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Use of Cord Blood Cells for Banking and Transplant

^a Bone Marrow Transplant Unit; ^b Department of Biostatistics, Hôpital Saint-Louis, Paris, France, on behalf of EUROCORD Transplant Group

Correspondence: Eliane G. Gluckman, M.D., Bone Marrow Transplant Unit, Hôpital Saint-Louis, 1 Avenue Claude Vellefaux, 75475 Paris Cedex 10, France. Telephone: 33-1-42-49-96-44; Fax: 33-1-42-49-96-34.

	INTRODUCTION

Top Introduction Cord Blood Banking Collection Cell Processing Ethical and Legal Aspects Results of Cord Blood... Conclusions References

 
Allogeneic hematopoietic stem cell (HSC) transplantation has been used to treat thousands of patients, both adults and children, who have life-threatening hematological diseases. The principal limitations of allogeneic bone marrow transplantation (BMT) are, for the majority of patients, the lack of suitable HLA-matched donors and the complications of graft-versus-host disease (GVHD) associated with HLA mismatches. The lack of an HLA-identical sibling donor in 70% of the cases has been overcome through the establishment of registries of potential marrow donors. These registries, however, often are restricted in terms of HLA polymorphism and ethnic diversity. Despite a bone marrow donor registry which contains >3.7 million donors worldwide, some patients cannot be transplanted because of the lack of a suitable HLA-identical donor. New approaches have been investigated, including the use of HLA partially mismatched, T cell-depleted, mobilized peripheral blood HSC or umbilical cord HSC.

The expected advantages of using umbilical cord HSC for transplantation are the enrichment of immature progenitor HSC, which should facilitate engraftment [1, 2], and the immaturity of the immune system at birth, which should decrease the incidence and severity of GVHD [3]. Cord blood HSC have distinctive proliferative advantages including increased cell cycle rate, production of autocrine growth factors, and increased telomere length. The small number and the relative immaturity of cord blood T cells should reduce the risk and severity of GVHD [3]. This feature may permit a greater degree of HLA disparity between donor and recipient than is usually accepted with adult blood or marrow HSC transplantation.

Since the first cord blood transplant performed in 1988 [4], cord blood transplantation has been increasingly used as a new source of HSC, and more than 200 transplants have been reported. To develop and evaluate cord blood transplant results, the European Blood and Marrow Transplantation group (EBMT) organized a concerted action, the EUROCORD group. The objectives of EUROCORD are given in Table 1.

	CORD BLOOD BANKING

Top Introduction Cord Blood Banking Collection Cell Processing Ethical and Legal Aspects Results of Cord Blood... Conclusions References

	COLLECTION

Top Introduction Cord Blood Banking Collection Cell Processing Ethical and Legal Aspects Results of Cord Blood... Conclusions References

 
The issue of informed consent and its purpose have been debated. It is generally agreed that cord and placental blood is a discarded product and can be used without asking permission, but informed consent must be asked if tests are to be done on either maternal or cord blood. In some countries, the woman’s informed consent is solicited after delivery and, if it is obtained, a full medical history is taken and a blood sample drawn to test for infectious disease markers. In other countries, information on cord blood donation for allogeneic use is given before delivery and the informed consent process done in advance. This gives the blood banks the opportunity to exclude donors with a high risk of transmitting infectious or genetic diseases. There have been some concerns about the process of informing the family about the results of infectious and genetic disease screening. Another issue is the follow-up of the donor and, in some cases, the possibility for the family to retrieve the autologous cord blood.

Two collection techniques are used: one collects cord blood in the delivery room while the placenta is still in the uterus; the other collects cord blood in an adjacent room after delivery [5, 6]. Both techniques have advantages and disadvantages (Table 2).

Testing for genetic diseases should be directed by the family history, the ethnic background, and the follow-up of the donor. Tests on cord blood are expensive, and there is no consensus on the type and number of tests that should be done. There are some concerns, too, about relaying the results to the family.

Recent studies have shown that the presence of maternal cells in cord blood is very frequent, and the detection depends on the sensitivity of the technique used [8, 9]. With very sensitive techniques, maternal cells are always detected in low numbers in cord blood. Some researchers believe that maternal cells might engraft, resulting in GVHD in the recipient. So far, this has not been observed. To the contrary, there is one report of a patient who received a transplant heavily contaminated by maternal cells who had no evidence of GVHD [10]. For these reasons, screening for maternal cell contamination is not included in the general practice of cord blood banking.

HLA typing is done on an aliquot of cord blood. In addition, EUROCORD is collecting DNA from donors and recipients to perform molecular typing for other markers. Some banks routinely type the mother for HLA to have the information on the haplotype and to be able to control the accuracy of cord blood typing.

