PubMed Health⌕ Search

Biomedical subjects

E C Gordon-Smith

Publications and source records attributed to E C Gordon-Smith.

At least 73 records · Page 4Linked to original sources
PubMed1996

Campath-1G in vivo confers a low incidence of graft-versus-host disease associated with a high incidence of mixed chimaerism after bone marrow transplantation for severe aplastic anaemia using HLA-identical sibling donors.

We have evaluated the effect of in vivo Campath-1G on engraftment and GVHD in 23 patients with severe aplastic anaemia transplanted from HLA-identical sibling donors. In 14 patients Campath 1g was given pre-transplant for up to 9 days in an attempt to overcome graft rejection (group 1). In nine patients Campath-1G was given pre-transplant, but also continued post-transplant until day +5 to reduce GVHD (group 2). There were three patients with late graft failure in group I following initial neutrophil engraftment, and four cases of grade II+ GVHD. In group II, two patients had early graft failure (no take), and there were no cases of acute GVHD out of seven evaluable patients. One patient in group I developed chronic GVHD of the liver, and two patients (one in each group) had transient localised chronic GVHD. PCR of short tandem repeats was used to evaluate chimaeric status in 13 patients. Of 11 patients with initial neutrophil engraftment, only one had 100% donor haemopoiesis at all times. The remaining patients had either transient mixed chimaerism or persistence of recipient (< 20%) cells. We conclude that in vivo Campath-1G is associated with a high incidence of mixed chimaerism which tips the balance away from GVHD but towards graft rejection.

Adolescent↗
PubMed1996

Fatal autoimmune pancytopenia following bone marrow transplantation for aplastic anaemia.

We report a case of autoimmune pancytopenia 10 months after allogeneic bone marrow transplantation (BMT) for severe aplastic anaemia (SAA). The autoimmune haemolytic anaemia (AIHA) and immune thrombocytopenic purpura (ITP) were refractory to conventional immunosuppressive therapy which included steroids, azathioprine, vincristine and intravenous immunoglobulin. Splenectomy led to a recovery of the thrombocytopenia but the haemolysis continued despite further immunosuppressive therapy. Four months after the onset of haemolysis granulocyte-specific antibodies were detected. The patient subsequently received total lymph node irradiation (TLI) with a peripheral blood stem cell transplant (PBSCT) from his original donor, but died 9 days later from cerebral aspergillosis. The severe nature of autoimmune cytopenias and their lack of response to conventional treatment following allogeneic BMT is discussed further.

Adult↗
PubMed1995

Bone marrow transplantation for Fanconi anemia.

Fanconi anemia is a genetic disorder associated with diverse congenital abnormalities, progressive bone marrow failure, and increased risk of leukemia and other cancers. Affected persons often die before 30 years of age. Bone marrow transplantation is an effective treatment, but there are few data regarding factors associated with transplant outcome. We analyzed outcomes of HLA-identical sibling (N = 151) or alternative related or unrelated donor (N = 48) bone marrow transplants for Fanconi anemia performed between 1978 and 1994 and reported to the International Bone Marrow Transplant Registry. Fanconi anemia was documented by cytogenetic studies in all cases. Patient, disease, and treatment factors associated with survival were determined using Cox proportional hazards regression. Two-year probabilities (95% confidence interval) of survival were 66% (58% to 73%) after HLA-identical siblings transplants and 29% (18% to 43%) after alternative donor transplants. Younger patient age (P .0001), higher pretransplant platelet counts (P = .04), use of antithymocyte globulin (P = .005), and use of low-dose (15 to 25 mg/kg) cyclophosphamide plus limited field irradiation (P = .009) for pretransplant conditioning and cyclosporine for graft-versus-host disease prophylaxis (P = .002) were associated with increased survival. Bone marrow transplants are effective therapy for Fanconi anemia. The adverse impact of increasing age and lower pretransplant platelet count on transplant outcome favors earlier intervention, especially when there is an HLA-identical sibling donor.

Adolescent↗
PubMed1995

Rapid progression of fibrosing alveolitis and thyrotoxicosis after antithymocyte globulin therapy for aplastic anemia.

