Chelation treatment in sickle-cell-anaemia: much ado about nothing?

Questioning Established Theories and Treatment Methods Related to Iron and Other Metal Metabolic Changes, Affecting All Major Diseases and Billions of Patients

The medical and scientific literature is dominated by highly cited historical theories and findings [...].

Differences between the European Union and United States of America in Drug Regulatory Affairs Affect Global Patient Safety Standards and Public Health Awareness: The Case of Deferasirox and Other Iron Chelating Drugs

Regulatory policies on drugs have a major impact on patient safety and survival. Some pharmaceutical companies employ all possible methods to achieve maximum sales in relation to the monopoly of their patented drugs, leading sometimes to irregularities and illegal activities. Misinformation on the orphan drug deferasirox has reached the stage of criminal investigations and fines exceeding USD 100 million. Additional lawsuits of USD 3.5 billion for damages and civil fines were also filed by the FBI of the USA involving deferasirox and mycophenolic acid, which were later settled with an additional fine of USD 390 million. Furthermore, a USD 345 million fine was also settled for bribes and other illegal overseas operations including an EU country. However, no similar fines for illegal practises or regulatory control violations have been issued in the EU. Misconceptions and a lack of clear guidelines for the use of deferasirox in comparison to deferiprone and deferoxamine appear to reduce the effective treatment prospects and to increase the toxicity risks for thalassaemia and other iron loaded patients. Similar issues have been raised for the activities of other pharmaceutical companies promoting the use of new patented versus generic drugs. Treatments for different categories of patients using new patented drugs are mostly market driven with no clear safeguards or guidelines for risk/benefit assessment indications or for individualised effective and safe optimum therapies. There is a need for the establishment of an international organisation, which can monitor and assess the risk/benefit assessment and marketing of drugs in the EU and globally for the benefit of patients. The pivotal role of the regulatory drug authorities and the prescribing physicians for identifying individualised optimum therapies is essential for improving the survival and safety of millions of patients worldwide.

Management of Iron Overload in Resource Poor Nations: A Systematic Review of Phlebotomy and Natural Chelators

Iron is an essential element and the most abundant trace metal in the body involved in oxygen transport and oxygen sensing, electron transfer, energy metabolism, and DNA synthesis. Excess labile and unchelated iron can catalyze the formation of tissue-damaging radicals and induce oxidative stress. English abstracts were identified in PubMed and Google Scholar using multiple and various search terms based on defined inclusion and exclusion criteria. Full-length articles were selected for systematic review, and secondary and tertiary references were developed. Although bloodletting or phlebotomy remains the gold standard in the management of iron overload, this systematic review is an updated account of the pitfalls of phlebotomy and classical synthetic chelators with scientific justification for the use of natural iron chelators of dietary origin in resource-poor nations.

The History of Deferiprone (L1) and the Paradigm of the Complete Treatment of Iron Overload in Thalassaemia

Deferiprone (L1) was originally designed, synthesised and screened in vitro and in vivo in 1981 by Kontoghiorghes G. J. following his discovery of the novel alpha-ketohydroxypyridine class of iron chelators (1978–1981), which were intended for clinical use. The journey through the years for the treatment of thalassaemia with L1 has been a very difficult one with an intriguing turn of events, which continue until today. Despite many complications, such as the extensive use of L1 suboptimal dose protocols, the aim of chelation therapy-namely, the complete removal of excess iron in thalassaemia major patients, has been achieved in most cases following the introduction of specific L1 and L1/deferoxamine combinations. Many such patients continue to maintain normal iron stores. Thalassemia has changed from a fatal to chronic disease; also thanks to L1 therapy and thalassaemia patients are active professional members in all sectors of society, have their own families with children and grandchildren and their lifespan is approaching that of normal individuals. No changes in the low toxicity profile of L1 have been observed in more than 30 years of clinical use and prophylaxis against the low incidence of agranulocytosis is maintained using mandatory monitoring of weekly white blood cells’ count. Thousands of thalassaemia patients are still denied the cardioprotective and other beneficial effects of L1 therapy. The safety of L1 in thalassaemia and other non-iron loaded diseases resulted in its selection as one of the leading therapeutics for the treatment of Friedreich’s ataxia, pantothenate kinase-associated neurodegeneration and other similar cases. There are also increasing prospects for the application of L1 as a main, alternative or adjuvant therapy in many pathological conditions including cancer, infectious diseases and as a general antioxidant for diseases related to free radical pathology.

