Transfusion Haemosiderosis and Chelation Therapy

Multimodal imaging in a case of deferoxamine-induced maculopathy

PURPOSE

To report a case of deferoxamine-induced maculopathy and present the use of multimodal retinal imaging to study this disease entity.

METHODS

This is an observational case report of one patient. Multimodal imaging with fundus autofluorescence, infrared imaging, and spectral domain optical coherence tomography was used to investigate the macular changes induced by deferoxamine toxicity.

RESULTS

A 53-year-old man with history of β-thalassemia presented with decreased vision in both eyes 1 month after initiating deferoxamine therapy. Infrared imaging showed areas of increased stippled infrared intensity through the macula. Fundus autofluorescence revealed diffuse areas of stippled hyperautofluorescence and hypoautofluorescence. Spectral domain optical coherence tomography changes included disruption of the ellipsoid zone, attenuation of the photoreceptors, and deposits within the retinal pigment epithelium.

CONCLUSION

A case of deferoxamine-induced maculopathy was described and the use of multimodal retinal imaging to study this disease entity was presented.

Beneficial effect of sesame oil on heavy metal toxicity

Heavy metals become toxic when they are not metabolized by the body and accumulate in the soft tissue. Chelation therapy is mainly for the management of heavy metal-induced toxicity; however, it usually causes adverse effects or completely blocks the vital function of the particular metal chelated. Much attention has been paid to the development of chelating agents from natural sources to counteract lead- and iron-induced hepatic and renal damage. Sesame oil (a natural edible oil) and sesamol (an active antioxidant) are potently beneficial for treating lead- and iron-induced hepatic and renal toxicity and have no adverse effects. Sesame oil and sesamol significantly inhibit iron-induced lipid peroxidation by inhibiting the xanthine oxidase, nitric oxide, superoxide anion, and hydroxyl radical generation. In addition, sesame oil is a potent inhibitor of proinflammatory mediators, and it attenuates lead-induced hepatic damage by inhibiting nitric oxide, tumor necrosis factor-α, and interleukin-1β levels. Because metal chelating therapy is associated with adverse effects, treating heavy metal toxicity in addition with sesame oil and sesamol may be better alternatives. This review deals with the possible use and beneficial effects of sesame oil and sesamol during heavy metal toxicity treatment.

Red blood cell transfusion risks in patients with end-stage renal disease

Prior to the introduction of recombinant human erythropoietin (EPO), red blood cell (RBC) transfusions were frequently required when iron and anabolic steroids failed to improve the clinical symptoms of anemia associated with hemoglobin (Hb) levels that were commonly less than 7 g/dl. After the approval of EPO in the United States in 1989, the Hb levels of patients on hemodialysis dramatically improved and the need for RBC transfusions decreased significantly. The need for RBC transfusion remains for patients who require an immediate increase in their RBC mass due to symptomatic anemia and is likely to increase due to changes in the management of anemia in dialysis patients resulting from clinical trials data, regulatory changes, and new reimbursement policies for EPO. The safety of the blood supply has greatly improved over the last few decades, and the risk of transfusion-transmitted diseases has now been dramatically reduced. Noninfectious complications of transfusion currently cause the majority of morbidity and mortality associated with transfusion in the United States. Transfusion also brings a risk of alloimmunization, a particular concern for dialysis patients waiting for kidney transplantation. Knowledge of the risks of RBC transfusions will help clinicians better assess the risks and benefits of transfusing patients with ESRD. This article reviews the modern day infectious and noninfectious risks of allogeneic RBC transfusions.

