Search PubMed⌕ Search

Biomedical subjects

S R McCann

Publications and source records attributed to S R McCann.

At least 19 recordsLinked to original sources
PubMed2006

Wilms' tumor gene 1 (WT1) expression in childhood acute lymphoblastic leukemia: a wide range of WT1 expression levels, its impact on prognosis and minimal residual disease monitoring.

Wilms' tumor gene 1 (WT1) is overexpressed in the majority (70-90%) of acute leukemias and has been identified as an independent adverse prognostic factor, a convenient minimal residual disease (MRD) marker and potential therapeutic target in acute leukemia. We examined WT1 expression patterns in childhood acute lymphoblastic leukemia (ALL), where its clinical implication remains unclear. Using a real-time quantitative PCR designed according to Europe Against Cancer Program recommendations, we evaluated WT1 expression in 125 consecutively enrolled patients with childhood ALL (106 BCP-ALL, 19 T-ALL) and compared it with physiologic WT1 expression in normal and regenerating bone marrow (BM). In childhood B-cell precursor (BCP)-ALL, we detected a wide range of WT1 levels (5 logs) with a median WT1 expression close to that of normal BM. WT1 expression in childhood T-ALL was significantly higher than in BCP-ALL (P<0.001). Patients with MLL-AF4 translocation showed high WT1 overexpression (P<0.01) compared to patients with other or no chromosomal aberrations. Older children (> or =10 years) expressed higher WT1 levels than children under 10 years of age (P<0.001), while there was no difference in WT1 expression in patients with peripheral blood leukocyte count (WBC) > or =50 x 10(9)/l and lower. Analysis of relapsed cases (14/125) indicated that an abnormal increase or decrease in WT1 expression was associated with a significantly increased risk of relapse (P=0.0006), and this prognostic impact of WT1 was independent of other main risk factors (P=0.0012). In summary, our study suggests that WT1 expression in childhood ALL is very variable and much lower than in AML or adult ALL. WT1, thus, will not be a useful marker for MRD detection in childhood ALL, however, it does represent a potential independent risk factor in childhood ALL. Interestingly, a proportion of childhood ALL patients express WT1 at levels below the normal physiological BM WT1 expression, and this reduced WT1 expression appears to be associated with a higher risk of relapse.

Adolescent↗
PubMed2006

Marrow aplasia developing 13 years after HLA-identical sibling allogeneic transplantation for chronic myeloid leukaemia: successful treatment with antithymocyte globulin and peripheral blood stem cell infusion from the original donor.

Secondary or late graft failure has been defined as the development of inadequate marrow function after initial engraftment has been achieved. We describe a case of profound marrow aplasia occurring 13 years after sibling allogeneic bone marrow transplantation for chronic myeloid leukaemia (CML) in first chronic phase. Although the patient remained a complete donor chimera, thereby suggesting that an unselected infusion of donor peripheral blood stem cells (PBSC) or bone marrow might be indicated, the newly acquired aplasia was thought to be immune in aetiology and some immunosuppression was therefore considered appropriate. Rapid haematological recovery was achieved after the infusion of unselected PBSC from the original donor following conditioning with anti-thymocyte globulin (ATG).

Antilymphocyte Serum↗
PubMed2004

A single-centre assessment of long-term quality-of-life status after sibling allogeneic stem cell transplantation for chronic myeloid leukaemia in first chronic phase.

A total of 75 patients underwent sibling allogeneic stem cell transplantation (SCT) for chronic myeloid leukaemia in first chronic phase from 1984 to 2000. Of these patients, 51 (68%) were alive at a median follow-up of 98 months (range 34-217 months). Nine (18%) patients relapsed and seven (14%) received donor lymphocyte transfusions. Quality of life (QoL) was assessed cross-sectionally using the EORTC QLQ-C30, a Leukaemia-BMT-specific module and questionnaires on sexual functioning, fertility and late effects. A total of 46 (90%) replied. Scores for Role (P=0.018) and Cognitive (P<0.001) function were significantly lower when compared to an age-adjusted general population. Dyspnoea (P=0.022) and Financial Difficulties (P<0.001) were significantly more common in the SCT group. No difference was found for scores in the Physical, Emotional and Social domains or the overall Global Health Status/QoL. Decreased sexual functioning was found in one-third of respondents. Although most BMT recipients reported a good QoL, a minority have difficulty with reintegration into professional roles and consequent monetary problems. Identified cognitive and sexual impairments highlight the need for long-term access to psychosocial support.

ABO Blood-Group System↗
PubMed2002

Leukaemic transformation of donor cells in a patient receiving a second allogeneic bone marrow transplant for severe aplastic anaemia.

