Stelios Graphakos

Intracoronary Infusion of CD133+ and CD133−CD34+ Selected Autologous Bone Marrow Progenitor Cells in Patients with Chronic Ischemic Cardiomyopathy: Cell Isolation, Adherence to the Infarcted Area, and Body Distribution

Central issues in intracoronary infusion (ICI) of bone marrow (BM)‐cells to damaged myocardium for improving cardiac function are the cell number that is feasible and safe to be administrated as well as the retention of cells in the target area. Our study addressed these issues in eight patients with chronic ischemic cardiomyopathy undergoing ICI of selected BM‐progenitors. We could immunomagnetically isolate 0.8 ± 0.32 × 107 CD133+ cells and 0.75 ± 0.24 × 107 CD133−CD34+ cells from 310 ± 40 ml BM. After labeling these cells with 99mTc‐hexamethylpropylenamineoxime, they were infused into the infarct‐related artery without any complication. Scintigraphic images 1 (eight patients) and 24 hours (four patients) after ICI revealed an uptake of 9.2% ± 3.6 and 6.8% ± 2.4 of the total infused radioactivity in the infarcted area of the heart, respectively; the remaining activity was distributed mainly to liver and spleen. We conclude that through ICI of CD133+ and CD133−CD34+ BM‐progenitors a significant number of them are preferentially attracted to and retained in the chronic ischemic myocardium.

Pilot study to evaluate the safety and feasibility of intracoronary CD133(+) and CD133(-) CD34(+) cell therapy in patients with nonviable anterior myocardial infarction.

Objectives: The long‐term effect of intracoronary infusion of progenitor cells in patients with chronic ischemic cardiomyopathy. Background: Bone marrow stem‐cell administration in patients with myocardial infarction improved myocardial performance and in some studies contributed to favorable left ventricular remodeling. Methods: We report on the results of a pilot, single center, controlled safety, and feasibility study, including 24 patients with old, nonviable anterior myocardial infarction. Twelve patients underwent intracoronary administration of selected CD133+ and CD133−CD34+ progenitor cells and 12 were followed up on medical therapy. Left ventricular volumes and ejection fraction, at rest and during low‐dose dobutamine, and myocardial viability, using TL‐201 reinjection scintigraphy, were analyzed at baseline and long‐term follow‐up. Results: Patients in the treatment group experienced a sustained decrease in left ventricular end‐diastolic and end‐systolic resting volumes (P = 0.008 and P = 0.002, respectively), as well as an improvement in global ejection fraction at rest [from (27.2 ± 6.8)% to (29.7 ± 7.3)%, P = 0.016]. Segmental anterior and apical wall perfusion, during TL‐201 reinjection, were similarly improved (P = 0.005 and P << 0.001, respectively). One patient developed restenosis at the cell delivery site and one progression of atherosclerosis. During 28.0 ± 8.7 months of clinical follow‐up, only one patient experienced deterioration of heart failure. In the control group, we observed stability in the perfusion defect and deterioration in end‐diastolic and end‐systolic volumes (P= 0.002 and P = 0.003, respectively) and a nonsignificant decrease in ejection fraction (P = 0.11). Conclusion: Intracoronary infusion of selected CD133+ and CD133−CD34+ progenitor cells to a previously infarcted and nonviable anterior wall is safe, and results in sustained improvement in segmental myocardial perfusion and in favorable left ventricular remodeling.

