Management of Transfusion-Related Iron Overload in Patients With Myelodysplastic Syndromes

Exenatide-Modified Deferoxamine-Based Nanoparticles Ameliorates Neurological Deficits in Parkinson's Disease Mice

Purpose

To avoid the biotoxicity and poor bioavailability of deferoxamine mesylate (DFO), an iron chelation for the treatment of Parkinson's disease (PD), a self-oriented DFO nanoparticle functionalized with Exendin-4 was developed, which can be targeted delivered into the lesion brain area to achieve synergistic effects against PD by iron chelation and inflammatory suppression.

Methods

The self-oriented DFO nanoparticles (Ex-4@DFO NPs) were synthesized by double emulsion technique, and characterized in terms of the particle size, morphology and DFO encapsulation efficiency. The cellular internalization, biocompatibility and cytoprotection of NPs were assessed on BV-2 and SH-SY5Y cells. The brain targeting and therapeutic effect of NPs were investigated in MPTP-induced PD mice by near-infrared II fluorescence imaging and immunofluorescence staining, as well as mobility behavioral tests.

Results

Ex-4@DFO NPs with a particle size of about 100 nm, showed great biocompatibility and cytoprotection in vitro, which inhibited the decrease of mitochondrial membrane potential of SH-SY5Y cells and the release of inflammatory factors of BV-2 cells. In MPTP-induced PD mice, Ex-4@DFO NPs could penetrate the BBB into brain, and significantly mitigate the loss of dopaminergic neurons and inflammation in the substantia nigra, finally alleviate the mobility deficits.

Conclusion

This self-oriented nanosystem not only improved the biocompatibility of DFO, but also enhanced therapeutic effects synergistically by ameliorating neuronal damage and neuroinflammation, showing a potential therapeutic strategy for PD.

The effect of iron chelation therapy on overall survival in sickle cell disease and β-thalassemia: A systematic review

Red blood cell transfusions have become standard of care for the prevention of life-threatening anemia in patients with β-thalassemia and sickle cell disease (SCD). However, frequent transfusions can lead to accumulation of iron that can result in liver cirrhosis, diabetes mellitus, arthritis, arrhythmias, cardiomyopathy, heart failure, and hypogonadotropic hypogonadism. Iron chelation therapy has been shown to reduce serum ferritin levels and liver iron content, but limitations of trial design have prevented any demonstration of improved survival. The objective of this systematic review was to investigate the impact of iron chelation therapy on overall and event-free survival in patients with β-thalassemia and SCD. Eighteen articles discussing survival in β-thalassemia and 3 in SCD were identified. Overall iron chelation therapy resulted in better overall survival, especially if it is instituted early and compliance is maintained. Comparative studies did not show any significant differences between available iron chelation agents, although there is evidence that deferiprone is better tolerated than deferoxamine and that compliance is more readily maintained with the newer oral drugs, deferiprone and deferasirox. Iron chelation therapy, particularly the second-generation oral agents, appears to be associated with improved overall and event-free survival in transfusion-dependent patients with β-thalassemia and patients with SCD.

Targeted Brain Delivery of Rabies Virus Glycoprotein 29-Modified Deferoxamine-Loaded Nanoparticles Reverses Functional Deficits in Parkinsonian Mice

Excess iron deposition in the brain often causes oxidative stress-related damage and necrosis of dopaminergic neurons in the substantia nigra and has been reported to be one of the major vulnerability factors in Parkinson's disease (PD). Iron chelation therapy using deferoxamine (DFO) may inhibit this nigrostriatal degeneration and prevent the progress of PD. However, DFO shows very short half-life in vivo and hardly penetrates the blood brain barrier (BBB). Hence, it is of great interest to develop DFO formulations for safe and efficient intracerebral drug delivery. Herein, we report a polymeric nanoparticle system modified with brain-targeting peptide rabies virus glycoprotein (RVG) 29 that can intracerebrally deliver DFO. The nanoparticle system penetrates the BBB possibly through specific receptor-mediated endocytosis triggered by the RVG29 peptide. Administration of these nanoparticles significantly decreased iron content and oxidative stress levels in the substantia nigra and striatum of PD mice and effectively reduced their dopaminergic neuron damage and as reversed their neurobehavioral deficits, without causing any overt adverse effects in the brain or other organs. This DFO-based nanoformulation holds great promise for delivery of DFO into the brain and for realizing iron chelation therapy in PD treatment.

Management of iron overload in the Canadian hematology/oncology population: Implications for nursing practice

Red blood cell (RBC) transfusions are vital for many patients with chronic anemias associated with oncologic/hematologic disorders. However, repeated transfusions over time can lead to iron overload, which, if left untreated, can increase the risk of further malignancy and end-organ damage. Nurses and other health care professionals may not be aware of the significant implications of RBC transfusions and iron overload in patients with hematological/oncological disorders. This article was developed by a group of Canadian nurse practitioners and specialized oncology nurses to help improve health care professionals' understanding of iron overload in oncology patients and its associated risks, as well as provide a practical guide for the management of patients receiving treatment for this potentially serious condition.

The role of magnetic resonance imaging in the evaluation of transfusional iron overload in myelodysplastic syndromes

Myelodysplastic syndromes represent a group of heterogeneous hematopoietic neoplasms derived from an abnormal multipotent progenitor cell, characterized by a hyperproliferative bone marrow, dysplasia of the cellular hemopoietic elements and ineffective erythropoiesis. Anemia is a common finding in myelodysplastic syndrome patients, and blood transfusions are the only therapeutic option in approximately 40% of cases. The most serious side effect of regular blood transfusion is iron overload.

