Ecotoxicology and environmental safety toxicity of pyrethroid cypermethrin on the freshwater snail Chilina parchappii: Lethal and sublethal effects.

The aim of the present work was to study the effect of the pyrethroid cypermethrin (CYP) on the non-target freshwater snail Chilina parchappi. Initially, the sensitivity of adult snails to CYP was evaluated via the 96-h LC50 test. Then, snails were exposed to subtethal CYP concentrations (0.1 and 10 mg/l) for 1, 4 and 10 days and the digestive glands were dissected for biomarkers analyses. Enzymatic activity of catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), as well as total glutathione reduced (GSH) levels, were determined. Histological analyses of morphology, intracellular accumulation of lipofucsins and neutral lipids accumulation in the digestive gland were also evaluated. As compared to other molluscs, C. parchappi showed high resistance to CYP exposure evidenced by the 96-h LC50 value (44.59 mg/l). Snails exposed to sublethal CYP concentrations showed a statistically significant increase (p < 0.01) in GST (79-116%) and GPx (45-190%) activities with respect to controls. However, CAT activity showed a tendency to decrease with CYP treatment but was not statistically significantly different compared to control. Only high CYP concentration caused a statistically significant increase (p < 0.01) in GSH content (95-196%). There was evidence of structural changes in the digestive gland of snails exposed to CYP, showing a dose-dependent response. In exposed snails, some of the main symptoms included a reduction in the thickness of the epithelium, vacuolisation of the digestive cells and an increase in the number of excretory cells. Accumulation of lipofuscins (933-1006%) and neutral lipids (403%) were statistically significantly higher (p < 0.05) in snails exposed to CYP compared to control. This study showed that C. parchappii is quite tolerant to CYP exposure and that at sublethal concentrations, GSH metabolism could play a protective role against the pesticide harm in snails. Therefore, it would be interesting to study the response of this organism to other environmental stressors to assess its potential use in monitoring programs.

Feasibility of allogeneic stem-cell transplantation after azacitidine bridge in higher-risk myelodysplastic syndromes and low blast count acute myeloid leukemia: results of the BMT-AZA prospective study.

BACKGROUND: Allogeneic stem-cell transplantation (HSCT) is the only curative treatment in myelodysplastic syndromes (MDS). Azacitidine (AZA) is increasingly used prior to HSCT, however in Europe it is only approved for patients who are not eligible for HSCT. PATIENTS AND METHODS: We conducted a phase II multicenter study to prospectively evaluate the feasibility of HSCT after treatment with AZA in 70 patients with a myelodysplastic syndrome (MDS), 19 with acute myeloid leukemia (AML), and 8 with chronic myelomonocytic leukemia (CMML). After a median of four cycles (range 1-11): 24% of patients achieved complete remission, 14% partial remission, 8% hematologic improvement, 32% had stable and 22% progressive disease. Ten patients discontinued treatment before the planned four cycles, due to an adverse event in nine cases. RESULTS: A HSC donor was identified in 73 patients, and HSCT was performed in 54 patients (74% of patients with a donor). Main reasons for turning down HSCT were lack of a donor, an adverse event, or progressive disease (9, 12, and 16 patients, respectively). At a median follow-up of 20.5 months from enrolment, response to AZA was the only independent prognostic factor for survival. Compared to baseline assessment, AZA treatment did not affect patients' comorbidities at HSCT: the HCT-CI remained stable in 62% patients, and worsened or improved in 23% and 15% of patients, respectively. CONCLUSIONS: Our study shows that HSCT is feasible in the majority of patients with HR-MDS/AML/CMML-2 after AZA treatment. As matched unrelated donor was the most frequent source of donor cells, the time between diagnosis and HSCT needed for donor search could be 'bridged' using azacitidine. These data show that AZA prior to HSCT could be a better option than intensive chemotherapy in higher-risk MDS. The trial has been registered with the EudraCT number 2010-019673-1.

Ecological risk assessment of pesticides in sediments of Pampean streams, Argentina.