Mechanisms of 2-Butoxyethanol–Induced Hemangiosarcomas

Chronic exposure to 2-butoxyethanol increased liver hemangiosarcomas in male mice. The mechanism for the selective induction of hemangiosarcomas by 2-butoxyethanol is unknown but has been suggested to occur through non-DNA-reactive mechanisms. The occurrence of liver hemangiosarcomas in male mice has been linked to oxidative damage subsequent to RBC hemolysis and iron deposition and activation of macrophages (Kupffer cells) in the liver, events that exhibit a threshold in both animals and humans. 2-Butoxyethanol is metabolized to 2-butoxyacetaldehyde and 2-butoxyacetic acid, and although the aldehyde metabolite is short lived, the potential exists for this metabolite to cause DNA damage. The present study examined whether 2-butoxyethanol and its metabolites, 2-butoxyacetaldehyde and 2-butoxyacetic acid, damaged mouse endothelial cell DNA using the comet assay. No increase in DNA damage was observed following 2-butoxyethanol (1-10mM), 2-butoxyacetaldehyde (0.1-1.0mM), or 2-butoxyacetic acid (1-10mM) in endothelial cells after 2, 4, or 24 h of exposure. Additional studies examined the involvement of hemolysis and macrophage activation in 2-butoxyethanol carcinogenesis. DNA damage was produced by hemolyzed RBCs (10 x 10(6), 4 h), ferrous sulfate (0.1-1.0 microM; 2-24 h), and hydrogen peroxide (50-100 microM; 1-4 h) in endothelial cells. Hemolyzed RBCs also activated macrophages, as evidenced by increased tumor necrosis factor (TNF) alpha, while neither 2-butoxyethanol nor butoxyacetic acid increased TNF-alpha from macrophages. The effect of activated macrophages on endothelial cell DNA damage and DNA synthesis was also studied. Coculture of endothelial cells with activated macrophages increased endothelial cell DNA damage after 4 or 24 h and increased endothelial cell DNA synthesis after 24 h. These data demonstrate that 2-butoxyethanol and related metabolites do not directly cause DNA damage. Supportive evidence also demonstrated that damaged RBCs, iron, and/or products from macrophage activation (possibly reactive oxygen species) produce DNA damage in endothelial cells and that activated macrophages stimulate endothelial cell proliferation. These events coupled together provide the events necessary for the induction of hemangiosarcomas by 2-butoxyethanol.

Abdominal lymphadenopathy in beta-thalassemia: MRI features and correlation with liver iron overload and posttransfusion chronic hepatitis C

OBJECTIVE

The objective of our study was to describe the MRI features of abdominal lymphadenopathy in patients with beta-thalassemia major and investigate the relation of abdominal lymphadenopathy with the severity of iron overload and posttransfusion chronic hepatitis C.

MATERIALS AND METHODS

Abdominal MRI studies of 60 consecutive patients with beta-thalassemia major, performed for quantification of liver iron overload at a single institution, were retrospectively studied for the presence of lymph nodes and their distribution, size, and number. The signal intensity ratios of liver, spleen, and the largest lymph node to the right paraspinous muscle (L/M, S/M, and LN/M, respectively) were calculated on T1-weighted gradient-echo images. MRI findings for the lymph nodes were compared with the histologically assigned activity level of chronic hepatitis C that was available in 17 patients who had undergone liver biopsy within 1 month of the MRI examination.

RESULTS

Hypointense abdominal lymph nodes larger than 7 mm were seen in 19 (32%) of 60 thalassemic patients in perihepatic and paraortic distributions. Lymphadenopathy was related to both the severity of hepatic siderosis, as expressed by the L/M values, and the presence of chronic hepatitis C, given that 18 (95%) of the 19 thalassemic patients with lymphadenopathy had chronic hepatitis C. Moreover, thalassemic patients with a moderate or severe level of hepatic inflammation presented with abdominal lymphadenopathy more frequently than those with mild hepatic inflammation.

CONCLUSION

The development of hypointense abdominal lymphadenopathy in patients with beta-thalassemia major who have received multiple transfusions depends both on the severity of liver iron overload and on the presence and the activity level of coexistent chronic hepatitis C.

Time course study of the influence of acute iron overload on Kupffer cell functioning and hepatotoxicity assessed in the isolated perfused rat liver

