Transplanted human cord blood-derived unrestricted somatic stem cells improve left-ventricular function and prevent left-ventricular dilation and scar formation after acute myocardial infarction.

OBJECTIVE: Functional improvement after acute myocardial ischaemia (MI) has been achieved by transplantation of different adult stem and progenitor cell types. It is controversial whether these cell types are able to form novel functional myocardium. Alternatively, graft-related or immune-related paracrine mechanisms may preserve existing myocardium, improve neovascularisation, affect tissue remodelling or induce endogenous de novo formation of functional myocardium. We have applied an alternative somatic cell type, human cord-blood-derived unrestricted somatic stem cells (USSCs) in a porcine model of acute MI. METHODS: USSCs were transplanted into the acutely ischaemic lateral wall of the left ventricle (LV). LV dimension and function were assessed by transoesophageal echocardiography (TEE) pre-MI, immediately post-MI, 48 hours and 8 weeks after USSC injection. Additionally, apoptosis, mitosis and recruitment of macrophages were examined 48 hours post-engraftment. RESULTS: Gender-specific and species-specific FISH/immunostaining failed to detect engrafted donor cells 8 weeks post-MI. Nevertheless, cell treatment effectively preserved natural myocardial architecture. Global left ventricular ejection fraction (LVEF) before MI was 60% (7%). Post-MI, LVEF decreased to 34% (8%). After 8 weeks, LVEF had further decreased to 27% (6%) in the control group and recovered to 52% (2%) in the USSC group (p<0.01). Left-ventricular end-diastolic volume (LVEDV) before MI was 28 (2) ml. 8 weeks post-MI, LVEDV had increased to 77 (4) ml in the control group. No LV dilation was detected in the USSC group (LVEDV: 26 (2) ml, p<0.01). Neither apoptosis nor recruitment of macrophages and mitosis were different in either groups. CONCLUSIONS: Transplantation of USSCs significantly improved LV function and prevented scar formation as well as LV dilation. Since differentiation, apoptosis and macrophage mobilisation at infarct site were excluded as underlying mechanisms, paracrine effects are most likely to account for the observed effects of USSC treatment.

Separation of adult bone marrow mononuclear cells using the automated closed separation system Sepax.

BACKGROUND: The Düsseldorf-based cardiologist Professor Strauer was the first to present a therapeutic concept for the repair of acute infarcted myocardium in 2001: the autologous intracoronary transplantation of unfractionated human bone marrow (BM) mononuclear cells (MNC). The Division of Cardiology, Pneumology and Angiology, University of Duesseldorf Medical School, Duesseldorf, Germany, was also able to show the regenerative potential of BM stem cell transplantation in patients with chronic heart disease (CHD) and peripheral arterial disease (PAD). In the mean time, several clinical trials have been set up worldwide, predominantly by using MNC isolated manually from BM aspirates via density-gradient centrifugation; 374 patients have been treated here with unselected BM MNC since 2001. Altogether 217 BM aspirates have been processed manually. In order to maintain the high standards required for cellular therapeutics, the Sepax cell-separation system was implemented into routine BM processing in 2006. The closed Sepax system provides a reproducible MNC isolation method, and 157 BM samples have been processed with the Sepax device. The results of manual MNC isolation were compared with the Sepax-mediated MNC isolation. METHODS: The manual Ficoll separation method was compared with the Sepax density gradient-based separation (DGBS) protocol using Ficoll with the kit CS-900 and the Sepax S-100 main processing unit from Biosafe. RESULTS: Nucleated cell and MNC recovery were significantly higher after Sepax processing (P<0.0001) whereas no significance was found for red blood cell depletion. DISCUSSION: The Sepax cell-separation system is a time-saving method providing clinical-grade MNC isolated automatically from human BM by Ficoll density centrifugation.

Transplantation of autologous mononuclear bone marrow stem cells in patients with peripheral arterial disease (the TAM-PAD study).