Antithymocyte globulin (ATG) therapy is an established form of treatment for aplastic anaemia and has also been used as prophylaxis against graft rejection of bone marrow and renal allografts. Administration of ATG preparations has been associated with many mild clinical reactions, as have other forms of immunomodulatory therapy. However, serious adverse effects appear to be rare. We report a case of rapidly progressive fibrosing alveolitis and thyrotoxicosis in relation to ATG therapy, highlighting its potential toxicity and emphasising that its administration should be undertaken by experienced physicians in specialised centres.

Anemia, Aplastic↗
PubMed1995

Treatment of aplastic anaemia with antilymphocyte globulin and cyclosporin.

Improved survival of patients with aplastic anaemia (AA) has been reported over the last 20 years with immunosuppressive (IS) therapy using antilymphocyte globulin (ALG), and more recently cyclosporin (CSA). The antibody specificities of ALG have now been more clearly defined and are not only T cell directed but also include activities against B cells, NK cells and monocytes. Consequently, the effectiveness of ALG in AA may involve several different mechanisms, and may also help to explain the delayed response that occurs in AA. CSA increases the response rate to ALG in the first 3-6 months, but does not result in improved survival compared with ALG alone. Better supportive care has undoubtedly contributed to the improved survival of patients with time. Almost half the patients who do not respond to a first course of ALG can achieve a later response with a second course of ALG. Relapse occurs in 30% of patients, but up to 50% will respond again with a second course of ALG. Evaluation of the expression of (1) phosphatidylinositol-glycan (PIG)-anchored proteins on haemopoietic cells and (2) gamma-IFN in bone marrow mononuclear cells, may help to predict which patients are more likely to respond to IS therapy. Long term follow up of patients is required to assess the predictive value of X-inactivation DNA studies and PIG-protein expression for later clonal evolution.

Anemia, Aplastic↗
PubMed1995

A phase I/II trial of recombinant human interleukin-6 in patients with aplastic anaemia.

In a phase I/II study, 11 patients with marrow failure (10 with acquired aplastic anaemia and one with pancytopenic Fanconi anaemia) were treated with recombinant human interleukin-6 (rhIL-6) to assess the safety and tolerability of rhIL-6 and its effects on peripheral blood counts, bleeding complications and transfusion requirements. All patients with acquired aplastic anaemia were refractory to immunosuppressive treatment or had relapsed after immunosuppressive therapy and were not bone marrow transplantation candidates. Recombinant hIL-6 was to be given as a once-daily subcutaneous injection for 28 d at doses ranging from 0.5 to 5.0 micrograms/kg. After an observation period of 2 weeks, five patients received a second treatment course of 28 d. Only one patient had a sustained increase in platelet count from 18,000 to 72,000/microliters. Bleeding occurred in four patients and caused premature discontinuation of rhIL-6 therapy in three patients. A deterioration of pre-existing anaemia was observed in nine patients. No significant changes of leucocyte counts were observed during the first cycle. During the second cycle the peripheral blood monocyte counts decreased significantly. No significant changes in bone marrow cellularity were observed. Recombinant hIL-6 induced a dose-dependent increase in acute-phase reactants in all patients. Other adverse events included fever, headache, arthralgia, tachycardia and hypertension. In conclusion, rhIL-6 given alone at low doses does not increase platelet counts in the majority of patients with aplastic anaemia and can precipitate a sudden worsening of pre-existing anaemia and thrombocytopenia. This study was discontinued prematurely on account of the toxicity of rhIL-6 seen in patients with aplastic anaemia.

Acute-Phase Reaction↗
PubMed1995

The effect of human flt-3 ligand on committed progenitor cell production from normal, aplastic anaemia and Diamond-Blackfan anaemia bone marrow.

