Gamma-irradiation of pretransplant blood transfusions from unrelated donors prevents sensitization to minor histocompatibility antigens on dog leukocyte antigen-identical canine marrow grafts

Addition of Astatine-211-Labeled Anti-CD45 Antibody to TBI as Conditioning for DLA-Identical Marrow Transplantation: A Novel Strategy to Overcome Graft Rejection in a Canine Presensitization Model: "Radioimmunotherapy to Overcome Transfusion-Induced Sensitization"

In a canine model of presensitization using donor blood transfusions, 100% of historical control dogs receiving 9.2 Gy total body irradiation (TBI) conditioning before dog leukocyte antigen (DLA)-identical marrow grafts had graft rejection. In this presensitization model, we investigated whether the addition of monoclonal antibody (mAb)-based targeted radioimmunotherapy (RIT) with astatine-211 (²¹¹At) to TBI could overcome graft rejection. ²¹¹At is an alpha-particle-emitting isotope that has a short path length, very high energy, and a short t½ of 7.2 hours, which allowed targeting radiation to the T cells responsible for graft rejection. Normal canine recipients were given three preceding transfusions of unirradiated whole blood on days -24, -17, and -10 before transplant from their DLA-identical marrow donors. ²¹¹At-anti-CD45 mAb was administered on day -3, and TBI followed by marrow grafts on day 0. Six of the 7 dogs (86%) achieved sustained engraftment as assessed by 100% donor chimerism in mononuclear cells, granulocytes, and CD3⁺ T cells. One dog receiving the lowest CD34⁺ cell content (0.35 × 10⁶ cells/kg) rejected the graft. There were no late rejections in dogs followed up to 1 year. Graft-versus-host disease was seen in one dog. ²¹¹At-anti-CD45 mAb in combination with TBI as conditioning was successful in abrogating graft rejection in 86% of dogs in this presensitization model. ²¹¹At-anti-CD45 mAb conditioning with TBI may serve as a novel promising strategy to overcome graft rejection in heavily transfused patients with red cell disorders.

Mixed chimerism renders residual host dendritic cells incapable of alloimmunization of the marrow donor in the canine model of allogeneic marrow transplantation

This study tested whether an alloimmune response can occur in the marrow donor when infused or injected with leukocytes from their mixed chimeric transplant recipient. Two mixed chimeras were produced after conditioning with three Gray total body irradiation, donor marrow infusion, and post-grafting immunosuppression. The marrow donors were then repeatedly infused and injected with leukocytes from their respective chimeric recipient. A donor lymphocyte infusion (DLI) into their mixed chimeras had no effect, even after the experiments were repeated. The presence of blood dendritic cells (DCs) of recipient origin was confirmed in chimeric recipients, as well as the presence of microchimerism in the marrow donors. Donor sensitization did occur following placement of a recipient skin graft that was confirmed following DLI into recipients that changed the mixed chimeras into full donor chimeras. These observations suggest that mixed chimerism renders recipient peripheral blood DCs incapable of inducing a donor T cell response.

A preclinical model of double- versus single-unit unrelated cord blood transplantation

Cord blood transplantation (CBT) with units containing total nucleated cell (TNC) dose >2.5 x 10(7)/kg is associated with improved engraftment and decreased transplant-related mortality. For many adults no single cord blood units are available that meet the cell dose requirements. We developed a dog model of CBT to evaluate approaches to overcome the problem of low cell dose cord blood units. This study primarily compared double- versus single-unit CBT. Unrelated dogs were bred and cord blood units were harvested. We identified unrelated recipients that were dog leukocyte antigen (DLA)-88 (class I) and DLA-DRB1 (class II) allele-matched with cryopreserved units. Each unit contained Collapse

Key Words Collapse

MESH Headings

• Animals
• Cord Blood Stem Cell Transplantation/adverse effects
• Cord Blood Stem Cell Transplantation/methods
• Disease Models, Animal
• Dogs
• Female
• Graft Rejection/immunology
• Male
• Survival Rate

