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Biomedical subjects

E C Gordon-Smith

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

At least 19 recordsLinked to original sources
PubMed2005

Marrow transplants from matched unrelated donors for aplastic anaemia using alemtuzumab, fludarabine and cyclophosphamide based conditioning.

Graft failure, regimen-related toxicity and graft-versus-host disease (GVHD) are the critical barriers to unrelated donor transplants for aplastic anaemia (AA). We investigated the use of a novel conditioning regimen consisting of alemtuzumab (humanized CD52 antibody), fludarabine and cyclophosphamide in seven patients with AA, who underwent bone marrow transplant procedure using matched unrelated donors. The aetiology of AA was acquired (n=3), Fanconi's (n=3) and congenital (n=1). Median age was 13 years (range 8-35). All the donors were fully matched for HLA class I and II antigens using high-resolution typing. All the patients engrafted at a median of 18 days (range 13-35). Two patients died of transplant-related complications: one of adenovirus disease and the other developed extensive chronic GVHD of skin followed by cytomegalovirus (CMV) disease. Three patients developed Grade II acute GVHD disease (GVHD); none had Grade III-IV acute GVHD. Of the six evaluable patients, only one developed chronic GVHD. We conclude that this conditioning regimen for unrelated donor transplants for AA is sufficiently immunosuppressive to allow stable engraftment and appears to have a favourable impact on the incidence and severity of GVHD, warranting further investigation.

Adolescent↗
PubMed2003

Remission induced by Campath-1H for thymoma-associated agranulocytosis.

Thymoma-associated agranulocytosis is a rare but almost universally fatal condition. Reports to date have described several immunosuppressive therapies including steroids, cyclophosphamide and vincristine as adjuvants to thymectomy, in an effort to improve neutropenia. We report the response to the monoclonal antibody Campath-1H of a patient with a thymoma and associated agranulocytosis with complete absence of bone marrow granulocyte precursors, which had failed to respond to thymectomy. Treatment with Campath-1H resulted in complete responses of promising durability sustained with the addition of cyclosporin and mycophenolate mofetil as maintenance therapy.

Agranulocytosis↗
PubMed2003

The role of occupational and environmental exposures in the aetiology of acquired severe aplastic anaemia: a case control investigation.

Aplastic anaemia is a rare but serious disorder with a high morbidity and mortality rate. The causes of aplastic anaemia are, for the most part, unknown. We report on the hypothesis that aplastic anaemia may be caused by occupational and/or environmental exposures to certain chemicals. The UK Aplastic Anaemia Study was an interview-based case-control study covering the whole of Great Britain. Those patients diagnosed between 1 July 1993 and 20 October 1997, aged < or =75 years and born and diagnosed in the UK were eligible for the study. Two hundred eligible cases of aplastic anaemia were compared with 387 age- and sex-matched controls. A number of occupational exposures showed increases in risk. In a multivariate model of these exposures the odds ratios (ORs) for solvents/degreasing agents, pesticides and radiation were >2 and statistically significant. Reported chemical treatment of houses within 5 years of diagnosis had a significantly raised risk for adults [OR = 2.51, 95% confidence interval (CI) 1.02-12.01], particularly for woodworm treatment (OR = 5.1, 95% CI 1.5-17.4). This study identified significant risks associated with self-reported exposure to solvents, radiation and pesticides in the workplace. Self-reported chemical treatment of houses was also associated with an increased risk of developing aplastic anaemia, in keeping with previous literature.

Adolescent↗
PubMed2002

Autologous recovery following non-myeloablative unrelated donor bone marrow transplantation for severe aplastic anaemia.

We report the outcome of nine unrelated bone marrow transplants performed for acquired severe aplastic anaemia at a single centre. Six patients received transplants from fully matched donors. Three donor/recipient pairs were mismatched, two at a single allele on high resolution typing. Pre-transplant conditioning consisted of cyclophosphamide and in vivo Campath-1 monoclonal antibody. One patient also received total body irradiation (TBI), and another patient with a coexisting paroxysmal nocturnal haemoglobinuria (PNH) clone received additional busulphan. Cyclosporin A was given for 12 months as prophylaxis against graft-versus-host disease (GVHD). Six of nine patients are alive and transfusion independent with a mean follow-up of 24 months (range: 1.5-94). All six patients who received fully matched transplants are alive; the three who received mismatched grafts died. Four long-term survivors developed autologous haematological recovery following rejection of their grafts. Acute GVHD grade II+ occurred in two patients. We highlight the importance of high-resolution HLA typing, including Cw matching in reducing the incidence of graft rejection and GVHD, resulting in improved survival in our patient group. This study also shows that autologous recovery with long-term survival can occur following non-irradiation conditioning regimens.

