Risk assessment in haematopoietic stem cell transplantation: Stem cell source

Allogeneic stem cell transplantation in the treatment of acute myeloid leukemia: An overview of obstacles and opportunities

As an important treatment for acute myeloid leukemia, allogeneic hematopoietic stem cell transplantation (allo-HSCT) plays an important role in reducing relapse and improving long-term survival. With rapid advancements in basic research in molecular biology and immunology and with deepening understanding of the biological characteristics of hematopoietic stem cells, allo-HSCT has been widely applied in clinical practice. During allo-HSCT, preconditioning, the donor, and the source of stem cells can be tailored to the patient’s conditions, greatly broadening the indications for HSCT, with clear survival benefits. However, the risks associated with allo-HSCT remain high, i.e. hematopoietic reconstitution failure, delayed immune reconstitution, graft-versus-host disease, and post-transplant relapse, which are bottlenecks for further improvements in allo-HSCT efficacy and have become hot topics in the field of HSCT. Other bottlenecks recognized in the current treatment of individuals diagnosed with acute myeloid leukemia and subjected to allo-HSCT include the selection of the most appropriate conditioning regimen and post-transplantation management. In this paper, we reviewed the progress of relevant research regarding these aspects.

Infectious disease screening among stem cell transplant donors: An Institutional experience in Saudi Arabia

Background

Hematopoietic stem cell transplantation (HSCT) involves the infusion of hematopoietic stem cells from a suitable donor to a patient who has undergone chemotherapy. Stem Cell transplantation is used for the treatment for a wide variety of diseases, including leukemia and lymphoma.

Purpose

This study highlights prevention strategies of infectious diseases among HSCT donors and recipients in our institute as guided by International guidelines. We aim to highlight the strategy for extensive screening of HIV, Hepatitis B and C, CMV infection and syphilis cases in all the stem cell units stored in our facility

Methods

We searched the institutional database to identify cases of infectious diseases among HSC transplants. Extensive donor evaluation was conducted through screening and laboratory infectious disease testing for HIV, Hepatitis B and C, CMV infection and syphilis.

Results

Between 1996 and 2014, 263 consecutive adult HSCT were performed. An approximate equal number of autologous and allogeneic HSC collections were undertaken. The median age for autologous donors was 35 years, whereas that of allogeneic donors is 25 years. Of the 263 stem cell donors, we found 18 patients (autologous) and 2 donors (allogeneic) to be infected. We did not find any of the donors infected with HIV by the serology as well as the NAT testing protocol

Conclusion

Donor screening and testing is the most critical parameter in stem cell transplantation in order to ensure the safety of the product to be transplanted. Modifications in the regulations related to donor screening are aimed at providing safe transplantation and negate the risk of accidental infection of the donor.

Frequency and Outcome of Graft versus Host Disease after Stem Cell Transplantation: A Six-Year Experience from a Tertiary Care Center in Pakistan

Objective. The objective of this study was to evaluate the frequency and outcome of graft versus host disease after stem cell transplantation for various haematological disorders in Pakistan. Materials and Methods. Pretransplant workup of the patient and donor was performed. Mobilization was done with G-CSF 300 μg twice daily for five day. Standard GvHD prophylaxis was done with methotrexate 15 mg/m² on day +1 followed by 10 mg/m² on days +3 and +6 and cyclosporine. Grading was done according to the Glucksberg classification. Results. A total of 153 transplants were done from April 2004 to December 2011. Out of these were allogeneic transplants. There were females and males. The overall frequency of any degree of graft versus host disease was 34%. Acute GvHD was present in patients while had chronic GvHD. Grade II GvHD was present in patients while grade III and IV GvHD was seen in patients each. Acute myeloid leukemia and chronic myeloid leukemia were most commonly associated with GvHD. The mortality in acute and chronic GvHD was 8.8% and 12% respectively. Conclusion. The frequency of graft versus host disease in this study was 34% which is lower compared to international literature. The decreased incidence can be attributed to reduced diversity of histocompatibility antigens in our population.

Private cord blood banking: current use and clinical future

International private umbilical cord blood banking has expanded rapidly in recent years since the first cord blood transplant which was 20 years ago. Private companies offer parents the opportunity to store umbilical cord blood for the possible future use by their child or other family members. The private cord blood industry has been criticised by a number of professional bodies including the EU Ethics Committee, the Royal College of Obstetrics and Gynaecology, the Royal College of Midwives and the US College of Paediatrics. This review presents the arguments from the opponents of private cord blood banking, and then makes the case for private cord banking based on the latest scientific and clinical evidence.

