Bone marrow transplantation for hemoglobinopathies

Effect of Chinese Herbal Medicine Therapy on Risks of Overall, Diabetes-Related, and Cardiovascular Diseases-Related Mortalities in Taiwanese Patients With Hereditary Hemolytic Anemias

Hereditary Hemolytic Anemias (HHAs) are a rare but heterogeneous group of erythrocytic diseases, characterized by intrinsic cellular defects due to inherited genetic mutations. We investigated the efficacy of Chinese herbal medicine (CHM) in reducing the overall, diabetes-related, and cardiovascular diseases (CVDs)-related mortalities among patients with HHAs using a nationwide population database. In total, we identified 33,278 patients with HHAs and included 9,222 non-CHM and 9,222 CHM matched pairs after matching. The Cox proportional hazards model was used to compare the risk of mortality between non-CHM and CHM users. The Kaplan-Meier method and log-rank test were used to compare the cumulative incidence mortality between non-CHM and CHM users. The CHM prescription patterns were presented by the association rules and network analyses, respectively. The CHM prescription patterns were presented by the association rules and network analyses, respectively. CHM users showed significant reduced risks for of overall (adjusted hazard ratio [aHR]: 0.67, 95% confidence interval [CI]: 0.61-0.73, p < 0.001), diabetes-related (aHR: 0.57, 95% CI: 0.40-0.82, p < 0.001), and CVDs-related (aHR: 0.59, 95% CI: 0.49-0.72, p < 0.001) mortalities compared with non-CHM users. Two CHM clusters are frequently used to treat Taiwanese patients with HHAs. Cluster 1 is composed of six CHMs: Bei-Mu (BM; Fritillaria cirrhosa D.Don), Gan-Cao (GC; Glycyrrhiza uralensis Fisch.), Hai-Piao-Xiao (HPX; Endoconcha Sepiae), Jie-Geng (JG; Platycodon grandiflorus (Jacq.) A.DC.), Yu-Xing-Cao (YXC; Houttuynia cordata Thunb.), and Xin-Yi-Qing-Fei-Tang (XYQFT). Cluster 2 is composed of two CHMs, Dang-Gui (DG; Angelica sinensis (Oliv.) Diels) and Huang-Qi (HQi; Astragalus membranaceus (Fisch.) Bunge). Further randomized clinical trials are essential to evaluate the safety and effectiveness of above CHM products and to eliminate potential biases in the current retrospective study.

Reproductive capability in dogs with canine leukocyte adhesion deficiency treated with nonmyeloablative conditioning prior to allogeneic hematopoietic stem cell transplantation

Nonmyeloablative conditioning regimens are increasingly replacing myeolablative conditioning prior to allogeneic hematopoietic stem cell transplantation (SCT). The recent advent of these conditioning regimens has limited the assessment of the long-term effects of this treatment, including analysis of reproductive function. To address the question of reproductive function after nonmyeloablative transplantation, we analyzed a cohort of young dogs with the genetic disease canine leukocyte adhesion deficiency that were treated with a nonmyeloablative dose of 200 cGy total body irradiation followed by matched-littermate SCT. Five males and 5 females entered puberty; all 5 males and 4 females subsequently sired or delivered litters following transplantation. We demonstrate that fertility is intact and dogs have uncomplicated parturitions following nonmyeloablative conditioning for SCT. These results are encouraging for children and adults of childbearing age who receive similar conditioning regimens prior to allogeneic transplantation.

Unrelated umbilical cord blood transplantation for an infant with beta-thalassemia major

BACKGROUND

beta-thalassemia major, one of the most prevalent hemoglobinopathies throughout the world, can be cured by allogeneic stem cell transplantation therapy. Many patients, however, lack a suitably matched related donor. Unrelated umbilical cord blood can be used as an alternative stem cell source for some of these patients. This report describes the successful transplantation of a 2-month-old infant with beta-thalassemia major using partially HLA-matched unrelated umbilical cord blood.

METHODS

After cytoreduction with busulfan, cyclophosphamide, and antithymocyte globulin (ATG), the patient underwent transplantation at the age of 2 months with a 4/6 HLA matching umbilical cord blood unit from an unrelated donor.

RESULTS

The patient engrafted promptly with 100% donor chimerism. His only major complication was an autoimmune hemolytic anemia that resolved 2 years after transplantation. He is currently surviving, event-free, 5 years after transplantation with normal growth and cognitive development and full donor chimerism without evidence of beta-thalassemia.

