Experience with bone marrow transplantation for inborn errors of metabolism

Westminster experience had by 1973 evolved the concept of displacement bone marrow transplantation and extended the donors from matched siblings to other family and unrelated donors. The principles of its use to install donor bone marrow as a component factory for the life of the recipient, together with the importance of immunoprophylaxis are detailed. Satisfying correction has been achieved for 48 previously fatal genetic diseases, partial correction for another 5 with failure for 3 diseases. Displacement bone marrow transplantation is not a panacea, but could be applied to about 7% of known inborn errors, devising in vitro tests which can predict in vivo donor effects, especially since some 80% of our patients are not found in known families and could not have been prevented.     

An overview of bone marrow transplantation for chronic myeloid leukemia.

The use of intensive therapy together with transplantation of marrow from a suitable donor is the only established curative treatment for patients with chronic myeloid leukemia (CML). However, marrow transplantation is hazardous, costly and applicable to relatively few patients. Therefore, we evaluated the results and limitations of marrow transplantation for CML and discussed new treatment strategies. We decided to select a limited number of papers that focused on the relevant issues rather than to undertake an exhaustive comparison of treatment results from different centres. Patients with CML in the chronic phase who receive marrow from a sibling with the same human leukocyte antigen type can expect to have a long-term disease-free survival rate of 50%. However, the procedure is associated with a mortality rate of 30%, mainly because of graft-versus-host disease (GVHD) and interstitial pneumonitis. Moreover, because of the requirements for age and histocompatibility only 10% of patients with chronic-phase CML are currently eligible. Transplantation earlier in the chronic phase (within 1 year after diagnosis), the use of marrow from matched, unrelated donors and the development of improved methods for reducing the incidence of GVHD all hold promise. In addition, the preliminary results of intensive therapy followed by transplantation with cultured autologous marrow have been encouraging. If further progress is to be made, continued optimism coupled with carefully developed and executed studies will be necessary.     

Bone marrow transplantation--an expanding approach to treatment of many diseases

Thus, we can conclude that marrow transplantation has already influenced medical practice greatly. It has offered a treatment which often cures patients of more than 20 otherwise lethal diseases. The treatment so horrendously difficult and dangerous at first has already been greatly improved, simplified, and made much safer. The availability of a suitable donor has been much extended and real progress has been made in prevention and perhaps even in treatment of graft-versus-host disease. This has made possible the option of marrow transplantation for every patient in whom we think the treatment may be beneficial. The problem underlying many cases of interstitial pneumonia has been identified and patients are already benefitting clinically from this progress. Progress has also been made which promises antiviral therapy which could reduce, prevent, and ultimately eliminate the intercurrent virus infections which limit the applicability of marrow transplantation, especially for children with severe immunodeficiencies. I do not know how far this line of investigation can be taken. However, just as we have learned stepwise to use marrow transplants from matched siblings to treat many diseases, to use fetal liver in place of bone marrow, to employ matched relative donors when a matched sibling is not available, and, finally, even to use parental donors to achieve correction of SCID, we now have good reason to believe that, ultimately, we can use marrow transplantation without fear of GVHD to address many additional genetically determined and acquired diseases; certainly, for those diseases that involve any of the cells that are derived from bone marrow cells, and perhaps for those attributable even to cells of other organs and tissues, the functions of which are, in whole or in part, a consequence of interactions of marrow-derived cells and cells of ectodermal or endodermal origin, marrow transplantation may be useful. To us, the future of marrow transplantation as a major modality of treatment or prevention of many diseases, including hemoglobinopathesis, immunodeficiencies, hematologic abnormalities, abnormalities of function of marrow-derived cells, and even inborn errors of function of cells of organs and tissues not of marrow origin, seems bright, indeed. Further, with the capacity to introduce resistance genes against viruses and malignancies, autoimmune diseases, and diseases dependent on anomalies of immune response genes, marrow transplantation for many other diseases seems a more remote possibility.(ABSTRACT TRUNCATED AT 400 WORDS)     

Registry of unrelated bone marrow donors.

Reports of successful transplantation of bone marrow obtained from unrelated donors who were histocompatibility leukocyte antigen (HLA) identical prompted the Canadian Red Cross Blood Transfusion Service in Ottawa to assess the possibility of developing a bone marrow donor registry in Canada. We sent a pamphlet that explained the program to 1568 people who had undergone apheresis and asked them to reply, stating their interest. At the same time the pamphlets and a poster were placed in the blood donor clinic. We received 1232 replies (78.6%) from the apheresis donors, 838 (68.0%) of which indicated a willingness to attend information sessions. Of the 7158 people who gave blood during the 3-month study period, 225 (3.1%) were interested. At the time this paper was written 47 information sessions had been held, and 721 people had attended, 624 (86.5%) of whom had signed a consent form. This indicates a clear interest in a bone marrow donation program. We believe that the ethical issues are overcome by requesting the donation before identification of any patient. From our experience a national registry of unrelated donors seems feasible, and steps are being taken to implement such a program.     