After their application in agricultural areas, pesticides are dispersed throughout the environment, causing contamination problems. In Argentina, the main promoter of transgenic biotechnology in the region, the total consumption of agrochemicals has increased significantly in recent years. Most chemicals dumped near surface waters eventually end up in bottom sediments and can be toxic to the organisms that live there. However, published data on the mixing of pesticides in this compartment is still scarce. The objective of this work was to detect and quantify pesticide residues in the sediment of rural streams in the Pampas region and to carry out acute and chronic risk assessment in these aquatic ecosystems. The study area comprises the mountainous system of Tandilia, located in one of the most productive agricultural areas in the country. The concentration of atrazine, acetochlor, chlorpyrifos, cypermethrin, and 2,4-D in the sediment of four rural streams was determined in three different seasons, and the toxic units (TU) and the risk ratios (RQ) were calculated. All the compounds analyzed were detected in most of the sampling seasons and study sites, at concentrations higher than those established in the national and international quality guidelines for the protection of aquatic biota in surface waters and for human consumption. Chlorpyrifos, cypermethrin, and acetochlor were the main pesticides contributing to the TU and RQ values, representing a medium or high ecological risk in most of the sites. Therefore, the evaluation of these pesticides in the bottom sediments could be a decisive factor in assessing the risk to the aquatic environment.

Metabolic syndrome and cardiovascular disease after haematopoietic cell transplantation (HCT) in adults: an EBMT cross-sectional non-interventional study.

Metabolic syndrome (MetS) is associated with cardiovascular disease in the general population and is also a potential cardiovascular risk factor in survivors of haematopoietic cell transplantation (HCT). We report an EBMT cross-sectional, multi-centre, non-interventional study of 453 adult HCT patients surviving a minimum of 2 years post-transplant attending routine follow-up HCT and/or late effects clinics in 9 centres. The overall prevalence of MetS was 37.5% rising to 53% in patients >50 years of age at follow-up. There were no differences in rates of MetS between autologous and allogeneic HCT survivors, nor any association with graft-versus-host disease (GvHD) or current immunosuppressant therapy. Notably, there was a significantly higher occurrence of cardiovascular events (CVE, defined as cerebrovascular accident, coronary heart disease or peripheral vascular disease) in those with MetS than in those without MetS (26.7% versus 9%, p < 0.001, OR 3.69, 95% CI 2.09-6.54, p < 0.001), and, as expected, MetS and CVE were age-related. Unexpectedly, CVE were associated with occurrence of second malignancy. Screening for and management of MetS should be integrated within routine HCT long-term follow-up care for both allogeneic and autologous HCT survivors. Further research is warranted, including randomised controlled trials of interventional strategies and mechanistic studies of cardiovascular risk in HCT survivors.

Allogeneic hematopoietic stem cell transplantation for advanced mycosis fungoides and Sézary syndrome. An updated experience of the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option in advanced-stage mycosis fungoides (MF) and Sézary syndrome (SS). This study presents an updated analysis of the initial experience of the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation (EBMT) describing the outcomes after allo-HSCT for MF and SS, with special emphasis on the impact of the use of unrelated donors (URD). METHODS AND PATIENTS: Eligible for this study were patients with advanced-stage MF or SS who underwent a first allo-HSCT from matched HLA-identical related or URD between January/1997 and December/2011. Sixty patients have been previously reported. RESULTS: 113 patients were included [77 MF (68%)]; 61 (54%) were in complete or partial remission, 86 (76%) received reduced-intensity protocols and 44 (39%) an URD allo-HSCT. With a median follow up for surviving patients of 73 months, allo-HSCT resulted in an estimated overall survival (OS) of 38% at 5 years, and a progression-free survival (PFS) of 26% at 5 years. Multivariate analysis demonstrated that advanced-phase disease (complete remission/partial remission >3, primary refractory or relapse/progression in patients that had received 3 or more lines of systemic treatment prior to transplant or the number of treatment lines was not known), a short interval between diagnosis and transplant (<18 months) were independent adverse prognostic factors for PFS; advanced-phase disease and the use of URDs were independent adverse prognostic factors for OS. CONCLUSIONS: This extended series supports that allo-HSCT is able to effectively rescue over one third of the population of patients with advanced-stage MF/SS. High relapse rate is still the major cause of failure and needs to be improved with better strategies before and after transplant. The negative impact of URD is a matter of concern and needs to be further elucidated in future studies.

