Publications by authors named "Linda Hamelin"

7 Publications

  • Page 1 of 1

Effect of Donor Age and Donor Relatedness on Time to Allogeneic Hematopoietic Cell Transplantation in Acute Leukemia.

Biol Blood Marrow Transplant 2018 12 21;24(12):2466-2470. Epub 2018 Jul 21.

Department of Medicine (Hematology), University of Ottawa, Ottawa, Ontario, Canada; Blood and Marrow Transplant Program, The Ottawa Hospital, Ottawa, Ontario, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; OneMatch Stem Cell & Marrow Network, Canadian Blood Services, Ottawa, Ontario, Canada. Electronic address:

Relapse after allogeneic hematopoietic cell transplantation (HCT) for acute leukemia can be reduced when pursued early after first complete remission. The impact of donor age and donor relatedness on the time from diagnosis to transplant in patients with acute leukemia was examined to clarify the design of future prospective studies that can address optimal donor choice. Files of 100 consecutive patients undergoing transplantation for leukemia were reviewed. Recipients of related donors (RDs) and unrelated donors (UDs) were not significantly different in terms of recipient gender, age, underlying diagnosis, disease risk index, graft source, or donor HLA match. UDs were significantly younger than RDs (median age, 29 versus 51, P < .001). Multivariate linear regression revealed that when controlling for age of donor and recipient, the time from diagnosis to transplant was 35% longer with UDs compared with RDs (P = .018). No significant correlation was observed between donor and recipient age on length of time to transplant (P = .134 and P = .850, respectively), when controlling for other variables. The steps in UD procurement that contribute most to the longer time to transplant relate to activating the donor workup and scheduling the donor workup before cell collection. Understanding sources of delay in the transplant process will help transplant centers and UD registries reduce the time to transplant for patients with acute leukemia and will provide necessary insight for the design of prospective controlled studies that can address optimal donor choice.
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http://dx.doi.org/10.1016/j.bbmt.2018.07.022DOI Listing
December 2018

Immunoablation and autologous haemopoietic stem-cell transplantation for aggressive multiple sclerosis: a multicentre single-group phase 2 trial.

Lancet 2016 Aug 9;388(10044):576-85. Epub 2016 Jun 9.

Ottawa Hospital Research Institute, Ottawa, ON, Canada; Department of Medicine, University of Ottawa, Ottawa, ON, Canada; The Ottawa Hospital MS Clinic, Ottawa, ON, Canada.

Background: Strong immunosuppression, including chemotherapy and immune-depleting antibodies followed by autologous haemopoietic stem-cell transplantation (aHSCT), has been used to treat patients with multiple sclerosis, improving control of relapsing disease. We addressed whether near-complete immunoablation followed by immune cell depleted aHSCT would result in long-term control of multiple sclerosis.

Methods: We did this phase 2 single-arm trial at three hospitals in Canada. We enrolled patients with multiple sclerosis, aged 18-50 years with poor prognosis, ongoing disease activity, and an Expanded Disability Status Scale of 3.0-6.0. Autologous CD34 selected haemopoietic stem-cell grafts were collected after mobilisation with cyclophosphamide and filgrastim. Immunoablation with busulfan, cyclophosphamide, and rabbit anti-thymocyte globulin was followed by aHSCT. The primary outcome was multiple sclerosis activity-free survival (events were clinical relapse, appearance of a new or Gd-enhancing lesion on MRI, and sustained progression of Expanded Disability Status Scale score). This study was registered at ClinicalTrials.gov, NCT01099930.

Findings: Between diagnosis and aHSCT, 24 patients had 167 clinical relapses over 140 patient-years with 188 Gd-enhancing lesions on 48 pre-aHSCT MRI scans. Median follow-up was 6.7 years (range 3.9-12.7). The primary outcome, multiple sclerosis activity-free survival at 3 years after transplantation was 69.6% (95% CI 46.6-84.2). With up to 13 years of follow-up after aHSCT, no relapses occurred and no Gd enhancing lesions or new T2 lesions were seen on 314 MRI sequential scans. The rate of brain atrophy decreased to that expected for healthy controls. One of 24 patients died of transplantation-related complications. 35% of patients had a sustained improvement in their Expanded Disability Status Scale score.

Interpretation: We describe the first treatment to fully halt all detectable CNS inflammatory activity in patients with multiple sclerosis for a prolonged period in the absence of any ongoing disease-modifying drugs. Furthermore, many of the patients had substantial recovery of neurological function despite their disease's aggressive nature.