This study tested the hypothesis that acute iron overload (500 mg/kg) alters Kupffer cell functioning by promoting free radical reactions associated with the respiratory burst of liver macrophages, assessed in the isolated perfused rat liver under conditions of Kupffer cell stimulation by carbon infusion and inactivation by gadolinium chloride pretreatment. Total serum and hepatic iron levels were markedly enhanced compared with control values 2 to 24 hours after iron treatment. Total liver O2 uptake progressively increased by iron overload reaching a maximum at 6 hours after treatment, an effect that was completely blocked by GdCl3. Concomitantly, carbon-induced GdCl3-sensitive liver O2 uptake was either enhanced by 119% at 2 hours after iron overload, diminished compared with control values at 4 hours, or abolished at 6 hours. Iron-overloaded rats showed a marked increase in liver sinusoidal lactate dehydrogenase efflux at 4 and 6 hours after treatment, an effect that is exacerbated by carbon infusion and reduced (69%-89%) by GdCl3 pretreatment. Both basal and carbon-induced lactate dehydrogenase effluxes returned to control values at 24 hours after iron overload concomitantly with depression of the basal O2 uptake, without development of iron-induced GdCl3-sensitive respiration or Kupffer cell activation by carbon infusion. It is concluded that iron overload induces a derangement in the Kupffer cell functional status represented by early increases in macrophage-dependent respiratory activity, which may contribute to the concomitant liver injury that developed and to the impairment of both hepatic respiration and the macrophage response to particle stimulation observed at later times after treatment.

Pathology of the liver in leukaemia and lymphoma. A study of 110 autopsies

Histopathological findings in the liver in a series of autopsies on 110 patients suffering from leukaemia or lymphoma were reviewed. No treatment had been given to 23 patients, 50 had received chemotherapy alone, 23 chemo- and radiotherapy and 14 underwent bone marrow transplantation. The 23 untreated patients showed neoplastic infiltration in 10 (44%) and fibrosis in 16 cases (70%). The 14 bone marrow recipients showed mainly acute necrosis, zonal in six (43%) and focal in one (7%), and cholestasis in five (36%), together with marked siderosis in 11 (79%). Patients receiving chemotherapy or chemo-/radiotherapy showed similar changes consisting of neoplastic infiltration in 14 (28%) and in five (22%) cases respectively, and fibrosis in 31 (62%) and 17 (74%) cases respectively. Steatosis was seen in 70% of cases in the chemo-/radiotherapy group and in 50% of cases in the other groups. Infections were seen in all groups, particularly in the chemotherapy group (four fungal and two bacterial including one tuberculosis) and in the chemo-/radiotherapy group (one fungal and one bacterial). Cytomegalovirus infection was seen only in the bone marrow transplant group.

[Post-transfusion hemochromatosis. Results of a study carried out in Blood Transfusion Centers. Analysis of 15 cases treated with subcutaneous perfusion of Desferal. Working group "Transfusion Techniques and Therapeutics"]

Post-transfusional iron overload is a real problem for doctors in charge of transfusions, as shown by the survey we led in twenty French blood banks. Deferoxamine remains the most efficient chelator, but can be prescribed only in a parenteral way. It is now proved that continuous infusions, intravenous or subcutaneous, are preferable to intermittent injections as far as iron excretion is concerned. In our study, we selected 15 polytransfused patients for dysmyelopoiesis. 13 cases were analysed by measuring the serum ferritin level. A clear decrease was noted, as well as a relative normalization of serum alanine amino transferases. However, if this treatment is effective and well tolerated, the problem is that it obviously requires the patient's compliance. It seems important to us to optimize prevention and treatment of post-transfusional iron overload through a consensus.

Fate of iron stores in thalassaemia after bone-marrow transplantation

After successful bone-marrow transplantation (BMT) in thalassaemia, the individual acquires the pattern of globin synthesis of the donor. We call such an individual "ex-thalassaemic after BMT", a term that underscores the cure of the genetic defect but maintenance of residual signs of organ damage due to iron overload and dysfunction acquired during the pretransplant years. We have analysed the extent and fate of tissue iron overload in 151 ex-thalassaemic patients after BMT, according to the risk factors of hepatomegaly, hepatic portal fibrosis, and inadequate chelation therapy. Serum ferritin concentrations decreased and unbound iron binding capacity (UIBC) increased slowly during the years after the transplant. When analysed according to risk group (assigned at the time of the transplant), ferritin and UIBC returned within the normal ranges in only the low-risk group (without hepatomegaly or portal fibrosis, and with adequate chelation pre-BMT). Ferritin and UIBC were still abnormal 7 years after the transplant in the moderate-risk group (those with one or two risk factors) and highly abnormal in the high-risk group (all three risk factors) indicating persistence of, respectively, moderate and severe iron overload at the time of transplant. In ex-thalassaemic patients who were studied before and yearly after the transplant the extent of haemosiderosis, as judged by staining of liver biopsy samples, decreased during the years after transplant. The degree of iron deposition and rate of post-BMT linear growth seem to influence rate of post-BMT decrease in tissue iron overload in different risk groups at the time of BMT.