We investigated the effect of the human ligand for flt-3 (FL) on the committed progenitor colony formation of normal bone marrow (BM) (n = 9) and BM from four aplastic anaemia (AA) and three Diamond-Blackfan anaemia (DBA) patients. Methylcellulose committed progenitor cell assays were carried out using FL alone and in combinations with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) and c-kit ligand (KL). FL alone had a limited, though significant, effect on the production of granulocyte-macrophage colony-forming unit (CFU-GM) colonies from normal BM and showed an additive effect with IL-3 and GM-CSF separately, but not in combination. FL did not increase the stimulation of KL and did not have an effect on the production of erythroid progenitor colonies. FL had no effect on the AA and DBA BMs studied.

Adult↗
PubMed1995

Haemopoietic growth factor production by normal and aplastic anaemia stroma in long-term bone marrow culture.

Defective marrow stroma, or microenvironment, have been proposed as one of several mechanisms to account for bone marrow failure in aplastic anaemia (AA). This could involve defects in positive- or negative-acting haemopoietic regulator expression by AA stroma, or alteration of normal stroma-stem cell interactions. We have used a sensitive bioassay to investigate production of granulocyte-colony stimulating factor (G-CSF), granulocyte-macrophage-colony stimulating factor (GM-CSF), interleukin (IL)-3, IL-6 and stem cell growth factor (SCF), by normal and AA stroma in long-term bone marrow culture (LTBMC). LTBMC were grown to confluence, irradiated and harvested to yield a single cell suspension. These cells were cocultured with normal target bone marrow mononuclear cells (BMMC), or CD34+ cells, in clonogenic assays, in the absence of exogenous cytokines. Cytokines responsible for the colony-stimulating activity (CSA) and burst-promoting activity (BPA) produced by stromal cells were identified by neutralizing antibodies to specific cytokines. All normal stroma populations produced G-CSF and GM-CSF, 93% produced IL-3, 80% produced IL-6, and 70% produced SCF. Similarly, all AA stroma produced G-CSF and GM-CSF, and 71% produced SCF. In contrast, only 71% of AA stroma produced IL-3 and 36% produced IL-6. Target cell stimulation was not dependent on direct stroma-target cell contact, suggesting production of soluble cytokines. However, although both IL-6 and G-CSF were detected in LTBMC supernatants by enzyme-linked immunoassay (ELISA), IL-3 and GM-CSF were undetectable, perhaps indicating low-level local production of these factors.

Adolescent↗
PubMed1995

Adhesion molecule expression on CD34+ progenitor cells from normal and aplastic anaemia bone marrow.

Aplastic anaemia (AA) is a disease of bone marrow failure. Evidence has been produced for both a stem cell and a stromal cell defect in this disease. The contribution of deficient or defective cell adhesion molecules (CAMs) has not been determined. CAMs have been shown to be important in stem cell-stromal cell interactions and maintenance of haemopoiesis. In this study the expression of CAMs (LFA-1, LFA-3, ICAM-1. VLA-4, CD44, sLex and L-selectin) on CD34+ progenitor cells from 10 normal donors and eight patients with AA was investigated using double immunofluorescence. There was no significant difference in the percentage of CD34+ cells that were CAM+ between normal and AA bone marrow, suggesting that abnormal CAM expression on AA progenitor cells is not responsible for nor contributes to the pathogenesis of the disease. However, these findings do not exclude abnormal CAM function on progenitor cells, or abnormal expression or function of CAM ligands or counter-receptors on AA stromal cells.

Adult↗
PubMed1995

Absence of N-RAS point mutations in peripheral blood cells of patients with aplastic anaemia and paroxysmal nocturnal haemoglobinurea.

The myelodysplastic syndromes (MDS) have a significant frequency of evolution into acute myeloid leukaemia (AML). Approximately 30% of MDS patients show activating mutations of the N-RAS proto-oncogene, and these patients are at increased risk of leukaemic evolution. Long-term survivors of aplastic anaemia (AA) and paroxysmal nocturnal haemoglobinurea (PNH) are also at significant risk of developing AML. We have screened peripheral blood DNA from 42 AA patients and 15 PNH patients for the presence of N-RAS point mutations. No mutations were detected in these samples, indicating that the mechanisms of evolution into AML may be different from those in MDS.

Acute Disease↗
PubMed1995

IL-3 is produced by normal stroma in long-term bone marrow cultures.