Adolescent↗
PubMed2002

Combined immunocytochemistry and FISH: an improved method to study engraftment of accessory bone marrow stromal cells.

In aplastic anaemia (AA), correction of bone marrow (BM) stromal function may contribute to the outcome of bone marrow transplantation (BMT). Engraftment of BM stromal cells is rarely observed, but engraftment of accessory cells (macrophages and T cells) may be important. We have improved a method of combined immunocytochemistry and FISH described by van Tol et al. (1998) to define the cellular origin and time course of engraftment of BM stromal accessory cells after sex-mismatched BMT. Long-term bone marrow cultures were trypsinized and cytospin preparations stained by immunocytochemistry using monoclonal antibodies against specific cell lineages followed by FISH for X and Y chromosomes. Low level phase contrast microscopy was used to study staining of individual cells simultaneously with fluorescence microscopy to define chromosomal pattern. In controls, the combined procedure did not affect the intensity of APAAP staining or the accuracy of sex chromosome determination. In cultures from AA patients after sex-mismatched BMT, cell lineages could be identified and donor or recipient origin determined unequivocally. This procedure enabled us to examine the origin (host/donor) of different cell lineages with high confidence, in addition to producing images of the combined staining.

Adult↗
PubMed2001

Assessment of bone marrow stem cell reserve and function and stromal cell function in patients with severe congenital neutropenia.

OBJECTIVE: To investigate further the cellular defect responsible for impaired granulopoiesis in severe congenital neutropenia (SCN), we have evaluated bone marrow (BM) stem cell reserve and function and BM stromal cell myelopoiesis supporting capacity in two patients with SCN. METHODS: BM primitive stem cells and myeloid progenitor cells were assessed using flow cytometry, limiting dilution assay, clonogenic assays, and long-term BM cultures (LTBMC). BM stroma function was assessed by evaluating the ability of irradiated stromal layers from the patients to induce granulocyte-macrophage colony formation (CFU-GM) by normal CD34+ cells. RESULTS: Compared to the normal controls (n = 37), SCN patients displayed a low percentage of CD34+/CD38+ cells (P < 0.05), low CFU-GM colony formation by highly purified CD34+ cells (P < 0.05), low CFU-GM recovery in LTBMC (P < 0.05), and normal primitive stem cells as indicated by the frequency of CD34+/CD38- cells and the number of long-term culture initiating cells. Patient BM stromal layers exhibited normal myelopoiesis supporting capacity as shown by the CFU-GM content of irradiated LTBMC recharged with normal CD34+ cells. In addition, patient LTBMC supernatants displayed 20-fold normal granulocyte colony stimulating factor and 2-fold normal granulocyte-macrophage colony stimulating factor levels. CONCLUSION: These data show that primitive BM stem cells and stromal cells are not affected in SCN patients, while they support further the concept of a primary defect at the myeloid progenitor cell level. To know the differentiation stage at which the underlying defect causes the malfunction will be relevant for further elucidation of its nature at the molecular level.

Adult↗
PubMed2001

Bcl-2 and Bcl-x expression in the CD34+ cells of aplastic anaemia patients: relationship with increased apoptosis and upregulation of Fas antigen.