A functional hierarchy among the CD34+ hematopoietic cells based on in vitro proliferative and differentiative potential of AC133+ CD34bright and AC133dim/-CD34+ human cord blood cells

The 5-transmembrane receptor AC133 is expressed on a subpopulation of human hematopoietic cells that includes the CD34(bright) cells. We evaluated the developmental potential of AC133+CD34(bright) and AC133(dim/-)CD34+ cells isolated from 5 cord blood (CB) samples by studying the in vitro proliferative and differentiative potential of each population in both progenitor and mature cell expansion cultures. Seven-day culture of AC133+CD34(bright) cells with a cytokine combination favoring primitive progenitor cells causes a significant increase in CD34+, CFU-C and noncycling stem/progenitor cells HPP-Q (High Proliferative Potential-Quiescent), whereas culture of AC133(dim/-)CD34+ cells shows a limited increase in committed progenitor cells only. HPP-Q cells were not found in freshly isolated AC133(dim/-)CD34+ nor in expanded CD34+ cells derived from AC133(dim/-)CD34+ cells. No statistically significant difference was observed between the 1-week expanded AC133+ and the initial AC133+CD34(bright) cells regarding their clonogenic efficiency (CE), while expanded CD34+ cells derived from AC133(dim/-)CD34+ cells exhibited a decreased CE. Subexpansion of the reselected AC133+ derived from AC133+CD34(bright) cells reveals a further increase of stem/progenitor cells and the 14-day expanded AC133+ cells reveal an unchanged CE. Subexpansion of reselected 7-day CD34+ cells derived from AC133(dim/-)CD34+ cells was not possible. Culture of AC133+CD34(bright) cells in cytokines that favor megakaryopoiesis or erythropoiesis resulted in a significant expansion of CD41+ and CD71+ cells, respectively; AC133(dim/-)CD34+, in comparison, showed a limited potential to megakaryocytic differentiation and a decreased production of erythroid cells. Our data indicate that early high proliferating stem/progenitor cells and early committed progenitors are present in AC133+CD34(bright) cells, but not in AC133(dim/-)CD34+ cells; the latter represent late committed progenitors with limited proliferative potential.

Successful Hematopoietic Stem Cell Transplantation in 2 Children with X-Linked Chronic Granulomatous Disease from Their Unaffected HLA-Identical Siblings Selected Using Preimplantation Genetic Diagnosis Combined with HLA Typing

We report 2 children with X-linked chronic granulomatous disease (X-CGD) who underwent hematopoietic stem cell transplantation (HSCT) using grafts from their siblings selected before implantation to be both unaffected and HLA-matched donors. Preimplantation genetic diagnosis (PGD) along with HLA-typing were performed on preimplantation embryos by single-cell multiplex polymerase chain reaction using informative short tandem repeat markers in the HLA locus together with the gene region containing the mutations. Two singleton pregnancies resulted from the intrauterine transfer of selected embryos; these developed to term, producing 1 healthy female and 1 X-CGD carrier female, which are HLA-identical siblings to the 2 affected children. Combined grafts of umbilical cord blood (UCB) and bone marrow (BM) stem cells were administered to the recipients after myeloablative (MA) conditioning at the ages of 4.5 years and 4 years, respectively. Both patients are well, with complete donor hematopoietic and immunologic reconstitution, at 18 and 13 months posttransplantation, respectively. This report demonstrates that HSCT with HLA-matched sibling donors created by PGD/HLA typing of in vitro fertilized embryos is a realistic therapeutic option and should be presented as such to families with children who require a non-urgent HSCT but lack an HLA-genoidentical donor.

HLA-matched sibling stem cell transplantation in children with β-thalassemia with anti-thymocyte globulin as part of the preparative regimen: the Greek experience.

BU combined with CY, the preferred preparatory regimen for thalassemic patients, is associated with a substantial incidence of graft rejection especially in patients with advanced disease stage. This study retrospectively analyzes the outcome of 75 consecutive pediatric patients with β-thalassemia who underwent HLA-matched sibling transplantation after anti-thymocyte globulin (ATG)-containing myeloablative conditioning regimens. With a median follow-up of 9 years (range 1–15 years), the overall survival (OS) and thalassemia free survival (TFS) rates were 96% and 92%, respectively. Both the estimated TRM and the cumulative incidence of rejection/failure were 4%. The cumulative incidences of acute GVHD grade II–III and grade III were 20% and 5.3%, respectively. No patient developed acute GVHD grade IV. Only two patients developed extensive chronic GVHD. The estimated OS and TFS for patients with Class 1 and 2 disease according to Pesaro criteria were 96.3% and 94.4%, whereas for patients with Class 3 disease they were 94.1% and 88.2%, respectively. In our series, the use of myeloablative conditioning regimens, which include ATG for the transplantation of thalassemic children from matched sibling donors, resulted in excellent outcomes with very low incidences of TRM and rejection.