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Grants

• U19 AI067770-02 NIAID NIH HHS
• U19 AI067770-030005 NIAID NIH HHS
• U19 AI067770-05 NIAID NIH HHS
• U19 AI 067770 NIAID NIH HHS
• U19 AI067770-01 NIAID NIH HHS
• R01 DK042716 NIDDK NIH HHS
• DK42716 NIDDK NIH HHS
• R01 DK042716-15 NIDDK NIH HHS
• P30 CA015704 NCI NIH HHS
• CA78902 NCI NIH HHS
• U19 AI067770 NIAID NIH HHS
• U19 AI067770-050005 NIAID NIH HHS
• P30 CA015704-35 NCI NIH HHS
• CA15704 NCI NIH HHS
• U19 AI067770-010005 NIAID NIH HHS
• R01 DK042716-16 NIDDK NIH HHS
• P30 CA015704-34 NCI NIH HHS
• U19 AI067770-04 NIAID NIH HHS
• P01 CA078902 NCI NIH HHS
• P01 CA078902-11 NCI NIH HHS
• P01 CA078902-10 NCI NIH HHS
• U19 AI067770-040005 NIAID NIH HHS
• U19 AI067770-020005 NIAID NIH HHS

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Affiliation(s)

George E Georges Clinical Research Division, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington 98109, USA.
Vladimir Lesnikov
Szczepan W Baran
Anna Aragon
Marina Lesnikova
Robert Jordan
Ya-Ju Laura Yang
Murad Y Yunusov
Eustacia Zellmer
Shelly Heimfeld
Gopalakrishnan M Venkataraman
Michael A Harkey
Scott S Graves
Rainer Storb
Barry E Storer
Richard A Nash

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Outcome of allogeneic hematopoietic cell transplantation from HLA-identical siblings for severe aplastic anemia in patients over 40 years of age

Patients with severe aplastic anemia (SAA) over 40 years of age are often not offered treatment with hematopoietic cell transplantation (HCT) because of concerns about treatment-related morbidity or mortality. To evaluate this risk, we analyzed outcomes after allogeneic HCT from HLA-identical sibling donors for all older patients with SAA at our center since 1988. The 23 consecutive patients ranged in age from 40 to 68 years. The conditioning regimen was cyclophosphamide (200 mg/kg) and horse antithymocyte globulin. Methotrexate and cyclosporine were given for postgrafting immunosuppression. The cumulative incidences of grades II, III, and IV acute graft-versus-host-disease were 30%, 4%, and 0%, respectively; that for chronic GVHD was 26%. With a median follow-up of 9.1 years, overall survival was 65%. Documented infections within 1 month before HCT were significantly associated with risk of early treatment-related mortality (P < .001). The median time to discontinuation of posttransplant immunosuppression was 6.2 (range: 5.9-92.0) months. Three patients developed superficial basal cell carcinoma between 5.5 and 15 years after HCT. Our data favor a practice of extending HLA-identical sibling HCT for treatment of SAA in patients older than 40 years of age who are without significant medical comorbidities.

Graft failure after allogeneic hematopoietic cell transplantation

Graft failure is a significant complication following allogeneic hematopoietic cell transplantation (alloHCT). It may result from rejection caused by recipient T cells, natural killer (NK) cells, or antibodies. It is increased in HLA-mismatched grafts, unrelated grafts, T cell-replete transplants, sensitized patients, and in patients treated with reduced-intensity conditioning (RIC). In recipients of unrelated grafts, graft failure is increased in patients receiving major AB0 blood group mismatched transplants (P = .008). Recent data also suggest that donor-specific antibodies to CD34(+)/VEGFR-2(+) cells may be involved in graft failure after alloHCT. Graft failure may be overcome by more intensified conditioning, increased cell dose, or more effective immunosuppression. With more frequent use of RIC, cord blood grafts and other HLA-mismatched transplants, graft failure is an increasing problem after alloHCT.

Diagnosis and treatment of acquired aplastic anemia

Acquired severe aplastic anemia can be treated successfully with either immunosuppressive therapy or bone marrow transplantation. Although immunosuppressive therapy can be readily administered to all patients, it is not a curative approach and is associated with a higher risk of clonal evolution than is transplantation, which yields rapid and long-lasting hematologic remission. This article reviews the key diagnostic and prognostic factors that influence the choice of therapy in patients with acquired aplastic anemia.

Outcome of bone marrow transplantation in acquired and inherited aplastic anaemia in the Republic of Ireland

BACKGROUND

Severe Aplastic Anaemia (SAA) and Fanconi Anaemia (FA) are rare haematological disorders characterised by pancytopenia and bone marrow hypoplasia.

AIMS

We performed a retrospective study of all patients who underwent BMT for SAA and FA at St James's Hospital, Dublin, and at OLHSC, Crumlin, between 1985 and 2002.

