Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endothelial activation and subclinical microvascular occlusions are an ongoing process during steady-state sickle cell disease, leading to interleukin production and an acute-phase response. Alpha-2-macroglobulin (alpha2M) is an acute-phase protein mainly regulated by interleukin-6 (IL-6). On the other hand, alpha2M acts as a carrier protein for IL-6 during inflammatory stress. The purpose of this study is to further assess the interactions between IL-6 and alpha2M as potent modulators of inflammatory reactions during the steady state of sickle cell disease. We measured alpha2M and IL-6 levels in 21 patients (12 male, 9 female; age range 12-44 years) in the steady state of sickle cell disease. Four patients had homozygous sickle cell anaemia and 17 had double heterozygous sickle cell/beta-thalassaemia. Diagnostic quantification of alpha2M was performed by rate nephelometry. Commercial enzyme immunoassay test kits were used for the quantitative measurement of IL-6. The alpha2M and IL-6 levels were compared to the values obtained from healthy volunteers. Mean values (+/- SD) of alpha2M and IL-6 were found to be significantly increased (p < 0.0005) in the patients (alpha2M: 337.2 +/- 104 mg/dl; IL-6: 4 +/- 2.1 pg/ml) compared to the healthy controls (alpha2M: 204.2 +/- 45.8 mg/dl; IL-6: 1.15 +/- 2.5 pg/ml). IL-6 values were positively correlated with alpha2M levels (r = 0.61, p < 0.01). We observed increased alpha2M and IL-6 levels in steady-state sickle cell disease and a positive correlation between these two inflammatory mediators. We suggest that alpha2M is a potent modulator of the inflammatory reaction and tissue repair mechanism during steady-state microvascular occlusions. Elucidating the role of alpha2M in sickle cell disease could lead to the development of novel strategies and therapies for preventing the harmful systemic or local effects of excess cytokine production.
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PMID:Alpha-2-macroglobulin and interleukin-6 levels in steady-state sickle cell disease patients. 1127 5

Several immunological defects can be found in patients with beta-thalassaemia, among which the impairment of neurophil and macrophage phagocytic and killing functions and the production of some cytokines are the most important. It is known that interleukin-6 (IL-6) and interleukin-8 (IL-8) are important components of the pro-inflammatory response. The plasma levels of these cytokines may be relevant in the pathophysiology of beta-thalassaemia. To assess this hypothesis, the plasma IL-6 and IL-8 concentrations in patients with beta-thalassaemia, were investigated. Fourteen patients with thalassaemia major were studied by evaluating body iron status, iron supply for erythropoiesis, and plasma IL-6 and IL-8 levels, together with 12 age-matched healthy controls. The plasma levels of IL-6 and IL-8 were determined by enzyme-linked immunosorbent assay (ELISA). Patients with beta-thalassaemia were found to have higher IL-8 concentrations than normal controls (p < 0.001) and plasma IL-6 concentrations increased significantly in the beta-thalassaemic patients compared with control subjects (p = 0.01). Serum ferritin levels of beta-thalassaemic patients were significantly higher than those of control groups (p < 0.05). IL-8 levels correlated with ferritin levels (r = 0.694; p < 0.05) and the total number of transfusions (r = 0.64; p < 0.05). Plasma IL-6 levels in beta-thalassaemic patients did not correlate with any clinical, haematological or biochemical parameters. It was also found that plasma IL-8 levels in the patients who had blood transfusions over 100 times were significantly higher than those of under 100 times (p < 0.05), whereas there was no statistical difference for IL-6. Markedly increased plasma IL-6 and IL-8 levels were documented in patients with beta-thalassaemia. Increased production of IL-6 and IL-8 might have contributed to abnormalities in iron metabolism and it is probably due to overstimulation of macrophages. Before a clinical value can be ascribed to these changes in plasma cytokine levels in beta-thalassaemia, the follow-up samples of larger series of patients with 8-thalassaemia should be evaluated.
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PMID:Increased plasma levels of interleukin-6 and interleukin-8 in beta-thalassaemia major. 1185 86

