and should have a minimum TE < or = 2 msec. ROI analysis techniques are accurate; however, offset-correction is essential.

Anemia, Sickle Cell↗
PubMed1996

Iron overload increases hepatic development of Plasmodium yoelii in mice.

Iron overload in BALB/c mice by treatment with ferric ammonium citrate promotes the hepatic development of Plasmodium yoelii in vivo and in vitro. This was the result of increased penetration of the parasite into hepatocytes since no effect was observed on parasite transformation or maturation. These results could explain why in endemic regions iron supplementation led, in certain studies, to an increase in clinical episodes of malaria and in the prevalence of malaria infection.

Animals↗
PubMedDate not supplied

MR imaging technique for the diagnosis of pituitary iron overload in patients with transfusion-dependent beta-thalassemia major.

To identify the optimal MR imaging technique for diagnosing pituitary iron overload, we compared spin-echo and gradient-echo MR imaging with measurements of pituitary T2 relaxation times in 30 patients with secondary hemochromatosis due to transfusion-dependent beta-thalassemia major and in 10 healthy volunteers. We found that the optimal MR imaging technique to evaluate pituitary iron overload is the gradient-echo T2*-weighted technique, as it best demonstrated signal reduction in the anterior lobe of the pituitary gland.

Adolescent↗
PubMedDate not supplied

Iron overload in thalassemia: comparative analysis of magnetic resonance imaging, serum ferritin and iron content of the liver.

BACKGROUND: Iron overload in patients with thalassemia is a common feature which requires continuous chelation therapy and monitoring. Serum ferritin determination is widely accepted as a simple method for following iron load in patients with primary hemochromatosis; however, several reports on thalassemic patients emphasize that ferritinemia is not accurate and that other methods such as direct measurement of iron in the liver (HIC) and magnetic resonance imaging (MRI) are more precise. MATERIALS AND METHODS: In order to contribute to the general understanding of iron load in thalassemia we used liver MRI to study 33 thalassemic patients, most of whom were also evaluated for iron content by liver biopsy. The data were then compared with serum ferritin levels. RESULTS: Ferritin levels ranged between 276 and 8031 ng/mL, and liver iron content ranged from 1.6 to 31.0 mg/g dry weight; grade III or IV liver siderosis was recorded in 23/33 patients, just as 23/33 patients were found to have severe or very severe siderosis at MRI. Significant correlations with ferritin levels were recorded between grade IV and grades III, II and I (p < 0.01, p = 0.02, and p = 0.03, respectively). Ferritinemia also showed significant linearity with liver iron content (r = 0.603, p = 0.001). No significant differences of levels were recorded, however, between patients found to have severe and those with mild iron load at MRI (p = 0.073). CONCLUSIONS: Our study shows that serum ferritin levels exhibit a tendency to be significantly correlated with the true status of hemochromatosis in thalassemic patients; however, the discrepancies recorded in several patients and the scarce or total lack of correlation with MRI suggest exploring other approaches to this problem in order to make proper decisions about therapy.

Adolescent↗
PubMed2004

Homozygosity for transferrin receptor-2 Y250X mutation induces early iron overload.

Two Italian subjects, aged three and sixteen years, presented with early iron overload as shown by increased serum iron indices and hepatic iron concentration. They both carried the Y250X mutation of the TFR2 gene in the homozygous state. We suggest that transferrin receptor-2 is important in maintaining iron balance in the first decades of life.

Adolescent↗
PubMed1995

Blood cardioplegia increases plasma iron overload and thiol levels during cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass and crossclamping of the ascending aorta introduce two well-characterized phases of oxidative stress, namely, the extracorporeal circulation of blood and the reoxygenation of ischemic tissue. A feature of both forms of stress is the release of reactive and damaging oxygen species. METHODS: Forty-seven patients undergoing aortic valve replacement received either cold crystalloid, cold blood, or warm blood cardioplegia. Plasma thiol levels were measured in all groups before and during bypass. All cardiopulmonary bypass patients had, before going onto bypass, low plasma thiol levels (3.80 +/- 0.22 nmol/mg protein) compared with normal healthy controls (5.48 +/- 0.14 nmol/mg protein). RESULTS: Thiol values remained low throughout bypass in patients receiving cold crystalloid cardioplegia, but rose in patients receiving cold blood cardioplegia, and rose even more in patients receiving warm blood cardioplegia to reach normal plasma values. During cardiopulmonary bypass it has previously been reported that plasma transferrin can become fully saturated with iron and cause transient iron overload. Two patients (13%) receiving cold crystalloid cardioplegia went into plasma iron overload, whereas 18% receiving cold blood and 27% receiving warm blood cardioplegia showed plasma iron overload. CONCLUSIONS: We suggest that blood cardioplegia provides an additional source of thiols as well as a source of reactive iron. However, the reactive iron and thiol-containing molecules have the potential to interact and exacerbate oxidative stress, already a feature of bypass. Control of reactive iron by chelation may be strongly indicated when blood cardioplegia is used.

Adult↗
PubMed2000

Exogenous apotransferrin and exchange transfusions in hereditary iron overload disease.

OBJECTIVE: To investigate whether apotransferrin administration and exchange transfusion can improve outcome in patients with the recently described recessive congenital iron overload disease, presenting with intrauterine growth retardation, severe lactic acidosis, aminoaciduria, and hemosiderosis of the liver that so far has been treatment-resistant and lethal. METHODOLOGY: Because the patients have hypotransferrinemia, hyperferritinemia, increased transferrin saturation, and bleomycin detectable iron in plasma, we designed a treatment regime aiming at decreasing free iron and iron overload. The serum transferrrin concentration was increased to adult level (2-5 g/L) by intravenous apotransferrin administrations and thereafter exchange transfusion was performed. RESULTS: Two patients were treated. In patient 1, the transferrin saturation decreased from a baseline value of 100% and remained normal after the third exchange transfusion, and in patient 2, a reversible beneficial effect was seen on transferrin saturation and bleomycin-detectable iron. However, both infants died later of the disease, at 10 and 8 weeks of age, respectively. CONCLUSIONS: Exogenous apotransferrin administration proved to be safe and might deserve evaluation in other neonatal diseases with presence of free iron in plasma.

Apoproteins↗
PubMed1992

Noninvasive liver-iron quantification by computed tomography in iron-overloaded rats.

RATIONALE AND OBJECTIVES: The benefit of computed tomography (CT) for the noninvasive determination of liver-iron concentration in human iron-overload diseases is a controversy in the literature. To study the sensitivity of CT for liver-iron quantification under experimental conditions, the authors measured single- and dual-energy CT numbers in vivo in the livers of iron-overloaded rats. METHODS: Thirty-five rats were subjected to an iron-rich diet for various periods, from 1 to 20 weeks, then scanned by single- and dual-energy CT. CT absorption was correlated to liver-iron content, which was determined by wet ashing and spectrophotometry. RESULTS: Whereas a good correlation (r = 0.99 at 96 kV; r = 0.95 at 125 kV) between CT numbers and liver-iron concentration was found, CT was insensitive to low concentrations of iron. Dual-energy CT scanning results showed greater scattering in liver-iron quantification compared with single-energy CT. CONCLUSIONS: In rats, the sensitivity of single- and dual-energy CT is too low to quantify liver iron in the diagnostically most relevant region of mild liver siderosis (1-3 mg iron/g wet weight [w.wt]).

Animals↗