CONCLUSIONS

Umbilical cord blood transplantation from related and unrelated donors should be considered for patients with beta-thalassemia major who lack traditional bone marrow donors. As most newborns undergo screening for hemoglobinopathies, those with disease could be transplanted early in life before experiencing the morbidity and mortality caused by transfusion therapy, alloimmunization, and iron overload, increasing the likelihood of successful transplantation therapy.

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.

Availability of unrelated donors for hematopoietic stem cell transplantation for hemoglobinopathies

Hematopoietic stem cell transplantation (HSCT) is the only curative option for patients with hemoglobinopathies. However, fewer than 30% of individuals will have an HLA-identical sibling. Improvement in outcomes after HSCT using unrelated donors (URD), and the development of novel nontoxic preparative regimens may make URD HSCT an option for hemoglobinopathy patients who do not have an HLA-identical sibling donor. The National Marrow Donor Program (NMDP) maintains a Registry of 4 million volunteer donors, and facilitates URD HSCT for patients with life-threatening blood diseases. In light of the increased representation of minorities in the NMDP registry, donor searches were run in April 2001 for a cohort of 272 thalassemia patients and 77 sickle cell disease (SCD) patients for whom searches had been submitted between 1989 and 2001 in order to determine the current likelihood of finding a potential donor of hematopoietic stem cells for hemoglobinopathy patients. About 59.7% SCD patients 80.2% thalassemia patients will find at least one potential 6/6 HLA matched donor or umbilical cord blood (UCB) unit. All patients will find at least one donor or UCB that is a potential 5/6 HLA match. In conclusion the majority of hemoglobinopathy patients will find at least one potential HLA matched unrelated bone marrow donor or UCB.

A cure for murine sickle cell disease through stable mixed chimerism and tolerance induction after nonmyeloablative conditioning and major histocompatibility complex-mismatched bone marrow transplantation

The morbidity and mortality associated with sickle cell disease (SCD) is caused by hemolytic anemia, vaso-occlusion, and progressive multiorgan damage. Bone marrow transplantation (BMT) is currently the only curative therapy; however, toxic myeloablative preconditioning and barriers to allotransplantation limit this therapy to children with major SCD complications and HLA-matched donors. In trials of myeloablative BMT designed to yield total marrow replacement with donor stem cells, a subset of patients developed mixed chimerism. Importantly, these patients showed resolution of SCD complications. This implies that less toxic preparative regimens, purposefully yielding mixed chimerism after transplantation, may be sufficient to cure SCD without the risks of myeloablation. To rigorously test this hypothesis, we used a murine model for SCD to investigate whether nonmyeloablative preconditioning coupled with tolerance induction could intentionally create mixed chimerism and a clinical cure. We applied a well-tolerated, nonirradiation-based, allogeneic transplantation protocol using nonmyeloablative preconditioning (low-dose busulfan) and costimulation blockade (CTLA4-Ig and anti-CD40L) to produce mixed chimerism and transplantation tolerance to fully major histocompatibility complex-mismatched donor marrow. Chimeric mice were phenotypically cured of SCD and had normal RBC morphology and hematologic indices (hemoglobin, hematocrit, reticulocyte, and white blood cell counts) without evidence of graft versus host disease. Importantly, they also showed normalization of characteristic spleen and kidney pathology. These experiments demonstrate the ability to produce a phenotypic cure for murine SCD using a nonmyeloablative protocol with fully histocompatibility complex-mismatched donors. They suggest a future treatment strategy for human SCD patients that reduces the toxicity of conventional BMT and expands the use of allotransplantation to non-HLA-matched donors.

Novel conditioning regimens and nonmyeloablative stem cell transplants

Allogeneic stem cell transplantation has proven an effective means of treatment for a variety of malignant and nonmalignant conditions. Stem cell transplantation has traditionally been preceded by the patient receiving high (myeloablative) doses of chemotherapy and total body irradiation, which have been associated with significant transplant-related morbidity and mortality. This finding has precluded some older or heavily pretreated patients from being offered stem cell transplantation and has made other populations, such as those with nonmalignant conditions, reluctant to consider this therapy. Preclinical studies demonstrated that engraftment of donor stem cells could be achieved with nonmyeloablative, but immunosuppressive, preparative regimens that are significantly less toxic. Preliminary clinical studies have shown that patients previously ineligible for allogeneic stem cell transplantation can frequently be safely transplanted and that an immune-mediated graft-versus-malignancy effect plays an important role in the antitumor efficacy of this treatment. The potential to use this nonmyeloablative approach in nonmalignant disorders in which regimen-related toxicity must be minimized is of particular interest in children.