Autologous hematopoietic stem cell transplantation has better outcomes than conventional therapies in patients with rapidly progressive systemic sclerosis.

We retrospectively evaluated the efficacy of autologous hematopoietic stem cell transplantation (AHSCT) in 18 patients with rapidly progressive diffuse cutaneous systemic sclerosis (rp-dcSSc), and compared their disease outcomes with those of 36 demographically- and clinically-matched patients treated with conventional therapies. Cutaneous involvement, by performing modified Rodnan skin score (mRss), lung diffusion capacity, by measuring diffusing capacity of lung for carbon monoxide (DLCO), and disease activity, by applying the European Scleroderma Study Group (ESSG) scoring system, were the outcome variables measured at the baseline time and then every 12 months for the following 60 months in both the AHSCT-treated patients and the control group. In the AHSCT group, treatment-related mortality was 5.6%. In this group, both mRss and ESSG scores showed a significant reduction 1 year after AHSCT (P<0.002); and these results were maintained until the end of follow-up. Conversely, DLCO values remained stable during the whole period of follow-up. Survival rate of AHSCT group was much higher than that observed in the whole control group (P=0.0005). The probability that the ESSG score and mRss would remain at a high level, and DLCO could decrease, was significantly higher in the control group as a whole and in the subgroup of control patients treated with cyclophosphamide than in the AHSCT group. This study confirms that the AHSCT is effective in prolonging survival, as well as in inducing a rapid reduction of skin involvement and disease activity, and preserving lung function in patients with rp-dcSSc.

Treating chronic lymphocytic leukemia with obinutuzumab: safety and efficacy considerations.

INTRODUCTION: Obinutuzumab is a novel glycoengineered type II anti-CD20 monoclonal antibody (MoAb) with a higher affinity for CD20 epitope. It was approved by the United States Food and Drug Administration (FDA) in November 2013 for use in combination with chlorambucil for previously untreated chronic lymphocytic leukemia (CLL). AREAS COVERED: This article evaluates the safety of obinutuzumab in CLL patients, also addressing pharmacokinetics/pharmacodynamics (PK/PD), clinical use and efficacy. Moreover, a comparison with other anti-CD20 MoAb is performed. The principal available studies on obinutuzumab are reviewed, focusing on CLL. A PubMed literature search (August 2002 to September 2015) was conducted using the terms obinutuzumab, GA101, anti-CD20 antibody, and CLL. EXPERT OPINION: Obinutuzumab, a third-generation anti-CD20 MoAb, is a safe and effective treatment for elderly patients who are un-fit for fludarabine-based regimen. Its use, proven in the CLL11 study and the results of many ongoing trials evaluating other obinutuzumab-based regimen can lead obinutuzumab to be a candidate to replace rituximab as the first-line treatment option.

lncRNA profiling in early-stage chronic lymphocytic leukemia identifies transcriptional fingerprints with relevance in clinical outcome.