OBJECTIVES: For patients with severe, chronic limb ischemia in many cases interventional or surgical treatment is not possible anymore. In the past, both intramuscular and intraarterial transplantation of autologous BMCs had been proved therapeutically beneficial. The TAM-PAD study is the first one to analyze combined intraarterial and intramuscular BMC transplantation in its acute and long-term effects. METHODS: 13 patients with chronically ischemic limbs due to peripheral arterial disease (Fontaine stage IIb) were recruited and underwent follow-up examinations after 2 and 13 months. Mononuclear cells from bone marrow were injected intramuscular and intraarterial into the ischemic limb. RESULTS: In contrast to the control group, after 2 months the pain-free walking distance of the transplanted patients significantly increased (from 147 +/- 90 to 500 +/- 614 m, p = 0.001). Furthermore the ankle-brachial index was significantly improved (at rest from 0.66+/-0.18 to 0.80+/-0.15, p = 0.003, after stress from 0.64 +/- 0.19 to 0.76 +/- 0.16, p = 0.006). Similar improvement was documented in capillary-venous oxygen-saturation (thigh from 59 +/- 9 to 66 +/- 5, p = 0.005, lower leg from 56 +/- 14 to 63 +/- 5, p = 0.021) and venous occlusion plethysmography (rest from 2.1 +/- 0.7 to 2.5 +/- 0.7, p = 0.009, mean reactive hyperemia from 5.3 +/- 1.8 to 7.2 +/- 1.8, p = 0.003, and peak flow from 7.2 +/- 3.2 to 10.8 +/- 2.8, p = 0.002). After 13 months these positive effects persisted at their improved level. No side effects or complications were monitored. CONCLUSIONS: Combined intraarterial and intramuscular transplantation of autologous mononuclear bone marrow stem cells is a clinically feasible and minimally invasive therapeutic option for patients with severe chronic peripheral occlusive arterial disease.

In vitro differentiation of human cord blood-derived unrestricted somatic stem cells towards an endodermal pathway.

BACKGROUND: Pluripotent unrestricted somatic stem cells (USSC) from UC blood can differentiate into hepatic cells in the in utero sheep model, resulting in 20% human albumin-producing parenchymal hepatic cells without cell fusion or tumor-formation events. Additionally, we have shown in vitro differentiation of USSC by hepatocyte growth factor and oncostatin M induction, causing changes in the gene expression towards the endodermal lineage. Positive glycogen synthase expression and a positive periodic acid-schiff reaction demonstrated a functional production of polysaccharides in the cells. METHODS: We describe the in vitro differentiation of USSC towards an endodermal pathway using different matrices, growth factors and organic substances. Also, co-cultures of USSC with primary cells of endodermal tissue were prepared to mimic the biologic niche. We investigated the effect of direct co-culture of USSC with primary rat hepatocytes or with sheep tissue of endodermal origin. Direct co-cultures were set up to ensure cell-cell contacts. For co-cultures without cell-cell contacts, transwell inlays with 1-microm membranes were used to separate the cells. Furthermore, the effect of endodermally conditioned medium was investigated. Changes in the gene expression patterns were analyzed by RT-PCR. RESULTS: We have shown that USSC can differentiate in vitro into an endodermal-like cell with a phenotype similar to hepatic cells. Differentiation of USSC with growth factors, retinoic acid, matrigel matrix and different co-cultures led to an increased expression of albumin and also to the detection of GSC, SOX 17, Cyp2B6, Cyp3A4, Gys2, HNF4a, ISL-1 and Nkx6.1. In addition, functional albumin secretion was observed. DISCUSSION: Although the differentiation assays demonstrated here produce only an immature hepatocyte-like cell, endodermaly differentiated USSC might be a useful alternative for cell replacement in the future.

Intracoronary autologous bone marrow cell transplantation beneficially modulates heart rate variability.

The effect of intracoronary administration of autologous bone marrow cells on autonomic modulation of heart rate has not yet been demonstrated. Therefore, we investigated different parameters of heart rate variability (HRV) in 46 patients without (n=23) or with (n=23) intracoronary stem cell therapy after transmural myocardial infarction. After three to twelve months of follow up, patients receiving stem cells showed a significant increase of HRV parameters that have been linked to cardiovascular prognosis.

[Intra-arterial and intramuscular transplantation of adult, autologous bone marrow stem cells. Novel treatment for therapy-refractory peripheral arterial occlusive disease]. / Intraarterielle und intramuskuläre Transplantation adulter, autologer Knochenmarkstammzellen -- Neue Therapie bei therapierefraktärer peripherer arterieller Verschlusskrankheit.