Iron is a crucial element for many central metabolic pathways of the body. Lack of iron leads to growth arrest and anaemia while increased accumulation of this metal, as it occurs in highly frequent inherited diseases such as hereditary haemochromatosis and thalassaemia, is associated with toxic radical formation and progressive tissue damage. As shown by several groups, iron also modulates immune effector mechanisms, such as cytokine activities (IFN-gamma effector pathways towards macrophages), nitric oxide (NO) formation or immune cell proliferation, and thus host immune surveillance. Therefore, gaining control over iron homeostasis is one of the central battlefields in deciding the fate of an infection with intracellular pathogens or a malignant disease. Thus, the reticulo-endothelial system has evoked sophisticated strategies to control iron metabolism in general and especially the handling of the metal within immune cells.
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PMID:Iron and immunity: a double-edged sword. 1188 35

Human pythiosis is an emerging disease in the tropical, subtropical and temperate regions of the world. It is caused by the straminipilan, fungus-like, aquatic organism Pythium insidiosum. Pythiosis occurs in localized as well as systemic or vascular forms. Most patients with arterial pythiosis usually have underlying hematologic disorders such as thalassemia and aplastic anemia/paroxysmal nocturnal hemoglobinuria (PNH) syndrome. Vascular pythiosis is characterized by ascending blood vessel infections and thrombosis of the major arteries especially those of the lower extremities. When the infection reaches a main artery, the patient usually dies within weeks. Since this pathogen is resistant to most antifungal drugs, immunotherapy was recently used to cure humans and animals with the disease. A modified P. insidiosum-antigen (PIA) formulation had already saved a young boy with life-threatening arterial pythiosis. Here, we report the therapeutic benefits of the PIA in eight patients with vascular pythiosis. Six of them had thalassemia and the other two had PNH. All of the patients had arterial occlusion of the lower limbs. P. insidiosum was isolated and identified by culture and by histopathology. All patients had evidence of active infection when immunotherapy began. After two injections of 100-200 microl of PIA (2.0mg/ml), at a 14-day interval, four patients (50%) had dramatic and complete remission. Two patients showed partial responses to PIA while the other two did not. Clinical responses correlated with the immunological reactions at the site of injection, clearance of the arteries and cytokine production. The latter included the shifting in serum levels of IL4 and IL5 to IL2 suggesting a switching from a T helper 2 (Th2) to a T helper 1 (Th1) subset. Our findings provide further evidence that immunotherapy using PIA is a safe and effective method to treat pythiosis in humans.
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PMID:Efficacy of immunotherapy using antigens of Pythium insidiosum in the treatment of vascular pythiosis in humans. 1531 40

Cell-based therapies have potential widespread applications in clinical medicine, and methods for controlling the fate of transplanted cells are needed. We have previously described a means for directing the growth of genetically modified cells in vivo using a derivative of the thrombopoietin receptor, mpl, that is reversibly activated by a drug called a chemical inducer of dimerization (CID). Since Jak2 participates in signaling from a number of different cytokine receptors (including mpl), we tested whether direct activation of the JH1 domain of Jak2 would broaden the repertoire of hematopoietic lineages responsive to the CID. While the engineered Jak2 induced a significant rise in genetically modified red cells, as we have observed previously with mpl, it lacked mpl's ability to expand genetically modified platelets and failed to expand genetically modified granulocytes, B cells, or T cells. These findings identify a signaling molecule other than mpl that can function as a cell growth switch in vivo and demonstrate that signaling molecules used for in vivo selection need not be confined to receptors. The erythroid-restricted growth response suggests that CID-activated Jak2 may be well suited to gene therapy applications in sickle cell anemia or beta-thalassemia.
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PMID:In vivo selection of genetically modified erythroid cells using a jak2-based cell growth switch. 1533 46

