Torstein Egeland

Anterior myocardial infarction with acute percutaneous coronary intervention and intracoronary injection of autologous mononuclear bone marrow cells: safety, clinical outcome, and serial changes in left ventricular function during 12-months' follow-up.

To the Editor: Intracoronary injection of bone marrow cells (BMC) has been introduced for improvement of left ventricular (LV) function after acute myocardial infarction (AMI). In the randomized ASTAMI (Autologous Stem cell Transplantation in Acute Myocardial Infarction) study, BMC treatment did not

Donation of stem cells from blood or bone marrow: results of a randomised study of safety and complaints

Biological consequences and physical complaints were compared for donors randomly assigned either to blood stem cell (BSC) or bone marrow (BM) donation. In the period 1994–1999, 61 consecutive donors were included. The BSC donors were given G-CSF 10 μg/kg s.c., daily during 5 days before the first leukapheresis. Nineteen donors had one leukapheresis, 10 required two and one donor needed three leukaphereses in order to reach the target cell number of 2 × 106 CD34+ cells/kg bw of the recipient. A median platelet nadir of 102 × 109/l was reached shortly after the last leukapheresis. Three weeks post harvest, 17 of 30 BSC donors had a mild leukopenia. Six had a leukopenia lasting more than a year before returning to normal values. Both groups were monitored prospectively through a standardised questionnaire completed by the donors. BSC donation was significantly less burdensome than BM donation and was preferred by the donors. The short-term risks of BSC mobilisation and harvest seem negligible. The potential long-term effects of G-CSF are unresolved and the donors must be followed closely.Bone Marrow Transplantation (2002) 29, 479–486. doi:10.1038/sj.bmt.1703418

Estimating drop-out probabilities in forensic DNA samples: A simulation approach to evaluate different models

Allele drop-out is a well known phenomenon that is primarily caused by the stochastic effects associated with low quantity or low quality DNA samples. Recently, new interpretation models that employ the use of logistic regression have been utilised in order to estimate the probability of drop-out. The model parameters are estimated using profiles from samples of extracted DNA diluted to low template levels in order to induce drop-out. However, we propose that this approach is over-simplistic, because several sources of variability are not taken into account in this generalised model. For example, in real-life, small (discrete) crime-stains are analysed where cells are (or were) intact. The integrity of the paired chromosomes of the diploid cell is preserved. In extracted DNA that is diluted to low template levels, we argue that the paired-chromosome integrity is lost. This directly affects the outcome of the logistic model. To date, current experimentation procedures are more akin to haploid cells and thus, different logistic models are needed for haploid and diploid cells. In order to simplify the methodology to estimate the multiple logistic regressions, we propose the use of a simulation model of the entire process associated with the analysis of STR loci, as a supplement to the purely experimental approach to support the validation of new methods. We illustrate with an evaluation of some features of the logistic model proposed by Gill et al., 2009 [12] and discuss alternative models.

Differences in the distribution of CD34 epitopes on normal haemopoietic progenitor cells and leukaemic blast cells

The CD34 molecule expressed on haemopoietic progenitor cells contains a large number of epitopes whose expression may be related to the maturation or function of the cells. Monoclonal antibodies specific for different epitopes have been reported to detect different numbers of CD34+ leukaemic blast cells. We wanted to confirm this observation and study whether parallel findings could be observed for normal haemopoietic progenitor cells. The cells were immunophenotyped by flow cytometry with a series of monoclonal antibodies reactive with different CD34 epitopes. Class III epitopes (resistant to enzymatic cleavage with neuraminidase, chymopapain and a glycoprotease from Pasteurella haemolytica) showed a broader distribution on normal haemopoietic progenitor cells and leukaemic blast cells than class I epitopes (sensitive to cleavage with all three enzymes) and class II epitopes (sensitive to degradation with glycoprotease and chymopapain, and resistant to neuraminidase). The subpopulation of normal progenitor cells which exclusively expressed class III epitopes had flow cytometric characteristics compatible with mature myeloid progenitor cells, whereas class I, II and III epitopes were equally expressed on cells enriched for immature subsets. No discordant epitope expression could be observed for the more immature leukaemias (AML‐M0/1) and a higher percentage of the more mature leukaemic blast cells (AML‐M3 and AML‐M4/5) expressed class III epitopes compared to the percentage expressing class I and II epitopes.

Age and stress related phenotypical changes in bone marrow CD34+ cells

Objective. Phenotypical changes in the human bone marrow (BM) due to age and stress have not so far been properly addressed in the literature. In the present study, we compared CD34+ BM cells between older and young volunteers. The influence of stress on CD34+ cell phenotype in older patients was investigated in an age‐matched group with acute myocardial infarction (AMI). Cytokines thought to influence BM CD34+ cell homeostasis were also analysed. Material and methods. BM mononuclear cells of 10 older volunteers and of 7 young volunteers (18–25 years), as well as 22 AMI patients, were analysed by flow cytometry for the following markers: CD34, CD38, CD117 (c‐kit) and CD133. Blood samples were analysed for CRP, IL‐6, MCP‐1, IL‐8, MMP‐9, TIMP‐1 and TNFα by ELISA methods. Results. Significantly higher numbers of CD34+ CD38− cells (both absolute and relative) were observed in older volunteers than in young volunteers and AMI patients. Higher numbers of immature progenitors, namely CD34+CD38− cells and CD34+CD38−CD117+CD133+ cells, were observed among older volunteers compared to the other groups. However, the relative number of CD34+ cells lacking CD38 expression or expressing CD133 was higher in the old volunteers and AMI patients. None of the circulating factors investigated correlated with any of the cell population yields. Conclusion. In this study, we found that the absolute and relative numbers of BM CD34+CD38− progenitor cells increase with age. The increment is attenuated in patients with AMI.

