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Stephen Mackinnon

Publications and source records attributed to Stephen Mackinnon.

At least 19 recordsLinked to original sources
PubMed2007

Reduced intensity conditioning for allogeneic hematopoietic cell transplantation: current perspectives.

Allogeneic HCT after myeloablative conditioning is an effective therapy for patients with hematologic malignancies. In an attempt to extend this therapy to older patients or those with comorbidities, reduced intensity or truly nonmyeloablative regimens have been developed over the past decade. The principle underlying reduced intensity regimens is to provide some tumor kill with lessened regimen-related morbidity and mortality and then rely on graft-versus-tumor (GVT) effects to eradicate remaining malignant cells, whereas nonmyeloablative regimens rely primarily on GVT effects. In this article, 3 representative approaches are described, demonstrating the clinical application for hematopoietic and nonhematopoietic malignancies. Current challenges include controlling GVHD while allowing GVT to occur. In the future, clinical trials using reduced intensity and nonmyeloablative conditioning will be compared with myeloablative conditioning in selected malignancies to extend the application to standard-risk patients.

Graft vs Host Disease↗
PubMed2006

The fate of human Langerhans cells in hematopoietic stem cell transplantation.

Langerhans cells (LC) and other antigen-presenting cells are believed to be critical in initiating graft versus host responses that influence the outcome of allogeneic hematopoietic stem cell transplantation. However, their fate in humans is poorly understood. We have sought to define the effect of conditioning regimes and graft versus host disease (GVHD) on the survival of recipient LC and reconstitution of donor cells after transplant. Confocal microscopy of epidermal sheets shows that full intensity transplant (FIT) depletes LC more rapidly than reduced intensity transplant (RIT) at day 0, although the nadir is similar in both at 14-21 d. Recovery occurs rapidly within 40 d in the absence of acute GVHD, but is delayed beyond 100 d when GVHD is active. LC chimerism was determined in sex-mismatched transplants using a two-step Giemsa/fluorescence in situ hybridization assay on isolated cells. Acquisition of donor chimerism at 40 d is more rapid after FIT (97%) than RIT (36.5%), irrespective of blood myeloid engraftment. At 100 d, all transplants achieve at least 90% LC donor chimerism and over half achieve 100%. Complete donor chimerism is associated with prior acute cutaneous GVHD, suggesting a role for allogeneic T cells in promoting LC engraftment.

Adult↗
PubMed2006

The importance of age, fludarabine, and total body irradiation in the incidence and severity of chronic renal failure after allogeneic hematopoietic cell transplantation.

Nonmalignant late effects, including chronic renal failure (CRF), impair the quality of life of long-term survivors after allogeneic hematopoietic cell transplantation. One of the major risk factors is the use of total body irradiation (TBI) in the preparative regimen; TBI is currently fractionated in an attempt to reduce toxicity. We analyzed 241 patients who had TBI-based preparative regimens for allogeneic hematopoietic cell transplantation. TBI was delivered as a single fraction of 7.5 Gy (7.5S group), 12 Gy in 6 fractions (12F group), or 14.4 Gy in 8 fractions (14.4F group). The cumulative incidence of CRF at 2 years was 12%. Statistical analysis revealed that older age (P < .001) and fludarabine administration (P = .016) had a significant effect on the incidence of CRF. Furthermore, single-fraction TBI was also significantly associated with CRF severity, because 7 (6.3%) of 111 patients in the 7.5S group developed severe CRF, as opposed to 1 (0.8%) of 130 patients in the 12F and 14.4F groups combined (P = .044). However, these conclusions should be regarded as preliminary in view of the retrospective and nonrandomized nature of this study.

Adolescent↗
PubMed2006

The outcome of sibling and unrelated donor allogeneic stem cell transplantation in adult patients with acute myeloid leukemia in first remission who were initially refractory to first induction chemotherapy.