Allogeneic blood or bone marrow transplantation is a successful treatment for leukaemia and severe aplastic anaemia (SAA). Graft rejection following transplantation for leukaemia is a rare event but leukaemic relapse may occur at varying rates, depending upon the stage of leukaemia at which the transplant was undertaken and the type of leukaemia. Relapse is generally assumed to occur in residual host cells, which are refractory to, or escape from the myeloablative conditioning therapy. Rare cases have been described, however, in which the leukaemia recurs in cells of donor origin. Lack of a successful outcome of blood or bone marrow transplantation for severe aplastic anaemia (SAA), however, is due to late graft rejection or graft-versus-host disease. Leukaemia in cells of donor origin has rarely been reported in patients following allogeneic bone marrow transplantation for SAA. This report describes leukaemic transformation in donor cells following a second allogeneic BMT for severe aplastic anaemia. PCR of short tandem repeats in bone marrow aspirates and in colonies derived from BFUE and CFU-GM indicated the donor origin of leukaemia. Donor leukaemia is a rare event following transplantation for severe aplastic anaemia but may represent the persistence or perturbation of a stromal defect in these patients inducing leukaemic change in donor haemopoietic stem cells.

Anemia, Aplastic↗
PubMed2001

Effective progenitor cell mobilization in lymphoproliferative disorders using ifosfamide, epirubicin and etoposide (IEV).

The combination of ifosfamide, epirubicin and etoposide (IEV) is an effective salvage regimen for lymphoproliferative disease. We report our experience with this combination in mobilization of peripheral blood stem cells (PBSC) in patients with relapsed or refractory/high-risk lymphoma. The median time to leukapheresis was 14 days, with 85% of patients commencing PBSC collection in the range of 13-15 days. Mobilization was successful in 26 of 28 patients (93%), who achieved the minimum transplant dose of 2 x 10(6)/kg CD34+ cells in a median of 2 leukaphereses. Overall, the median CD34+ cell yield was 6.94 x 10(6)/kg (range 0.73-27.4). In 15 of 27 patients (54%), the yield was sufficient (> 6 x 10(6)/kg) to permit CD34+ cell selection and/or a second autograft. IEV was given as an inpatient in all cases. Patients were scheduled for discharge after chemotherapy. This was achieved in 71%, with readmission 1 week later for harvest. Therapy was complicated by neutropenic fever in 13 patients and mild nausea. In autografts carried out using IEV-mobilized PBSC (n = 20), the median time to neutrophils > 0.5 x 10(9)/L was 10 days (range 7-13 days), and to platelets > 20 x 10(9)/L was 13 days (range 11-18 days). There was no mobilization- or transplant-related mortality. We conclude that IEV is a safe, predictable and highly effective mobilization regimen in patients with lymphoma.

Adolescent↗
PubMed2000

The use of itraconazole as prophylaxis against invasive fungal infection in blood and marrow transplant recipients.

Invasive fungal infections play a key role in contributing to morbidity and mortality in patients undergoing treatment for haematological malignancies and related diseases. Risk factors for development of invasive fungal infections after blood or bone marrow transplantation include the use of broad-spectrum antibiotics, steroids, mismatched or unrelated donor transplant, right atrial catheters, and prolonged or profound neutropenia. Previous attempts at use of oral itraconazole as antifungal prophylaxis in the setting of chemotherapy-induced neutropenia were unsuccessful because of its poor absorption in capsule form. Itraconazole-cyclodextrin is well absorbed even in the presence of chemotherapy-induced neutropenia. Plasma levels of 250-500 ng/ml are required for prophylaxis. Studies to date show a favourable outcome in patients receiving itraconazole as prophylaxis against invasive fungal infections, although many studies looked at small numbers of patients and the incidence of invasive fungal infection in the control groups was low, prohibiting meaningful statistical evaluation. Fungi differ in their sensitivity to antifungal agents, and itraconazole is not the agent of choice in all patients. With the widespread use of antifungal prophylaxis, the possibility of resistance to antifungal agents and an increase in the number of invasive fungal infections caused by ubiquitous fungi previously considered nonpathogenic must be considered as potential problems.

Antifungal Agents↗
PubMed2000

An outbreak of multiply resistant Serratia marcescens: the importance of persistent carriage.

An outbreak of multi-resistant Serratia marcescens involving 24 patients occurred in a bone marrow transplant and oncology unit, from September 1998 to June 1999, of whom 14 developed serious infection. This is the first such outbreak described in a BMT unit. All isolates demonstrated the same antimicrobial susceptibility pattern and were the same unusual serotype O21:K14. The antimicrobial susceptibility profile showed reduced susceptibility to ciprofloxacin, gentamicin and piperacillin-tazobactam. As the latter two antimicrobials are part of our empiric therapy for febrile neutropenia, they were substituted with meropenem and amikacin during the outbreak. Investigation revealed breaches in infection control practices. Subsequently, the outbreak was contained following implementation of strict infection control measures. A prominent feature of the outbreak was prolonged carriage in some patients. These patients may have acted as reservoirs for cross-infection. This report also indicates that patients who become colonised with Serratia marcescens may subsequently develop invasive infection during neutropenic periods.