Unrelated donor hematopoietic transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for a range of malignant and non-malignant diseases. Unfortunately, fewer than 30% of patients have a human leukocyte antigen (HLA)-matched sibling. Advances in our understanding of the HLA system and the development of large international donor registries are supporting the increasing use of unrelated donors as an alternative source of stem cells. Unrelated donor transplantation, however, is still associated with higher complication rates than in HLA-identical sibling donor transplants. Improvements in graft-vs.-host disease prevention and treatment, new conditioning regimens and better donor selection will likely expand the indications of unrelated donor HSCT in the next decade.     

A human autoreactive T cell line specific for minor histocompatibility antigen(s) isolated from a bone marrow-grafted patient

A human autoreactive T cell line named Bur-1 has been obtained from a woman 4 mo after an allogeneic bone marrow transplantation (BMT) from one of her HLA-identical brothers. The phenotype of the cell line is 100% T11+ and over 90% T4+, and the karyotype confirms its donor (male) origin. These donor T cells proliferate specifically in the presence of donor's peripheral blood monocytes (PBM) but not recipient's cells, and they kill specifically donor's but not recipient's Epstein-Barr virus (EBV)-induced lymphoblastoid cell lines (LCL). PBM from another HLA-identical brother and from several unrelated donors also stimulate Bur-1 cells, and EBV-induced LCL from the same donors are killed in cytotoxicity assays. All of these donors share HLA-DR5 or HLA-DRw11 (the major split of HLA-DR5) with Bur-1 cells. However, some but not all of the PBM sharing HLA-DR5 with Bur-1 cells are recognized. Therefore, in contrast with the previously described autoreactive T cells, Bur-1 cells are not directed against self-MHC antigens but rather recognize autologous minor histocompatibility (mH) antigens in the context of autologous HLA class II molecules. Because both male and female cells can be recognized, the reacting minor antigen could not be the male-specific HY antigen. It is suggested that autoreactivity against mH antigens can be observed in bone marrow-grafted patients due to the education of bone marrow donor precursors in the recipient thymus not allowing tolerance to autologous (donor) mH antigens not shared by the recipient.     

An apparent discrepancy between the number of colony forming units transplanted and survival of busulphan lethally treated rats

Conditions for keeping busulphan lethally treated rats alive by transplantation of bone marrow cells from syngeneic donors are described. After busulphan treatment of the donor rats with a dose which only reduces the colony forming units (CFU's) in the marrow (assayed by the spleen colony technique) to half the normal numbers, at least 100 times as many cells from these treated donors, compared to untreated rats, are required to produce an equivalent increase in survival of busulphan lethally treated recipients. In contrast, aminochlorambucil, despite producing a marked fall in bone marrow cellularity, has no effect on the number of CFU/femur, yet the marrow from these aminochlorambucil treated donors is no more effective in increasing the survival of busulphan lethally treated recipients than untreated marrow. Theories which may explain this apparent discrepancy and evidence which it affords on the mode of action of busulphan are discussed.     

Legal issues in bone marrow transplantation

The article discusses some of the more common legal issues involved in bone marrow transplantation. These include malpractice claims, testing prospective donors for AIDS, sale of bone marrow, informed consent for both donor and recipient, and questions that arise when the donor is a child.     

Requirements for the adoptive transfer of antibody responses to a priming antigen in man

Antibody responses to recall vaccines can be adoptively transferred after marrow transplantation in man. Transfer of responses to priming Ag has not been successful, although this would broaden the range of organisms to which recipients could be protected. To investigate the importance of T cells and Ag in such transfer we primed marrow donors with keyhole limpet hemocyanin (KLH) 1 or 3 wk before marrow harvesting. B cells secreting IgM and IgG anti-KLH antibody were present in donor marrow at both 1 and 3 wk after immunization. After T cell depletion, donor marrow was infused into chemo-irradiated recipients, half of whom were immunized pretransplant with KLH. We found no evidence for the transfer of the IgM component of the response. Clonal expansion of the transferred IgG antibody-secreting cells with a corresponding rise in recipient serum IgG antibody levels was seen only when donors were primed 3 wk before marrow harvest and when the recipients were also immunized. IEF and immunoblotting demonstrated that successful transfer coincided with maturation of the IgG primary response from a polyclonal to an oligoclonal pattern and confirmed that donor oligoclonal bands appeared in the recipient serum. We conclude that the immunization protocols required for the transfer of antibody responses to priming Ag reflect the initial dependence of unprimed B cells on T cell help and on prolonged Ag stimulation. Ag-stimulated primary B cells in T cell-depleted marrow respond only to the noncognate growth and differentiation signals available in the chemo-irradiated recipient after an initial period of clonal selection and expansion in the donor which is both T cell and Ag dependent. Even after this initial selection, continued expansion of antibody-secreting clones in recipients retains an absolute dependence on Ag stimulation. Immunization techniques to protect transplant recipients against organisms such as Pseudomonas and CMV may need to be modified accordingly.     

