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

An increasing number of diseases may be treated successfully by allogeneic bone marrow transplantation (BMT). Initially used for the treatment of immunodeficiency where a cell series or product is replaced, it has now become routine treatment for many forms of leukemia where the transplant provides the rescue after lethal marrow ablation. Recently, diseases such as thalassemia and other inherited metabolic diseases have also been treated by BMT. Formerly the problems of BMT were mainly concerned with graft versus host disease (GVHD) in HLA-matched transplants with HLA-mismatched ones not being possible as GVHD was usually fatal. Since the development of techniques for T cell removal the incidence of GVHD has greatly diminished. T cell removal has also allowed HLA haploidentical mismatched grafts to be performed successfully for immunodeficiency, but there is still a high graft rejection rate in leukemia. This also occurs to a lesser extent with HLA-matched grafts in leukemia. Furthermore, in certain forms of leukemia, particularly chronic granulocytic leukemia, the relapse rate after T cell-depleted BMT is much higher. Trials of better forms of bone marrow conditioning of the recipient are being attempted in order to prevent graft rejection and leukemia relapse. These include total lymphoid irradiation, heavier irradiation and chemotherapeutic regimens, or the use of in vivo monoclonal antibodies such as CAMPATH 1G or anti-LFA-1 (CD11a). In the future, positive selection of stem cells combined with hemopoietic growth factors may allow engraftment without graft versus host disease. This should become the method of choice for autologous transplantation for malignancy. Two monoclonal antibodies directed against the human progenitor cell antigen 1 (HPCA-1) (CD34) have been used for autologous positive stem cell selection in primates and these cells gave full hemopoietic reconstitution in the animals following lethal total body irradiation.
 ...
PMID:Recent advances in bone marrow transplantation. 256 39

Allogeneic peripheral blood stem cell (PBSC) transplant has recently been introduced for the treatment of hematological malignancies. As the data were limited mainly to adult patients, this study aimed to assess the feasibility and safety of this procedure in pediatric patients and donors. Eleven children aged 2-16 years received allogeneic PBSC transplant for acute lymphoblastic leukemia (n = 4), acute myeloid leukemia (n = 1), myelodysplastic syndrome (n = 1), severe aplastic anemia (n = 3), and thalassemia (n = 2). Nine donors were human leukocyte antigen (HLA)-identical siblings and the other two were one antigen mismatched family members. Eight donors were younger than 18 years old (10 months to 17 years). Donors were primed with granulocyte colony-stimulating factor (G-CSF) at 10-16 micrograms/kg for 4-5 days. Aphereses were performed on 1 or 2 consecutive days, and the patients received a mean of 14.4 x 10(8)/kg nucleated cells, 6.9 x 10(6)/kg CD34 cells, and 6.9 x 10(8)/kg T cells. All patients achieved neutrophil counts of > 0.5 x 10(9)/l at a median of 16 days. Nine patients achieved platelet counts of > 20 x 10(9)/l at a median of 13 days. Grade II acute graft vs. host disease (GVHD) occurred in only one patient. Chronic GVHD was not observed in the seven patients with follow-up of more than 3 months. Eight patients remained in continuous complete remission after transplant ranged from 2 to 26 months. Allogeneic PBSC transplant appears safe in pediatric patients and donors, and it seems not to be associated with increase of acute GVHD or chronic GVHD.
 ...
PMID:Allogeneic peripheral blood stem cell transplant in children. 943 21

