The Effect of Oral Iron Chelator Deferiprone on Iron Overload and Oxidative Stress in Patients with Myelodysplastic Syndromes: A Study by the Israeli MDS Working Group.

BACKGROUND: Most patients with lower risk myelodysplastic neoplasms or syndromes (MDSs) become RBC transfusion-dependent, resulting in iron overload, which is associated with an increased oxidative stress state. Iron-chelation therapy is applied to attenuate the toxic effects of this state. Deferiprone (DFP) is an oral iron chelator, which is not commonly used in this patient population, due to safety concerns, mainly agranulocytosis. The purpose of this study was to assess the effect of DFP, on oxidative stress parameters in iron-overloaded RBC transfusion-dependent patients with lower risk MDSs. METHODS: Adult lower risk MDS patients with a cumulative transfusion burden of >20 red blood cell units and evidence of iron overload (serum ferritin >1,000 ng/mL) were included in this study. DFP was administered (100 mg/kg/day) for 4 months. Blood samples for oxidative stress parameters and iron overload parameters were done at baseline and monthly: reactive oxygen species (ROS), phosphatidylserine, reduced glutathione, membrane lipid peroxidation, serum ferritin, and cellular labile iron pool. The primary efficacy variable was ROS. Tolerability and side effects were recorded as well. A paired t test was applied for statistical analyses. RESULTS: Eighteen patients were treated with DFP. ROS significantly decreased in all cell lineages: median decrease of 58.6% in RBC, 33.3% in PMN, and 39.8% in platelets (p < 0.01 for all). Other oxidative stress markers improved: phosphatidylserine decreased by 57.95%, lipid peroxidase decreased by 141.3%, and reduced gluthathione increased by 72.8% (p < 0.01 for all). The iron-overload marker and cellular labile iron pool decreased by 35% in RBCs, 44.3% in PMN, and 46.3% in platelets (p < 0.01 for all). No significant changes were observed in SF levels. There were no events of agranulocytosis. All AEs were grades 1-2. CONCLUSIONS: Herein, we showed preliminary evidence that DFP decreases iron-induced oxidative stress in MDS patients with a good tolerability profile (albeit a short follow-up period). No cases of severe neutropenia or agranulocytosis were reported. The future challenge is to prove that reduction in iron toxicity will eventually be translated into a clinically meaningful improvement.

Intracellular ROS profile in hematopoietic progenitors of MDS patients: association with blast count and iron overload.

Objectives: Reactive oxygen species (ROS) are under scrutiny as a participant in the pathophysiology of myelodysplastic syndrome (MDS) and the progression of MDS to acute myeloid leukemia (AML). Measurement of intracellular ROS (iROS) is particularly important since iROS is a direct indicator of cellular health and integrity.Methods: We developed a technique to measure standardize iROS (siROS) level in lymphocytes and bone marrow (BM) CD34+ hematopoietic progenitors using the fluorescent probe dichlorofluorescein (DCF). We then quantified the siROS in 38 consecutive BM specimens from 27 MDS patients over the course of 10 months. Disease outcome of these patients were also assessed.Results: High serum ferritin, high blast count and poor IPSS were associated with inferior survival and AML progression in this cohort. High blast MDS patients had lower siROS in their BM CD34+ cells than those of low blast patients, consistent with increased reliance on glycolysis and enhanced ROS defense in high blast MDS. We also observed narrower siROS distribution in the BM CD34+ cells of high blast patients, suggesting that loss of heterogeneity in ROS content accompanies the clonal evolution of MDS. Furthermore, we observed a strong correlation between CD34+ cells siROS and serum ferritin level in high blast patients. In one case, iron chelation therapy (ICT) resulted in parallel decreases in serum ferritin and CD34+ cells siROS.Conclusion: Our findings established the siROS profile in early hematopoietic cells of MDS patients and its relationship with blast count and iron overload.

Prospects for Venetoclax in Myelodysplastic Syndromes.