METHODS

The medical records of 63 patients, 50 with acquired SAA and 13 with FA, were reviewed.

RESULTS

The median age at the time of transplant was 14 years (range 3-43 years). The actuarial survival (OS) (n = 63) was 76% at 17 years. The transplant related mortality (TRM) was 22% (n = 14). The most common cause of death was infection (46%). The survival was significantly better in patients receiving their transplant after 1995 (p = 0.002). Outcome was superior in those receiving less than 20 red cell transfusions prior to transplant: OS 91% (< 20 Units) versus 62% (> or = 20 Units).

CONCLUSIONS

These national results are comparable to those of published international series and support the use of BMT in the treatment of SAA and FA. The known adverse effect of prior transfusion was confirmed.

Diagnosis and treatment of children with aplastic anemia

BACKGROUND

Long-term survival rates among children diagnosed with severe aplastic anemia (SAA) are excellent due to the success of human leukocyte antigen (HLA)-identical related hematopoietic stem cell transplantation (HSCT), concurrent advances in immunosuppressive treatment (IST), and improved supportive care. The challenge in making treatment recommendations for children with SAA, therefore, is to balance the apparent chronicity and morbidity following IST, with the potential up-front toxicity and complications of HSCT.

METHODS

This review provides an update on the diagnosis and a risk-based treatment algorithm for children with acquired SAA. Recent experience using alternative donor HSCT and efforts to extend HSCT eligibility through advances in donor matching, de-escalation of conditioning regimens, and potential marrow graft engineering are highlighted. We discuss IST response rates, risks of relapse, and complications including clonal evolution.

CONCLUSIONS

While good treatment options exist for a majority of children diagnosed with SAA, novel non-transplantation treatments for unresponsive and relapsed patients without suitable transplant donors are needed. Further improvements in outcome will ultimately require a more complete understanding of the pathophysiology of aplastic anemia (AA).

Non-total body irradiation containing preparative regimen in alternative donor bone marrow transplantation for severe aplastic anemia

Using non-total body irradiation (TBI) containing preparative regimens, 13 patients with severe aplastic anemia (SAA) were transplanted from an alternative donor in a single institute. In total, 12 donors were unrelated volunteers and one was an HLA one-locus mismatched sibling. Median time from diagnosis of SAA to bone marrow transplantation (BMT) was 10.1 months (range, 1.6-180.1). Nine patients had received immunosuppressive treatment with ATG before BMT, while four had not. Preparative regimens consisted of cyclophosphamide plus ATG in nine patients, cyclophosphamide plus fludarabine in two patients, and cyclophosphamide plus fludarabine plus ATG in two patients. All patients received non-T-cell depleted bone marrow from the donor. Cyclosporine plus methotrexate were given for GVHD prophylaxis. All patients engrafted on a median of day 21 (range, 15-27). Grade III-IV acute GVHD developed in three (23%) of 13 patients and extensive chronic GVHD in four (31%) of 12 evaluable patients. With a median follow-up duration of 1138 days (range, 118-1553), 10 patients are alive with durable engraftment showing 74.6% (95% confidence interval, 49.5-99.7%) of survival rate. Cause of the deaths was CNS bleeding in one and chronic GVHD in two. In conclusion, non-TBI containing preparative regimen could ensure durable engraftment in alternative donor BMT for SAA and showed promising results.

Novel therapeutic approaches in sickle cell disease

In this update, selected clinical features of sickle cell disease and their management are reviewed. In addition, the current status of interventions that have curative potential for sickle cell disease is discussed, with particular attention focused on indications, methodology, recent results, and challenges to wider clinical application. In Section I, Dr. Nienhuis describes recent improvements in vector technology, safety, and replacement gene expression that are creating the potential for clinical application of this technology. In Section II, Dr. Vichinsky reviews our current understanding of the pathophysiology and treatment of pulmonary injury in sickle cell disease. The acute and chronic pulmonary complications of sickle cell disease, modulators and predictors of severity, and conventional and novel treatment of these complications are discussed. In Section III, Dr. Walters reviews the current status of hematopoietic cell transplantation for sickle cell disease. Newer efforts to expand its availability by identifying alternate sources of stem cells and by reducing the toxicity of transplantation are discussed.