Funding: Multiple Sclerosis Scientific Research Foundation.
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http://dx.doi.org/10.1016/S0140-6736(16)30169-6DOI Listing
August 2016

Myasthenia Gravis Treated With Autologous Hematopoietic Stem Cell Transplantation.

JAMA Neurol 2016 06;73(6):652-8

Division of Hematology, University of Ottawa, Ottawa, Ontario, Canada2The Ottawa Hospital Research Institute, Ottawa, Ontario, Canada3The Bone Marrow Transplant Programme, University of Ottawa, The Ottawa Hospital, Ottawa, Ontario, Canada.

Importance: Some patients with myasthenia gravis (MG) do not respond to conventional treatment and have severe or life-threatening symptoms. Alternate and emerging therapies have not yet proved consistently or durably effective. Autologous hematopoietic stem cell transplant (HSCT) has been effective in treating other severe autoimmune neurologic conditions and may have similar application in MG.

Objective: To report 7 cases of severe MG treated with autologous HSCT in which consistent, durable, symptom-free, and treatment-free remission was achieved.

Design, Setting, And Participants: This retrospective cohort study reports outcomes at The Ottawa Hospital, a large, Canadian, tertiary care referral center with expertise in neurology and HSCT, from January 1, 2001, through December 31, 2014, with a median follow-up of 40 months (range, 29-149 months). Data collection and analysis were performed from February 1 through August 31, 2015. All patients with MG treated with autologous HSCT at The Ottawa Hospital were included. All had persistent severe or life-threatening MG-related symptoms despite continued use of intensive immunosuppressive therapies.

Interventions: Autologous hematopoietic stem cell grafts were mobilized with cyclophosphamide and granulocyte colony-stimulating factor, collected by peripheral blood leukapheresis, and purified away from contaminating lymphocytes using CD34 immunomagnetic selection. Patients were treated with intensive conditioning chemotherapy regimens to destroy the autoreactive immune system followed by graft reinfusion for blood and immune reconstitution.

Main Outcomes And Measures: The primary outcome was MG disease activity after autologous HSCT measured by frequency of emergency department visits and hospitalizations and Myasthenia Gravis Foundation of America (MGFA) clinical classification, MGFA therapy status, and MGFA postintervention status. Safety outcomes included all severe autologous HSCT-related complications.

Results: Seven patients underwent autologous HSCT, 6 for MG and 1 for follicular lymphoma with coincident active MG. Mean (SD) ages at MG diagnosis and at autologous HSCT were 37 (11) and 44 (10) years, respectively. Five patients (71%) had concurrent autoimmune or lymphoproliferative illnesses related to immune dysregulation. All patients had distinct clinical and electromyographic evidence of MG (MGFA clinical classification IIIb-V). All patients achieved durable MGFA complete stable remission with no residual MG symptoms and freedom from any ongoing MG therapy (MGFA postintervention status of complete stable remission). Three patients (43%) experienced transient viral reactivations, and 1 (14%) developed a secondary autoimmune disease after autologous HSCT, all of which resolved or stabilized with treatment. There were no treatment- or MG-related deaths.

Conclusions And Relevance: Autologous HSCT results in long-term symptom- and treatment-free remission in patients with severe MG. The application of autologous HSCT for this and other autoimmune neurologic conditions warrants prospective study.
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http://dx.doi.org/10.1001/jamaneurol.2016.0113DOI Listing
June 2016

Improved Prediction of CD34+ Cell Yield before Peripheral Blood Hematopoietic Progenitor Cell Collection Using a Modified Target Value-Tailored Approach.

Biol Blood Marrow Transplant 2016 Apr 28;22(4):763-767. Epub 2015 Nov 28.

Ottawa Hospital Research Institute, Ottawa, Canada.