Transient Elastography (TE) is a Useful Tool for Assessing the Response of Liver Iron Chelation in Sickle Cell Disease Patients

Sickle cell disease patients often need regular blood transfusions to improve both the quality of life and survival from the veno-occlusive complications of the disease. Deferasirox, a convenient long acting oral agent, has recently been introduced in clinical practice with promising efficacy.

This study aims to evaluate the association of liver stiffness and possible fibrosis with iron deposition and confirm the use of elastography as a validated test of responding to chelation with low cost and easy access.

15 patients with sickle cell disease and systemic or occasional transfusions were evaluated with MRI, transient elastography and biochemistry, for liver iron(LIC) and liver stiffness(LSM) before onset and one year after taking Deferasirox. All patients completed the study.

Our results showed improvement in hepatic iron and hepatic stiffness after chelation therapy; Furthermore ALT, AST, LDH and ferritin levels have improved after 12 months of therapy with deferasirox. During the study no serious adverse events were encountered indicating the safety of the drug.

Transient liver elastography findings correlate with serum ferritin and LIC in patients with sickle cell disease and it is a useful tool for assessing the response of liver iron chelation therapy.

Liver Iron Content (LIC) in Adults with Sickle Cell Disease (SCD): Correlation with Serum Ferritin and Liver Enzymes Concentrations in Trasfusion Dependent (TD-SCD) and Non-Transfusion Dependent (NT-SCD) Patients

Introduction

Sickle cell disease (SCD) is one of the leading causes of morbidity and mortality worldwide, causing damage and dysfunction in multiple organs. The complications of this disease are numerous, affect every organ and/or tissue in the body and vary considerably among patients over the time challenging its management.

The aim of our study

To determine the iron status of 17 patients with non-transfusion-dependent sickle cell disease ( NT-SCD) patients and six patients with transfusion dependent sickle cell disease (TD- SCD) using both serum ferritin level (SF) and Ferriscan® evaluation of liver iron content (LIC). We correlated the values of LIC with SF levels and some hepatic enzymes (alanine transaminase-ALT, aspartate aminotransferase -AST, alkaline phosphatase -ALP and albumin).

Results

17 adults with NT-SCD (n = 17, age: 32±15 years) were studied. Seven of NT-SCD had SF > 500 μg/L, 4 out of the seven had high liver iron measured by FerriScan® (> 30 mg/g/ tissue dry weight - dw). Two patients had high LIC despite a concomitant SF concentration < 500 μg/L. Two patients had high SF (1.117 μg/L and 675 μg/L) while their LIC was normal (< 30 mg/g/dw). Five patients had elevated ALT and/or AST) concentrations. In TD-SCD (n = 6, age = 25 ± 11 years), 2 patients had SF <500 μg/L, one of them had high LIC (127 mg/g/DW). Liver enzymes were high in two patients. SF concentration correlated significantly with LIC (r = 0.85, p < 0.001). Neither SF level nor LIC was correlated significantly with hepatic enzyme levels.

Conclusions

A significant number of our patients with NT-SCD had high LIC, high SF and elevated liver enzymes (ALT and AST). Despite some limitations of our study, due to the limited number of NT-SCD patients, these findings have important clinical implications. Therefore, we recommend measuring SF and LIC in NT-SCD patients to apply preventive measures with iron chelation therapy in patients with high LIC.

How we manage iron overload in sickle cell patients

Blood transfusion plays a prominent role in the management of patients with sickle cell disease (SCD), but causes significant iron overload. As transfusions are used to treat the severe complications of SCD, it remains difficult to distinguish whether organ damage is a consequence of iron overload or is due to the complications treated by transfusion. Better management has resulted in increased survival, but prolonged exposure to iron puts SCD patients at greater risk for iron-related complications that should be treated. The success of chelation therapy is dominated by patient adherence to prescribed treatment; thus, adjustment of drug regimens to increase adherence to treatment is critical. This review will discuss the current biology of iron homeostasis in patients with SCD and how this informs our clinical approach to treatment. We will present the clinical approach to treatment of iron overload at our centre using serial assessment of organ iron by magnetic resonance imaging.