	CELL PROCESSING

Top Introduction Cord Blood Banking Collection Cell Processing Ethical and Legal Aspects Results of Cord Blood... Conclusions References

 
Because of the small volume of cord blood (40 to 150 ml), there is some concern that any attempt at cell manipulation and concentration might result in a considerable cell loss that might impair engraftment. Many banks freeze whole cord blood in 10% dimethyl sulfoxide (DMSO) while others use HES (hydroxyl-ethyl starch) sedimentation for volume reduction and red cell removal [6]. This last technique, if proven safe, would have the considerable advantage of reducing storage space in liquid-nitrogen freezers. Thawing techniques are well established and aim at removing red cells and DMSO [6].

Evaluation of stem cell content is a very important issue, since several studies have shown that there is a correlation between the number of nucleated cells infused and time to engraftment. There is a correlation between placental weight, time of clamping, speed of processing, volume collected, stem cell content, and the number of nucleated cells collected. Quantification of HSC in cord blood is not always easy, and most studies refer to nucleated or mononucleated cells infused per kg before or after thawing.

	ETHICAL AND LEGAL ASPECTS

Top Introduction Cord Blood Banking Collection Cell Processing Ethical and Legal Aspects Results of Cord Blood... Conclusions References

 
Cord blood can be collected for an unrelated or a related transplant, and, hypothetically, for autologous use. For use by an unrelated recipient, the woman must be aware that the donation is anonymous and free, and there is no guarantee to be able to retrieve the blood for family use [11]. Private banks have been set up, primarily in the United States, for collecting cord blood for autologous use. The widespread use of cord blood HSC has become controversial since an American company applied for a patent covering storage and use of placental blood for all human clinical uses. This company hopes to retain control of all future licensing. EUROCORD and EBMT groups are opposed to this patent on moral and legal grounds since cord blood is a gift of nature and not a human invention, and that its use, or the use of any sources of HSC that have not been modified, is beyond the realm of commercial exploitation [12]. Furthermore, the use of fetal and cord blood cells has raised ethical concerns related to the procedure of informed consent, the detection of infectious and genetic diseases, and how to inform the donor, while preserving the anonymity and freedom of both the donor and the recipient.

	RESULTS OF CORD BLOOD TRANSPLANTATIONS

Top Introduction Cord Blood Banking Collection Cell Processing Ethical and Legal Aspects Results of Cord Blood... Conclusions References

 
The results of 143 cord blood transplantations done between October 1, 1988 and December 31, 1996 in 45 EUROCORD centers and reported to the EUROCORD registry have been published [13, 14]. A database containing information about European and non-European transplant centers was reviewed. Of the 148 transplants reported during the time of the study, five were excluded because the patients had received bone marrow as well as cord blood. Seventy-eight patients received related transplants and 65 received unrelated transplants.

Conditioning regimens of the transplant recipients varied according to diagnosis, previous treatment, and disease status. Patients who received cord blood from an HLA-identical sibling had conditioning regimens used in standard BMT. Total body irradiation (TBI) combined with cyclophosphamide or other chemotherapy was used in 60 patients. Busulfan was used in place of TBI in 40 patients who received a related cord blood transplant and in 24 patients who received an unrelated transplant. In the 49 patients receiving an unrelated transplant, anti-thymocyte globulin or monoclonal anti-T cell antibody was given before transplantation. Prophylaxis for GVHD consisted of cyclosporin, alone or with prednisone or methotrexate. Established GVHD was usually treated with prednisone.

The methods of cord blood collection, cryopreservation, storage, and thawing varied among the centers. Blood was usually preserved in 10% DMSO and thawed according to the method of the New York Cord Blood Bank [12]. Table 3 lists the characteristics of the blood grafts before and after freezing/thawing. Collections from related and unrelated donors had similar properties.

Neutrophil recovery was defined as the time to reach an absolute neutrophil count (ANC) 0.5 x 10⁹/l for three consecutive days. Patients who did not show signs of engraftment by day 60, or patients who required another transplant or autologous reconstitution were considered not to have engrafted. Platelet engraftment was defined as the time to reach a platelet count 20 x 10⁹/l in the absence of platelet transfusions. Graft rejection was defined as engraftment followed by pancytopenia or GVHD without signs of myeloid engraftment. Patients in whom there was no engraftment were censored if they died before day 60. Acute GVHD was scored according to standard criteria; for patients surviving >100 days, GVHD was defined as chronic, and was coded as limited or extensive. Relapse, complications, and causes of death were reported, also.

The median age of the patients was six years (range 0.2 to 45). The overall survival at one year was 49 ± 5% for the entire group. Recipients of related transplants had a one-year survival of 63 ± 6%, and recipients of unrelated transplants had a one-year survival of 29 ± 7% (p = 0.0001). Because the outcome was statistically significant, the two groups were analyzed separately. Variables associated with improved survival in recipients of related donor transplants included age <6 years, weight <20 kg, negative recipient CMV serology, and HLA identity. Weight and serology were most important. Variables associated with improved survival in recipients of unrelated donor transplants included negative recipient CMV serology and infusion of 3.7 x 10⁷ nucleated cells. The number of HLA differences between donors and recipients did not appear to influence survival.