Stem cell bioprocessing: fundamentals and principles

In recent years, the potential of stem cell research for tissue engineering-based therapies and regenerative medicine clinical applications has become well established. In 2006, Chung pioneered the first entire organ transplant using adult stem cells and a scaffold for clinical evaluation. With this a new milestone was achieved, with seven patients with myelomeningocele receiving stem cell-derived bladder transplants resulting in substantial improvements in their quality of life. While a bladder is a relatively simple organ, the breakthrough highlights the incredible benefits that can be gained from the cross-disciplinary nature of tissue engineering and regenerative medicine (TERM) that encompasses stem cell research and stem cell bioprocessing. Unquestionably, the development of bioprocess technologies for the transfer of the current laboratory-based practice of stem cell tissue culture to the clinic as therapeutics necessitates the application of engineering principles and practices to achieve control, reproducibility, automation, validation and safety of the process and the product. The successful translation will require contributions from fundamental research (from developmental biology to the 'omics' technologies and advances in immunology) and from existing industrial practice (biologics), especially on automation, quality assurance and regulation. The timely development, integration and execution of various components will be critical-failures of the past (such as in the commercialization of skin equivalents) on marketing, pricing, production and advertising should not be repeated. This review aims to address the principles required for successful stem cell bioprocessing so that they can be applied deftly to clinical applications.

Understanding and harnessing the graft-versus-leukaemia effect

The graft-versus-leukaemia (GVL) effect is a central component of the stem cell allograft's ability to cure haematological malignancies. The GVL effect is mediated by donor-derived natural killer cells and T lymphocytes, which have distinct mechanisms of recognizing and targeting the recipient's malignant cells. After transplantation the cytokine milieu is favourable to the early establishment of a GVL effect, but the need to prevent graft-versus-host disease limits the full potential of this process. Clinical studies have identified some critical components of the transplant preparation, donor selection, stem cell source (peripheral blood versus bone marrow) and post-transplant management that can be manipulated to optimize the GVL effect. However, further developments focusing on the selective depletion of unwanted alloreactivity with preservation of GVL effects, and the use of vaccines or the adoptive transfer of leukaemia-specific lymphocytes, will be required to enhance the GVL effect to reliably eradicate more resistant leukaemias.

Peripheral blood progenitor cell or bone marrow transplantation: controversy remains

PURPOSE OF REVIEW

The paper compares bone marrow and peripheral blood progenitor cell transplantations in the allogeneic setting.

RECENT FINDINGS

Peripheral blood progenitor cell use has emerged as an international standard of care for hematopoietic transplantation. These cells have a different cellular composition including higher numbers of CD34 cells and markedly higher numbers of T lymphocytes. Current data support the general safety of this approach for normal transplant donors. Results consistently indicate more rapid hematopoietic recovery compared with bone marrow transplantation. This may result in improved early survival in adults with high-risk leukemias, but longer follow-up has demonstrated an increased rate of chronic graft-versus-host disease morbidity and mortality which may obviate the long-term benefit.

SUMMARY

It is unclear whether peripheral blood progenitor cell or bone marrow transplantation will produce improved disease-free or overall survival. Additional studies with long-term follow-up are necessary to resolve these controversies.

The EBMT activity survey 2006 on hematopoietic stem cell transplantation: focus on the use of cord blood products

This report describes the hematopoietic stem cell transplantation (HSCT) activity in Europe in 2006 by indication, donor type and stem cell source. It illustrates differences compared to previous years and concentrates on the use of cord blood transplants. In 2006, there were 25 050 first HSCT, 9661 allogeneic (39%), 15 389 autologous (61%) and 3690 additional re- or multiple transplants reported from 605 centers in 43 participating countries. Main indications were leukemias (7963 (32%; 85% allogeneic)); lymphomas (14 169 (56%; 89% autologous)); solid tumors (1564 (6%; 95% autologous)); non-malignant disorders (1242 (5%; 90% allogeneic)) and non-classified 'others' (112 (1%)). There was an increase in allogeneic HSCT of 9% when compared to 2005, while autologous HSCT numbers remained similar. There were 544 allogeneic cord blood HSCT, which corresponds to 5% of all allogeneic HSCT. The majority, 67%, were used for patients with leukemia. The highest percentage of cord blood transplants, 27%, was seen for inherited disorders of metabolism. No autologous cord blood transplants were reported. The highest increase in allogeneic HSCT was observed for AML, which comprises 31% of all allogeneic HSCT. Numbers of autologous HSCT remained similar in most main indications. This data provide an update of the current HSCT experience in Europe.