Long non-coding RNAs (lncRNAs) represent a novel class of functional RNA molecules with an important emerging role in cancer. To elucidate their potential pathogenetic role in chronic lymphocytic leukemia (CLL), a biologically and clinically heterogeneous neoplasia, we investigated lncRNAs expression in a prospective series of 217 early-stage Binet A CLL patients and 26 different subpopulations of normal B-cells, through a custom annotation pipeline of microarray data. Our study identified a 24-lncRNA-signature specifically deregulated in CLL compared with the normal B-cell counterpart. Importantly, this classifier was validated on an independent data set of CLL samples. Belonging to the lncRNA signature characterizing distinct molecular CLL subgroups, we identified lncRNAs recurrently associated with adverse prognostic markers, such as unmutated IGHV status, CD38 expression, 11q and 17p deletions, and NOTCH1 mutations. In addition, correlation analyses predicted a putative lncRNAs interplay with genes and miRNAs expression. Finally, we generated a 2-lncRNA independent risk model, based on lnc-IRF2-3 and lnc-KIAA1755-4 expression, able to distinguish three different prognostic groups in our series of early-stage patients. Overall, our study provides an important resource for future studies on the functions of lncRNAs in CLL, and contributes to the discovery of novel molecular markers with clinical relevance associated with the disease.

Endothelial precursors and mature endothelial cells are increased in the peripheral blood of myelodysplastic syndromes.

Increased angiogenesis has been demonstrated to be a significant prognostic factor in many solid tumors. In the oncohematological setting, it has been associated with myelodysplastic syndromes (MDS), chronic myeloid leukemia, acute lymphoid, and myeloid leukemias. Recently, increased circulating endothelial cells (CECs) have been associated with breast cancer and non-Hodgkin lymphoma (NHL). Based on these premises we analysed total and activated CECs, and endothelial precursors (CEPs) in 50 MDS patients and 20 healthy donors. CECs and CEPs were quantified by flow cytometry. CEC levels were compared with bone marrow (BM) microvessel density (MVD). In addition, some angiogenic factors, namely vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and soluble VEGF-Receptor2 (VEGFR2), were tested in the sera from 25 MDS patients. Total, activated CECs and CEPs were significantly increased in MDS when compared to control group (p<0.0001); whereas in the MDS cases no association was found with French--American--British (FAB), International Prognostic Scoring System (IPSS) subtypes or survival. Patients with higher CECs also showed higher MVD. Among the cytokines analysed, sVEGFR2 was significantly higher in the lower IPSS risk classes, while the levels of bFGF directly correlated with total and activated CECs. Taken together these data strengthen the hypothesis of a possible role of angiogenesis in MDS pathogenesis.

Recombinant gamma-interferon as first line therapy for high risk myelodysplastic syndromes. Italian MDS Study Group.

Thirty patients affected by previously untreated high risk myelodysplastic syndromes (MDS) were treated with human recombinant gamma-interferon (r-IFN-gamma): 15 of them with a higher dose (HD) of 0.1 mg/sqm, three times a week and 15 with a lower dose (LD) of 0.01 mg/sqm, three times a week, both doses administered subcutaneously (s.c.). The therapy was fairly well tolerated and few major toxic events were documented. Sustained improvement of one or more clinico-hematologic parameters was observed in 43.3% of the patients (26.6% and 60.0% for the lower and higher dose, respectively). Median survival time from the start of IFN-gamma therapy was 15+ months (range: 1-26) for patients with refractory anemia with excess of blasts (RAEB) versus 5 months (range 2-12) for patients with RAEB in transformation (RAEB-t); 15+ months (range 1-26) for HD patients versus 8 months (range 2-23) for patients treated with LD regimen; 16+ months (range 9-26) for responders versus 7 months (range 1-22) for nonresponders. All these three variables (diagnosis, treatment, and response to treatment) turned out to be statistically significant (p = at least less than 0.01) at Cox's analysis.

In vitro effects of IL-12 and IL-2 on NK cells, cytokine release and clonogenic activity in myelodysplastic syndromes (MDS).