Hematopoietic Cell Transplantation for Benign Hematological Disorders and Solid Tumors

Allogeneic hematopoietic cell transplantation (HCT) has been successfully used as replacement therapy for patients with aplastic anemia and hemoglobinopathies. Both autologous and allogeneic HCT following high-dose chemotherapy can correct manifestations of autoimmune diseases. The impressive allogeneic graft-versus-tumor effects seen in patients given HCT for hematological malignancies have stimulated trials of allogeneic immunotherapy in patients with otherwise refractory metastatic solid tumors. This session will update the status of HCT in the treatment of benign hematological diseases and solid tumors.

In Section I, Dr. Rainer Storb reviews the development of nonmyeloablative conditioning for patients with severe aplastic anemia who have HLA-matched family members. He also describes the results in patients with aplastic anemia given HCT from unrelated donors after failure of responding to immunosuppressive therapy. The importance of leuko-poor and in vitro irradiated blood product transfusions for avoiding graft rejection will be discussed.

In Section II, Dr. Guido Lucarelli reviews the status of marrow transplantation for thalassemia major and updates results obtained in children with class I and class II severity of thalassemia. He also describes results of new protocols for class III patients and efforts to extend HCT to thalassemic patients without HLA-matched family members.

In Section III, Dr. Peter McSweeney reviews the current status of HCT for severe autoimmune diseases. He summarizes the results of autologous HCT for systemic sclerosis, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus, and reviews the status of planned Phase III studies for autologous HCT for these diseases in North America and Europe. He also discusses a possible role of allogeneic HCT in the treatment of these diseases.

In Section IV, Dr. Richard Childs discusses the development and application of nonmyeloablative HCT as allogeneic immunotherapy for treatment-refractory solid tumors. He reviews the results of pilot clinical trials demonstrating graft-versus-solid tumor effects in a variety of metastatic cancers and describes efforts to characterize the immune cell populations mediating these effects, as well as newer methods to target the donor immune system to the tumor.

Hematopoietic Cell Transplantation for Benign Hematological Disorders and Solid Tumors

Allogeneic hematopoietic cell transplantation (HCT) has been successfully used as replacement therapy for patients with aplastic anemia and hemoglobinopathies. Both autologous and allogeneic HCT following high-dose chemotherapy can correct manifestations of autoimmune diseases. The impressive allogeneic graft-versus-tumor effects seen in patients given HCT for hematological malignancies have stimulated trials of allogeneic immunotherapy in patients with otherwise refractory metastatic solid tumors. This session will update the status of HCT in the treatment of benign hematological diseases and solid tumors.

In Section I, Dr. Rainer Storb reviews the development of nonmyeloablative conditioning for patients with severe aplastic anemia who have HLA-matched family members. He also describes the results in patients with aplastic anemia given HCT from unrelated donors after failure of responding to immunosuppressive therapy. The importance of leuko-poor and in vitro irradiated blood product transfusions for avoiding graft rejection will be discussed.

In Section II, Dr. Guido Lucarelli reviews the status of marrow transplantation for thalassemia major and updates results obtained in children with class I and class II severity of thalassemia. He also describes results of new protocols for class III patients and efforts to extend HCT to thalassemic patients without HLA-matched family members.

In Section III, Dr. Peter McSweeney reviews the current status of HCT for severe autoimmune diseases. He summarizes the results of autologous HCT for systemic sclerosis, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus, and reviews the status of planned Phase III studies for autologous HCT for these diseases in North America and Europe. He also discusses a possible role of allogeneic HCT in the treatment of these diseases.

In Section IV, Dr. Richard Childs discusses the development and application of nonmyeloablative HCT as allogeneic immunotherapy for treatment-refractory solid tumors. He reviews the results of pilot clinical trials demonstrating graft-versus-solid tumor effects in a variety of metastatic cancers and describes efforts to characterize the immune cell populations mediating these effects, as well as newer methods to target the donor immune system to the tumor.

Stem cell transplantation for aplastic anemia

Survival of patients with aplastic anemia treated with transplantation of bone marrow has improved significantly over the past several decades. Allogeneic bone marrow transplantation (BMT) for patients with HLA-identical siblings is now the first-line therapy, and long-term survival of approximately 90% can be expected with cyclophosphamide/antithymocyte globulin conditioning and postgrafting methotrexate/cyclosporine immunosuppression. The outcome of unrelated donor BMT has also improved significantly with the identification of a preparative regimen with less toxicity combined with the development of high-resolution DNA-based HLA typing to identify the optimal unrelated marrow donor. Patients with fully HLA-matched unrelated donors should be considered candidates for transplantation prior to exposure to repeat courses of immunosuppression. Future progress in hematopoietic stem cell transplantation for aplastic anemia will be directed toward further decreasing the acute toxicity and decreasing the delayed effects of the conditioning regimens while maintaining highly reliable rates of sustained engraftment with prevention of acute and chronic graft-versus-host disease.