Accelerated apoptosis of erythroid progenitors is a characteristic of beta-thalassemia which presents a significant barrier to definitive therapeutic approaches utilizing induction of endogenous fetal globin gene expression. gamma-globin gene expression may not be inducible in, or may not be able to rescue, erythroid cells in which programmed cell death is initiated early in erythroblast development. In this report, short-chain fatty acid derivatives (SCFADs) which induce fetal globin gene expression were tested for their ability to promote proliferation and survival of erythroid progenitors cultured from beta-thalassemic subjects, and of cytokine-dependent erythroid cell lines. Certain SCFADs promoted thalassemic Bfu-e growth and cytokine-independent growth and survival of erythroid cell lines. A 40-80% increase in erythroid Bfu-e colony number was observed in cultures established with any of five mitogenic SCFADs, compared to control or butyrate-treated cultures from the same subjects. Immunoblot analysis demonstrated that these same SCFADs also regulated the expression of specific protein inhibitors of apoptosis. Anti-apoptotic ratios of the proteins Bcl-xL/Bcl-xS in thalassemic Bfu-e were increased by 30-120% with exposure to the SCFDs, compared to the ratios in the same cells cultured under control conditions. Similar anti-apoptotic increases in Mcl-1L/Mcl-1S ratios were induced by the SCFADs. These findings suggest that select fetal globin-inducing SCFADs which enhance proliferation of beta-thalassemia progenitors may enhance survival of these progenitors by altering levels of Bcl-family protein members. This combination of effects should enhance erythroid cell survival in the beta-thalassemia syndromes, allowing fetal globin gene expression to be induced more effectively than currently available, growth-suppressing, fetal globin-inducing agents, such as the butyrates or chemotherapeutic agents.
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PMID:Enhancement of growth and survival and alterations in Bcl-family proteins in beta-thalassemic erythroid progenitors by novel short-chain fatty acid derivatives. 1609 82

Heme-regulated eIF2alpha kinase (HRI) plays an essential protective role in anemias of iron deficiency, erythroid protoporphyria, and beta-thalassemia. In this study, we report that HRI protein is present in murine macrophages, albeit at a lower level than in erythroid precursors. Hri-/- mice exhibited impaired macrophage maturation and a weaker antiinflammatory response with reduced cytokine production upon LPS challenge. The level of production of hepcidin, an important player in the pathogenesis of the anemia of inflammation, was significantly decreased in Hri-/- mice, accompanied by decreased splenic macrophage iron content and increased serum iron content. Hepcidin expression was also significantly lower, with a concomitant increase in serum iron in Hri-/- mice upon LPS treatment. We also demonstrated an impairment of erythrophagocytosis by Hri-/- macrophages both in vitro and in vivo under chronic hemolytic anemia, providing evidence for the role of HRI in recycling iron from senescent red blood cells. This work demonstrates that HRI deficiency attenuates hepcidin expression and iron homeostasis in mice, indicating a potential role for HRI in the anemia of inflammation.
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PMID:The function of heme-regulated eIF2alpha kinase in murine iron homeostasis and macrophage maturation. 1793 63

In order to study the role of the cytokine interleukin-3 (IL-3) and its signaling pathways in erythropoiesis of beta-thalassemia/HbE erythroid progenitor cells, CD34 positive cells were isolated from peripheral blood of patients and healthy subjects. After culturing the cells in the presence or absence of IL-3, cell viability was measured by trypan blue staining and apoptotic cells were analyzed by flow cytometry. After 7 days of culture the highest percent erythroid progenitor cell viability was obtained with cells from healthy subjects, while the lowest percentage was found in those from splenectomized beta-thalassemia/HbE. Viability of beta-thalassemia/HbE erythroid progenitor cells in the presence of IL-3 was higher than that of nonsupplemented cells. In addition, specific inhibitors of protein kinase C (Ro-318220), phospholipase C (U-73122) and Janus kinase 2 (AG-490) were used to investigate the involvement of signaling pathways in erythropoiesis. Percent apoptosis of erythroid progenitor cells from splenectomized beta-thalassemia/HbE subjects treated with RO-318220 was higher than those of nonsplenectomized beta-thalassemia/HbE and healthy subjects. Treatment with U-73122 resulted in enhanced percent apoptotic cells from normal and beta-thalassemia/HbE subjects. All these effects were independent of IL-3 treatment.
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PMID:Role of interleukin-3 and signaling pathways on beta-thalassemia/HbE erythroid progenitor cell in culture. 1804 9