The optimal management of patients with initially refractory acute myeloid leukemia is unknown. We analyzed the outcomes of 68 adult patients (median age, 37 years) with acute myeloid leukemia in first complete remission with initially refractory disease who were treated with matched sibling (n=44) or unrelated donor (n=22) stem cell transplantation or who received transplants from other donors (n=2). Thirty-one patients took 2 courses of chemotherapy to achieve first complete remission, a further 31 took 3 courses, and 6 patients took 4 or 5 courses. Ten patients (15%) had adverse cytogenetics. Patients were mainly conditioned with cyclophosphamide and total body irradiation (87%). Four patients (6%) did not engraft by day 28; 2 of these engrafted at 47 and 60 days. Grades II to IV and III/IV acute graft-versus-host disease (GVHD) were seen in 34% and 14% of patients, respectively. Chronic GVHD was seen in 50% of patients. The estimated actuarial disease-free and overall survivals were 34% and 37%, respectively, at 4 years. The performance status of survivors is good; 82% of patients have Karnofsky scores of 90 to 100. On multivariate analysis, overall and disease-free survival were associated with adverse cytogenetics (P=.055 and .023). Approximately one third of patients survived 4 years after allogeneic stem cell transplantation for initially refractory acute myeloid leukemia in first complete remission: relapse and treatment-related mortality were the major causes of treatment failure. Further studies are needed to determine the optimal conditioning regimens and GVHD prophylaxis.

Adolescent↗
PubMed2006

Peripheral blood stem cell yield in 400 normal donors mobilised with granulocyte colony-stimulating factor (G-CSF): impact of age, sex, donor weight and type of G-CSF used.

Mobilised peripheral blood is now the main source of stem cells collected from normal donors. We report our experience of mobilising and collecting 400 normal healthy donors using standardised procedures and techniques. Target recipient doses were reached with one aphaeresis in 63% of donors and with two aphereses in 81% of donors. Approximately 2% of donors yielded such low progenitor values that they were termed 'poor mobilisers'. There were minor effects of donor age, weight and sex and where possible, larger male donors under the age of 55 years should be selected. Two forms of granulocyte colony-stimulating factor (G-CSF) were used at the same dose and no significant difference was seen in the yield of CD34+ cells collected/l of blood processed. However, a greater number of granulocyte-macrophage colony-forming cells were harvested using lenograstim (glycosylated G-CSF) compared with filgrastim (non-glycosylated G-CSF; P = 0.002). CD34+ cell yields were also measured halfway through the aphaeresis procedure. This was found to be highly predictive of final yield and facilitated distribution of the stem cell product to other centres. The observation that CD34+ yields did not decline in the second half compared with the first half of aphaeresis suggests that the circulating cell numbers are not static.

Adolescent↗
PubMed2005

Allogeneic stem-cell transplantation using a reduced-intensity conditioning regimen has the capacity to produce durable remissions and long-term disease-free survival in patients with high-risk acute myeloid leukemia and myelodysplasia.

PURPOSE: The toxicity of allogeneic stem-cell transplantation can be substantially reduced using a reduced-intensity conditioning (RIC) regimen. This has increased the proportion of patients with myeloid malignancies eligible for allogeneic transplantation. However, the capacity of RIC allografts to produce durable remissions in patients with acute myeloid leukemia (AML) and myelodysplasia (MDS) has not yet been defined, and consequently, the role of RIC allografts in the management of these diseases remains conjectural. PATIENTS AND METHODS: Seventy-six patients with high-risk AML or MDS received an allograft using a fludarabine/melphalan RIC regimen incorporating alemtuzumab. The median age of the cohort was 52 years (range, 18 to 71 years). RESULTS: The 100-day transplantation-related mortality rate was 9%, and no patient developed greater than grade 2 graft-versus-host disease. With a median follow-up of 36 months (range, 13 to 70 months), 27 patients were alive and in remission, with 3-year actuarial overall survival (OS) and disease-free survival (DFS) rates of 41% and 37%, respectively. The 3-year OS and DFS rates of patients with AML in complete remission at the time of transplantation were 48% and 42%, respectively. Disease relapse was the most common cause of treatment failure and occurred at a median time of 6 months after transplantation. All but one patient destined to relapse did so within 24 months of transplantation. CONCLUSION: The extended follow-up in this series identifies a high risk of early disease relapse but provides evidence that RIC allografts can produce sustained DFS in a significant number of patients with AML who would be ineligible for allogeneic transplantation with myeloablative conditioning.

Acute Disease↗
PubMed2005

Results of alemtuzumab-based reduced-intensity allogeneic transplantation for chronic lymphocytic leukemia: a British Society of Blood and Marrow Transplantation Study.