HISTORY AND CLINICAL FINDINGS: A 62-year-old man had limb ischemia in stage IIb (Fontaine's classification). After surgical and interventional measures the right superficial femoral artery had remained occluded for more than one year. The patient's walking distance was only 100 meters. It was therefore decided to do a combined intraarterial and intramuscular transplantation of stem cells into the right limb. INVESTIGATIONS: Before and 10 weeks after the transplantation noninvasive tests, namely walking distance, ankle-brachial index at rest and during exercise, occlusion plethysmography and capillary venous oxygen saturation were measured. The patient was also asked to fill in a questionnaire of his symptoms. THERAPY AND RESULTS: After harvesting the patient's bone marrow the mononuclear cell fraction was separated (109.8 x 10(6)). Afterwards 10 ml of the cell suspension were injected into the right superficial femoral artery and 5 ml each of the suspension was injected into 5 different locations of the quadriceps femoris and the gastrocnemius muscles. After 10 weeks" follow-up a seven-fold improvement of walking distance and an increase of tissue oxygen saturation of more then 50% were recorded. The ankle-brachial index at rest remained unchanged, but on exercise it increased by 24%. CONCLUSION: The combined intraarterial and intramuscular transplantation of human autologous bone marrow stem cells may be a novel and clinically feasible treatment for patients with severe chronic limb ischemia. The success of this approach may be the result of increased neo-angiogenesis, especially of the small muscle-supplying vessels.

High-resolution HLA typing by sequencing for HLA-A, -B, -C, -DR, -DQ in 122 unrelated cord blood/patient pair transplants hardly improves long-term clinical outcome.

To determine the impact of high-resolution (HR) HLA typing with outcomes after UCBT, DNAs of 122 pairs were analysed for HLA class I and class II mismatches (MM) based on HR typing. For HLA-A, -B on low-resolution typing and -DRB1 on HR typing, the following MM situation resulted: no MM (13%), one MM (40%), two MM (36%), three MM (8%), four MM (3%). For A, B, C, DR and DQ based on HR typing the following MM occurred: No MM (4%), one MM (10%), two MM (15%), three MM (22%), four MM (25%), five MM (12%), six MM (6%), seven MM (3%), eight MM (2%). There was no significant association between number of MM (HR) for both HLA-A, -B and -DRB1 and HLA-A, -B, -C, -DRB1 and DQB1 and aGvHD grade II-IV. There was a trend that MM in class I HR were associated with neutrophil recovery; HLA-A locus typing analysed in HvG direction was associated with reduced cumulative incidence of engraftment (P=0.04), the same for C-KIR in HvG direction (P=0.01). No significant correlation was found between numbers of HLA-MM on the HR level with 2-year survival. The analysis shows that the degree of mismatching in UCBT is even higher than expected.

Similar survival following HLA-identical sibling transplantation for standard indication in children with haematologic malignancies: a single center comparison of mobilized peripheral blood stem cell with bone marrow transplantation.

BACKGROUND: Peripheral blood stem cell (PBSC) grafts are increasingly used for autologous and allogeneic haematopoietic stem cell transplantation (alloHSCT) with the aim to hasten neutrophil and platelet engraftment and thereby to reduce transplant-related complications due to infections, bleeding and graft failure. Based on the paucity of data on PBSC transplantation in children we performed a retrospective single-center analysis comparing the outcome of children receiving mobilized PBSC from human leukocyte antigen (HLA)-identical sibling donors to bone marrow (BM) transplant recipients. PATIENTS AND METHODS: Between 1996 and 2004, 16 children with haematologic malignancies and standard indication for alloHSCT underwent PBSC transplantation from HLA-identical sibling donors. The outcome of these children was compared to a historic control group of 19 bone marrow (BM) transplant recipients. Time to neutrophil engraftment, incidence of acute and chronic graft-versus-host disease (GvHD), relapse rate, transplant-related mortality, event-free and overall survival were analyzed. RESULTS: Neutrophil engraftment was achieved significantly faster after PBSC compared to BM transplantation with a median time to neutrophil engraftment of 11 (range: 8-21) and 19 (16-44) days for the PBSC and BM cohort, respectively (p < 0.001). Two of 19 (11 %) BM recipients did not achieve primary neutrophil engraftment and both patients died due to infectious complications. The rate of clinically significant acute GvHD > or = grade II was higher in the PBSC compared to the BM group (75 vs. 39 %; p = 0.045). Incidences of chronic GvHD (PBSC vs. BM: 60 vs. 44 %), death of disease (13 vs. 21 %) and death of complication (13 vs. 16 %) were comparable between both groups (p = ns). With a median follow up of 4.7 years (PBSC) and 10.2 years (BM) overall survival (PBSC vs. BM: 68.6 +/- 13.5 vs. 63.2 +/- 11.1 %; p = 0.65) and event-free survival (67.0 +/- 12.1 vs. 63.2 +/- 11.1 %; p = 0.80) is without demonstrable difference in both groups. CONCLUSIONS: Transplantation of PBSC compared to BM is associated with faster neutrophil engraftment and a higher rate of > or = grade II acute GvHD. As overall survival and event-free survival is similar when using PBSC and BM, PBSC is an alternative stem cell source for HLA-identical sibling transplantation. Further prospective analyses with higher number of patients stratified according to well established risk factors are required to define the precise role of both stem cell sources for children with haematologic malignancies.