BCL-2 is an antiapoptotic protein that plays a critical role acute and chronic leukemias. Venetoclax is an orally selective BCL-2 inhibitor and BH3 mimetic approved in chronic lymphocytic leukemia and in combination with low dose cytarabine or hypomethylating agent in acute myeloid leukemia for the treatment of patients unfit for intensive chemotherapy. This article reviews the biology of BCL-2, focusing on its relationship to the myeloid microenvironment, and discusses the rationale for BCL-2 inhibition in myelodysplastic syndrome (MDS). Clinical trials testing venetoclax in MDS patients are under way. Potential biomarkers for clinical response to BCL-2 inhibition are discussed. Therapeutic opportunities for venetoclax in the therapeutic landscape of MDS are explored.

Iron chelation therapy for myelodysplastic syndrome: a systematic review and meta-analysis.

Iron overload remains a concern in myelodysplastic syndrome (MDS) patients especially those requiring recurrent blood transfusions. Whether iron chelating therapy (ICT) is beneficial to the long-term survival of myelodysplastic syndrome is still a controversial issue. Therefore, we conducted a systematic review and meta-analysis to clarify the relationship between ICT and long-term survival in patients with MDS. A total of 14 studies involving 7242 participants were identified; the outcomes revealed that for patients with MDS, ICT resulted in a lower risk of mortality compared to those with no ICT (HR 0.57; 95% CI 0.44-0.70; P < 0.001); what is more, ICT led to a lower risk of leukemia transformation (HR 0.70; 95% CI 0.52-0.93; P = 0.016). Results of subgroup analyses based on adequate ICT or any ICT, low/int-1 IPSS or unclassified IPSS and study types indicated that the ICT had a beneficial role in all these groups of patients.

Effect of iron chelation therapy on EPO-STAT5 signalling pathway and EPO resistance in iron-overloaded low-risk myelodysplastic syndrome patients.

Objectives: Background/aims: We aim to explore low-risk MDS patients' ESA response and the difference between iron-overloaded (IO) group and the control group in the expression of SOCS1, STAT5 and BCL2L1 which play a key role to EPO-STAT5 signal pathway.Methods: 56 low-risk MDS patients were divided into experimental group, IO patients; control group, non-IO patients. Among experimental group, 28 IO patients were treated with iron chelation therapy (ICT). SOCS1, phosphorylated STAT5 (p-STAT5) and BCL2L1 protein concentration in bone marrow supernatant have been analyzed by ELISA, STAT5a+b protein concentration in bone marrow mononuclear cells (BMMC) have been analyzed by Western blot, and mRNA expression of them have been detected in BMMC by RQ-PCR. The percentage of CD71+ cells in BMMC, apoptotic rate of CD71+ cells and ROS expression in CD71+ cells were detected by Flow cytometry.Results: Compared with the control group, the sEPO concentration, the efficacy of ESA and the expression of SOCS1, apoptotic rates of CD71+ cells and ROS expression in CD71+ cells in IO group were increased, the expression of STAT5 and BCL2L1 was reduced. Interestingly, after receiving ICT, some patients with EPO resistance have responded again to ESA treatment, with the decrease of the expression of SOCS1, apoptotic rates of CD71+ cells, ROS expression in CD71+ cells and the increase of the expression of STAT5 and BCL2L1.Conclusion: Iron overload can increase EPO resistance and the expression of SOCS1, inhibit the expression of STAT5 and BCL2L1. ICT could allivation of EPO resistance.

Cellular senescence induced by S100A9 in mesenchymal stromal cells through NLRP3 inflammasome activation.

Bone marrow stromal cells from patients with myelodysplastic syndrome (MDS) display a senescence phenotype, but the underlying mechanism has not been elucidated. Pro-inflammatory signaling within the malignant clone and the bone marrow microenvironment has been identified as a key pathogenetic driver of MDS. Our study revealed that S100A9 is highly-expressed in lower-risk MDS. Moreover, normal primary mesenchymal stromal cells (MSCs) and the human stromal cell line HS-27a co-cultured with lower-risk MDS bone marrow mononuclear cells acquired a senescence phenotype. Exogenous supplemented S100A9 also induced cellular senescence in MSCs and HS-27a cells. Importantly, Toll-like receptor 4 (TLR4) inhibition or knockdown attenuated the cellular senescence induced by S100A9. Furthermore, we showed that S100A9 induces NLRP3 inflammasome formation, and IL-1ß secretion; findings in samples from MDS patients further confirmed these thoughts. Moreover, ROS and IL-1ß inhibition suppressed the cellular senescence induced by S100A9, whereas NLRP3 overexpression and exogenous IL-1ß supplementation induces cellular senescence. Our study demonstrated that S100A9 promotes cellular senescence of bone marrow stromal cells via TLR4, NLRP3 inflammasome formation, and IL-1ß secretion for its effects. Our findings deepen the understanding of the molecular mechanisms involved in MDS reprogramming of MSCs and indicated the essential role of S100A9 in tumor-environment interactions in bone marrow.