In the entire group of 143 recipients, median time to reach ANC 0.5 x 10⁹/l was 30 days (range 8 to 56), and to reach a platelet count 20 x 10⁹/l was 56 days (range 9 to 180). Variables associated with improved neutrophil engraftment in recipients of related donor transplants included age, weight, and number of nucleated cells infused. Age <6 years was associated with a higher chance of ANC 0.5 x 10⁹/l by day 60. The variable associated with improved platelet engraftment in recipients of related donor transplants was HLA identity. The variables associated with improved ANC and platelet engraftment in recipients of unrelated donor transplants included HLA identity and number of nucleated cells infused.

Graft-versus-host disease grade II was seen in 14 patients receiving related donor grafts and in 21 patients receiving unrelated donor grafts. For recipients of related donor grafts, the number of HLA differences was the most important variable; for recipients of unrelated donor grafts, the number of HLA differences and negative donor CMV serology were most important.

Malignant relapse was seen in 22 of 95 patients on whom information was available. This included 15 of 46 recipients of related donor grafts and 7 of 49 recipients of unrelated donor grafts.

	CONCLUSIONS

Top Introduction Cord Blood Banking Collection Cell Processing Ethical and Legal Aspects Results of Cord Blood... Conclusions References

 
There are possible clinical advantages to using cord blood as a source of HSC for transplantation and these advantages may be related to differences between fetal and adult HSC. The relative immaturity of cord blood lymphocytes might reduce the risk and severity of GVHD, and this may permit a greater HLA disparity between donor and recipient than is usually acceptable with adult blood or marrow. This EUROCORD report suggests that cord blood may be an alternate source of HSC for use in patients with malignant and non-malignant hematological diseases. With this new source of HSC and other technical developments in HSC transplantation, we may be able to identify a donor for any given patient who needs a transplant. This new situation requires carefully planned prospective studies of the clinical efficacy of different strategies of selecting donors.

	REFERENCES

Top Introduction Cord Blood Banking Collection Cell Processing Ethical and Legal Aspects Results of Cord Blood... Conclusions References

 

1. Broxmeyer HE, Gordon GW, Hangoc G et al. Human umbilical cord blood as a potential source of transplantable hematopoietic stem/progenitor cells. Proc Natl Acad Sci USA 1989;86:3828–3832.[Abstract/Free Full Text]
2. Broxmeyer HE, Hangoc G, Cooper S et al. Characteristics and expansion of human umbilical cord blood and estimation of its potential for transplantation in adults. Proc Natl Acad Sci USA 1992;89:4109–4113.[Abstract/Free Full Text]
3. Delaselle V, Gluckman E, Bruley Rosset M. Newborn blood can engraft adult mice without inducing graft versus host disease across non H2 antigens. Blood 1996;87:3977–3983.[Abstract/Free Full Text]
4. Gluckman E, Broxmeyer HE, Auerbach AD et al. Hematopoietic reconstitution in a patient with Fanconi’s anemia by means of umbilical cord blood from an HLA-identified sibling. New Engl J Med 1989;321:214–219.
5. Rubinstein P, Rosenfield RD, Adamson JW et al. Stored placental blood for unrelated bone marrow reconstitution. Blood 1993;81:1679–1690.[Free Full Text]
6. Rubinstein P, Dobrila L, Rosenfield RE et al. Processing and cryopreservation of placental/umbilical cord blood for unrelated bone marrow reconstitution. Proc Natl Acad Sci USA 1995;92:10112–10119.
7. Schreiber GB, Busch MP, Kleinman SH et al. The risk of transfusion-transmitted viral infection. New Engl J Med 1996;334:1685–1690.[Abstract/Free Full Text]
8. Socie G, Gluckman E, Carosella E et al. Search for maternal cells in human cord blood by polymerase chain reaction amplification of two minisatellite sequences. Blood 1994;83:340–344.[Abstract/Free Full Text]
9. Petit T, Gluckman E, Carosella E et al. A highly sensitive polymerase chain reaction method reveals the ubiquitous presence of maternal cells in human umbilical cord blood. Exp Hematol 1995;23:1601–1605.[Medline]
10. Abecasis MM, Machado AM, Boavida G et al. Haploidentical cord blood transplant contaminated with maternal T cells in a patient with advanced leukaemia. Bone Marrow Transplant 1996;17:891–895.[Medline]
11. Sugarman J, Reisner EG, Kurtzberg J. Ethical aspects of banking placental blood for transplantation. JAMA 1995;274:1783–1785.[Abstract/Free Full Text]
12. Gluckman E, O’Reilly RJ, Wagner J et al. Patents versus transplants. Nature 1996;382:108.[Medline]
13. Gluckman E, Rocha V, Boyer-Chammard A et al., for the EUROCORD Transplant group and the European Blood and Marrow Transplantation Group. Outcome of cord blood transplantation from related and unrelated donors. New Engl J Med 1997;337:373–381.[Abstract/Free Full Text]
14. Gluckman E, Rocha V, Boyer-Chammard A et al., for EUROCORD transplant group. Results of cord blood transplants in Europe. Blood 1996;88(suppl 1)485a.

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