Cardiac iron overload in chronically transfused patients with thalassemia, sickle cell anemia, or myelodysplastic syndrome

The risk and clinical significance of cardiac iron overload due to chronic transfusion varies with the underlying disease. Cardiac iron overload shortens the life expectancy of patients with thalassemia, whereas its effect is unclear in those with myelodysplastic syndromes (MDS). In patients with sickle cell anemia (SCA), iron does not seem to deposit quickly in the heart. Our primary objective was to assess through a multicentric study the prevalence of cardiac iron overload, defined as a cardiovascular magnetic resonance T2*<20 ms, in patients with thalassemia, SCA, or MDS. Patient inclusion criteria were an accurate record of erythrocyte concentrates (ECs) received, a transfusion history >8 ECs in the past year, and age older than 6 years. We included from 9 centers 20 patients with thalassemia, 41 with SCA, and 25 with MDS in 2012-2014. Erythrocytapharesis did not consistently prevent iron overload in patients with SCA. Cardiac iron overload was found in 3 (15%) patients with thalassemia, none with SCA, and 4 (16%) with MDS. The liver iron content (LIC) ranged from 10.4 to 15.2 mg/g dry weight, with no significant differences across groups (P = 0.29). Abnormal T2* was not significantly associated with any of the measures of transfusion or chelation. Ferritin levels showed a strong association with LIC. Non-transferrin-bound iron was high in the thalassemia and MDS groups but low in the SCA group (P<0.001). Hepcidin was low in thalassemia, normal in SCA, and markedly elevated in MDS (P<0.001). Two mechanisms may explain that iron deposition largely spares the heart in SCA: the high level of erythropoiesis recycles the iron and the chronic inflammation retains iron within the macrophages. Thalassemia, in contrast, is characterized by inefficient erythropoiesis, unable to handle free iron. Iron accumulation varies widely in MDS syndromes due to the competing influences of abnormal erythropoiesis, excess iron supply, and inflammation.

Transfusion Therapy in Children With Sickle Cell Disease

Hydroxyurea, blood transfusions, and hematopoietic stem cell transplantation represent the 3 disease-modifying therapies in children with sickle cell disease (SCD). Blood transfusions play an increasingly important role in both prevention and management of SCD complications in this age group. This review will focus on the indications of blood transfusion in children with SCD and modalities of its administration. It will also highlight the complications of this life-saving therapy and ways of optimizing transfusion to minimize its associated risks.

Sickle Cell Disease: A Brief Update

Sickle cell disease (SCD) is an inherited monogenic disease characterized by misshapen red blood cells that causes vaso-occlusive disease, vasculopathy, and systemic inflammation. Approximately 300,000 infants are born per year with SCD globally. Acute, chronic, and acute-on-chronic complications contribute to end-organ damage and adversely affect quantity and quality of life. Hematopoietic stem cell transplantation is the only cure available today, but is not feasible for the vast majority of people suffering from SCD. Fortunately, new therapies are in late clinical trials and more are in the pipeline, offering hope for this unfortunate disease, which has increasing global burden.

Quality of life, clinical effectiveness, and satisfaction in patients with beta thalassemia major and sickle cell anemia receiving deferasirox chelation therapy

Objectives:

There is a need to remove excess iron with iron chelation therapy (ICT) to avoid the serious clinical sequelae associated with iron overload in patients with beta thalassemia major (BTM) and sickle cell anemia (SCA). Due to the effects of the diseases and their treatments, ICT is still a major reason for unsatisfactory compliance. The aim of this single-center observational study was to evaluate the quality of life, clinical effectiveness, and satisfaction in pediatric and adult patients with BTM and SCA receiving deferasirox (DFX) chelation therapy.

Methods:

In this study, 37 pediatric and 35 adult patients with BTM or SCA receiving DFX for at least 6 months participated. Upon receipt of Informed Consent Form, Case Report Form, Demographic Data Collection Form, Child Health Questionnaire-Parent Form, Life Quality Survey Short Form-36, and ICT Satisfaction Survey were used to obtain data for the effectiveness of ICT and parameters that may affect compliance to treatment and life quality of the participants.

Results:

As a main index for the effectiveness of DFX chelation therapy, serum ferritin levels were higher than the normal values in the patients receiving DFX. The increased ferritin levels were also associated with hematological and biochemical abnormalities. Our findings regarding quality of life and satisfaction with DFX chelation therapy indicated that the patients with BTM or SCA had lower scores. Overall, problems with treatment regimen and side effects appeared to be common causes of poor compliance to DFX chelation therapy.