[Myelodysplastic syndromes and iron metabolism].

Myelodysplastic syndromes (MDS) are clonal hematopoietic disorders characterized by ineffective hematopoiesis in bone marrow and cytopenias in peripheral blood. In patients with MDS, iron overload is frequent due to red blood cell transfusions and ineffective erythropoiesis. Dysplastic erythroblasts in MDS secrete humoral factors such as erythroferrone, which suppress hepatic expression of hepcidin. Hepcidin is the key regulator of systemic iron homeostasis, and suppression of hepcidin expression leads to an increase in iron absorption from the intestines, exacerbating systemic iron overload. Patients with MDS with ring sideroblasts (MDS-RS) are prone to iron overload, with most harboring splicing factor 3B subunit 1 (SF3B1) mutations in hematopoietic cells. SF3B1 mutations may induce ring sideroblasts by downregulating ATP binding cassette subfamily B member 7, which exports iron-sulfur clusters from the mitochondria to the cytoplasm. Iron overload in MDS causes hepatic dysfunction, diabetes, cardiac failure, and atherosclerosis, whereas excess iron may suppress normal hematopoiesis. Though randomized control studies are lacking, results from retrospective and cohort studies indicate that iron chelation therapy is appropriate for lower-risk MSD patients with transfusion-related iron overload, although it is not recommended for higher-risk MSD patients with short life expectancy.

Iron overload in myelodysplastic syndromes: Evidence based guidelines from the Canadian consortium on MDS.

In 2008 the first evidence-based Canadian consensus guideline addressing the diagnosis, monitoring and management of transfusional iron overload in patients with myelodysplastic syndromes (MDS) was published. The Canadian Consortium on MDS, comprised of hematologists from across Canada with a clinical and academic interest in MDS, reconvened to update these guidelines. A literature search was updated in 2017; topics reviewed include mechanisms of iron overload induced cellular damage, evidence for clinical endpoints impacted by iron overload including organ dysfunction, infections, marrow failure, overall survival, acute myeloid leukemia progression, and endpoints around hematopoietic stem-cell transplant. Evidence for an impact of iron reduction on the same endpoints is discussed, guidelines are updated, and areas identified where evidence is suboptimal. The guidelines address common questions around the diagnosis, workup and management of iron overload in clinical practice, and take the approach of who, when, why and how to treat iron overload in MDS. Practical recommendations for treatment and monitoring are made. Evidence levels and grading of recommendations are provided for all clinical endpoints examined.

Iron toxicity - Its effect on the bone marrow.

Excess iron can be extremely toxic for the body and may cause organ damage in the absence of iron chelation therapy. Preclinical studies on the role of free iron on bone marrow function have shown that iron toxicity leads to the accumulation of reactive oxygen species, affects the expression of genes coding for proteins that regulate hematopoiesis, and disrupts hematopoiesis. These effects could be partially attenuated by iron-chelation treatment with deferasirox, suggesting iron toxicity may have a negative impact on the hematopoietic microenvironment. Iron toxicity is of concern in transfusion-dependent patients. Importantly, iron chelation with deferasirox can cause the loss of transfusion dependency and may induce hematological responses, although the mechanisms through which deferasirox exerts this action are currently unknown. This review will focus on the possible mechanisms of toxicity of free iron at the bone marrow level and in the bone marrow microenvironment.

Integrative Genomics Identifies the Molecular Basis of Resistance to Azacitidine Therapy in Myelodysplastic Syndromes.