We report results in 41 consecutive patients with chronic lymphocytic leukemia (CLL) who underwent allogeneic hematopoietic cell transplantation (HCT) after fludarabine, melphalan, and alemtuzumab conditioning. Donors were 24 HLA-matched siblings and 17 unrelated volunteers, 4 of them mismatched with recipients. All but 3 patients had initial hematologic recovery, but 5 more patients had secondary graft failure. Median intervals to neutrophil (greater than 0.5 x 10(9)/L) and platelet (greater than 20 x 10(9)/L) recovery were 14 days (range, 9-30 days) and 11 days (range, 8-45 days), respectively. Eleven (27%) patients had relapses and received escalated donor lymphocyte infusions, but only 3 of them had sustained responses. Acute and chronic graft-versus-host disease (GVHD) was observed in 17 (41%) and 13 (33%) patients, respectively. Seventeen (41%) patients have died, 5 of progressive disease. The 2-year overall survival and transplantation-related mortality (TRM) rates were 51% (95% confidence interval [CI], 33%-69%) and 26% (95% CI, 14%-46%), respectively. The alemtuzumabbased regimen was feasible and effective in patients with CLL with a relatively low rate of GVHD. However, TRM remains relatively high as a result of a variety of viral and fungal infections. Studies are ongoing to address the efficacy of reduced doses of alemtuzumab in this group of immunosuppressed patients.

Adult↗
PubMed2005

Outcomes for reduced-intensity allogeneic transplantation for multiple myeloma: an analysis of prognostic factors from the Chronic Leukaemia Working Party of the EBMT.

We report the outcome of 229 patients who received an allograft for myeloma with reduced-intensity conditioning (RIC) regimens from 33 centers within the European Group for Blood and Marrow Transplantation (EBMT). The median age was 52 years and 64% were male. Conditioning regimens were heterogeneous, but most were fludarabine based and T cell depleted with antithymocyte globulin or alemtuzumab. Transplantation-related mortality (TRM) at 1 year was 22%. The 3-year overall survival (OS) and progression-free survival (PFS) were 41% and 21%, respectively. Adverse OS was associated with chemoresistant disease (relative risk [RR], 2.9), more than 1 prior transplantation (RR, 2.0), and male patients with female donors (RR, 1.45). Adverse PFS was associated with chemoresistance (RR, 2.4) and alemtuzumab (RR, 1.8). TRM was increased with female-to-male donation (RR, 2.5) and transplantation more than 1 year from diagnosis (RR, 2.3). Grades II to IV acute graft-versus-host disease (aGvHD) occurred in 31%. Chronic GvHD was associated with better OS and PFS and were 84% and 46% for limited, 58% and 30% for extensive, and 29% and 12% in its absence suggesting that a graft-versus-myeloma effect is important. While RIC is feasible, heavily pretreated patients and patients with progressive disease do not benefit.

Adult↗
PubMed2005

Histologic features of the liver biopsy predict the clinical outcome for patients with graft-versus-host disease of the liver.

We reviewed liver histologic results from all allogeneic hematopoietic stem cell transplant recipients from our institution with a confirmed diagnosis of liver graft-versus-host disease (L-GVHD), no concomitant causes of liver dysfunction, and at least 1 diagnostic liver biopsy sample (n=33) to ascertain whether histologic features predicted clinical outcome. The 1-year probability of nonrelapse mortality (NRM) from the onset of liver dysfunction was 68.15%, with a median overall survival (OS) of 6.2 months for the entire group. Histologic features traditionally linked to the diagnosis of L-GVHD (eg, bile duct damage, bile duct lymphocytic infiltration, portal inflammation, and ductopenia) had no association with patient outcome. However, an extended histologic analysis showed that a high level of lobular inflammation (LI) and a low level of hepatocyte ballooning (HB) were independent favorable prognostic factors for NRM (RR, 5.14; P=.033; and relative risk (RR), 0.18; P=.018, respectively) and OS (RR, 3.99; P=.032; and RR, 0.23; P=.037, respectively). The presence and severity of LI and HB were not associated with patient- or transplant-related characteristics or L-GVHD clinical factors such as timing of the biopsy from the onset of L-GVHD, acute versus chronic presentation, or whether the patients had started immunosuppressive treatment with steroids at the time of the biopsy. In multivariate analysis that included clinical prognostic factors, the combined histologic risk posed by high LI and low HB retained independent favorable prognostic value for NRM (RR, 5.05; P=.015) and OS (RR, 3.31; P=.038). This information, if replicated in other studies, could expand current indications for liver biopsy in patients with L-GVHD, not only to exclude other causes of liver injury, but also to predict clinical outcome, and should be considered in the selection of patients and the design of future trials with new experimental therapies for this complication. Prospective validation of our findings is warranted.

Adolescent↗
PubMed2005

Reduced intensity allogeneic stem cell transplantation for low grade non-Hodgkin's lymphoma.