Cord blood stem cell transplantation. Why it is necessary to establish a Bulgarian cord blood bank?

The allogenic transplantation of hemopoietic stem cell from bone marrow and peripheral blood is limited due to the necessity to identify HLA matched donor within the family or in bone marrow donor registries. Although, more than 10 million donors are available worldwide, completely HLA matched donors could be found only for 75% of the patients. It is well known that transplantations of hematopoietic stem cell from cord blood are characterized with a lower risk of GvHD and therefore do not require so strict criteria for HLA matching, and less time for search of matched donor is needed. The necessity to establish a National cord blood bank in Bulgaria is emphasized further by the heterogeneity of HLA allele and haplotype distribution in the Bulgarian population. That could be explained by the ethnic diversity of the population. As a result some alleles are more frequent in Bulgarians compared to other populations. The organization, accreditation, and development of a strategy for a National cord blood bank will be discussed.     

Evaluation of the autopsy report before releasing musculoskeletal tissue donors; what is the benefit?

EU directive 2006/17/EC requires that all available medical information, including the autopsy report, is evaluated before releasing tissues for transplantation. The study objective was to investigate whether evaluation of autopsy results of musculoskeletal tissue donors contributes to safety and availability of transplantable tissues. The files of all donors of whom musculoskeletal tissues were retrieved by BIS in 2006 were reviewed for death cause and autopsy results. Of 84 donors musculoskeletal tissues were retrieved. In 47 donors autopsy was performed (56.0%). The groups with and without autopsy were similar in sex, age, length, and weight. In one donor no autopsy results were evaluated, since the donor was already rejected because of positive blood tests. In 13 donors (28.1%) death causes before autopsy were unknown. In 12 of these donors a death cause could be established after autopsy. In nine of the donors with a clear suspected death cause (27.3%), the death cause after autopsy differed from the suspected death cause. Four donors with autopsy (8.7%) had a general contraindication for donation, a (possible) sepsis in three and a persisting unknown death cause in one. Eight donors (17.4%) had musculoskeletal-specific contraindications, i.e. local infections. In conclusion, in 26.1% of the donors with autopsy, general or musculoskeletal-specific contraindications for donation were found. Furthermore, performance of autopsies enlarges the potential donor pool, since death causes can be established in almost all autopsies done in case of an unknown death cause. Therefore, evaluation of autopsy results improves the safety and quantity of tissues for transplantation.     

Canine models of bone marrow transplantation

Progress in experimental bone marrow transplantation in dogs has provided for the direct transfer of research data to the clinical setting and the therapeutic application of marrow grafting to a variety of human diseases. Animal models of total body irradiation, engraftment and graft-versus-host disease are still needed to solve the existing clinical problems of marrow transplantation. Therefore, work in various canine model systems continues to be of interest. Pet dogs with spontaneously occurring lymphomas are used to study the clinical parameters necessary for applying the technique of transplanting their own marrow (autologous), in conjunction with high dose radiation and/or chemotherapy, to human patients with cancer. A major consideration in the successful transplantation of donor bone marrow (allogeneic) is overcoming histocompatibility barriers to assure engraftment and the prevention of graft-versus-host disease, a major limiting aspect of clinical marrow transplantation. Chemicals, radiation, radiotherapeutic techniques, antisera and monoclonal antibodies have been and continue to be developed in laboratory bred dogs. These approaches suppress the immune system either nonspecifically by ablation of immune reactive tissue, or specifically by affecting certain types of immune reactive cells. Parameters such as clinical effectiveness (engraftment or prevention of graft-versus-host disease), immune reconstitution and undesirable side affects in long-term survivors are all used to determine whether new technology can be transferred from preclinical canine studies to human bone marrow transplantation protocols.     