Myelodysplastic syndromes and chronic myelomonocytic leukemia are blood disorders characterized by ineffective hematopoiesis and progressive marrow failure that can transform into acute leukemia. The DNA methyltransferase inhibitor 5-azacytidine (AZA) is the most effective pharmacological option, but only ∼50% of patients respond. A response only manifests after many months of treatment and is transient. The reasons underlying AZA resistance are unknown, and few alternatives exist for non-responders. Here, we show that AZA responders have more hematopoietic progenitor cells (HPCs) in the cell cycle. Non-responder HPC quiescence is mediated by integrin α5 (ITGA5) signaling and their hematopoietic potential improved by combining AZA with an ITGA5 inhibitor. AZA response is associated with the induction of an inflammatory response in HPCs in vivo. By molecular bar coding and tracking individual clones, we found that, although AZA alters the sub-clonal contribution to different lineages, founder clones are not eliminated and continue to drive hematopoiesis even in complete responders.

Total coumarins of Hedyotis diffusa induces apoptosis of myelodysplastic syndrome SKM-1 cells by activation of caspases and inhibition of PI3K/Akt pathway proteins.

ETHNOPHARMACOLOGICAL RELEVANCE: Hedyotis diffusa is an ethno-medicine used for anti-cancer treatment in the clinic of traditional Chinese medicine (TCM). The total coumarins of Hedyotis diffusa (TCHD) was a selected extract with observed antiproliferative activity, which has not been tested in treatment of myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML). AIM OF THE STUDY: This study aimed to evaluate the apoptosis-inducing effect of TCHD on human MDS cell line (SKM-1) and explore its action mechanism in association with caspase family and PI3K/Akt signaling pathway. MATERIALS AND METHODS: The chemical constituents and total coumarins content of TCHD were determined by High Performance Liquid Chromatography-tandem mass spectrometry (HPLC-MS/MS) and UV-vis spectrophotometry, respectively. MTT assay, Hoechst 33258 staining, and Annexin V-FITC/PI double labeling were applied to evaluate TCHD's efficacy on SKM-1 cells. Western blot analysis was also used to clarify the action mechanism of TCHD on protein expression level. RESULTS: Two compounds, p-coumaric acid and E-6-O-p-coumaroyl scandoside methyl ester, were identified in TCHD, and its total coumarins content reached 87.4%. By MTT assay, apoptosis-inducing effect of TCHD on SKM-1 cells was found in a dose-dependent manner after 24-48h treatment, with IC50 values of 104.48µg/ml and 100.66µg/ml, respectively. Morphological and flow cytometry observation also confirmed such effect of TCHD. Western blot analysis clarified its action mechanism associating with the activation of caspases and inhibition of PI3K/Akt pathway proteins. CONCLUSIONS: This is the first report regarding the apoptosis-inducing efficacy and mechanism of TCHD on SKM-1 cells, providing a promising candidate of TCM for MDS and AML therapy with fewer side effects.

Decision points in the treatment of transfusional iron overload in patients with myelodysplastic syndromes: why, when, and how to chelate.

INTRODUCTION: Patients with myelodysplastic syndromes (MDS) differ from those with other transfusion-dependent conditions (eg, thalassemia) as they are typically older, have comorbid conditions, and a generally shorter life expectancy. The underlying disease process in MDS and frequent use of red blood cell transfusions lead to iron accumulation and ultimately organ damage. Whether iron-reducing interventions such as chelation therapy can improve outcomes in this population is currently under investigation. Areas covered: We reviewed published English-language articles from PubMed on the topic of iron overload (IO) in MDS, and the use of iron chelation therapies (ICTs) to alleviate iron burden. Expert commentary: Data on IO-associated complications in MDS are derived largely from retrospective studies and there are limited data to guide clinicians on major treatment decisions. Although effective and well-tolerated oral ICTs are available, and general recommendations may be made regarding usage in MDS, guidance is not yet based on prospective data. The clinical endpoints and assessments for MDS may differ substantively from those used in patients with thalassemia, as an older population may have competing causes for morbidity. We expect that emergent data from clinical trials currently underway will define more appropriate endpoints/assessments for the MDS population in clinical trials.

Health-related quality of life in transfusion-dependent patients with myelodysplastic syndromes: a prospective study to assess the impact of iron chelation therapy.