[In vivo and in vitro bone regeneration from cord blood derived mesenchymal stem cells]. / In-vitro- und In-vivo-Knochenregenerierung durch mesenchymale Stammzellen aus dem Nabelschnurblut.

BACKGROUND: Mesenchymal stem cells with an osteoblastic differentiating potency are investigated in regard of probable tissue engineering for further clinical application. The following report describes the use of cord blood derived stem cells as an alternative to other stem cell populations for bone regenerating tissue engineering. METHODS: To demonstrate the multipotency of cord blood derived mesenchymal stem cells, unrestringated somatic stem cells (USSC) were isolated from cord blood and underwent an osteo-, chondro- and adipoblastic in vitro stimulation. To evaluate the osteoinductive potency of a porcine collagen I/III cell carrier USSC were incubated on this matrix. To investigate the in vivo effects of human USSC an athymic rat model was developed. These cells were transplanted into a femoral defect. RESULTS: Cord blood derived mesenchymal stem cells (USSC) have an in vitro multipotency and show adipo-, chondro- and osteogenic differentiation. The porcine collagen I/III carrier promoted an osteoblastic differentiation. USSC survived after xenotransplantation in an athymic rat and differentiated into osteoblasts filling the bony defect zone. CONCLUSION: Human USSC are a mesenchymal multipotent stem cell population that shows osteoblastic differentiation onto a collagen I/III carrier in vitro as well as in an athymic rat in vivo.

Transplantation of haematopoietic stem cells derived from cord blood, bone marrow or peripheral blood: a single centre matched-pair analysis in a heterogeneous risk population.

BACKGROUND: Beside the transplantation of haematopoietic stem cells derived from bone marrow (BMT) and peripheral blood (PBSCT) in the absence of a well-matched donor, transplantation of cord blood (CBT) has been shown to be a valid alternative. To validate the efficacy of CBT in comparison to BMT and PBSCT we performed a single-centre based matched-pair analysis. PATIENTS AND METHODS: Between 1996 and 2003, 15 paediatric patients with non-malignant and malignant diseases of heterogenous risk underwent CBT. 198 paediatric patients undergoing BMT or PBSCT during the same time and at the same centre were available for selection as appropriate controls for matched-pair analysis. Matching criteria in descending hierarchy were disease, risk status, type of donor, age at HSCT, gender and year of transplantation. 47 % of CB grafts were < or = 4/6 HLA-matched whereas close to 90 % of grafts in the BMT and PBSCT cohorts were completely matched. RESULTS: Neutrophil engraftment was comparable in CB and BM recipients (p = 0.529) while engraftment following PBSCT occurs significantly earlier (p < 0.01). Median time to neutrophil recovery was 20 (range: 13-36), 19 (14-28) and 14 (9-24) days for the CBT, BMT and PBSCT cohort respectively. Of note contrary to the expectation, with regard to a reduced risk of Graft-versus-Host-Disease (GvHD) there was no clear advantage in the CBT cohort with a similar overall GvHD rate in all 3 groups. This observation can be attributed to the fact that in the CBT cohort the proportion of patients with an HLA-mismatched donor was higher than in the other cohorts. Rate of death of complications (DOC) was high in CB recipients (40 %), but not statistically different from BM (27 %) and PBSC recipients (13 %). In contrast to the CBT and BMT cohort with only 1 patient dead of disease (DOD), 4 PBSC recipients (31 %) died suffering from a relapse. 2-year event-free survival (EFS) in patients with malignant disease was 38.5 %, 69.2 % and 33.0 % for the CBT, BMT and PBSCT cohort respectively. 5-year overall survival (OS) was 53.3 % in the CBT, 66.4 % in the BMT and 50.9 % in the PBSCT cohort. There was no statistical difference between the cohorts transplanted with CB and BM or PBSC regarding EFS and OS (EFS: p = 0.24 and p = 0.72; OS: p = 0.53 and p = 0.64). CONCLUSIONS: Transplantation of < or = 4/6 HLA-matched CB grafts seems to be associated with a higher risk of GvHD, graft rejection and lethal opportunistic infection. With an overall survival of 53 % in our 15 patients this analysis documents that even in high risk patients, CB may be a valid alternate HSC source in children who lack a well-matched donor. This is especially true, if a > 4/6 HLA-matched CB with > 2.0 x 10 (7) total nucleated cells/kg bodyweight is available. Thus, parallel to the search for a BM or PBSC donor, searching for an adequate CB unit should be initiated.