Differentiating Functional Roles of Gene Expression from Immune and Non-immune Cells in Mouse Colitis by Bone Marrow Transplantation

To understand the role of a gene in the development of colitis, we compared the responses of wild-type mice and gene-of-interest deficient knockout mice to colitis. If the gene-of-interest is expressed in both bone marrow derived cells and non-bone marrow derived cells of the host; however, it is possible to differentiate the role of a gene of interest in bone marrow derived cells and non- bone marrow derived cells by bone marrow transplantation technique. To change the bone marrow derived cell genotype of mice, the original bone marrow of recipient mice were destroyed by irradiation and then replaced by new donor bone marrow of different genotype. When wild-type mice donor bone marrow was transplanted to knockout mice, we could generate knockout mice with wild-type gene expression in bone marrow derived cells. Alternatively, when knockout mice donor bone marrow was transplanted to wild-type recipient mice, wild-type mice without gene-of-interest expressing from bone marrow derived cells were produced. However, bone marrow transplantation may not be 100% complete. Therefore, we utilized cluster of differentiation (CD) molecules (CD45.1 and CD45.2) as markers of donor and recipient cells to track the proportion of donor bone marrow derived cells in recipient mice and success of bone marrow transplantation. Wild-type mice with CD45.1 genotype and knockout mice with CD45.2 genotype were used. After irradiation of recipient mice, the donor bone marrow cells of different genotypes were infused into the recipient mice. When the new bone marrow regenerated to take over its immunity, the mice were challenged by chemical agent (dextran sodium sulfate, DSS 5%) to induce colitis. Here we also showed the method to induce colitis in mice and evaluate the role of the gene of interest expressed from bone-marrow derived cells. If the gene-of-interest from the bone derived cells plays an important role in the development of the disease (such as colitis), the phenotype of the recipient mice with bone marrow transplantation can be significantly altered. At the end of colitis experiments, the bone marrow derived cells in blood and bone marrow were labeled with antibodies against CD45.1 and CD45.2 and their quantitative ratio of existence could be used to evaluate the success of bone marrow transplantation by flow cytometry. Successful bone marrow transplantation should show a vast majority of donor genotype (in term of CD molecule marker) over recipient genotype in both the bone marrow and blood of recipient mice.     

Post-Irradiation Thymocyte Regeneration After Bone Marrow Transplantation I. Regeneration and Quantification of Thymocyte Progenitor Cells In the Bone Marrow

Growth kinetics of the donor-type thymus cell population after transplantation of bone marrow into irradiated syngeneic recipient mice is biphasic. During the first rapid phase of regeneration, lasting until day 19 after transplantation, the rate of development of the donor cells is independent of the number of bone marrow cells inoculated. the second slow phase is observed only when low numbers of bone marrow cells (2.5 × 10⁴) are transplanted. the decrease in the rate of development is attributed to an efflux of donor cells from the thymus because, at the same time, the first immunologically competent cells are found in spleen. After bone marrow transplantation the regeneration of thymocyte progenitor cells in the marrow is delayed when compared to regeneration of CFUs. Therefore, regenerating marrow has a greatly reduced capacity to restore the thymus cell population. One week after transplantation of 3 × 10⁶ cells, 1% of normal capacity of bone marrow is found. It is concluded that the regenerating thymus cells population after bone marrow transplantation is composed of the direct progeny of precursor cells in the inoculum.     

Fanconi anemia: contribution of molecular analyses to the identification of bone marrow graft donors and the study of chimerism in grafted patients

We report on the effectiveness of molecular studies regarding Fanconi anemia (FA) for a better selection of bone marrow graft donors and for post-transplant follow up. Ten unrelated FA patients and their families were analyzed by microsatellite markers. In 9 cases, the cytogenetic investigation of potential human leukocyte antigen (HLA)-identical related donors was normal, and the molecular analyses confirmed that they were also either normal or heterozygous carriers. For 1 patient, cytogenetic analysis of an HLA-identical sibling donor yielded ambiguous results with a relatively high number of chromosomal breakages using cross-linking agents. However, genotyping of this potential donor demonstrated his heterozygous state. Nine patients have received allogeneic bone marrow transplantation from HLA-matched related donors. Microsatellite analysis showed complete chimerism (CC) in all cases. The median follow up was 54 months (range 8-144 months). One patient out of 9 with CC rejected her graft without prior detection of a transitional mixed chimerism. Among these patients, 1 died 25 months after the transplantation of a chronic graft-versus-host-disease (GVHD). We conclude that, when the cytogenetic studies are not conclusive, molecular analyses are crucial to distinguish heterozygous carriers from asymptomatic FA Tunisian patients. Molecular analyses also allowed the evaluation of hematopoietic chimerism after allogeneic bone marrow transplantation and might be of value to identify patients with a high risk for graft rejection.     