We evaluated the in vitro effects of IL-12, alone and in association with IL-2 on MDS bone marrow and peripheral blood cells. Thirty-six patients and 14 healthy subjects were studied. Natural killer-activity (NK-a) levels and lymphocyte immunophenotypes were determined in fresh bone marrow (BMMNC) and peripheral blood mononuclear cells (PBMNC), which then were resuspended in medium containing IL-2, IL-12 or IL-2 + IL-12 for 7 days. Re-evaluation of NK-a levels, lymphocyte immunophenotypes, clonogenic activity and cytokine release showed that, unlike IL-2, IL-12 did not significantly increase NK-a or CD3-/56+ cell levels in either bone marrow or peripheral blood; IL-2 + 12 led to a significant increase that fell between the values reached by each cytokine alone. IL-2 + 12 and, although to a lesser extent, also IL-12 alone induced the release of large amounts of gamma-IFN and alpha-TNF. In addition, the number of clusters particularly decreased in the samples treated with IL-2 + 12 and IL-12 alone. Clonogenic activity was not modified after stimulation with any of the treatment. These data suggest that IL-12 induces the release of inhibitory cytokines in normal as well as MDS cells and that it could be used in patients with elevated bone marrow blastosis.

Diagnostic role and prognostic significance of a simplified immunophenotypic classification of mature B cell chronic lymphoid leukemias.

We verified the diagnostic and prognostic role of a simplified immunophenotypic classification (IC) in a series of 258 patients (M/F: 1.4; median age: 64 years; median follow-up: 64 months; 75 deaths) with mature B cell lymphoid leukemias (MBC-LL) for whom no histopathological diagnosis was available because of minimal or no lymph node involvement. The IC was based on the reactivity of three pivotal immunophenotypic markers: CD5, CD23 and SIg intensity. On the basis of different expression patterns, we identified four diagnostic clusters (C) characterized by distinct clinico-biological features and different prognoses: C1 (149 patients) identified most classical B cell chronic lymphocytic leukemias (CLL-type cluster; SIg(dim)/CD5+/CD23+); C2, 38 patients whose clinico-hematological characteristics were intermediate between C1 and C3 (CLL-variant cluster; SIg(bright)/CD5+/CD23+/-or SIg(dim)/CD5-/-/CD23 indifferent); C3 (16 patients) most situations consistent with mantle cell lymphoma in leukemic phase (MCL-type cluster; SIg(bright)/CD5+/CD23-); and C4, 55 cases, most of whom were consistent with leukemic phase lymphoplasmacytic/splenic marginal zone lymphomas (LP/S-type cluster; SIg(bright)/CD5-/+/CD23 indifferent). At univariate survival analysis, prognosis worsened from C1 to C4, C2 and C3 (P = 0.0001), and this was maintained at multivariate analysis (P = 0.006), together with CD11c expression (P = 0.0043), age at diagnosis (cut-off 70 years; P = 0.0008) and platelet count (cut-off 140 x 10(9)/l; P = 0.0034). Besides recognising the two well-known situations of classic B-CLL and MCL, our IC identified situations with distinct prognostic and/or clinical behaviors.

In vitro effects of IL-2 on NK-activity, clonogenic potential, blast cell proliferation and cytokine release of MDS bone marrow patients.

To evaluate the clinical usefulness of IL-2 in myelodysplastic syndromes (MDS) the in vitro effects of interleukin-2 (IL-2) on blast cell proliferation, clonogenic activity, cytokine release and cell mediated cytotoxicity were examined in 49 MDS patients. Morphological analyses of bone marrow (BM) cytospin preparations showed a significant decrease in the number of blast cells in MDS after incubation with IL-2. Incubation of bone marrow mononuclear cells (BMMNCs) with IL-2 induced a significant increase in the number of CFU-GM in comparison with untreated controls. gamma-IFN and GM-CSF, but not alpha-TNF were found to be released in significant amounts by the BMMNCs cultured with IL-2. No significant differences in the surface phenotypes of fresh lymphocytes were observed between the normal and MDS subjects. After incubation with IL-2, we observed a significant increase in the number of CD3-/CD56+ cells in both normal and MDS subjects. Peripheral blood (PB) and BM NK activity against K562 was significantly greater in MDS after stimulation with IL-2. These data suggest the clinical usefulness of IL-2 in a large subgroup of patients as it may reduce the percentage of blasts and increase clonogenic capacity and cell-mediated cytotoxicity.