A fetus homozygous for alpha-thalassemia-1 was given haploidentical paternal CD34 cells at 13, 19 and 24 weeks' gestation and supported through pregnancy by blood transfusion. The fetal hematocrit ranged between 27 and 47% and between one half and three quarters of this hemoglobin was of recipient (Bart's) type. Intrauterine growth proceeded normally and no significant fetal hydrops was detected. Tests for donor HLA antigens, and alpha-globin DNA, were negative on fetal blood samples drawn before birth. A positive signal for alpha-globin DNA was obtained from cord blood and from marrow obtained at 3 months of age, suggesting that some donor stem cells had persisted in the recipient. The infant's blood mononuclear cells showed little proliferative and no cytotoxic response to the donor while responses to a third party were present. Additional paternal CD34 cells given at 3 months age did not reduce transfusion dependency in the subsequent 6 months. Our results show that repeated transfusions can support an alpha-thalassemia-1 fetus through pregnancy, in this instance without significant birth defects or apparent hypoxic tissue injury. The donor stem cells did not have a survival advantage compared with endogenous stem cells, but appeared to survive in the recipient as judged by the persistence of an alpha-globin DNA signal. In vitro studies of alloreactivity suggest tolerization of the host to the donor's MHC disparity. Future efforts will focus on exploiting this tolerance to improve the level of donor chimerism.
 ...
PMID:Microchimerism and tolerance following intrauterine transplantation and transfusion for alpha-thalassemia-1. 960 9

Lentiviral vectors efficiently transduce human CD34(+) cells that mediate long-term engraftment of nonobese diabetic/severe combined immunodeficient mice. However, hematopoiesis in these animals is abnormal. Typically, 95% of the human cells in peripheral blood are B lymphocytes. To determine whether lentiviral vectors efficiently transduce stem cells that maintain normal hematopoiesis in vivo, we isolated Sca-1(+)c-Kit(+)Lin(-) bone marrow cells from mice without 5-fluorouracil treatment, and transduced these cells in the absence of cytokine stimulation with a novel lentiviral vector containing a GFP (green flourescent protein) reporter gene. These cells were transplanted into lethally irradiated C57Bl/6 mice. In fully reconstituted animals, GFP expression was observed in 8.0% of peripheral blood mononuclear cells for 20 weeks posttransplantation. Lineage analysis demonstrated that a similar percentage (approximately 8.0%) of GFP-positive cells was detected in peripheral blood B cells, T cells, granulocytes and monocytes, bone marrow erythroid precursor cells, splenic B cells, and thymic T cells. In secondary transplant recipients, up to 20% of some lineages expressed GFP. Our results suggest that quiescent, hematopoietic stem cells are efficiently transduced by lentiviral vectors without impairing self-renewal and normal lineage specification in vivo. Efficient gene delivery into murine stem cells with lentiviral vectors will allow direct tests of genetic therapies in mouse models of hematopoietic diseases such as sickle cell anemia and thalassemia, in which corrected cells may have a selective survival advantage.
 ...
PMID:Lentiviral vector transduction of hematopoietic stem cells that mediate long-term reconstitution of lethally irradiated mice. 1100 19

The design and evaluation of therapies for the sickle cell and beta-thalassemia syndromes rely on our understanding of hemoglobin accumulation during human erythropoiesis. Here we report direct measurements of hemoglobin composition and messenger RNA (mRNA) levels in cultured CD34(+) cells and correlate those measurements with studies of freshly obtained bone marrow samples. Hemoglobin levels in differentiating cells were also compared with morphologic, immunophenotypic, and cell cycle assessments. A population of large preproerythroblasts was first identified within 24 hours and became the dominant population by day 5. The transition from proerythroblast to basophilic normoblast occurred later, from days 7 to 9, and correlated with a peak of 74.1% +/- 3.9% of the cells in the S phase of cell cycle. Orthochromatic normoblasts were the dominant and final cell type by day 13. High-performance liquid chromatography-based quantitation of fetal (HbF) and adult (HbA) hemoglobin and real-time polymerase chain reaction globin mRNA quantitation demonstrated a coordinate rise in the accumulation of both proteins and mRNA among these developmentally staged populations. Quantitative analyses on freshly sorted bone marrow populations demonstrated a similar rising pattern with beta-globin and HbA as the dominant species at both early and late stages of differentiation. We found no evidence for HbF dominant populations or switching during differentiation in adult cells. Instead, rapid increases in both HbF (heterocellular) and HbA (pancellular) content were observed, which coincided with the apex in cell cycling and the proerythroblast-basophilic normoblast transition. Based on these measurements, we conclude that HbF and HbA content are regulated with the rate of proliferation during adult erythropoiesis.
 ...
PMID:Fetal and adult hemoglobin production during adult erythropoiesis: coordinate expression correlates with cell proliferation. 1192 93