OBJECTIVE: The primary objective of this study was to evaluate the health-related quality of life (HRQOL) in lower-risk, transfusion-dependent patients with myelodysplastic syndromes (MDS) treated with deferasirox. A secondary objective was to investigate the relationship between HRQOL, serum ferritin levels and transfusion dependency. PATIENTS AND METHODS: This was a prospective multicentre study enrolling 159 patients, of whom 152 received at least one dose of deferasirox. HRQOL was assessed with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) at baseline and then at 3, 6, 9 and 12 months. Primary analysis was performed estimating mean HRQOL scores over time by a linear mixed model on selected scales. RESULTS: The median age of treated patients was 72 years (range 24-87 years). No statistically significant changes over time were found in mean scores for global health status/quality of life (p=0.564), physical functioning (p=0.409) and fatigue (p=0.471) scales. Also, no significant changes were found for constipation (p=0.292), diarrhoea (p=0.815) and nausea and vomiting (p=0.643). Serum ferritin levels were not associated with HRQOL outcomes. A higher patient-reported baseline pain severity was an independent predictive factor of an earlier achievement of transfusion independence with a HR of 1.032 (99% CI 1.004 to 1.060; p=0.003). CONCLUSIONS: HRQOL of transfusion-dependent patients with MDS receiving deferasirox therapy remains stable over time. HRQOL assessment might also provide important predictive information on treatment outcomes. TRIAL REGISTRATION NUMBER: NCT00469560.

DNA-mediated adjuvant immunotherapy extends survival in two different mouse models of myeloid malignancies.

We have previously shown that a specific promyelocytic leukemia-retinoic acid receptor alpha (PML-RARA) DNA vaccine combined with all-trans retinoic acid (ATRA) increases the number of long term survivors with enhanced immune responses in a mouse model of acute promyelocytic leukemia (APL). This study reports the efficacy of a non-specific DNA vaccine, pVAX14Flipper (pVAX14), in both APL and high risk myelodysplastic syndrome (HR-MDS) models. PVAX14 is comprised of novel immunogenic DNA sequences inserted into the pVAX1 therapeutic plasmid. APL mice treated with pVAX14 combined with ATRA had increased survival comparable to that obtained with a specific PML-RARA vaccine. Moreover, the survival advantage correlated with decreased PML-RARA transcript levels and increase in anti-RARA antibody production. In HR-MDS mice, pVAX14 significantly improved survival and reduced biomarkers of leukemic transformation such as phosphorylated mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) 1. In both preclinical models, pVAX14 vaccine significantly increased interferon gamma (IFNγ) production, memory T-cells (memT), reduced the number of colony forming units (CFU) and increased expression of the adapter molecule signalling to NF-κB, MyD88. These results demonstrate the adjuvant properties of pVAX14 providing thus new approaches to improve clinical outcome in two different models of myeloid malignancies, which may have potential for a broader applicability in other cancers.

Deferasirox Decreases Liver Iron Concentration in Iron-Overloaded Patients with Myelodysplastic Syndromes, Aplastic Anemia and Other Rare Anemias.

Iron overload in transfusion-dependent patients with rare anemias can be managed with chelation therapy. This study evaluated deferasirox efficacy and safety in patients with myelodysplastic syndromes (MDS), aplastic anemia (AA) or other rare anemias. A 1-year, open-label, multicenter, single-arm, phase II trial was performed with deferasirox (10­40 mg/kg/day, based on transfusion frequency and therapeutic goals), including an optional 1-year extension. The primary end point was a change in liver iron concentration (LIC) after 1 year. Secondary end points included changes in efficacy and safety parameters (including ophthalmologic assessments) overall as well as in a Japanese subpopulation. Overall, 102 patients (42 with MDS, 29 with AA and 31 with other rare anemias) were enrolled; 57 continued into the extension. Mean absolute change in LIC was ­10.9 mg Fe/g dry weight (d.w.) after 1 year (baseline: 24.5 mg Fe/g d.w.) and ­13.5 mg Fe/g d.w. after 2 years. The most common drug-related adverse event was increased serum creatinine (23.5%), predominantly in MDS patients. Four patients had suspected drug-related ophthalmologic abnormalities. Outcomes in Japanese patients were generally consistent with the overall population. Results confirm deferasirox efficacy in patients with rare anemias, including a Japanese subpopulation. The safety profile was consistent with previous studies and ophthalmologic parameters generally agreed with baseline values (EUDRACT 2006-003337-32).