[Long-term results of homologous penetrating limbokeratoplasty in total limbal stem cell insufficiency after chemical/thermal burns]. / Langzeitergebnisse der homologen perforierenden Limbokeratoplastik bei totaler Limbusstammzellinsuffizienz nach Verätzungen/Verbrennungen.

BACKGROUND: Since 1991 homologous penetrating limbokeratoplasty has been performed in 32 patients with severe limbal stem cell insufficiency following chemical/thermal burns. The long-term results considering the effects of HLA matching are presented for the first time. PATIENTS: All patients received systemic cyclosporin A and/or mycophenolate mofetil in the postoperative course. In 9 patients grafts with 0-1 HLA mismatches in the HLA A, B and DR loci, in 6 patients grafts with 2-6 mismatches and in 17 patients untyped grafts were used. Long-term clear graft survival was estimated according to Kaplan and Meier. RESULTS: Five years postoperatively, 50% of the grafts with 0-1 mismatches, 32% of the grafts with 2-6 mismatches and 18% of the untyped grafts were centrally clear (log-rank-test, p>0.05). CONCLUSIONS: Although statistically not significant, HLA matched grafts seem to deliver better results than untyped grafts in penetrating limbokeratoplasty. Improvement of matching strategies and immunosuppression may possibly further improve current results.

Improvement of graft prognosis in penetrating normal-risk keratoplasty by HLA class I and II matching.

BACKGROUND: Owing to contradictory results, HLA matching in penetrating keratoplasty still is equivocal. Different surgical techniques in multicentre studies, missing risk differentiation in high-risk situations, and faulty HLA typing can be identified as main reasons for these contradictory results. In this monocentre study, the value of HLA class I and II matching (A, B, DR loci) was examined in a homogeneous group of 418 normal-risk keratoplasty patients using serological typing techniques for HLA class I and immunogenetic typing techniques for class II. METHODS: Penetrating normal-risk keratoplasty was performed in two groups of patients (group I with 0-2, group II with 3-6 mismatches in the A/B/DR loci). All surgery was carried out by three experienced surgeons according to a standardized scheme. Furthermore, postoperative therapy and controls were standardized. There were no statistically significant differences between the two study groups with regard to the number of ABO or H-Y compatibilities, patient age, patient gender, ratio of previous intraocular surgery, ratio of triple procedures, indication for surgery, follow-up period, donor age, donor gender, post-mortem time of the graft, and endothelial cell density of the graft at the end of organ culture. All HLA typing was performed in a quality-controlled laboratory, serologically for HLA class I (A and B loci) and immunogenetically for HLA class II (DR locus). RESULTS: At 4 years postoperatively, the ratio of clear and rejection-free graft survival was 92% in group I and 66% in group II (Kaplan-Meier estimation, log rank test, P=0.03). Monovariate analysis in the Cox model gave no influence of solitary HLA class I or II matching, but only an influence of combined HLA class I and II matching (P=0.03). CONCLUSIONS: In this monocentre study with proper typing techniques, the beneficial effect of HLA class I plus II matching on clear and rejection-free graft survival could be demonstrated in a homogeneous group of normal-risk keratoplasty patients.

Hematopoietic stem cell donor registry strategies for assigning search determinants and matching relationships.