Conclusions:

Our findings suggest that health care providers should be aware of the importance of monitoring iron load with timely initiation of DFX chelation therapy and ongoing adjustments to chelation regimens and/or transfusion methods to decrease hospitalizations and improve compliance to ICT of the patients with BTM and SCA.

Evaluation of a new tablet formulation of deferasirox to reduce chronic iron overload after long-term blood transfusions

Transfusion-dependent anemia is a common feature in a wide array of hematological disorders, including thalassemia, sickle cell disease, aplastic anemia, myelofibrosis, and myelo-dysplastic syndromes. In the absence of a physiological mechanism to excrete excess iron, chronic transfusions ultimately cause iron overload. Without correction, iron overload can lead to end-organ damage, resulting in cardiac, hepatic, and endocrine dysfunction/failure. Iron chelating agents are utilized to reduce iron overload, as they form a complex with iron, leading to its clearance. Iron chelation has been proven to decrease organ dysfunction and improve survival in certain transfusion-dependent anemias, such as β-thalassemia. Several chelating agents have been approved by the United States Food and Drug Administration for the treatment of iron overload, including deferoxamine, deferiprone, and deferasirox. A variety of factors have to be considered when choosing an iron chelator, including dosing schedule, route of administration, tolerability, and side effect profile. Deferasirox is an orally administered iron chelator with proven efficacy and safety in multiple hematological disorders. There are two formulations of deferasirox, a tablet for suspension, and a new tablet form. This paper is intended to provide an overview of iron overload, with a focus on deferasirox, and its recently approved formulation Jadenu^® for the reduction of transfusional iron overload in hematological disorders.

Management of the Dialysis Patient with Sickle Cell Disease

While patients with sickle cell disease currently constitute a very small minority of the US dialysis population (0.1%), there is anticipated growth of this group as the life expectancy of those with sickle cell disease (SCD) increases. SCD patients suffer a high burden of morbidity, which is enhanced by the presence of end-stage renal disease (ESRD). In this review, we discuss the pathophysiology of SCD and the basic tenets of its management with focus on the dialysis patient with SCD. Anemia in dialysis patients with SCD is a unique challenge. The hemoglobin target in SCD dialysis patients with ESRD should not exceed 10 g/dl. SCD patients, and particularly those on dialysis, are likely to be poorly responsive to erythropoietin-stimulating agent (ESA) therapy and might be at increased risk for vaso-occlusive crisis (VOC) with ESA. Iron chelation and hydroyxurea therapy require special considerations and modifications in dialysis patients with SCD. There are theoretical advantages to both hemodialysis (HD) and peritoneal dialysis (PD) in SCD patients. With HD, there is a secure vascular access available for both standard and exchange blood transfusion in patients who need them. With PD, the absence of an acute rise in hematocrit with ultrafiltration (UF) might offer lower risk of VOC. During VOC, reduction in UF goals should be considered but administration of intravenous fluids should be reserved only for clear cases of volume depletion. Finally, renal transplantation appears to confer a survival advantage to dialysis in SCD patients and should be pursued when possible.

Transfusional iron overload and iron chelation therapy in thalassemia major and sickle cell disease

Iron overload is an inevitable consequence of blood transfusions and is often accompanied by increased iron absorption from the gut. Chelation therapy is necessary to prevent the consequences of hemosiderosis. Three chelators, deferoxamine, deferiprone, and deferasirox, are presently available and a fourth is undergoing clinical trials. The efficacy of all 3 available chelators has been demonstrated. Also, many studies have shown the efficacy of the combination of deferoxamine plus deferiprone as an intensive treatment of severe iron overload. Alternating chelators can reduce adverse effects and improve compliance. Adherence to therapy is crucial for good results.

Deferasirox for managing transfusional iron overload in people with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a group of genetic haemoglobin disorders, that occurs in about 2.2 per 1000 births worldwide. Increasingly, some people with SCD develop secondary iron overload due to occasional red blood cell transfusions or are on long-term transfusion programmes for e.g. secondary stroke prevention. Iron chelation therapy can prevent long-term complications.Deferoxamine and deferiprone have been found to be efficacious. However, questions exist about the effectiveness and safety of the newer oral chelator deferasirox.

OBJECTIVES

To assess the effectiveness and safety of oral deferasirox in people with SCD and secondary iron overload.