A drug that specifically inhibits erythropoiesis would be clinically useful. The erythropoietin (Epo) mutant Epo (R103A) could potentially be used for this purpose. Epo (R103A) has a single amino acid substitution of alanine for arginine at position 103. Because of this mutation, Epo (R103A) is only able to bind to one of the 2 subunits of the erythropoietin receptor (EpoR) homodimer and is thus a competitive inhibitor of Epo activity. To produce large quantities of Epo (R103A) to test in animal models of thalassemia and sickle cell disease, we expressed and purified recombinant Epo (R103A) from the yeast Pichia pastoris. Using this method milligram quantities of highly purified Epo (R103A) are obtained. The yeast-expressed Epo (R103A) is properly processed and glycosylated and specifically inhibits Epo-dependent cell growth and (125)I-Epo binding. Epo (R103A) does not, however, directly induce apoptosis in 32D cells expressing EpoR. Epo (R103A) inhibits erythropoiesis of human CD34(+) hematopoietic cells and completely blocks erythroid burst-forming unit formation in normal human bone marrow colony assays. Yeast-expressed Epo (R103A) is a specific inhibitor of primary erythropoiesis suitable for testing in animal models.
 ...
PMID:Purification and characterization of the yeast-expressed erythropoietin mutant Epo (R103A), a specific inhibitor of human primary hematopoietic cell erythropoiesis. 1203 68

Allogeneic hematopoietic stem cell transplantation is the only curative therapy for severe beta-thalassemia. This time, the experience of utilizing HLA 2-loci mismatched sibling cord blood transplantation (CBT) in a child with severe beta-thalassemia was firstly reported in our country. A 3-year-male patient had been diagnosed with severe beta-thalassemia at 6 months of age (HbF 86.6%, HbA1 1.7%, HbA2 1.7%, beta globin gene mutation CD17, A-->T/IVS-II-654, C-->T). The patient's HLA typing was A 24,11, B 58,35 and DRB1 03,15. During a subsequent maternal pregnancy. The prenatal diagnosis for thalassemia and prenatal HLA typing analysis were performed on 18 weeks of pregnancy. The results indicated that the male fetus was a heterozygote (beta globin gene mutation N/CD17, A-->T), HLA typing was A 24,11, B 58,51 and DRB1 03,12. 120 ml cord blood was collected at time of delivery, the total numbers of nucleated cells, CFU-GM and CD34(+) cells were 1.830 x 10(9), 16.653 x 10(5) and 3.11 x 10(6), respectively. A new conditioning regimen including: hypertransfusion, continuous i.v. desferrioxamine, busulfan, cyclophosphamide, antithymocyte globulin plus hydroxyurea and fludarabine. GVHD prophylaxis comprised cyclosporin A and mycophenolate mofetil. The viability of cord blood at the time infusion was 92%, The total numbers of nucleated cells, CFU-GM and CD34(+) cells in the transfused cord blood were 12.06 x 10(7)/kg, 1.098 x 10(5)/kg, and 2.04 x 10(6)/kg, respectively. Results showed that the patient's clinical course after cord blood transplantation was unremarkable. Acute GVHD grade I developed on day 15, methylprednisolone 2 mg/kg was given to cure. Neutrophil engraftment (ANC > 0.5 x 10(9)/L) on day 17, platelet engraftment (> 50 x 10(9)/L) on day 50. The patients became independent from red blood cell transfusion since day 80 (when his hemoglobin level kept > 12.5 g/L). His beta globin gene mutation and HLA typing were all the same as the donor's analyzed on day 60 and 200. There was also a switch in blood group from A pre-transplant to O post-transplant. It is concluded that the new conditioning and GVHD prophylaxis regimens allow a successful engraftment in this case. This observation may contribute in developing UCBT as an alternative when matched sibling donors are not available.
 ...
PMID:[Two HLA-loci mismatched sibling cord blood transplantation in a severe beta-thalassemia patient]. 1266 97