Registries and cord blood banks around the world collect and store the HLA types of volunteers in order to identify matched unrelated donors for patients requiring hematopoietic stem cell transplantation. This task is complicated by the many formats in which HLA types are provided by the testing laboratories (types obtained by serology vs by DNA-based methods; high vs intermediate vs low resolution) and by the need to identify which of these diverse types are most likely to match the HLA assignments of a searching patient as closely as possible. Conversion of the assignments to 'search determinants' may be included within the algorithm used to select and prioritize a list of potentially suitable donors, either as an aid to matching or as a tool to optimize the performance of comparisons within large data files. The strategies used by registries to create search determinants are described. A set of search determinants, utilized by the National Marrow Donor Program, is provided as an example and is intended to initiate further discussion aimed at understanding the process used by each registry with the possibility of developing a standard process among registries worldwide.

Phenotypic and functional comparison of monocytes from cord blood and granulocyte colony-stimulating factor-mobilized apheresis products.

OBJECTIVE: It is well established that T cells are effector cells in graft-vs-host disease (GVHD), yet the contribution of graft monocytes is less well characterized. Therefore, monocytes in cord blood (CB) and granulocyte colony-stimulating factor-mobilized apheresis products (G-AP), two stem cell grafts associated with reduction of acute and chronic GVHD and relative reduction of acute GVHD, respectively, were compared phenotypically and functionally. MATERIALS AND METHODS: The frequencies, phenotypes, and pinocytosis activities of monocytes from CB and G-AP were determined by flow cytometry and their allostimulatory potential in a primary mixed leukocyte reaction. RESULTS: G-AP contained significantly more monocytes than CB (24.9% +/- 7.1% vs 8.8% +/- 1.5% CD14+ and 62.4 +/- 27.5 x 10(6) vs 0.9 +/- 0.2 x 10(6) CD14+ cells/mL). Monocytes from both sources revealed similar phenotypes. They expressed CD4, CD11a, CD11b, CD11c, CD18, CD32, CD33, CD45R0, CD48, CD50, CD54, CD58, CD64, CD86, CD102, CD116, CD123, and HLA-DR; showed no expression of CD1a and CD83; and weak expression of CD16, CD45RA, and CD80. The levels of CD80 and CD86 expression were comparable; however, in contrast to G-AP monocytes, CB monocytes lacked CD40. There was no difference in pinocytosis activity and allostimulatory capacity of CB and G-AP monocytes. CONCLUSIONS: Monocytes in CB and G-AP are phenotypically and functionally comparable. The only difference observed is the lack of CD40 on CB monocytes.

[Intracoronary, human autologous stem cell transplantation for myocardial regeneration following myocardial infarction]. / Intrakoronare, humane autologe Stammzelltransplantation zur Myokardregeneration nach Herzinfarkt.

OBJECTIVE: The regenerative potential of human autologous adult stem cells on myocardial regeneration and neovascularisation after myocardial infarction may contribute to healing of the infarction area. But no clinical application has previously been reported. We here describe for the first time the results of this method applied in a patient who had sustained an acute myocardial infarction. HISTORY AND CLINICAL FINDINGS: 14 hours after the onset of left precordial pain a 46-year-old man was admitted to our hospital for interventional diagnosis and treatment. Coronary angiography demonstrated occlusion of the anterior descending branch of the left coronary artery with transmural infarction. This was treated by percutaneous transluminal catheter angioplasty and stent placement. THERAPY AND RESULTS: Mononuclear bone marrow cells of the patient were prepared and 6 days after infaction 1,2 infinity 107 cells were transplanted at low pressure via a percutaneous transluminal catheter placed in the infarct-related artery. Before and 10 weeks after this procedure left ventricular function, infarct size, ventricular geometry and myocardial perfusion were measured by (201)thallium SPECT both at rest and on exercise, together with bull's-eye analysis, dobutamine stress echocardiography, right heart catheterisation and radionuclide ventriculography. At 10 weeks after the stem cell transplantation the transmural infarct area had been reduced from 24.6 % to 15.7 % of left ventricular circumference, while ejection fraction, cardiac index and stroke volume had increased by 20-30 %. On exercise the end diastolic volume had decreased by 30 % and there was a comparable fall in left ventricular filling pressure (mean pulmonary capillary pressure). CONCLUSION: These results for the first time demonstrate that selective intracoronary transplantation of human autologous adult stem cells is possible under clinical conditions and that it can lead to regeneration of the myocardial scar after transmural infarction. The therapeutic effects may be ascribed to stem cell-associated myocardial regeneration and neovascularisation.