Gene expression analysis of hematopoietic progenitor cells identifies Dlg7 as a potential stem cell gene

Inducible hematopoietic stem/progenitor cell lines represent a model for studying genes involved in self‐renewal and differentiation. Here, gene expression was studied in the inducible human CD34+ acute myelogenous leukemia cell line KG1 using oligonucleotide arrays and suppression subtractive cloning. Using this approach, we identified Dlg7, the homolog of the Drosophila Dlg1 tumor suppressor gene, as downregulated at the early stages of KG1 differentiation. Similarly, Dlg7 was expressed in normal purified umbilical cord blood CD34+CD38− progenitors but not in the more committed CD34+CD38+ population. Dlg7 expression was not detected in differentiated cells obtained from hematopoietic colonies, nor was expression detected in purified T‐cells, B‐cells, and monocytes. When analyzed in different types of stem cells, Dlg7 expression was detected in purified human bone marrow‐derived CD133+ progenitor cells, human mesenchymal stem cells, and mouse embryonic stem (ES) cells. Overexpression of Dlg7 in mouse ES cells increased their growth rate and reduced the number of EBs emerging upon differentiation. In addition, the EBs were significantly smaller, indicating an inhibition in differentiation. This inhibition was further supported by higher expression of Bmp4, Oct4, Rex1, and Nanog in EBs overexpressing Dlg7 and lower expression of Brachyury. Finally, the Dlg7 protein was detected in liver and colon carcinoma tumors but not in normal adjacent tissues, suggesting a role for the gene in carcinogenesis. In conclusion, our results suggest that Dlg7 has a role in stem cell survival, in maintaining stem cell properties, and in carcinogenesis.

Informed Consent – suggested procedures for informed consent for unrelated haematopoietic stem cell donors at various stages of recruitment, donor evaluation, and donor workup

Summary:The Ethics Working Group of the World Marrow Donor Association (WMDA) was established to address the increasing and complex number of ethical issues surrounding unrelated haematopoietic stem cell donation where the selected donor and recipient reside in different countries. This paper considers the topic of informed donor consent, but recognises that the recommendations contained within the paper may be subject to cultural variances in interpretation, and to adjustment to meet the legal requirements of individual countries. Nevertheless, the extent of international cooperation establishes sufficient common denominators for the recommendations to be widely adhered to in the interests of best practice.

Donor commitment and patient needs

Summary:The article discusses views and recommendations of the World Marrow Donor Association concerning ethical issues related to the donation of hematopoietic stem cell products with respect to recruitment, evaluation, workup, and follow-up of unrelated donors. Particular emphasis is placed upon commitment of individual donors, in particular, with respect to the needs of patients to find HLA-matched donors, who may be asked to donate stem cell and other cell products more than once for given patients.

Fewer relapses and increased chronic GVHD in patients transplanted with blood stem cells: a 5-year follow-up in a single centre study

Summary:A total of 61 consecutive adult patients with haematological malignancies with an HLA-identical or one antigen-mismatched haploidentical family donor were randomised to allogeneic transplantation with blood stem cells (BSC) or bone marrow (BM). The median observation time was 5 years. Apart from engraftment parameters and acute graft-versus-host disease (GVHD), transplant-related mortality (TRM), incidence and severity of chronic GVHD, relapse, leukaemia-free survival (LFS) and overall survival (OS) were recorded. In the BSC and BM group, respectively, TRM was 8/30 and 4/30 (P=0.405), the incidence of chronic GVHD was 15/26 and 11/30 (P=0.138), extensive chronic GVHD was 10/26 and 4/30 (P=0.034), and relapse one and 10 patients (P=0.007). In log-rank test restricted to the cases allografted from HLA-identical donors, the difference remained significant with regard to relapse incidence (P=0.039), but not extensive chronic GVHD (P=0.072). No difference in LFS and OS was observed. In conclusion, our study strongly indicates an enhanced graft-versus-leukaemia effect in BSC recipients, which is not expressed in increased survival. The increased chronic GVHD in these patients may contribute, but the relation is complex and not yet understood.

Remuneration of hematopoietic stem cell donors: principles and perspective of the World Marrow Donor Association

Hematopoietic stem cell transplantation is a curative procedure for life-threatening hematologic diseases. Donation of hematopoietic stem cells (HSCs) from an unrelated donor, frequently residing in another country, may be the only option for 70% of those in need of unrelated hematopoietic stem cell transplantation. To maximize the opportunity to find the best available donor, individual donor registries collaborate internationally. To provide homogeneity of practice among registries, the World Marrow Donor Association (WMDA) sets standards against which registries are accredited and provides guidance and regulations about unrelated donor safety and care. A basic tenet of the donor registries is that unrelated HSC donation is an altruistic act; nonpayment of donors is entrenched in the WMDA standards and in international practice. In the United States, the prohibition against remuneration of donors has recently been challenged. Here, we describe the reasons that the WMDA continues to believe that HSC donors should not be paid because of ethical concerns raised by remuneration, potential to damage the public will to act altruistically, the potential for coercion and exploitation of donors, increased risk to patients, harm to local transplantation programs and international stem cell exchange, and the possibility of benefiting some patients while disadvantaging others.