[Raised levels of circulating endothelial cells in systemic sclerosis]. / Cellule endoteliali circolanti quale marker diretto di danno endoteliale in corso di sclerosi sistemica.

OBJECTIVE: Circulating endothelial cells (CECs) have been described in different conditions with vascular injury. Vascular abnormalities play a key role in the pathogenesis of Systemic Sclerosis (SSc). The aim of our study was to look for the presence of CECs in SSc patients and to evaluate their clinical significance. METHODS: We studied 52 SSc patients and 40 healthy controls (HC). Five-parameter, 3-color flow cytometry was performed with a FACScan. CECs were defined as CD45 negative, CD31 and P1H12 positive, and activated CECs as CD45 negative and P1H12, CD62, or CD106 positive. RESULTS: Total and activated CEC counts were significantly higher in SSc patients when compared with HC and positively correlated with disease activity score. We found a significant association between CECs and disease activity; as regard with organ involvement, CEC number correlate with the severity of pulmonary hypertension. CONCLUSIONS: Raised counts of CECs may represent direct evidence of active vascular disease in SSc as regard as visceral involvement, the association between CECs and pulmonary hypertension suggest a relevant role for CECs as a marker of prominent endothelial involvement.

[Endothelial progenitor cells in systemic sclerosis: their possible role in angiogenesis]. / Progenitori delle cellule endoteliali di origine midollare in corso di sclerosi sistemica: possibile ruolo nell'angiogenesi.

BACKGROUND: Recently, several studies have demonstrated the presence of circulating endothelial progenitors (CEPs) responsible for angiogenesis. Notably, these cells are able to migrate to ischemic tissues and differentiate in situ in mature endothelial cells. Aim of this study was to assess the presence of CEPs in the peripheral blood of patients with Sistemic Sclerosis (SSc) and evaluate their significance as an attempt of re-vascularization MATERIAL AND METHODS: Samples of peripheral blood from 40 healthy subjects and 56 patients with SSc were studied. Five-parameter, 3-color flow cytometry was performed with a FACScan. CEPs were defined as CD45 negative, CD34 and CD133 positive. In addition, plasma levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) were detected by commercial ELISA (R&D Systems). RESULTS: Levels of CEPs (CD133+/CD34+/CD45-) were significantly higher in patients with SSc in comparison to HC (P = 0.01). No correlation was found between CEPs and any clinical parameter of disease neither activity score. CEPs were significantly higher in the group of patients with early disease, while their number decreased in the late phases of disease. Plasma levels of VEGF, but not bFGF, were significantly higher in SSc in comparison to HC (P<0.001) but no correlation was found between VEGF concentrations and CEP number. CONCLUSIONS: The presence of CEPs in patients with SSc suggest that sclerodermic hypoxic tissues could induce the mobilization of bone-marrow derived cells in an attempt to provided new vessels, in the early phase of the disease, at least.

Interferon therapy during the plateau phase of multiple myeloma: an update of the Swedish study.

A multicentre clinical trial was carried out in order to evaluate the effect of interferon (IFN) in patients with multiple myeloma. Patients (n = 120) who had shown response to conventional intermittent melphalan-prednisone induction therapy, and achieved a plateau phase, were randomized at that point to receive either interferon alfa-2b in a dose of 5 million units (MU) three times per week or no therapy. This report presents the results of an interim analysis, performed when the patients had been followed for a median of 20 months. The duration of the plateau phase was significantly longer in the IFN arm (59 weeks), compared to the no therapy arm (26 weeks). A total of 34 deaths have occurred, 13 in the IFN arm and 21 in the no therapy arm. In spite of the high median age of the patients studied (70 years), most patients were able to tolerate a full or only slightly reduced IFN dose.

Idarubicin in the therapy of acute myeloid leukemia: final analysis in 57 previously untreated patients.