The most commonly used stem cell source for both autologous and allogeneic transplantation is mobilized peripheral blood hematopoietic progenitor cells collected by apheresis. In the 1990s, an Italian group used the correlation between the preapheresis peripheral blood CD34+ cell count and the final number of CD34+ cells collected to devise a formula for "target value-tailored" (TVT) apheresis. Using local patient data, the Canadian Blood Services Stem Cell Laboratory created a similar model to determine the blood volume to process during apheresis collection. The objectives of this study were to determine the correlation between the number of CD34+ cells predicted by the TVT formula and the actual number of CD34+ cells collected and to determine whether the TVT formula remains predictive when applied to an external data set. All apheresis collections performed at the Ottawa Hospital between January 1, 2003 and October 2, 2013 were reviewed. The primary outcome was the correlation between the number of CD34+ cells predicted by the TVT formula and the actual number of CD34+ cells collected on day 1 of apheresis. For the external data set, all autologous collections performed at the London Health Sciences Centre between December 1, 2008 and December 1, 2013 were reviewed. The external data set was divided into test and validation sets to determine whether a model could be created to predict the final number of CD34+ cells collected on day 1 based on the preapheresis CD34+ count. A total of 1252 collections were included in the analysis. The Ottawa data set included 1012 collections, 836 of which were autologous and 176 of which were from donors. Of the autologous collections in Ottawa, 764 (92.5%) were first collections. In 759 (91%) collections, chemotherapy plus granulocyte colony-stimulating factor (G-CSF) was used as the mobilization regimen. In 747 collections (89%), only 1 collection day was required to achieve the desired number of CD34+ cells. The TVT estimate was highly predictive of the number of CD34+ cells × 10(6)/kg actually collected on apheresis day 1 (r = .90, P < .0001). The London data set included 240 autologous collections. All mobilizations were with G-CSF alone. For the test set, the precollection CD34+ count was highly predictive of the number of CD34+ cells × 10(6)/kg collected on day 1 of apheresis. Applying this model to the validation set, the correlation between the predicted and final and day 1 CD34+ cells × 10(6)/kg count was .9186 (P < .0001). Using a modified TVT approach, the preapheresis CD34+ count can be used to accurately predict the number of CD34+ cells × 10(6)/kg collected on day 1. This approach can be applied at other centers and for different diseases and mobilization regimens. This method can be used to individualize the blood volume processed and, thus, optimize resource utilization.
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http://dx.doi.org/10.1016/j.bbmt.2015.11.016DOI Listing
April 2016

Autologous stem cell transplantation for stiff person syndrome: two cases from the Ottawa blood and marrow transplant program.

JAMA Neurol 2014 Oct;71(10):1296-9

Ottawa Hospital Blood and Marrow Transplant Program, Ottawa, Ontario, Canada3Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.

Importance: Stiff person syndrome (SPS) is a rare neurological disease causing significant functional disability for patients and presenting a therapeutic challenge for clinicians. Autologous hematopoietic stem cell transplantation (auto-HSCT) has been used successfully to remit autoimmune-mediated neurological diseases. We report 2 cases of severe SPS treated with auto-HSCT, a novel therapy for this disease.

Observations: Two anti-glutamic acid decarboxylase antibody-positive patients with SPS had an autologous hematopoietic stem cell graft collected and stored. Subsequently, the patients underwent auto-HSCT. Both patients achieved clinical remission with sustained, marked improvement in symptoms and a return to premorbid functioning, now more than 2.5 and 4.5 years after the procedure.

Conclusions And Relevance: Stiff person syndrome represents a novel indication for auto-HSCT. The resolution of clinical manifestations of SPS despite the persistence of anti-glutamic acid decarboxylase antibodies following auto-HSCT suggests that the antibody does not play a direct role in pathogenesis of SPS.
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http://dx.doi.org/10.1001/jamaneurol.2014.1297DOI Listing
October 2014

Leading change: Retrospective evaluation of a nurse-led initiative in vascular access options for autologous stem cell transplant recipients ranging from Hickman catheters to peripherally inserted central catheters.

J Infus Nurs 2006 Mar-Apr;29(2):81-8

Blood and Marrow Transplant Program, Ottawa Hospital-General Campus, Ontario, Canada.

Central venous access is essential for patients undergoing autologous hematopoietic stem cell transplantation (ASCT). Traditionally, tunneled silastic catheters have been inserted in these patients. However, changes in resource allocation, resulting in reduced surgery and surgeon time and decreasing toxicity associated with ASCT, have caused changes in venous access needs and options. This led the advanced practice nurse in the transplant program to evaluate other central access devices, which resulted in the introduction of peripherally inserted central catheters (PICCs) for this patient population. This study reports the results of a retrospective analysis comparing efficacy and complication profiles between 50 patients with the traditional Hickman catheter and 70 patients with PICCs.
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http://dx.doi.org/10.1097/00129804-200603000-00005DOI Listing
May 2006
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