Interleukin-3 (IL-3) has been shown to have significant effects on haemopoiesis in vitro, but early investigations of normal human long-term bone marrow cultures (LTBMC) have failed to demonstrate IL-3 production by stromal cells, either by Northern blotting for mRNA, or assaying for bioactivity in culture supernatants. One recent report, using reverse transcription-polymerase chain reaction (RT-PCR), demonstrated IL-3 expression in only one of eight cultures. We have developed a sensitive bioassay for the detection of IL-3 production from normal stroma in LTBMC. LTBMC were grown until confluent, irradiated, and stroma harvested by trypsinization to yield single-cell suspensions. These cells were then cocultured with target bone marrow mononuclear cells (BMMC), or CD34+ cells in clonogenic assays, either in the presence or absence of anti-IL-3 neutralizing antibodies. We have demonstrated IL-3 production in 32/34 cases. In addition, by separating stroma from target cells using cell culture inserts, we have shown that direct stroma:stem cell contact is not necessary for colony growth, suggesting that IL-3 diffuses into the supernatant. However, when supernatants from LTBMC were assayed by enzyme-linked immunoassay (ELISA), no IL-3 was detected. This suggests that IL-3 is probably produced at low levels and has a short-range interaction. Stroma production of IL-3 was confirmed by the detection by RT-PCR of IL-3 mRNA in 3/3 cases. The simultaneous detection of CD2 mRNA demonstrated that T cells are part of the bone marrow stroma. It is therefore possible and probably likely that these cells are the source of IL-3.

Base Sequence↗
PubMed1995

Diamond-Blackfan anaemia: three patterns of in vitro response to haemopoietic growth factors.

Culture of bone marrow from patients with Diamond-Blackfan anaemia (DBA) has previously shown a variable progenitor response to growth factor stimulation. An extensive standardized study has now been undertaken to investigate the presence of distinct sub-groups in this disorder. In vitro response of bone marrow progenitors to recombinant human growth factors, including stem cell factor, was examined in 18 DBA patients and five normal donors, assessing BFU-E, CFU-GM and CFU-GEMM development. In 16 of the DBA patients a synergistic response to combinations of growth factors was observed with optimal growth in cultures containing erythropoietin, interleukin-3 and stem cell factor. Growth factor induced erythroid response formed three distinct groups, based on BFU-E numbers: type I (mean age 4.87 years) showed > 70% normal erythroid response; type II (mean age 13.87 years) showed < 70% normal; and type III (mean age 15.29 years) < 5% normal. CFU-GM response also followed the trigrouping. The results suggest more than one pathogenic mechanism for the erythroid failure in DBA, indicating DBA may be composed of more than one distinct disorder, and further suggest the defect in DBA may not be confined to the erythroid series.

Adolescent↗
PubMed1995

The in vitro effects of granulocyte and granulocyte-macrophage colony-stimulating factor on interleukin-3-dependent proliferation of human neonatal circulating progenitor cells.

Recombinant human granulocyte (rhG) colony-stimulating factor (CSF) and recombinant human granulocyte-macrophage (rhGM) CSF have been used to enhance neonatal neutrophil host defense. We aimed to determine the comparative efficacy of rhG-CSF and rhGM-CSF in increasing numbers of granulocyte colony-forming unit (CFU-G) and granulocyte-macrophage colony-forming unit (CFU-GM) in recombinant human (rh) IL-3-dependent cultures of human neonatal circulating hematopoietic progenitor cells, including cells from infants born to hypertensive mothers. We also investigated the relationship between fractional increase in CFU-G and endogenous plasma concentration of G-CSF. Circulating mononuclear cells were harvested from 25 neonates, and standard short-term assays in semisolid agar were established in the presence of rhIL-3 alone, rhIL-3 with rhG-CSF and rhGM-CSF, and both rhG-CSF and rhGM-CSF. CFU-G and CFU-GM were counted on d 14. Total colony number and CFU-G were significantly greater in cultures supplemented with rhG-CSF, with or without rhGM-CSF (p < 0.001 and p < 0.0005 for total colony number and CFU-G, respectively), when compared with cultures with rhIL-3 alone. Progenitor cells from three infants born to hypertensive mothers responded similarly. Total colony numbers and CFU-G were not increased by rhGM-CSF alone or by addition of rhGM-CSF to rhG-CSF; however, the proportions of CFU-GM were (p < 0.05 and p < 0.001, respectively, compared with rhIL-3 alone).(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Division↗
PubMed1995