The treatment of thalassemia is still essentially based on continuous transfusion supporting using red cell concentrates (RCC) prepared in different ways. For patients with sickle-cell disorders, either urgent or chronic red blood cell transfusion therapy, is widely used in the management of sickle cell disease (SCD) because it reduces HbS level and generally prevents recurrent vaso-occlusive disease (VOD). Recently, the introduction of pre-storage filtration to remove leukocytes and the use of techniques for multicomponent donation have increased the types of blood components available for transfusion purposes. The clinical effects of different types of blood components in thalassaemic and sickle-cell patients have not been extensively studied so far. We evaluated the impact of the various different blood components currently available on transfusion needs, transfusion intervals and adverse reactions in order to determine which is the most advantageous for transfusion-dependent thalassaemic and sickle-cell patients followed in our centre. We believe that the optimal characteristics of the RCC are aged less than 10 days from time of collection; Hb content greater than 56 g per unit; Hct: 55-60%; volume (including additive) 300 mL+/-20%; leucodepleted to less than 200,000 leukocytes per unit; low cytokine content (achievable by pre-storage filtration carried out between two and 24 hours after the collection); lack of microaggregates (achievable by pre-storage filtration or filtration in the laboratory) and protein content less than 0.5 g per unit for patients allergic to plasma proteins (achievable with manual or automated washing). It is still recommended that the blood transfused should be as fresh as possible, compatible with the centre's product availability and the centre's organisation should be continuously adapted to this aim. We always transfuse blood within 10 days of its collection, respecting Rh and Kell system phenotypes. Pre-storage filtration is strongly recommended, both in order to prevent adverse reactions through the marked leucodepletion (less than 200,000 leukocytes per unit) and for a better standardisation of the final product, including the certainty that the product does not contain clots, an assurance that bed-side filtration cannot give. The RCC should be produced using a method causing as little as possible stress to the red cell membrane. The use of RCC with a high content of Hb (less than 56 g per unit) is strongly recommended, because our study clearly shows that this reduces the number of exposures to donors and the number of accesses to hospital, thus improving the patient's quality of life.
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PMID:Clinical effects of different types of red cell concentrates in patients with thalassemia and sickle cell disease. 1843 27

Beta-thalassaemia is one of the most common inherited anaemias, arising from a partial or complete loss of beta-globin chain synthesis. In severe cases, marked bone marrow erythroid hyperplasia, believed to result from erythropoietin (EPO)-mediated feedback from the anaemic condition is common, however, as yet, no study has investigated EPO-mediated signal transduction in thalassaemic erythroid cells. Using proerythroblasts generated from peripheral blood circulating CD34+ haematopoietic progenitor cells, the activation of the mitogen-activated protein kinase/extracellular signal-regulated kinases (MAPK/ERKs) pathway was examined under conditions of steady state growth, cytokine deprivation and post-EPO stimulation. Levels of cellular cyclic adenosine monophosphate (cAMP) and Ca2+ were determined as was the degree of erythroid expansion. A significantly higher basal level of phosphorylation of ERK1/2 was observed in beta-thalassaemia/Hb E proerythroblasts as compared to normal controls, which was coupled with significantly higher levels of both cAMP and Ca2+. Modulation of either cAMP or Ca2+ or direct inhibition of MAPK/ERK kinase (MEK) reduced basal levels of ERK1/2 phosphorylation, as well as significantly reducing the level of erythroid expansion. These results suggest that, in contrast to current models, hyper proliferation of beta-thalassaemia/Hb E proerythroblasts is an intrinsic process driven by higher basal levels of ERK1/2 phosphorylation resulting from deregulation of levels of cAMP and Ca2+.
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PMID:Increased erythropoiesis of beta-thalassaemia/Hb E proerythroblasts is mediated by high basal levels of ERK1/2 activation. 1959 42


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