Nonmyeloablative transplantation in children. Current status and future prospects

Over the last few years a variety of conditioning regimens have been developed that allow allogeneic hematopoietic stem cell engraftment with significantly decreased transplant related-toxicity. While these reduced-intensity regimens have offered hope for patients with malignancies formerly not eligible for myeloablative transplantation due to excessive morbidity (older patients and patients with significant organ toxicity), the role of nonmyeloablative hematopoietic cell transplantation (NM-HCT) in children is unclear. A review of the available literature for pediatric and adult studies shows several malignancies in which approaches designed to limit long-term complications in children may be appropriate. In addition, NM-HCT may offer a safer approach for children with inherited disorders curable by marrow transplantation, such as immunodeficiencies, hemoglobinopathies, or storage diseases. Finally, use of this approach to establish partial donor chimerism may provide an immunologic platform that will allow specific cellular therapies, targeted gene therapy, or immunologic tolerance in solid organ transplantation.

Pharmacologic induction of fetal hemoglobin: raising the therapeutic bar in sickle cell disease

The favorable effects of high levels of fetal hemoglobin (Hb F) in sickle cell disease have been recognized for several decades. This has been an important incentive for the development of therapeutic agents that increase Hb F production. 5-Azacytidine, the first such agent in clinical use, was proposed based on a molecular understanding of the role of DNA methylation in globin gene regulation. Controversy over the mechanism of Hb F induction by 5-azacytidine led to the identification of hydroxyurea as another agent that can increase Hb F production. Although the clinical benefit of hydroxyurea has been demonstrated in a randomized clinical trial, greater increases in Hb F are clearly needed for optimal therapeutic effect. Butyrates also increase Hb F levels, and their use in combination with hydroxyurea appears to be synergistic. Now that multiple therapeutic agents are available for Hb F induction, the use of combination therapy to increase Hb F levels sufficiently to prevent all the complications of sickle cell disease has become a realistic goal.

Bone Marrow Transplantation for Non-Malignant Disease

This article reviews the experience in hematopoietic stem cell transplantation (HSCT) for non-malignant disease. HSCT has long been applied as treatment of life-threatening congenital immunodeficiency and metabolic diseases. In Section I, Dr. Parkman reviews that experience for severe combined immunodeficiency, Wiscott-Aldrich syndrome, hyper IGM syndrome, Chédiak-Higashi disease and hereditary lymphohistiocytosis. The value of HSCT in genetic metabolic diseases such as osteopetrosis, osteogenesis imperfecta and the storage diseases are reviewed. In Section II, Dr. Walters reviews the experience over the last decade with allogeneic stem cell transplantation in patients with thalassemia major and sickle cell disease. In Section III, Dr. Sullivan reviews the more recent investigations using stem cell transplantation in patients with advanced autoimmune diseases such as systemic sclerosis, systemic lupus erythematosus, multiple sclerosis and juvenile rheumatoid arthritis. The pathogenesis and outcome with conventional care of these patients, the selection criteria and current results for HSCT, and the future directions in clinical research and patient care using this modality are addressed.

Bone Marrow Transplantation for Non-Malignant Disease

This article reviews the experience in hematopoietic stem cell transplantation (HSCT) for non-malignant disease. HSCT has long been applied as treatment of life-threatening congenital immunodeficiency and metabolic diseases. In Section I, Dr. Parkman reviews that experience for severe combined immunodeficiency, Wiscott-Aldrich syndrome, hyper IGM syndrome, Chédiak-Higashi disease and hereditary lymphohistiocytosis. The value of HSCT in genetic metabolic diseases such as osteopetrosis, osteogenesis imperfecta and the storage diseases are reviewed. In Section II, Dr. Walters reviews the experience over the last decade with allogeneic stem cell transplantation in patients with thalassemia major and sickle cell disease. In Section III, Dr. Sullivan reviews the more recent investigations using stem cell transplantation in patients with advanced autoimmune diseases such as systemic sclerosis, systemic lupus erythematosus, multiple sclerosis and juvenile rheumatoid arthritis. The pathogenesis and outcome with conventional care of these patients, the selection criteria and current results for HSCT, and the future directions in clinical research and patient care using this modality are addressed.