Effect of inflammation induced by prolonged exercise on circulating erythroid progenitors and markers of erythropoiesis

Abstract Background: Exercise in humans augments the mobilization of circulating hematopoietic progenitor cells (CD34+) from the bone marrow. We investigated the effect of inflammation on erythroid marrow activity by mobilization of erythroid progenitor cells (EPs) along with soluble markers of erythropoiesis. Methods: Ten healthy athletes who participated in an ultradistance foot race participated in the study. Peripheral blood mononuclear cells were isolated, before (phase I), at the end (phase II), and at 48 h post-race (phase III). EPs were detected as burst colony forming units (BFU-e) and colonies were scored at day 14. Markers of inflammation (C-reactive protein, serum amyloid-A, interleukin-6, ferritin and S100B) and bone marrow activity (erythropoietin, soluble transferrin receptor and lipocalin-2) were assessed. Results: An approximately three-fold decrease in BFU-e number was observed at phase II. sTfR concentrations were also decreased at phase II and remained decreased at phase III. However, EPO and lipocalin-2 concentrations reached a maximum value at phase II, with a tendency to decrease at phase III. Conclusions: These findings indicate that exercise-induced inflammation modulates bone marrow homeostasis leading to an increase in leukocyte turnover and a decrease in erythroid compartment. It appears that lipocalin-2 is the main factor that regulates the production and mobilization of EPs. Clin Chem Lab Med 2010;48:199–203.

Extracorporeal photopheresis in the treatment of chronic graft-versus-host disease. The Hellenic experience: a study by the Hellenic association of hematology.

The Hellenic experience regarding the efficacy of extracorporeal photopheresis (ECP) in the treatment of 58 patients with chronic graft-versus-host disease (cGVHD) is presented in this article. All 58, except one patient, had failed at least one line of immunosuppressive treatment including steroids. Thirty-three out of 58 patients showed an objective overall response to ECP in a median time of 10 weeks after the onset of treatment. The cumulative incidence of overall response was 65.1%. In multivariate analysis, the presence of severe chronic GVHD was the only parameter associated with a significantly lower probability of response to treatment (RR=0.4, CI 95% 0.2-0.9, p=0.03). Responders to treatment with ECP were more likely to discontinue immunosuppression, had a lower probability of non-relapse mortality (RR=0.2, CI 95% 0.1-0.5, p=0.002), and a higher probability of overall survival (RR=7.8, CI 95% 3-20, p<0.001) in comparison with non-responders. Eight out of 58 patients experienced relapse of the original disease. The cumulative incidence of relapse in the group of responders to ECP was 6%, while it was 25% in the group of non-responders to ECP. In multivariate analysis, response to treatment with ECP was the only parameter statistically associated with a significantly decreased hazard of relapse (RR=0.1, CI 95% 0.1-0.7, p=0.02). ECP should be tested as first-line treatment in patients with cGVHD with the aim to minimize the duration of immunosuppression and the rate of relapse of the malignant disease.