Factors affecting lymphocyte subset reconstitution after either related or unrelated cord blood transplantation in children -- a Eurocord analysis.

Immune recovery after cord blood transplantation (CBT) is of concern owing to the low number of lymphocytes transferred with the graft and their immaturity. Risk factors influencing lymphocyte subset reconstitution related to disease, patient, donor and transplant were studied in 63 children (< 16 years), given either related (n = 14) or unrelated (n = 49) CBT for malignant (n = 33) or non-malignant diseases (n = 30). Only children with sustained myeloid engraftment were analysed. Absolute numbers of T (CD3(+), CD4(+), CD8(+)), B and natural killer (NK) cells were reported 2--3, 6, 9, 12 and 12--24 months after CBT. Median patient age was 4.0 years (0--15) and median follow-up was 23 months (1.7--61.0). Twenty-six patients received human leucocyte antigen (HLA)-matched CBT and 37 received HLA-mismatched CBT. The median number of nucleated cells (NCs) collected/recipient weight was 6.1 x 10(7)/kg. In this selected population, the estimate 2 year survival was 85%. Lymphocyte reconstitution (defined as the median time to reach the normal value of age-matched healthy children) was 3, 6 and 8 months for NK, B and CD8(+) cells, while it was 11.7 months for both CD3(+) and CD4(+) lymphocytes. In the multivariate analysis, factors favouring T-cell recovery were: related donor (P = 0.002); higher NCs/kg (P = 0.005) and recipient cytomegalovirus (CMV)-positive serology (P = 0.04). Presence of acute graft-versus-host disease (GVHD) delayed T-cell recovery (P = 0.04). To summarize, in children with sustained myeloid engraftment the concern that lymphocyte recovery after CBT could be delayed does not appear to be substantiated by our results.

Comparison of outcomes of unrelated bone marrow and umbilical cord blood transplants in children with acute leukemia.

In order to compare the outcomes of unrelated umbilical cord blood transplants (UCBTs) or bone marrow transplants, 541 children with acute leukemia (AL) transplanted with umbilical cord blood (n = 99), T-cell-depleted unrelated bone marrow transplants (T-UBMT) (n = 180), or nonmanipulated (UBMT) (n = 262), were analyzed in a retrospective multicenter study. Comparisons were performed after adjustment for patient, disease, and transplant variables. The major difference between the 3 groups was the higher number in the UCBT group of HLA mismatches (defined by serology for class I and molecular typing for DRB1). The donor was HLA mismatched in 92% of UCBTs, in 18% of UBMTs, and in 43% of T-UBMTs (P <.001). Other significant differences were observed in pretransplant disease characteristics, preparative regimens, graft-versus-host disease (GVHD) prophylaxis, and number of cells infused. Nonadjusted estimates of 2-year survival and event-free survival rates were 49% and 43%, respectively, in the UBMT group, 41% and 37% in the T-UBMT group, and 35% and 31% in the UCBT group. After adjustment, differences in outcomes appeared in the first 100 days after the transplantation. Compared with UBMT recipients, UCBT recipients had delayed hematopoietic recovery (Hazard ratio [HR] = 0.37; 95% confidence interval [95CI]: 0.27-0.52; P <.001), increased 100 day transplant-related mortality (HR = 2.13; 95CI: 1.20-3.76; P <.01) and decreased acute graft-versus-host disease (aGVHD) (HR = 0.50; 95CI: 0.34-0.73; P <.001). T-UBMT recipients had decreased aGVHD (HR = 0.25; 95CI: 0.17-0.36; P <.0001) and increased risk of relapse (HR = 1.96; 95CI: 1.11-3.45; P =.02). After day 100 posttransplant, the 3 groups achieved similar results in terms of relapse. Chronic GVHD was decreased after T-UBMT (HR = 0.21; 95CI: 0.11-0.37; P <.0001) and UCBT (HR = 0.24; 95CI: 0.01-0.66; P =.002), and overall mortality was higher in T-UBMT recipients (HR = 1.39; 95CI: 0.97-1.99; P <.07). In conclusion, the use of UCBT, as a source of hematopoietic stem cells, is a reasonable option for children with AL lacking an acceptably matched unrelated marrow donor.