SEARCH METHODS

We searched the Cystic Fibrosis &amp; Genetic Disorders Group's Haemoglobinopathies Trials Register: date of most recent search:13 March 2014.We searched MEDLINE, Embase, Biosis Previews, Web of Science, Derwent Drug File, XTOXLINE, EBMR and The Cochrane Library, respectively; date of most recent searches: 02 August 2013.We searched four trial registries: www.controlled-trials.com; www.clinicaltrials.gov; www.who.int./ictrp/en/; www.drks.de; date of most recent searches: 03 June 2013.

SELECTION CRITERIA

Randomised controlled trials comparing deferasirox with no therapy or placebo or with another iron chelating treatment schedule.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. We contacted the corresponding study authors for additional information.

MAIN RESULTS

Two studies (with 203 and 212 people) comparing the efficacy and safety of deferasirox and deferoxamine after 12 months and 24 weeks, respectively, were included. The overall quality, according to GRADE, for the main outcomes was moderate to low. Only limited data were available on mortality and end-organ damage, although one study did assess mortality, relative risk 1.26 (95% confidence interval 0.05 to 30.41), the 24-week follow up was too short to allow us to draw firm conclusions. One study reported a relative risk of 1.26 for the incidence of type 2 diabetes mellitus (95% confidence interval 0.05 to 30.41). Serum ferritin reduction was significantly greater with deferoxamine, mean difference of change of 440.69 µg/l (95% confidence interval 11.73 to 869.64). Liver iron concentration (reported in one study) measured by superconduction quantum interference device showed no significant difference for the overall group of patients adjusted for transfusion category, mean difference -0.20 mg Fe/g dry weight (95% confidence interval -3.15 to 2.75).The occurrence of serious adverse events did not differ between drugs. Nausea, diarrhoea and rash occurred significantly more often in people treated with deferasirox, while adverse events of any kind were more often reported for patients treated with deferoxamine (one study). The mean increase of creatinine was also significantly higher with deferasirox, mean difference 3.24 (95% confidence interval 0.45 to 6.03). Long-term adverse events could not be measured in the included studies (follow up 52 weeks and 24 weeks). Patient satisfaction and the likelihood of continuing treatment, were significantly better with deferasirox.

AUTHORS' CONCLUSIONS

Deferasirox appears to be of similar efficacy to deferoxamine depending on depending on the appropriate ratio of doses of deferoxamine and deferasirox being compared. However, only limited evidence is available assessing the efficacy regarding patient-important outcomes. The short-term safety of deferasirox seems to be acceptable, however, follow up in the available studies was too short to assess long-term side effects. Long-term safety and efficacy data are available from a non-controlled extension phase not included in our review; however, no valid comparative conclusions can be drawn and future studies should assess comparatively long-term outcomes both for safety and efficacy.

Current approach to iron chelation in children

Transfusion-dependent children, mostly with thalassaemia major, but also and occasionally to a more significant degree, with inherited bone marrow failures, can develop severe iron overload in early life. Moreover, chronic conditions associated with ineffective erythropoiesis, such as non-transfusion-dependent thalassaemia (NTDT), may lead to iron overload through increased gut absorption of iron starting in childhood. Currently, the goal of iron chelation has shifted from treating iron overload to preventing iron accumulation and iron-induced end-organ complications, in order to achieve a normal pattern of complication-free survival and of quality of life. New chelation options increase the likelihood of achieving these goals. Timely initiation, close monitoring and continuous adjustment are the cornerstones of optimal chelation therapy in children, who have a higher transfusional requirements compared to adults in order to reach haemoglobin levels adequate for normal growth and development. Despite increased knowledge, there are still uncertainties about the level of body iron at which iron chelation therapy should be started and about the appropriate degree of iron stores' depletion.

Organizing national responses for rare blood disorders: the Italian experience with sickle cell disease in childhood

Background

Sickle cell disease (SCD) is the most frequent hemoglobinopathy worldwide but remains a rare blood disorder in most western countries. Recommendations for standard of care have been produced in the United States, the United Kingdom and France, where this disease is relatively frequent because of earlier immigration from Africa. These recommendations have changed the clinical course of SCD but can be difficult to apply in other contexts. The Italian Association of Pediatric Hematology Oncology (AIEOP) decided to develop a common national response to the rising number of SCD patients in Italy with the following objectives: 1) to create a national working group focused on pediatric SCD, and 2) to develop tailored guidelines for the management of SCD that could be accessed and practiced by those involved in the care of children with SCD in Italy.