c-kit protein (stem cell factor receptor) expression on cells with erythroid characteristics and on normal human bone marrow without the use of monoclonal antibodies.

Stem cell factor (SCF) is a determining and crucial element in the development of early hematopoietic cells. The SCF receptor protein has been identified as the product of the protooncogene c-kit and has been detected using monoclonal antibodies (MAbs) on a broad selection of erythroid, myeloid, and lymphoid cell lines as well as on bone marrow mononuclear cells (BMMNC). SCF is known to increase both the number and size of burst-forming unit-erythroid (BFU-E) colonies in normal human BM culture in a dose-dependent fashion. A detailed study of the involvement of SCF and its receptor c-kit in normal erythropoiesis will help elucidate intrinsic irregularities of anemias such as Diamond Blackfan Anemia, an aregenerative congenital anemia. Abnormalities of this heterogeneous disorder are confined to the red cell lineage and are thought to arise through a defect at the stem/progenitor cell level. Our in vitro studies suggest that SCF therapy will influence BFU-E production in at least a portion of these patients, although in another group, SCF response is limited or absent. Additionally, further investigations have shown a possible c-kit signaling defect that clearly necessitates further c-kit characterization. To parallel this, we, therefore, attempted to study the relationship of c-kit with its ligand. This report describes a nonradioactive method for detecting SCF receptors that varies from conventional assays in that the fluorescent label conjugated to the SCF/c-kit complex is connected via an extended-ester linkage that reduces steric influence and promotes full normal structural ligand binding of the SCF to its receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1995

The novel monoclonal antibody By114 helps detect the early emergence of a paroxysmal nocturnal hemoglobinuria clone in aplastic anemia.

The newly described monoclonal antibody By114 has been used with flow cytometry to investigate the status of the 90-kD glycosylphosphatidyl-inositol (GPI)-anchored component of CD66 (CD66c) on neutrophils from nine patients with paroxysmal nocturnal hemoglobinuria (PNH), seven with aplastic anemia/PNH, and 63 with aplastic anemia (AA) and a negative Ham's test. We have found that By114 is a sensitive indicator for recognizing patients with PNH and has helped delineate a group of nine patients with aplastic anemia and a negative Ham's test who have evidence of a larger PNH clone than indicated by other monoclonal antibodies (mAbs). By114 is a valuable marker for detecting the emergence of a PNH clone before the Ham's test becomes positive and is a more sensitive detector of deficient GPI-anchored proteins than other mAbs.

Adolescent↗
PubMed1995

Increased apoptosis in aplastic anemia bone marrow progenitor cells: possible pathophysiologic significance.

We have quantitated apoptotic cells by flow cytometry in human bone marrow (BM) and peripheral blood (PB) from normal donors and aplastic anemia (AA) patients, using the fluorescent DNA-binding dye 7-amino actinomycin D (7AAD). No significant difference was found in baseline percent apoptosis between normal and AA samples. Serum deprivation induced cell death to a greater degree in AA samples than in normal samples, but this was not significant. Using dual staining with anti CD34 antibody and 7AAD, we have shown that CD34+ progenitors in normal PB are significantly more apoptotic than those in normal BM. AA BM CD34+ cells contain a significantly greater proportion of apoptotic cells than normal BM CD34+ cells. Those AA patients with the lowest absolute number of CD34+ cells showed the highest proportion of apoptotic CD34+ cells. This appears to be related to clinical severity (transfusion dependence) at the time of study. We conclude that apoptosis is accelerated in AA BM progenitors and that this may contribute to the stem cell deficiency characteristic of this disorder.

Adolescent↗