Aplastic anaemia (AA) is a syndrome of haemopoietic failure involving increased apoptosis in stem cells. AA CD34+ cells often have upregulated Fas antigen, but this does not explain the increased apoptosis in all patients. To examine whether abnormal expression of the apoptotic modulators Bcl-2 and Bcl-x is involved in increased apoptosis in the CD34+ cells of patients, we examined cells from 19 AA patients and 18 normal controls by triple staining for CD34, Bcl-2 or Bcl-x, together with 7-amino actinomycin D to determine viability or with staining for Fas antigen. We confirmed increased apoptosis of CD34+ cells in patients. All CD34+ cells in patients and controls expressed Bcl-2 and Bcl-x with no significant difference between the groups. In patients, viability of CD34+/Bcl-2hi cells was similar to that of CD34+/Bcl-2lo cells, but CD34+/Bcl-xhi cells were significantly more viable than CD34+/Bcl-xlo cells. CD34+ cells from AA patients expressed upregulated Fas antigen, but this did not correlate with Bcl-2 or Bcl-x expression. These results suggest a more significant role for Bcl-x as an anti-apoptotic regulator in CD34+ cells in AA than Bcl-2. The induction of death by Fas antigen may bypass the anti-apoptotic effect of Bcl-2 and Bcl-x in CD34+ cells in AA.

Adolescent↗
PubMed2001

The effect of treatment with Campath-1H in patients with autoimmune cytopenias.

We describe 21 patients with severe and life-threatening autoimmune cytopenias resistant to standard immunosuppression who were treated with the monoclonal antibody Campath-1H. Four patients had autoimmune neutropenia, four had autoimmune haemolytic anaemia, four had pure red cell aplasia, one had immune thrombocytopenia purpura (ITP), three had autoimmune haemolytic anaemia and ITP (Evan's syndrome), three had autoimmune pancytopenia (ITP, autoimmune neutropenia and autoimmune haemolytic anaemia), one had ITP (associated with acquired Glanzmann's disease) and autoimmune neutropenia, and one had ITP and red cell aplasia. Campath-1H was administered at a dose of 10 mg/d as an intravenous infusion for 10 d. Responses were seen in 15 patients, which were sustained in six. Relapse occurred in eight patients after Campath-1H treatment. Patients entering the study later, received cyclosporine after Campath-1H in an attempt to reduce the incidence of relapse. Three patients received a second course of Campath-1H; all responded but later relapsed. Fourteen patients are alive at a median of 12 months (range 4-61) after Campath-1H. Campath-1H represents an alternative therapeutic option for severe, refractory autoimmune cytopenias.

Adolescent↗
PubMed2001

Increased apoptosis of bone marrow CD34(+) cells and impaired function of bone marrow stromal cells in patients with systemic lupus erythematosus.

The changes in bone marrow (BM) stem cell reserve and function and stromal cell function in patients with active systemic lupus erythematosus (SLE) were investigated. The study was carried out on seven SLE patients and 28 healthy controls using flow cytometry and in vitro cell culture assays. We found that patients had low CD34(+) cells, compared with the control group, reflecting the decrease of both CD34(+)/CD38(-) and CD34(+)/CD38(+) cells. Patient CD34(+)/Fas(+) but not CD34(-)/Fas(+) cells were significantly increased. Apoptotic (7AAD(dim)) cells were higher among CD34(+)/Fas(+) than among CD34(+)/Fas(-) cells, and individual values of apoptotic CD34+ cells strongly correlated with the number of CD34(+)/Fas(+) cells. These findings are suggestive of a Fas-mediated apoptosis accounting for the low CD34(+) cells in SLE patients. Moreover, we found that patients had low numbers of granulocyte-macrophage colony-forming units (CFU-GM) and erythroid burst-forming units (BFU-E), compared with the control group, and that the generation of colony-forming cells in long-term BM cultures was significantly reduced. Patient BM stroma failed to support allogeneic progenitor cell growth. In one patient, CD34(+) cells were increased, apoptotic CD34(+)/Fas(+) cells were normalized and defective stromal cell function was restored after autologous stem cell transplantation. We concluded that defective haemopoiesis in SLE patients is probably caused, at least in part, to the presence of autoreactive lymphocytes in BM.

Adult↗
PubMed2001

Correction of stromal cell defect after bone marrow transplantation in aplastic anaemia.