Currently, cardiovascular magnetic resonance using T2 is routinely used to identify patients with myocardial iron overload and to guide chelation therapy, tailored to prevent iron toxicity in the heart. This is a major validated non-invasive measure of myocardial iron overloading and is superior to surrogates such as serum ferritin, liver iron, ventricular ejection fraction and tissue Doppler parameters.

The indication for iron chelation therapy in myelodysplastic syndrome patients is currently controversial. However, cardiovascular magnetic resonance may offer an excellent non-invasive, diagnostic tool for iron overload assessment in myelodysplastic syndromes. Further studies are needed to establish the precise indications of chelation therapy and the clinical implications of this treatment on survival in myelodysplastic syndromes.

Comfort and anxiety levels of women with early stage breast cancer who receive radiotherapy

BACKGROUND

The aim of this planned research was to determine the comfort and anxiety levels of women with breast cancer receiving radiotherapy.

MATERIALS AND METHODS

This descriptive type study covered patients that applied to the radiation oncology breast polyclinic of our university hospital between January and May 2011. Patient Identification Form, Radiation Therapy Comfort Questionnaire (RTCQ), Spielberger State Trait Anxiety Inventory (STAI) were completed and analysed.

RESULTS

The mean age of the women who participated in the study was 51.6 ± 10.4 years. Mean scores of women were 3.73 ± 0.31 for RTCQ, 29.1 ± 5.88 for SAI and 37.8±6.91 for TAI. While the comfort levels of the women with breast cancer receiving radiotherapy were moderate, they experienced only low levels of anxiety.

CONCLUSIONS

By determining the comfort level of the patient before radiotherapy, besides providing comfort in this direction, eliminating/minimizing anxiety and stress will positively affect radiotherapy application. More attention of nurses to this issue is to be recommended.

Deferasirox for managing iron overload in people with myelodysplastic syndrome

BACKGROUND

The myelodysplastic syndrome (MDS) comprises a diverse group of haematopoietic stem cell disorders. Due to symptomatic anaemia, most people with MDS require supportive therapy including repeated red blood cell (RBC) transfusions. In combination with increased iron absorption, this contributes to the accumulation of iron resulting in secondary iron overload and the risk of organ dysfunction and reduced life expectancy. Since the human body has no natural means of removing excess iron, iron chelation therapy, i.e. the pharmacological treatment of iron overload, is usually recommended. However, it is unclear whether or not the newer oral chelator deferasirox leads to relevant benefit.

OBJECTIVES

To evaluate the effectiveness and safety of oral deferasirox for managing iron overload in people with myelodysplastic syndrome (MDS).

SEARCH METHODS

We searched the following databases up to 03 April 2014: MEDLINE, EMBASE, The Cochrane Library, Biosis Previews, Web of Science, Derwent Drug File and four trial registries: Current Controlled Trials (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), ICTRP (www.who.int./ictrp/en/), and German Clinical Trial Register (www.drks.de).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing deferasirox with no therapy, placebo or with another iron-chelating treatment schedule.

DATA COLLECTION AND ANALYSIS

We did not identify any trials eligible for inclusion in this review.

MAIN RESULTS

No trials met our inclusion criteria. However, we identified three ongoing and one completed trial (published as an abstract only and in insufficient detail to permit us to decide on inclusion) comparing deferasirox with deferoxamine, placebo or no treatment.

AUTHORS' CONCLUSIONS

We planned to report evidence from RCTs that evaluated the effectiveness of deferasirox compared to either placebo, no treatment or other chelating regimens, such as deferoxamine, in people with MDS. However, we did not identify any completed RCTs addressing this question.We found three ongoing and one completed RCT (published as an abstract only and in insufficient detail) comparing deferasirox with deferoxamine, placebo or no treatment and data will hopefully be available soon. These results will be important to inform physicians and patients on the advantages and disadvantages of this treatment option.

Myelodysplastic syndromes: the challenge of developing clinical guidelines and supportive care strategies for a rare disease

Myelodysplastic syndromes (MDS) represent a group of clonal myeloid malignancies with variability in clinical presentation and disease trajectory, as well as prognosis and treatment recommendations (Kurtin & Demakos, 2010). MDS is considered to be a rare disease that is most common in adults older than age 70. The disease is characterized by ineffective hematopoiesis, progressive bone marrow failure, and a variable risk of leukemic transformation thought to result from complex interactions between the malignant clone and the bone marrow microenvironment (Kurtin, 2011). This supplement is intended to provide the oncology clinician with an overview of MDS and provide tools for the clinical management and support of patients with MDS.

Update on the science of myelodysplastic syndromes

Scientific research is only just beginning to shed light on the pathobiology underlying the various subtypes of myelodysplastic syndromes (MDS), a heterogeneous group of clonal stem cell disorders characterized by cytopenias that can progress to acute myeloid leukemia. Increased understanding of the disease and prognostic implications of specific clinical features has aided in the development of prescribing guidelines and new treatments for MDS. Because oncology nurses have frequent interactions with patients during diagnostic and therapeutic evaluations, an understanding of the science behind disease classification, prognostic scoring, and the goals of treatment for low- and high-risk disease is important to answer questions regarding diagnostic results, treatment outcomes, and adverse event monitoring.