Fifty-seven previously untreated adult acute myeloid leukemia patients received idarubicin (IDA) in sequential combination with cytarabine as induction therapy; post-remission treatment included two courses of IDA and cytarabine alternating with two courses of VP-16 and cytarabine. As late intensification, patients received either high-dose cytarabine or, in 10 cases, autologous bone marrow transplantation. Complete remission (CR) was achieved in 48 patients (84.2%), 41 after one induction course and seven after two courses. Median length of disease-free survival (DFS) was 26 months. Univariate analysis did not identify any of the investigated variables as having prognostic significance in predicting DFS. On the other hand, patients achieving CR after one induction course had a better DFS than those requiring two courses. Furthermore, the analysis of DFS slightly favors autologous bone marrow transplantation. In conclusion, the antileukemic activity of the present IDA protocol is testified by the high CR rate and by the possibility of minimizing the role of prognostic factors. The better outcome of patients achieving CR after one induction course further supports the opinion that the intensity of the induction treatment, offered by an agent as potent as IDA, might significantly influence DFS.

Efficacy of N-acetylcysteine and all-trans retinoic acid in restoring in vitro effective hemopoiesis in myelodysplastic syndromes.

We evaluated the in vitro effect on clonogenic potential (CFU-GM) and apoptosis in myelodysplastic syndromes (MDS) progenitors of an anti-oxidant (N-acetylcysteine, NAC) and/or a differentiating (all-trans retinoic acid, ATRA) agent. NAC significantly reduced apoptosis, both NAC and ATRA induced an increase in CFU-GM, but NAC seemed to be particularly effective in the high risk (HR) MDS. NAC + ATRA conferred a significant advantage in terms of CFU-GM with respect to NAC and ATRA alone. Tumor Necrosis Factor-alpha (TNF-alpha) levels decreased after incubation with NAC in the MDS samples. This study shows that ineffective hemopoiesis in MDS could benefit from both NAC and ATRA, suggesting that anti-oxidant treatment may play a role in guaranteeing MDS cell survival, predisposing them towards differentiation.

Low plasma stem cell factor levels correlate with in vitro leukemic growth in myelodysplastic syndromes.

We evaluated the effect of SCF on myeloid differentiation by correlating clonogenic potential (as CFU-GM), bone marrow (BM) plasma SCF levels and CD34/c-kit expression in 57 MDS samples. There was a significant correlation between low SCF levels and 'leukemic' in vitro growth, the number of clusters and the colony/cluster ratio. No correlation was found between BM plasma SCF levels, the pattern of growth and CD34+ c-kit+ expression. These data seem to exclude any direct effect of SCF on leukemogenesis, but suggest that low plasma SCF levels may be at least partially responsible for leukemic growth in MDS.

Non-transferrin-bound iron in myelodysplastic syndromes: a marker of ineffective erythropoiesis?

INTRODUCTION: Iron overload is usually observed in patients (even untransfused) with myelodysplastic syndromes (MDS), and contributes towards the generation of low molecular weight iron complexes or non-transferrin-bound iron (NTBI), which in turn favors oxidative DNA damage and consequent apoptosis. MATERIALS AND METHODS: Levels of NTBI and lipid peroxidation were evaluated by means of free serum malondyaldehyde (MDA) in untransfused MDS patients and we tried to correlate them with ineffective erythropoiesis, apoptosis and the pattern of in vitro growth. RESULTS: NTBI levels were found to be significantly higher in low-risk than in high-risk MDS patients, as well as in patients with a lower myeloid/erythroid ratio. MDA was found to be uniformly higher in the MDS patients as a whole than in normal controls. The bone marrow progenitor cells in the MDS patients with high NTBI levels showed a higher degree of apoptosis, but this difference was not statistically significant. Patients with a leukemic growth pattern had lower NTBI levels than those with a non-leukemic pattern. CONCLUSION: These data suggest that NTBI is related to the degree of ineffective erythropoiesis and that it contributes towards inducing apoptosis in MDS bone marrow precursors. The presence of leukemic growth is associated with low NTBI levels, probably due to increased iron consumption by blast cells.