Allogeneic bone marrow transplantation in the developing world: experience from a center in India

We describe our experience of setting up an allogeneic BMT program at the Christian Medical College Hospital, Vellore over a period of 13 years, from October 1986 to December 1999. Two hundred and twenty-one transplants were performed during this period in 214 patients, with seven patients undergoing second transplants. Indication for BMT were thalassemia major - 106 (48%), CML - 30, AML - 35, ALL - 10, SAA - 22, MDS - six and six for other miscellaneous disorders. The mean age of this patient cohort was 15.6 years (range 2-52). Graft-versus-host disease of grades III and IV was seen in 36 patients (17%) and this was the primary cause of death in 20 patients (9.2%). All patients and donors were CMV IgG positive. Sepsis was the primary cause of death in 16 patients (7.4%), 10 bacterial, four fungal and two viral. One hundred and ten of this series of patients are alive and disease free (50%) with a median follow-up of 24 months (range 2-116). These results are comparable to those achieved for patients with similar disease status in transplant units in the Western world and cost a mean of US$15 000.

Decreased Rejection and Improved Survival of First and Second Marrow Transplants for Severe Aplastic Anemia (A 26-Year Retrospective Analysis)

Between 1970 and 1996, 333 patients with severe aplastic anemia underwent HLA-matched related marrow transplant after conditioning with cyclophosphamide (CY). Thirty-five percent of patients transplanted between 1970 and 1976 (group 1), 12% of those transplanted between 1977 and 1981 (group 2), and 9% of patients transplanted between 1982 and 1997 (group 3) had graft rejection. Graft rejection occurred later among group 3 patients (median, 180 days) than among those in groups 1 and 2 (medians, 28 and 47 days, respectively; P < .001 group 3 v 2). In group 3, 92% of rejecting patients underwent a second transplant, compared with 78% and 77% in groups 1 and 2, respectively. Group 1 patients received various conditioning regimens before second transplant, whereas most patients of groups 2 and 3 received CY combined with antithymocyte globulin (ATG). Graft-versus-host disease (GVHD) prophylaxis after second transplant consisted of methotrexate (MTX) for all group 1 and 2 patients, whereas group 3 patients received MTX combined with cyclosporine (CSP). Over the three time periods studied, first graft rejection decreased from 35% to 9%, and the proportion of rejecting patients undergoing second transplants increased from 77% to 92%. The 10-year probability of survival after second transplants increased from 5% to 83%. Multivariate analysis showed MTX/CSP GVHD prophylaxis to be a significant factor accounting for the increase in patient survival after second transplant.

© 1998 by The American Society of Hematology.

Decreased Rejection and Improved Survival of First and Second Marrow Transplants for Severe Aplastic Anemia (A 26-Year Retrospective Analysis)

Between 1970 and 1996, 333 patients with severe aplastic anemia underwent HLA-matched related marrow transplant after conditioning with cyclophosphamide (CY). Thirty-five percent of patients transplanted between 1970 and 1976 (group 1), 12% of those transplanted between 1977 and 1981 (group 2), and 9% of patients transplanted between 1982 and 1997 (group 3) had graft rejection. Graft rejection occurred later among group 3 patients (median, 180 days) than among those in groups 1 and 2 (medians, 28 and 47 days, respectively; P &lt; .001 group 3 v 2). In group 3, 92% of rejecting patients underwent a second transplant, compared with 78% and 77% in groups 1 and 2, respectively. Group 1 patients received various conditioning regimens before second transplant, whereas most patients of groups 2 and 3 received CY combined with antithymocyte globulin (ATG). Graft-versus-host disease (GVHD) prophylaxis after second transplant consisted of methotrexate (MTX) for all group 1 and 2 patients, whereas group 3 patients received MTX combined with cyclosporine (CSP). Over the three time periods studied, first graft rejection decreased from 35% to 9%, and the proportion of rejecting patients undergoing second transplants increased from 77% to 92%. The 10-year probability of survival after second transplants increased from 5% to 83%. Multivariate analysis showed MTX/CSP GVHD prophylaxis to be a significant factor accounting for the increase in patient survival after second transplant.

© 1998 by The American Society of Hematology.