Biological aspects of limb transplantation: I. Migration of transplanted bone marrow cells into recipient

The transplanted limb contains bone marrow tissue. The hematopoietic cells contained in the bone of the graft normally differentiate after transplantation and can be released to the recipient. The cells migrate to the recipient bone marrow cavities and lymphoid organs. This causes the immune reaction between the donor and the recipient, which develops not only in the graft itself but also in the recipient immune organs where donor bone marrow cells home. The purpose of this study was to investigate the process of migration of the hematopoietic cells from the donor limb to the recipient bone marrow cavities and lymphoid tissues. The questions the authors asked were: what is the rate of release of bone marrow cells from the transplanted bone, where do the released bone marrow cells home in the recipient, how fast are donor bone marrow cells rejected by the recipient, and can some bone marrow cells homing in the recipient tissues survive and create a state of microchimerism. Experiments were performed on Brown Norway and Lewis inbred rat strains (n = 30). Limb donors received intravenous chromium-51-labeled bone marrow cells. Twenty-four hours later, the limb with homing labeled bone marrow cells was transplanted to an allogeneic or syngeneic recipient. The rate of radioactivity of bone marrow cells released from the graft and homing in recipient tissues was measured after another 24 hours. To eliminate factors adversely affecting homing such as the "crowding effect" and allogeneic elimination of bone marrow cells by natural killer cells, total body irradiation and antiasialo-GM1 antiserum were applied to recipients before limb transplantation. In rats surviving with the limb grafts for 7 and 30 days, homing of donor bone marrow cells was studied by specific labeling of donor cells and flow cytometry as well as by detecting donor male Y chromosome. The authors found that transplantation of the limb with bone marrow in its natural spatial relationship with stromal cells and blood perfusion brings about immediate but low-rate release of bone marrow cells and their migration to recipient bone marrow and lymphoid tissues. Large portions of allogeneic bone marrow cells are rapidly destroyed in the mechanism of allogeneic elimination by radioresistant but antiasialo-GM1-sensitive natural killer cells. Some transplanted bone marrow cells remain in the recipient's tissues and create a state of cellular and DNA microchimerism. A low number of physiologically released donor bone marrow cells do not seem to adversely affect the clinical outcome of limb grafting. Quite the opposite, a slight prolongation of the graft survival time was observed.     

Host NKT cells can prevent graft-versus-host disease and permit graft antitumor activity after bone marrow transplantation

Allogeneic bone marrow transplantation is a curative treatment for leukemia and lymphoma, but graft-vs-host disease (GVHD) remains a major complication. Using a GVHD protective nonmyeloablative conditioning regimen of total lymphoid irradiation and antithymocyte serum (TLI/ATS) in mice that has been recently adapted to clinical studies, we show that regulatory host NKT cells prevent the expansion and tissue inflammation induced by donor T cells, but allow retention of the killing activity of donor T cells against the BCL1 B cell lymphoma. Whereas wild-type hosts given transplants from wild-type donors were protected against progressive tumor growth and lethal GVHD, NKT cell-deficient CD1d-/- and Jalpha-18-/- host mice given wild-type transplants cleared the tumor cells but died of GVHD. In contrast, wild-type hosts given transplants from CD8-/- or perforin-/- donors had progressive tumor growth without GVHD. Injection of host-type NKT cells into Jalpha-18-/- host mice conditioned with TLI/ATS markedly reduced the early expansion and colon injury induced by donor T cells. In conclusion, after TLI/ATS host conditioning and allogeneic bone marrow transplantation, host NKT cells can separate the proinflammatory and tumor cytolytic functions of donor T cells.     

Supportive haemotherapy in bone marrow transplantation

The intensive supportive haemotherapy which has to be used in bone marrow transplantation is discussed, taking mainly into account platelet transfusions. Ways to avoid alloimmunizations against platelet antigens, especially HLA-ABC antigens, are shown (use of HLA-AB homozygous donors or of cross-reacting groups).     

Bone marrow transplantation in Canada.

Bone marrow transplantation is an established form of therapy for aplastic anemia and severe combined immunodeficiency. It is also a therapeutic option for acute leukemia in remission. Unfortunately, compatible donors are not available for most patients who could benefit from it. Further refinement of the techniques involved may make it suitable for more patients. Graft rejection, recurrent leukemia, graft-versus-host disease and interstitial pneumonia continue to be the main unsolved complications of bone marrow transplantation, but recent advances have decreased their frequency and severity. Most of the complications of allogeneic bone marrow transplantation may be eliminated with the use of autologous stem cells. For further refinement bone marrow transplantation should continue to be performed in large centres that combine treatment with research.