Transfusional hemosiderosis in sickle cell anemia: another cause of an echogenic pancreas

We report four sickle cell anemia patients who have received multiple blood transfusions and have been non-compliant on Desferal chelation therapy. Abdominal ultrasonography demonstrated an echogenic pancreas in all four patients. Magnetic resonance imaging in three patients revealed decreased signal intensity in all sequences in the pancreas and liver. All four patients had marked iron deposition on liver biopsy. To our knowledge, increased echogenicity of the pancreas secondary to hemosiderosis (2 degrees hemochromatosis) in sickle cell patients has not been reported in the radiologic literature.

Biological and ultrastructural aspects of iron overload: an overview

The morphologic aspects of iron overload have been studied in human subjects, mammals, and birds with spontaneous overload, in a variety of experimental animals, and also in cell cultures. Reviewed here are the contributions of electron microscopy to the understanding of the iron-loading process, as reported during the last 12 years. The electron-density of ferrihydrite cores located within the protein shell of the ferritin molecule enabled its identification within either cytosol or lysosomes (siderosomes) of iron-exposed cells. The process of (holo)ferritin assembly, its transfer into siderosomes, and its degradation to hemosiderin can be followed in various cells. Siderosomes display cell-line-specific ultrastructural features, and different cell types show varying iron-segregating capacity. The study of experimental animals and cultured cells show that an iron-rich milieu may be damaging, probably through iron-catalyzed lipid peroxidation. Recent ultrastructural studies stress the value of describing initial alterations as opposed to the irrelevant end-stage findings. Further efforts should be directed toward elucidating the origin of iron in neonatal hemochromatosis, the role of iron in infection and neoplasia, and the nature and role of brain iron.

Pseudoxanthoma elasticum and angioid streaks in two cases of beta-thalassaemia

Two cases of beta thalassaemia with pseudoxanthoma elasticum and angioid streaks (Grönblad-Strandberg syndrome) are reported. To the best of our knowledge, this is the first report of a combination between these two genetically determined disorders. The possible theories of the pathogenesis of pseudoxanthoma elasticum and angioid streaks are discussed.

The challenge of cardiomyopathy

The combined clinical and pathophysiologic characteristics and diagnostic features as well as current concepts of pathogenesis, therapy and prevention of the principal forms of cardiomyopathy are reviewed. These include hypertrophic cardiomyopathy, dilated cardiomyopathy, restrictive cardiomyopathy and specific cardiac muscle disease. Emphasis is placed on recent developments and unresolved questions requiring application of newer techniques of molecular biology and genetics and adult myocyte culturing.

Diagnosis and clinical evaluation of iron overload

Diagnostic evaluation of the various forms of iron overload requires information about the total amount and distribution of iron stores. Direct information on the quantity of storage iron can be obtained only by its mobilization in response to repeated phlebotomy or after dilution of a labelled iron test dose in the total body iron pool. Both approaches are cumbersome and time-consuming and are suitable only for research purposes. Detailed information on the amount and distribution of tissue iron in iron overload can be obtained from biopsy specimens of the major iron storage organs such as the liver and bone marrow. However, the invasive nature of these procedures limits their clinical usefulness. Indirect measures, such as serum iron concentration, TIBC saturation, serum ferritin, chelate-induced urinary iron excretion or intestinal iron absorption, and ferrokinetic measurements may provide useful information on the amount of total body iron reserve. However, they all have important limitations in their diagnostic use for evaluating iron overload. The most suitable indirect storage iron index among these methods is the ferritin assay, which has a well established place in the diagnosis of iron overload and monitoring of the effect of therapy. Recent developments in physical methods such as CT, SQUID and NMR have significantly improved the applicability of these techniques for non-invasive measurement of liver iron. It is expected that quantitative measurement of hepatic iron stores will soon be integrated into the diagnostic procedures available by imaging techniques such as CT and NMR. In combination with screening parameters such as serum ferritin and TIBC saturation these new but expensive diagnostic tools may simplify and shorten the diagnostic process and may also be useful for monitoring the treatment of iron overload by phlebotomy or chelating drugs.