An increase in hemoglobin, platelets and white blood cells levels by iron chelation as single treatment in multitransfused patients with myelodysplastic syndromes: clinical evidences and possible biological mechanisms.

Iron chelation therapy can improve hematopoiesis in myelodysplastic syndromes. Only few studies showed hematologic improvement with deferoxamine, and the erythroid responses were correlated with good compliance to long-term treatment. Indeed, single-case reports and data from clinical trials testing the efficacy of deferasirox reported hematologic improvements with varying rates of response in different lineages. Overall, about 760 myelodysplastic syndrome (MDS) patients with iron overload receiving deferasirox were included in six different studies, and an increase in hemoglobin level was reported to range from 6 to 44.5%, an increase in platelet count from 13 to 61%, and in neutrophil count from 3 to 76%. In all the published studies, hematologic improvements were not related to serum ferritin or to non-total binding iron changes; indeed, other pathways were indicated as possible pathogenetic mechanisms, such as decreased NF-kB activity, modulation of mTOR signalling, and reduced reactive oxygen species. The aims of this review are to provide all available information relating clinical and hematologic changes after chelation therapy and to discuss potential mechanisms involved in such responses.

[Iron chelation therapy and its influence on the alleviation of EPO resistance in MDS patients].

This study was aimed to investigate the changes of erythropoietin (EPO), hemoglobin(Hb) and recombinant EPO (rEPO) levels in MDS patients receiving iron chelation therapy, and to explore the relationship between EPO and serum ferritin(SF). A total of 172 MDS patients and 30 healthy controls were studied. The levels of SF, EPO, serum iron (SI), total iron binding capacity (TIBC), C-reaction protein (CRP) and Hb were measured respectively, the level of SF was adjusted according to the changes of CRP. Among them, there were 34 cases of low-risk (SF>1 000 mg/L) receiving deferoxamine therapy, whose changes of SF, EPO, SI, TIBC, Hb levels were detected and compared before and after treatment. Besides, the difference in the incidence of EPO resistance in iron overload group and non-iron overload group was assessed before and after therapy, and 58 cases of low-risk and EPO<1 000 U/L MDS patients were given rEPO therapy. The results showed that the level of EPO in non-iron overload group was higher than that in the normal control group (997.44 ± 473.48 vs 467.27 ± 238.49, P < 0.05). Obviously, the level of EPO in iron overload group was higher than that in non-iron overload group and control group (3257.59 ± 697.19 vs 997.44 ± 473.48, P = 0.012, 3257.59 ± 697.19 vs 467.27 ± 238.49, P = 0.002). Otherwise, the incidence of EPO resistance in iron overload group was higher than that in non-iron overload group (18/35 vs 2/23, P = 0.001), and the level of EPO and SF was positively related to each other in iron overload group (r = 0.310,P = 0.036). After receiving iron chelation therapy, the levels of SF, SI, TIBC and EPO in iron overload group were significantly lower than that before therapy (3942.38 ± 641.82 vs 2266.35 ± 367.31, P = 0.028;48.61 ± 10.65 vs 28.52 ± 12.61, P = 0.034;59.84 ± 12.62 vs 33.76 ± 15.43, P = 0.045;3808.01 ± 750.22 vs 1954.78 ± 473.18, P = 0.042). Moreover, the level of Hb increased (35 ± 18 vs 57 ± 21, P = 0.046) and the EPO resistance in some patients was decreased. It is concluded that iron chelation therapy can improve the efficacy of EPO to alleviate EPO resistance in patients wtih anemic MDS, decrease the pathological level of EPO, enhance Hb levels and reduce the dependency on blood transfusion.

Toward resolving the unsettled role of iron chelation therapy in myelodysplastic syndromes.