Defects in stromal cell function have been demonstrated in a number of aplastic anaemia (AA) patients. Here we have studied a patient with severe AA and abnormal stromal cell function who underwent bone marrow transplantation (BMT). The objective of this study was to investigate the timing and the mechanism of correction of the stromal defect after transplantation. The patient, a 25-year-old woman with severe AA, underwent BMT from her brother. BM was obtained from the patient on five occasions: 2 weeks pre BMT, and 3, 8, 16 and 21 months post BMT. Stromal cells were grown to confluence and recharged with purified CD34+ cells from normal donors. The support of such cells, as assessed by weekly colony-forming assay (CFU) of non-adherent cells, was compared with that of stromal layers grown from normal BM. A novel technique of combined fluorescence in situ hybridization (FISH) and immunocytochemistry was used to determine the origin of specific stromal cell types on cytospins of stroma post BMT. Stromal function was defective at 2 weeks pre BMT and at 3 months post BMT, but returned to normal at 8 and 16 months post BMT. At 21 months post BMT, stromal fibroblasts and endothelial cells were shown to be of recipient origin, and macrophages and T cells were of donor origin. We present here evidence in a case of severe AA for defective stromal function before BMT and delayed normalization of function after BMT. This correlated with engraftment of donor macrophages and T cells, but not fibroblasts and endothelial cells.

Adult↗
PubMed2001

CAMPATH-1H in the treatment of autoimmune cytopenias.

BACKGROUND: The autoimmune cytopenias encompass the disorders of immune thrombocytopenia purpura (ITP), pure red-cell aplasia (PRCA), autoimmune hemolytic anemia (AIHA), autoimmune neutropenia and various combinations of these conditions. T lymphocytes are thought to play an important role in the pathogenesis of autoimmune cytopenias, and the presence of autoantibody may represent an epiphenomenon, rather than the primary pathogenetic mechanism. The majority of patients usually respond to standard immunosuppressive therapy and can mostly be treated as out-patients. A small proportion, however, have severe, resistant and life-threatening disease, or may experience major morbidity from side effects of drugs given to treat their disease. METHODS: We have treated 21 patients with autoimmune cytopenias with the MAb Campath-1H, and for later patients in this series, in combination with low dose CYA. RESULTS: Responses were seen in 14 of 20 evaluable patients, although relapse occurred in seven patients. In many patients corticosteroid therapy could be discontinued or greatly reduced. DISCUSSION: We conclude that Campath-1H can induce remissions in autoimmune cytopenias and we critically review its role in the treatment of these disorders.

Adolescent↗
PubMed2000

Assessment of bone marrow stem cell reserve and function and stromal cell function in patients with autoimmune cytopenias.

To investigate whether bone marrow (BM) stem cell compartment and/or BM microenvironment are affected by the immune insult in autoimmune cytopenias (AICs), BM stem cell reserve and function and BM stromal function were studied in 15 AIC patients. Stem cells were evaluated by means of flow cytometry, clonogenic progenitor cell assays, long-term BM cultures (LTBMCs), and limiting dilution assay for quantification of long-term-culture initiating cells (LTC-ICs). Stromal cell function was assessed with the use of preformed irradiated LTBMCs from patients and normal controls, recharged with normal CD34(+) cells. AIC patients exhibited a high number of CD34(+), CD34(+)/CD38(+), and CD34(+)/CD38(-) cells; high frequency of granulocyte-macrophage colony forming units in the BM mononuclear cell fraction; high colony recovery in LTBMCs; and normal LTC-IC frequency. Patient BM stromal layers displayed normal hematopoietic-supporting capacity and increased production of granulocyte-colony stimulating factor. Data from this study support the concept that AIC patients with severe, resistant disease might be appropriate candidates for autologous stem cell transplantation.

ADP-ribosyl Cyclase↗
PubMed2000

T-cell depletion of bone marrow transplants for leukemia from donors other than HLA-identical siblings: advantage of T-cell antibodies with narrow specificities.