Treatment options for patients with low-grade non-Hodgkin's lymphomas (NHLs) are many and varied. For those with relapsed or refractory disease, outcome following conventional and high dose chemotherapy remains poor. Conventional allogeneic stem cell transplantation has been shown to have curative potential in the management of indolent NHL, but due to the high transplant-related mortality improvement in overall survival has been insignificant. Recent reports have confirmed the feasibility of reduced intensity conditioning allogeneic stem cell transplantation as a treatment option for many older patients with NHL. Here we will discuss the rationale behind reduced intensity transplantation (RIT), the development of the regimens currently adopted in clinical practice and review the published literature on RIT for indolent NHL.

Hematopoietic Stem Cell Transplantation↗
PubMed2005

Outcome following alemtuzumab (CAMPATH-1H)-containing reduced intensity allogeneic transplant regimen for relapsed and refractory non-Hodgkin's lymphoma (NHL).

We report the outcome following RIT for NHL in 88 patients (LG-NHL n = 41, HG-NHL n = 37, MCL n = 10). Thirty-seven had received prior autografts and 21 were in CR at transplant. Conditioning was with alemtuzumab, fludarabine and melphalan. Sixty-five patients received PBSC from HLA-identical siblings and 23 received BM from matched unrelated donors. GVHD prophylaxis was with cyclosporin A. Grade III-IV acute GVHD developed in 4 patients and chronic GVHD in 6 patients. With a median follow-up of 36 months (range 18-60), the actuarial overall survival (OS) at 3 years was 34% for HG-NHL, 60% for MCL and 73% for LG-NHL (p < or = 0.001). The 100-day and 3-year TRM for patients with LG-NHL were 2% and 11%, respectively, and were better (p = 0.01) than for patients with HG-NHL (27% and 38%, respectively). The actuarial current progression free survival (PFS) at 3 years, including those who achieved remission following DLI for progression, was 65% for LG-NHL 50% for MCL and 34% for HG-NHL (p = 0.002). Twenty-one patients received DLI for MRD, persistent disease or relapse and 15 received DLI for mixed hematopoietic chimerism. Patients with relapsed LG-NHL and CLL achieve excellent PFS with extremely low TRM and GVHD, even when matched family donors are unavailable.

Adolescent↗
PubMed2005

The role of allogeneic transplantation in non-Hodgkin's lymphoma.

The evolution of combination chemotherapy regimens, combined with improvements in supportive care, has incrementally improved survival outcomes for patients with non-Hodgkin's lymphomas (NHL). Although 40-60% of younger patients with diffuse large cell lymphoma can now expect to be cured, significant numbers will either fail to achieve a remission or relapse after attaining a remission. In addition, certain histological subtypes are associated with particularly poor prognoses with combination chemotherapy alone (e.g. mantle cell lymphoma, B-cell prolymphocytic leukaemia). Relatively few of these patients can achieve long-term responses. Other NHL subtypes, whilst associated with more favourable prognoses in terms of overall survival, are rarely, if ever, cured (e.g. most low grade NHL including follicular lymphoma, chronic lymphocytic leukaemia and small lymphocytic lymphoma). For these reasons dose escalation and allogeneic transplantation have been investigated as potential ways of improving outcome, although this has mainly been in the setting of advanced disease. Any possible benefits have frequently been out-weighed by procedural morbidity and mortality. The parallel development of transplantation approaches that limit procedural toxicity along with advances in supportive care require that the role of allogeneic haematopoietic stem cell transplantation in the management of lymphoma be re-evaluated.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Conventional second-line salvage chemotherapy regimens are not warranted in patients with malignant lymphomas who have progressive disease after first-line salvage therapy regimens.

This study aimed to determine the outcome of patients with relapsed or refractory lymphoma who have an inadequate response to first-line salvage therapy (1 degrees ST) and who subsequently receive a second-line salvage regimen (2 degrees ST) with the intention of ultimately proceeding to high-dose therapy. The outcome of 57 patients [Hodgkin's Lymphoma 17, histologically-aggressive non-Hodgkin's Lymphoma (NHL) 26, histologically-indolent NHL 14] who received more than one modality of conventional-dose salvage therapy was analysed. Sixteen patients had a partial response (PR) to 1 degrees ST, but subsequently received 2 degrees ST because the PR was judged to be inadequate (iPR) because of persisting disease bulk or marrow infiltration. Of these 16 patients, 10 (63%) continued to respond to 2 degrees ST. Of the 15 patients who had stable disease following 1 degrees ST, 5 (33%) responded to 2 degrees ST. Only one of the 24 (4%) with progressive disease (PD) following 1 degrees ST, responded to 2 degrees ST. 25 of the 57 patients ultimately underwent stem cell transplantation. The 2-year progression-free survival (PFS) and the 3-year overall survival (OS) for all patients was 24% and 31%, respectively. Long-term survival was highly dependent on response to 1 degrees ST (P = 0.0001); in patients with PD following 1 degrees ST, the PFS and OS at 3 years was only 4%. This analysis indicates that patients with malignant lymphomas, who have PD on 1 degrees ST, are not rescued by subsequent salvage regimens. They should either be treated palliatively or novel approaches should be explored.