Transfusion dependent low risk myelodysplastic syndromes (MDS) patients, eventually develop iron overload. Iron toxicity, via oxidative stress, can damage cellular components and impact organ function. In thalassemia major patients, iron chelation therapy lowered iron levels with recovery of cardiac and liver functions and significant improvement in survival. Several noncontrolled studies show inferior survival in MDS patients with iron overload, including an increase in transplant-related mortality and infection risk while iron chelation appears to improve survival in both lower risk MDS patients and in stem cell transplant settings. Collated data are presented on the pathophysiological impact of iron overload; measuring techniques and chelating agents' therapy positive impact on hematological status and overall survival are discussed. Although suggested by retrospective analyses, the lack of clear prospective data of the beneficial effects of iron chelation on morbidity and survival, the role of iron chelation therapy in MDS patients remains controversial.

[Effect of Qinghuang Powder combined Chinese herbs for Pi-strengthening and Shen-reinforcing on HIF-1alpha in bone marrow mononuclear cells of myelodysplastic syndrome patients: an experimental research].

OBJECTIVE: To study the effect of Qinghuang Powder (QHP) combined Chinese herbs for Pi-strengthening and Shen-reinforcing (CHPSSR) on hypoxia-inducible factor 1alpha (HIF-1alpha) in bone marrow mononuclear cells of myelodysplastic syndrome (MDS) patients. METHODS: Changes of HIF-1alpha in bone marrow mononuclear cells of MDS patients were detected in 25 MDS patients treated by QHP combined CHPSSR using flow cytometry. Meanwhile, 13 healthy subjects were recruited as the control group. Changes HIF-1alpha levels in various serial bone marrow mononuclear cells were detected. RESULTS: (1) Among the 25 patients in the treatment group, there were 19 patients effective and 6 patients ineffective, with the total effective rate being 76%. (2) Compared with before treatment, levels of peripheral blood WBC, Hb, PLT, and ANC significantly increased in the treatment group after treatment, showing statistical difference (P < 0.05, P < 0.01). (3) Compared with before treatment, the HIF-1alpha mean fluorescence intensity was enhanced in bone marrow lymphocytes, monocytes, granulocytes, and nucleated red blood cells of the treatment group after treatment (P < 0.05, P < 0.01). Compared with the control group, the HIF-1alpha mean fluorescence intensity was weakened in bone marrow lymphocytes, monocytes, and nucleated red blood cells of the treatment group before treatment; while it was obviously enhanced in granulocytes (P < 0.01). But after treatment the HIF-1alpha mean fluorescence intensity increased more in the granulocytes of the treatment group than in those of the control group (P < 0.01), but there was no statistical difference in bone marrow lymphocytes, monocytes, or nucleated red blood cells. CONCLUSION: QHP combined CHPSSR could improve HIF-1alpha levels in bone marrow lymphocytes, monocytes, granulocytes, and nucleated red blood cells of MDS patients, thus improving Hb levels of MDS patients, and improving their anemia and correlated symptoms.

Clofarabine in the treatment of myelodysplastic syndromes.

INTRODUCTION: Clofarabine is a second-generation purine nucleoside analog approved in 2004 for the treatment of pediatric patients with relapsed or refractory acute lymphocytic leukemia (ALL) following failure of at least two prior regimens. Clofarabine is a hybrid of fludarabine and cladribine, designed to overcome the pharmacologic limitations associated with its predecessors, while retaining their beneficial properties. In addition to providing a valuable treatment option for pediatric patients with ALL, clofarabine alone and in combination with cytarabine (Ara-C) has demonstrated substantial activity against myelodysplastic syndrome (MDS), thus rendering this agent a potential therapeutic option for MDS. AREAS COVERED: This review focuses on the pharmacology and clinical activity of clofarabine in MDS, as well as its emerging role in the treatment of MDS. Publications in English were selected from the MEDLINE (PubMed) database, as well articles of interest from bibliographies and abstracts based on the publication of meeting materials. EXPERT OPINION: DNA-methyltransferase inhibitors are the mainstay of therapy for many patients with MDS who require treatment. Although these agents are very well tolerated and represent a significant advancement in the treatment of MDS by improving transfusion requirements and prolonging survival in various subgroups of patients, response rates are modest and the duration of response is short. In addition to providing a valuable treatment option for pediatric ALL patients, clofarabine has substantial activity against MDS and is well tolerated by elderly patients, thus rendering it a potential therapeutic option.