T-cell depletion of donor marrow decreases graft-versus-host disease resulting from transplants from unrelated and human leukocyte antigen (HLA)-mismatched related donors. However, there are diverse strategies for T-cell-depleted transplantation, and it is uncertain whether any improve leukemia-free survival (LFS). To compare strategies for T-cell-depleted alternative donor transplants and to compare T-cell depleted with non-T-cell-depleted transplants, we studied 870 patients with leukemia who received T-cell-depleted transplants from unrelated or HLA-mismatched related donors from 1982 to 1994. Outcomes were compared with those of 998 non-T-cell-depleted transplants. We compared LFS using different strategies for T-cell-depleted transplantation considering T-cell depletion technique, intensity of pretransplant conditioning, and posttransplant immune suppression using proportional hazards regression to adjust for other prognostic variables. Five categories of T-cell depletion techniques were considered: narrow-specificity antibodies, broad-specificity antibodies, Campath antibodies, elutriation, and lectins. Strategies resulting in similar LFS were pooled to compare T-cell-depleted with non-T-cell-depleted transplants. Recipients of transplants T-cell depleted by narrow-specificity antibodies had lower treatment failure risk (higher LFS) than recipients of transplants T-cell depleted by other techniques. Compared with non-T-cell-depleted transplants (5-year probability +/- 95% confidence interval [CI] of LFS, 31% +/- 4%), 5-year LFS was 29% +/- 5% (P = NS) after transplants T-cell depleted by narrow-specificity antibodies and 16% +/- 4% (P <.0001) after transplants T-cell depleted by other techniques. After alternative donor transplantation, T-cell depletion of donor marrow by narrow-specificity antibodies resulted in LFS rates that were higher than those for transplants T-cell depleted using other techniques but similar to those for non-T-cell-depleted transplants. (Blood. 2000;95:3996-4003)

Adolescent↗
PubMed2000

N-RAS gene mutation in patients with aplastic anemia and aplastic anemia/ paroxysmal nocturnal hemoglobinuria during evolution to clonal disease.

Long-term survivors of aplastic anemia (AA) have a high incidence of clonal disorders, in particular paroxysmal nocturnal hemoglobinuria (PNH), myelodysplastic syndromes (MDS), and acute nonlymphocytic leukemia. To investigate the potential involvement of N-RAS gene mutations in the predisposition to leukemic evolution, a subset of patients at potentially increased risk for clonal disease was selected based on evidence of existing clonal evolution. Nine patients showed a monoclonal pattern of X-chromosome inactivation, 18 demonstrated a PNH clone, and in 3 MDS developed during the course of this study. No mutations were detected during the aplastic phase of disease; 2 of 3 patients with MDS after AA also showed no mutations. However, in 1 patient in whom the disease transformed from AA/PNH to MDS, a mutation of GGT --> GAT at N-RAS codon 13 became detectable, whereas the PNH mutation disappeared. The authors conclude that N-RAS mutations are not an early event preceding transformation of AA or AA/PNH to leukemia. In a subset of patients, RAS mutations may occur at the time of evolution to MDS, but preexisting RAS mutations do not explain the propensity of AA to leukemogenesis. Although PNH is also associated with leukemia, this may arise in the non-PNH cells, indicating that PIG-A gene mutation is not per se oncogenic. (Blood. 2000;95:646-650)

Adult↗
PubMed2000

Clonal patterns of X-chromosome inactivation in female patients with aplastic anaemia studies using a novel reverse transcription polymerase chain reaction method.

Conflicting results have been published on the frequency of clonal patterns of X-chromosome inactivation in female patients with aplastic anaemia. Previous studies have used DNA methylation to measure X-inactivation, but aberrant methylation is known to occur in some situations. We have developed a non-radioactive reverse transcription polymerase chain reaction (RT-PCR) method to study expression of the polymorphism at nt. 1311 of the G6PD gene at the RNA level. Using this, and a similar method for the iduronate-2-sulfatase (IDS) gene, we have re-evaluated X-inactivation in AA patients. 32/35 normal individuals showed polyclonal haemopoiesis. Patients with presumed clonal diseases showed both monoclonal and polyclonal patterns, consistent with previous reports. Overall, clonal patterns were observed in granulocytes of 10/26 AA patients (38%), a significantly higher proportion than in controls (p<0.01). Two cases showed discordance between lymphocytes and granulocytes, indicating clonality arising within the myeloid lineage. Eight cases showed clonal patterns in both myeloid and lymphoid cells, indicating the involvement of a pluripotent stem cell. Clonal patterns did not correlate with age, but there appeared to be an association with duration of disease. In PNH patients, CD59-negative cells showed clonal patterns of X-inactivation. In two cases, however, clonal patterns were also detected in CD59-positive cells.

Alleles↗