Adolescent↗
PubMed2005

The impact of donor factors on primary non-engraftment in recipients of reduced intensity conditioned transplants from unrelated donors.

BACKGROUND AND OBJECTIVES: Primary graft failure is a serious complication following hematopoietic cell transplants, particularly when using unrelated donors. We analyzed factors affecting primary graft failure in recipients of hematopoietic cell transplants from unrelated donors, which were performed using reduced intensity conditioning. DESIGN AND METHODS: This was a retrospective analysis of 144 patients whose transplants took place between March 1998 and October 2004. The data were analyzed in January 2005. RESULTS: The median age of the patients was 51 years. The diagnoses were varied. Conditioning regimens were fludarabine, melphalan, campath (n=80), fludarabine, busulphan, campath (n=38), fludarabine, BEAM, campath (n=9) and other (n=17). The donor was 10/10 allele matched in 95/144 (66%) cases; 94 donated bone marrow and 50 peripheral blood stem cells. The 3-year probability of overall survival was 43%. The median follow-up was 724 days (range: 91-1651 days). Of evaluable patients, 7/140 (5%) failed to achieve myeloid engraftment. Primary graft failure was significantly associated with the use of a mismatched donor (6/47,13% versus 1/93, 1%, p=0.006), as well as: bone marrow as the source of stem cells (p=0.046), chronic myeloid leukemia compared to other diagnoses (p=0.022), and a female rather than a male donor (p=0.019). In multivariate analysis chronic myeloid leukemia, HLA mismatched and/or female donors remained significantly associated with primary graft failure. Single HLA mismatches were tolerated, however in multiply mismatched grafts, overall survival was worse (p=0.005); transplanted-related mortality (p=0.005) and chronic graft-versus-host disease (p=0.025) were increased. INTERPRETATION AND CONCLUSIONS: These data have implications for the choice of donor and stem cell source in transplants performed using reduced intensity conditioning regimens, suggesting that the use of bone marrow, female donors and HLA-mismatched grafts increase the risk of primary graft failure, and should be avoided in certain situations.

Adolescent↗
PubMed2004

Outcomes after alemtuzumab-containing reduced-intensity allogeneic transplantation regimen for relapsed and refractory non-Hodgkin lymphoma.

We report the outcomes after reduced-intensity conditioning allogeneic stem cell transplantation (RIT) for non-Hodgkin lymphoma (NHL) in 88 patients (low-grade NHL [LG-NHL], n = 41; high-grade NHL [HG-NHL], n = 37; mantle cell lymphoma [MCL], n = 10). Thirty-seven patients had previously received autografts, and 21 were in complete remission (CR) at transplantation. Conditioning therapy consisted of alemtuzumab, fludarabine, and melphalan. Sixty-five patients received peripheral blood stem cells (PBSCs) from HLA-identical siblings, and 23 received bone marrow (BM) from matched unrelated donors. Prophylaxis for graft-versus-host disease (GVHD) consisted of cyclosporin A. Grade III-IV acute GVHD developed in 4 patients, and chronic GVHD developed in 6 patients. With a median follow-up of 36 months (range, 18-60 months), the actuarial overall survival (OS) rates at 3 years were 34% for HG-NHL, 60% for MCL, and 73% for LG-NHL (P < .001). The 100-day and 3-year transplant-related mortality (TRM) rates for patients with LG-NHL were 2% and 11%, respectively, and were better (P = .01) than they were for patients with HG-NHL (27% and 38%, respectively). The actuarial current progression-free survival (PFS) rate at 3 years, including the rate for patients who achieved remission after donor lymphocyte infusion (DLI) for progression, was 65% for LG-NHL, 50% for MCL, and 34% for HG-NHL (P = .002). Twenty-one patients underwent DLI for matched related donor (MD)-persistent disease or relapse, and 15 underwent DLI for mixed hematopoietic chimerism. Patients who experienced relapses of LG-NHL and chronic lymphocytic leukemia (CLL) achieved excellent PFS with extremely low TRM and GVHD, even when matched related donors were unavailable.

Actuarial Analysis↗