Bone marrow transplantation in beta-thalassemia major. The Israeli experience

The present report summarizes our experience in applying a new approach in bone marrow transplantation for the treatment of beta-thalassemia major. Ex-vivo pretransplant T-lymphocyte depletion with CAMPATH-1 was used for prevention of acute and chronic graft versus host disease and total lymphoid irradiation was added for the conditioning regimen for abrogation of potential rejection of T-cell depleted marrow allografts. Ten patients with homozygous beta-thalassemia major were 9-48 months of age (median 18.5 months) and received HLA-identical allogeneic T-cell depleted marrow after treatment with total lymphoid irradiation, busulfan and cyclophosphamide. Seven patients are alive and free of disease, 3-46 months post-transplantation. The actuarial probability of survival and of disease-free survival at two years was 70%. Three patients died: one of intracranial hemorrhage post-transplantation, one from busulfan interstitial pneumonitis, and one who rejected the first graft and developed fatal chronic graft versus host disease after a second transplant. Seven patients are alive and well with follow-up of 3-45 months, with no signs of acute or chronic GVHD. We conclude that T-cell depleted bone marrow transplantation is indicated for homozygous transfusion dependent young patients with beta-thalassemia who are minimally transfused, particularly in areas where optimal conventional therapy is not feasible.

Iron-chelating therapy

Because of the catalytic action of iron in one-electron redox reactions, it has a key role in the formation of harmful oxygen derivatives and production of peroxidative damage to vital cellular structures. The clinical manifestations of iron overload may be prevented and even reversed by the effective administration of the iron-chelating drug deferoxamine (DF). Recent experimental evidence suggests that DF may also be useful in modifying disease conditions unrelated to iron overload by preventing the formation of free radicals, the powerful final effectors of tissue damage resulting from the respiratory burst of granulocytes and macrophages participating in the inflammatory response. Although much experimental work is still needed, this novel approach in iron-chelating therapy may have far-reaching implications in the management of autoimmune disease, adult respiratory distress syndrome, and organ transplantation. The poor intestinal absorption of DF, its almost prohibitive price, and short duration of action underline the need for new, orally effective iron chelators. A number of very promising orally effective drugs have been identified in recent years, such as the polyanionic amines, aryl hydrazones, and hydroxypyridones. Further development for clinical use of this new generation of iron-chelating drugs is a major challenge for future research.

Bone marrow transplantation in two multiply transfused patients with thalassaemia major

Bone marrow transplantation has generally been unsuccessful when applied to patients with thalassaemia major over the age of 6 years. We report here two successful transplants for this disorder in a 7 1/2-year-old boy and an 11-year-old girl following a pre-transplant cytoreductive/immunosuppressive regimen of total body irradiation and cyclophosphamide. Complete durable engraftment of donor haematopoietic and lymphoid populations was documented through several approaches, including cytogenetic analysis, haemoglobin electrophoresis, globin chain synthetic ratios, red cell typing and DNA restriction enzyme analysis. Both patients are surviving in good health, 28 and 9 months from transplantation. The successful outcome in these patients demonstrates the feasibility of marrow transplantation for the treatment of thalassaemia in multiply transfused and, presumably, highly sensitized patients.

A prospective trial of young red cells in 48 patients with transfusion-dependent thalassaemia

Young red cells (YRBC) prepared on a cell washer were compared to whole blood in a randomized prospective trial in 48 transfusion dependent patients with thalassaemia major. A minor but statistically significant decrease in blood consumption was observed in the group receiving YRBC. However, no difference was seen in transfusion interval, mean haemoglobin and rate of haemoglobin fall between the two groups. Filtered blood was shown to be as effective as frozen blood in eliminating non-haemolytic febrile transfusion reactions in all the trial patients. We conclude that any reduction in the rate of iron loading brought about by the use of YRBC is clinically insignificant and does not justify the expense, time and work required to produce young red cells for use in a large transfusion dependent thalassaemic population.