Methods

Guidelines, adapted to the Italian social context and health system, were developed by 22 pediatric hematologists representing 54 AIEOP centers across Italy. The group met five times for a total of 128 hours in 22 months; documents and opinions were circulated via web.

Results

Recommendations regarding the prevention and treatment of the most relevant complications of SCD in childhood adapted to the Italian context and health system were produced.

For each topic, a pathway of diagnosis and care is detailed, and a selection of health management issues crucial to Italy or different from other countries is described (i.e., use of alternatives for infection prophylaxis because of the lack of oral penicillin in Italy).

Conclusions

Creating a network of physicians involved in the day-to-day care of children with SCD is feasible in a country where it remains rare. Providing hematologists, primary and secondary care physicians, and caregivers across the country with web-based guidelines for the management of SCD tailored to the Italian context is the first step in building a sustainable response to a rare but emerging childhood blood disorder and in implementing the World Health Organization’s suggestion “to design (and) implement … comprehensive national integrated programs for the prevention and management of SCD".

Iron: effect of overload and deficiency

Iron is a redox active metal which is abundant in the Earth's crust. It has played a key role in the evolution of living systems and as such is an essential element in a wide range of biological phenomena, being critical for the function of an enormous array of enzymes, energy transduction mechanisms, and oxygen carriers. The redox nature of iron renders the metal toxic in excess and consequently all biological organisms carefully control iron levels. In this overview the mechanisms adopted by man to control body iron levels are described.Low body iron levels are related to anemia which can be treated by various forms of iron fortification and supplementation. Elevated iron levels can occur systemically or locally, each giving rise to specific symptoms. Systemic iron overload results from either the hyperabsorption of iron or regular blood transfusion and can be treated by the use of a selection of iron chelating molecules. The symptoms of many forms of neurodegeneration are associated with elevated levels of iron in certain regions of the brain and iron chelation therapy is beginning to find an application in the treatment of such diseases. Iron chelators have also been widely investigated for the treatment of cancer, tuberculosis, and malaria. In these latter studies, selective removal of iron from key enzymes or iron binding proteins is sought. Sufficient selectivity between the invading organism and the host has yet to be established for such chelators to find application in the clinic.Iron chelation for systemic iron overload and iron supplementation therapy for the treatment of various forms of anemia are now established procedures in clinical medicine. Chelation therapy may find an important role in the treatment of various neurodegenerative diseases in the near future.

Consequences and management of iron overload in sickle cell disease

The aims of this review are to highlight the mechanisms and consequences of iron distribution that are most relevant to transfused sickle cell disease (SCD) patients and to address the particular challenges in the monitoring and treatment of iron overload. In contrast to many inherited anemias, in SCD, iron overload does not occur without blood transfusion. The rate of iron loading in SCD depends on the blood transfusion regime: with simple hypertransfusion regimes, rates approximate to thalassemia major, but iron loading can be minimal with automated erythrocyte apheresis. The consequences of transfusional iron overload largely reflect the distribution of storage iron. In SCD, a lower proportion of transfused iron distributes extrahepatically and occurs later than in thalassemia major, so complications of iron overload to the heart and endocrine system are less common. We discuss the mechanisms by which these differences may be mediated. Treatment with iron chelation and monitoring of transfusional iron overload in SCD aim principally at controlling liver iron, thereby reducing the risk of cirrhosis and hepatocellular carcinoma. Monitoring of liver iron concentration pretreatment and in response to chelation can be estimated using serum ferritin, but noninvasive measurement of liver iron concentration using validated and widely available MRI techniques reduces the risk of under- or overtreatment. The optimal use of chelation regimes to achieve these goals is described.

[Iron chelating therapy in adults: How and when ?]

Iron overload can lead to tissue damage derived from free radical toxicity. Phlebotomy is the treatment of choice for treating iron overload. However, iron chelating therapy can be used if phlebotomies are impossible, mainly because of anemia. In thalassemia major, iron chelating therapy has dramatically improved life expectancy; it is also used in sickle cell disease and myelodysplastic syndromes. Desferioxamine is the gold standard of iron chelation, but parenteral administration and the burden of a daily infusion pump hinder optimal compliance. Deferiprone is orally active but should be administered three times a day. It has the advantage of removing toxic iron from myocardium, but agranulocytosis (1 %) can limit its use. Deferasirox is orally active in a single daily dose, is well tolerated but its cardiac effect is limited. Iron chelating therapy can be considered if serum ferritin is above 1000μg/L and if liver iron concentration assessing by MRI exceeds 80μmol/g. MRI is a very important mean to monitor cardiac iron load. If the relaxing parameter T2* is lower than 20ms, a cardiac effective iron chelator agent or an association with deferoxamine should be used. Benefit/risk ratio should be closely evaluated, mainly in myelodysplastic syndromes.