Adult↗
PubMed1998

Monitoring of lineage-specific chimaerism allows early prediction of response following donor lymphocyte infusions for relapsed chronic myeloid leukaemia.

Donor lymphocyte infusions (DLI) have been shown to enhance the graft-versus-leukaemia (GVL) effect and induce haematological and molecular remission in patients with relapsed CML following allogeneic bone marrow transplantation (BMT). The potent donor cell-mediated cytolysis following DLI may lead to a short period of aplasia before the re-establishment of donor haematopoiesis. The absence of detectable donor cells in patients prior to DLI infusion may result in permanent aplasia in certain patients. We report on four patients who relapsed 1, 3, 6.5 and 7 years post-BMT for chronic phase CML and were treated with DLI from their original BMT donor. Polymorphic short tandem repeats (STRs) were used to assess haematological chimaerism both prior to and following DLI. At the time of relapse, STR-PCR indicated the presence of donor cells in all four patients, at levels ranging from 1-40%. A clinical and molecular response was seen in 4/4 patients following a short period of cytopenia and all patients remain in clinical remission with a follow-up of 2 months-3 years post-DLI. STR-PCR indicated that a response was occurring during the period of pancytopenia when metaphase analysis was unsuccessful. Lineage-specific analysis of the cellular response to DLI was monitored using STR-PCR of peripheral blood (PB) and bone marrow (BM) lymphocyte-enriched fractions and CD2-positive and -negative T cell fractions. In one patient BM and PB CD34-positive and -negative fractions were also assessed. A change in the ratio of donor:recipient cells in the PB lymphocyte fraction was the earliest molecular indication of an anti-leukaemic response. Subsequent conversion to donor chimaerism occurred in the other lineages and the granulocyte fraction was the last lineage to convert. In conclusion, lineage-specific STR-PCR permits detailed monitoring of subtle changes in donor/recipient cell dynamics in specific lineages following DLI during the crucial pancytopenic phase and may be a useful predictor of haematological response to DLI therapy.

Adult↗
PubMed1998

Influence of ultraviolet-B irradiation on engraftment, graft-versus-host disease and graft-versus-leukemia effect in a rat model for allogeneic bone marrow transplantation.

Ultraviolet-B (UVB) irradiation is known to inhibit lymphocyte activity and consequently to reduce the incidence of graft-versus-host disease (GVHD) in experimental models for allogeneic bone marrow transplantation (BMT). GVHD is frequently associated with morbidity and mortality, but also with the beneficial graft-versus-leukemia (GVL) effect, demonstrated by a reduction in the incidence of leukemia relapse. In this study, we investigated whether UVB treatment of allogeneic T cells could prevent GVHD while sparing the beneficial GVL effect following allogeneic BMT in the Brown Norway myelocytic leukemia (BNML) rat model analogous to human acute myelocytic leukemia (AML). The dose of UVB required to abolish lethal GVHD in the rat allogeneic BMT model (WAG/Rij donors into BN recipients) was 4000 J/m2. However, this UVB dose simultaneously abrogated all GVL activity mediated by the T cells in the graft, while the radio-protective capacity of rat BM cells was strongly reduced. The number of allogeneic BM cells required to protect lethally irradiated BN rats was increased 50 to 100-fold. It is concluded that UVB acts as a non-selective form of T cell inactivation, and that UVB pretreatment of an allogeneic marrow graft is unlikely to be useful clinically as a preventive measure for GVHD, since other means of reduction of the number of functional T cells are less damaging to bone marrow stem cells.

Animals↗
PubMed1998

Psychosocial adaptation of patients and families following bone marrow transplantation: a prospective, longitudinal study.

Using a prospective, repeated measures design, this study investigated the psychosocial functioning of patients and a close relative pre- and post-allogeneic and autologous bone marrow transplantation (BMT). All patients (n = 28) undergoing BMT in a 1 year period, and their relatives, were interviewed 1 week pre-transplant and at 3, 6 and 12 months post-BMT, using quantitative and qualitative measures. Pre-transplant data revealed a high level of anxiety (61% with moderate to severe anxiety), and a low level of depression (14% with moderate to severe depression). Twelve patients died in the study period. For the surviving patients there was a statistically significant improvement in physical, psychological and social functioning. Most relatives (88%) reported considerable psychological distress pre-transplant and at 3 months post-transplant, but this was largely resolved by 12 months post-transplant. Significant correlations between the relative's distress and patient's physical and psychological wellbeing were observed at 3 months post-transplant, but not at the other assessment points. The findings from this study will help in counselling patients and their relatives as to what to expect in the year following BMT.

Adaptation, Psychological↗