Iron deficiency and iron overload

An up to date review of our knowledge of human iron metabolism is given including problems of iron balance, internal transport, and intracellular mechanisms. Current knowledge of the iron proteins is summarized and this background is used in discussing the pathophysiology of iron deficiency and overload, together with the internal derangements such as sideroblastic anemia which form much of the clinical practice associated with disorders of iron metabolism. The therapeutic approach to these problems will be described.

Advances in the treatment of porphyria cutanea tarda. Effectiveness of slow subcutaneous desferrioxamine infusion

The authors present the results of long-term subcutaneous desferrioxamine (DFX) infusion in 16 porphyria cutanea tarda (PCT) patients who cannot undergo repeated phlebotomies because of severe liver damage, haemolytic anemia, cardiovascular impairment or pulmonary and bone tuberculosis. They employed an automatic, portable syringe pump for subcutaneous infusion (8-10 h) to overcome the short half-life of the drug. Photodynamic cutaneous lesions and hyperpigmentation quickly disappeared (2-3 months). Uroporphyrin excretion sharply decreased and normalized within 3-12 months. Also, serum iron and ferritin, as well as liver function, showed a significant improvement. The authors therefore propose subcutaneous DFX therapy in PCT treatment when phlebotomy is contraindicated.

Autoimmune haemolytic anaemia treated with multiple transfusions, immunosuppressive therapy, plasma exchange, and desferrioxamine

Severe autoimmune haemolytic anaemia in a five year old boy was unaffected by treatment with prednisone and splenectomy, but subsided after combined immunosuppressive therapy and three plasma exchanges. Over five months, a total of 93 transfusions of concentrated erythrocytes was given (equal to 18.6 grams of iron or 1.1 g/kg BW). This resulted in severe iron overload with cardiac, hepatic, and pancreatic complications, together with growth-retardation. These complications disappeared after treatment with desferrioxamine and vitamin C, but despite a normal growth hormone response to glucagon the concentration of somatomedin in serum remained low. Treatment by plasma exchanges and immunosuppressive agents may therefore be of value in severe haemolytic anaemia refractory to corticosteroids and splenectomy. Iron chelating therapy should be considered if multiple transfusions result in iron overload.

Splenic siderosis and parenteral iron dextran in maintenance haemodialysis patients

The histological features of 40 spleens surgically removed from maintenance haemodialysis patients are reported. Twenty-four of the 40 (60%) showed massive iron loading and a significant direct correlation was found between iron loading and the amount of intravenous iron dextran administered. Since parenteral iron dextran appears to be a major factor in causing iron overload in haemodialysis patients its use as a method of iron replacement in these patients would appear inappropriate.

5-azacytidine selectively increases gamma-globin synthesis in a patient with beta+ thalassemia

5-Azacytidine is a cytidine analogue that is capable of activating repressed genes in tissue-culture cells and has been shown to increase hemoglobin-F production in anemic baboons. This drug was administered to a patient with severe beta-thalassemia in an attempt to stimulate hemoglobin-F production. After seven days of 5-azacytidine treatment, gamma-globin synthesis increased approximately sevenfold, temporarily normalizing the patient's unbalanced globin synthesis. Erythropoiesis became more effective, leading to a temporary increase in the absolute reticulocyte count (from 5000 to 22,000 per cubic millimeter) and in hemoglobin concentration (from 8.0 to 10.8 g per deciliter). Hypomethylation of bone-marrow DNA near both the gamma-globin and epsilon-globin genes was directly demonstrated. At the time of peak drug effect, about 7000 gamma-globin messenger RNA molecules were present per erythroid bone-marrow cell, in contrast to 10 to 15 epsilon-globin messenger RNA molecules per cell. 5-Azacytidine selectivity increases gamma-globin synthesis and therefore provides a new approach to the treatment of severe beta-thalassemia. Further studies will be required to evaluate the efficacy, risks, and long-term toxicity of 5-azacytidine (or related compounds) before this approach can be used as a therapy for patients with disorders of hemoglobin synthesis.