How I treat transfusional iron overload

Patients with β-thalassemia major (TM) and other refractory anemias requiring regular blood transfusions accumulate iron that damages the liver, endocrine system, and most importantly the heart. The prognosis in TM has improved remarkably over the past 10 years. This improvement has resulted from the development of magnetic resonance imaging (MRI) techniques, especially T2*, to accurately measure cardiac and liver iron, and from the availability of 3 iron-chelating drugs. In this article we describe the use of MRI to determine which adult and pediatric patients need to begin iron chelation therapy and to monitor their progress. We summarize the properties of each of the 3 drugs, deferoxamine (DFO), deferiprone (DFP), and deferasirox (DFX), including their efficacy, patient acceptability, and side effects. We describe when to initiate or intensify therapy, switch to another drug, or use combined therapy. We also discuss the management of refractory anemias other than TM that may require multiple blood transfusions, including sickle cell anemia and myelodysplasia. The development of a potential fourth chelator FBS 0701 and the combined use of oral chelators may further improve the quality of life and survival in patients with TM and other transfusion-dependent patients.

Beyond the definitions of the phenotypic complications of sickle cell disease: an update on management

The sickle hemoglobin is an abnormal hemoglobin due to point mutation (GAG → GTG) in exon 1 of the β globin gene resulting in the substitution of glutamic acid by valine at position 6 of the β globin polypeptide chain. Although the molecular lesion is a single-point mutation, the sickle gene is pleiotropic in nature causing multiple phenotypic expressions that constitute the various complications of sickle cell disease in general and sickle cell anemia in particular. The disease itself is chronic in nature but many of its complications are acute such as the recurrent acute painful crises (its hallmark), acute chest syndrome, and priapism. These complications vary considerably among patients, in the same patient with time, among countries and with age and sex. To date, there is no well-established consensus among providers on the management of the complications of sickle cell disease due in part to lack of evidence and in part to differences in the experience of providers. It is the aim of this paper to review available current approaches to manage the major complications of sickle cell disease. We hope that this will establish another preliminary forum among providers that may eventually lead the way to better outcomes.

Indications and complications of transfusions in sickle cell disease

Red cell transfusion remains an important part of the management of acute and chronic complications in SCD. The ongoing and emerging uses of transfusions in SCD may have significant benefits; however, the potential complications of transfusions also deserve careful consideration. In this report we review current indications for transfusions, transfusion complications, modifications of transfusion practices to mitigate risk, and potential considerations to improve transfusion outcomes.

Sickle cell disease in children

Early identification of infants with sickle cell disease (SCD) by newborn screening, now universal in all 50 states in the US, has improved survival, mainly by preventing overwhelming sepsis with the early use of prophylactic penicillin. Routine transcranial Doppler screening with the institution of chronic transfusion decreases the risk of stroke from 10% to 1% in paediatric SCD patients. Hydroxyurea decreases the number and frequency of painful crises, acute chest syndromes and number of blood transfusions in children with SCD. Genetic research continues to be driven toward the prevention and ultimate cure of SCD before adulthood. This review focuses on clinical manifestations and therapeutic strategies for paediatric SCD as well as the evolving topic of gene-focused prevention and therapy.

Prospects for primary stroke prevention in children with sickle cell anaemia

This review will focus on the strengths and limitations associated with the current standard of care for primary prevention of ischaemic strokes in children with sickle cell anaemia (SCA) - transcranial Doppler ultrasound (TCD) screening followed by regular blood transfusion therapy when TCD measurement is above a threshold defined by a randomized clinical trial (RCT). The theoretical basis for potential alternative strategies for primary prevention of neurological injury in SCA is also discussed. These strategies will include, but will not be limited to: immunizations to prevent bacterial infections, particularly in low income countries; management of elevated blood pressure; and targeted strategies to increase baseline haemoglobin levels with therapies such as hyroxycarbamide or potentially definitive haematopoietic stem cell transplant.