Intracoronary infusion of selected autologous bone marrow stem cells improves longitudinal myocardial strain and strain rate in patients with old anterior myocardial infarction without recent revascularization

AIMS We sought to evaluate the efficacy of intracoronary infusion of selected bone marrow stem cells (BMSCs) in patients with remote, anterior non-viable MI by the use of tissue Doppler imaging. METHODS AND RESULTS We infused selected CD133+ and CD133-CD34+ BMSCs in 10 patients enrolled in the study. Peak systolic strain rate, maximum strain during the cardiac cycle (epsilon(max)), strain during ejection time (epsilon(et)), and post-systolic strain (epsilon(ps)) were measured. Peak systolic strain rate (-0.69 +/- 0.2 vs. -1.15 +/- 0.27, P = 0.001), epsilon(max) (-9.87 +/- 3.30 vs. -15.57 +/- 5, P = 0.006), and epsilon(et) (-7.45+/-2.86 vs. -10.92 +/- 4.45, P = 0.015) improved significantly during the rest study 6 months after cell infusion. Low-dose inotropic challenge also showed significant improvement of longitudinal deformation indices in the follow-up study. Global ejection fraction did not improve significantly after cell therapy. CONCLUSION Intracoronary infusion of selected BMSCs in patients with remote, anterior, non-viable myocardial infarction is safe and leads to improvement of longitudinal deformation indices 6 months after the infusion.

Rapid clinical-scale propagation of mesenchymal stem cells using cultures initiated with immunoselected bone marrow CD105 cells

Current clinical protocols used for isolation and purification of mesenchymal stem cells (MSC) are based on long‐term cultures starting with bone marrow (BM) mononuclear cells. Using a commercially available immunoselection kit for enrichment of MSC, we investigated whether culture of enriched BM‐CD105+ cells could provide an adequate number of pure MSC in a short time for clinical use in the context of graft versus host disease and graft failure/rejection. We isolated a mean of 5.4 × 105 ± 0.9 × 105 CD105+ cells from 10 small volume (10–25 ml) BM samples achieving an enrichment >100‐fold in MSC. Seeding 2 × 103 immunoselected cells/cm2 we were able to produce 2.5 × 108 ± 0.7 × 108 MSC from cultures with autologous serum enriched medium within 3 weeks. Neither haematopoietic nor endothelial cells were detectable even in the primary culture cell product. Expanded cells fulfilled both phenotypic and functional current criteria for MSC; they were CD29+, CD90+, CD73+, CD105+, CD45−; they suppressed allogeneic T‐cell reaction in mixed lymphocyte cultures and retained in vitro differentiation potential. Moreover, comparative genomic hybridization analysis revealed chromosomal stability of the cultured MSC. Our data indicate that adequate numbers of pure MSC suitable for clinical applications can be generated within a short time using enriched BM‐CD105+ cells.

Directed sibling donor cord blood banking for children with β-thalassemia major in Greece: Usage rate and outcome of transplantation for HLA-matched units

Several cord blood banks store cord blood units from healthy siblings of patients, who are candidates for stem cell transplantation. We analyzed the quality characteristics of 50 cord blood units collected from families with beta-thalassemia major and the outcome of subsequent stem cell transplantations during a 15-year period. All cord blood units were found suitable for banking based on a minimum net volume of 40 ml. The mean volume of the units was 98.9 ml; the mean total nucleated cell count (NC) was 7.8 x 10(8) and the mean CD34+ cell count was 2.8 x 10(6). Eight out of twelve HLA matched collections were released for transplantation. All but one recipient belonged to Pesaro II-III risk classes. Three patients received a cord blood graft with >5 x 10(7) NC/kg . One of them with Pesaro class I disease engrafted, whereas the other two who failed to engraft, were re-transplanted with bone marrow from the same donor later. Cord blood grafts containing NCs <4 x 10(7)/kg combined with reduced volume bone marrow from the same donor were used in all 5 remaining cases and stable engraftment was achieved. All patients survived, 7/8 thalassemia-free. Cord blood banking from healthy siblings of children with beta-thalassemia major can result in a successful transplantation in cases in which there is HLA compatibility. However, in high-risk patients, the use of combined cord blood and bone marrow grafts seems necessary in order to ensure stable engraftment, especially when cord blood unit cell counts are low.