We report here the first successful transplant of unrelated umbilical cord blood (UCB) for a child with beta-thalassemia major in Taiwan. A total of 2.48 x 10(5)/kg CD34 cells were infused into a 3(1/2)-year-old girl following conditioning with a pre-transplant cytoreductive/immunosuppressive regimen of busulfan and cyclophosphamide. The absolute neutrophil count first exceeded 0.5 x 10(9)/l on day 17, and the patient became red cell- and platelet-independent on days 34 and 49, respectively. Engraftment of donor hematopoietic populations was documented by cytogenetic analysis, hemoglobin electrophoresis, Southern blot analysis for thalassemia markers, and molecular analysis of short tandem repeats sequences. The patient was ex-thalassemic for more than 15 months post transplant. From this experience, it is postulated that UCB will indeed allow us to expand the available donor pool for recipients with an HLA DRB1 mismatched at one locus and reduce the risk of graft-versus-host disease.
 ...
PMID:Successful unrelated cord blood transplantation in a child with beta-thalassemia major. 1584 Jul 63

To augment graft cell dose, we evaluated the safety of the combined transplantation of two partially HLA-matched umbilical cord blood (UCB) units. Five patients with transfusion-dependent thalassemia, median age 11.1 years (range 10-13.1), received 2 UCB units after myeloablative conditioning. Cord blood units were a 4/6-HLA-match or better with the recipient, and contained a minimum combined pre-freeze CD34 cell dose of 3.0 x 10(5)/kg. All patients engrafted at a median of 15 days (range 12-19). Four patients with durable trilineage engraftment showed acute grade I-III GVHD; none developed extensive chronic GVHD until the date of last contact. The median times to red blood cell transfusion independence and platelet engraftment were 32 and 49 days after transplant, respectively. With a median follow-up of 18.5 months (range 11-32), four patients transplanted with UCB from two different partially HLA-matched donors were transfusion-independent. Therefore, transfusion of two partially HLA-matched UCB units is safe, and may overcome the cell-dose barrier that limits the use of UCB in long-term recipients of multiple transfusions for thalassemia.
 ...
PMID:Transplantation of unrelated donor umbilical cord blood utilizing double-unit grafts for five teenagers with transfusion-dependent thalassemia. 1757 10

Bone marrow transplantation is the only therapeutic option that can potentially eliminate thalassemic disease. Early results indicated that children in Class 3 Lucarelli had a much worse outcome because of high nonrejection mortality and high rejection rate. In the present study, reduced intensity stem cell transplantation (RIT) was performed in eight Class 3 Lucarelli patients conditioned by busulfan, fludarabine, and antilymphpcute globulin. One of the eight patients additionally received thiotepa, and total lymphoid irradiation (TLI), while one only received TLI. All patients received hydroxyurea 20 mg/kg/day daily >/=3 months before RIT. Peripheral blood stem cell (PBSCs) were given to a target number of CD34(+) cells more than 5 x 10(6) cells/kg of recipient weight. Seven patients received T cell nondepleted PBSCs from matched siblings while one patient received purified CD34(+) cells from two HLA antigen mismatched maternal PBSCs. The graft-versus-host disease (GvHD) prophylaxis included cyclosporine or tacrolimus and mycophenolate mofetil. Initially, an engraftment of donor cells was observed in all eight patients, but subsequently only six of eight patients had stable full donor engraftment. There were no deaths or Grade 3-4 acute GvHD in our patients. The present study lends support that the regimens described here produced minimal toxicity and resulted in stable full donor engraftment in the majority of the severe Class 3 Lucarelli thalassemia patients.
 ...
PMID:Reduced intensity stem cell transplantation for treatment of class 3 Lucarelli severe thalassemia patients. 1767 72


1 2 3 4 5 6 7 Next >>